Change search
Refine search result
1 - 45 of 45
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Arcos, D.
    et al.
    Lopez-Noriega, A.
    Ruiz-Hernandez, E.
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Vallet-Reg, M.
    Ordered Mesoporous Microspheres for Bone Grafting and Drug Delivery2009In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 21, no 6, p. 1000-1009Article in journal (Refereed)
    Abstract [en]

    Bioactive microspheres with ordered mesoporous structure have been synthesized by means of the evaporation-induced self-assembly (EISA) method and following an aerosol-assisted route. The bioactive microspheres belong to the SiO2-CaO-P2O5 systems, and the mesoporous structure closely depends on the structure-directing agent as well as its interaction with the Ca2+ cations during the mesophase formation. Among the different tested surfactants, the triblock copolymer F127 leads to hexagonal ordered structures for low CaO contents, P123 leads to wormlike mesoporous structures for any CaO content, whereas the ionic surfactant cetyltrimethyl ammonium bromide (C16TAB) does not produce accessible mesopores at the external surface, for any CaO content. All the mesoporous SiO2-CaO-P2O5 microspheres develop an apatite like layer when reacting with simulated body fluid. Preliminary tests indicate the capability to load and release triclosan with kinetic profiles that depend on the pore structure, thus showing interesting features to be used in periodontal regenerative surgery and infection profilaxis.

     

  • 2. Buscaglia, Maria Teresa
    et al.
    Buscaglia, Vincenzo
    Curecheriu, Lavinia
    Postolache, Petronel
    Mitoseriu, Liliana
    Ianculescu, Adelina C.
    Vasile, Bogdan S.
    Zhao, Zhe
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Nanni, Paolo
    Fe2O3@BaTiO3 core-shell particles as reactive precursors for the preparation of multifunctional composites containing different magnetic phases2010In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 22, no 16, p. 4740-4748Article in journal (Refereed)
    Abstract [en]

    Well-designed reactive precursors and templates allow for careful control of solid-state reactions at the nanoscale level, thus enabling the fabrication of materials with specific microstructures and properties. In this study, Fe2O3@BaTiO3 core−shell particles have been used as precursors for the in situ fabrication of multifunctional composites containing a dielectric/ferroelectric phase and two magnetic phases with contrasting coercivities (Fe2O3/Fe3O4, BaFe12O19/Ba12Fe28Ti15O84). The formation of new magnetic phases occurs during sintering or post-annealing via reaction between BaTiO3 and Fe2O3. The starting powders have been prepared using a multistep process that combines colloidal chemistry methods and a solid-state reaction. The nature and the amount of the magnetic phases and, consequently, the final magnetic properties of the composite can be controlled by varying the relative amount of Fe2O3 (30 or 50 vol%), the densification method (conventional or spark plasma sintering), and the processing temperature. The composites show constricted magnetic hysteresis loops with a coercivity of 0.1−2.5 kOe and a saturation magnetization of 5−16 emu/g. Composites obtained from powders containing 30 vol% Fe2O3 show, at temperatures of 20−80 °C and frequencies between 10 kHz and 1 MHz, a relative dielectric constant of 50 and dielectric losses of <10%.

  • 3.
    Chen, Hong
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Deng, Youqian
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Yu, Zhengbao
    Zhao, Huishuang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Yao, Qingxia
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Bäckvall, Jan-E.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    3D Open-Framework Vanadoborate as a Highly Effective Heterogeneous Pre-catalyst for the Oxidation of Alkylbenzenes2013In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 25, no 24, p. 5031-5036Article in journal (Refereed)
    Abstract [en]

    Three three-dimensional (3D) open-framework vanadoborates, denoted as SUT-6-Zn, SUT-6-Mn, and SUT-6-Ni, were synthesized using diethylenetriamine as a template. SUT-6-Zn, SUT-6-Mn, and SUT-6-Ni are isostructural and built from (VO)(12)O-6 B18O36(OH)(6) clusters bridged by ZnO5, MnO6, and NiO6 polyhedra, respectively, to form the 3D frameworks. SUT-6 is the first vanadoborate with a 3D framework. The framework follows a semiregular hxg net topology with a 2-fold interpenetrated diamond-like channel system. The amount of template used in the synthesis played an important role in the dimensionality of the resulting vanadoborate structures. A small amount of diethylenetriamine led to the formation of this first 3D vanadoborate framework, while an increased amount of diethylenetriamine resulted in vanadoborates with zero-dimensional (0D) and one-dimensional (1D) structures. SUT-6-Zn was proved to be an efficient heterogeneous precatalyst for the oxidation of alkylbenzenes.

  • 4.
    Cho, Kanghee
    et al.
    Graduate School of Nanoscience and Technology (WCU).
    Na, Kyungsu
    Graduate School of Nanoscience and Technology (WCU).
    Kim, Jaeheon
    Center for Functional Nanomaterials.
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Ryoo, Ryong
    Graduate School of EEWS (WCU), KAIST, Daejeon 305-701, Korea.
    Zeolite Synthesis Using Hierarchical Structure-Directing Surfactants: Retaining Porous Structure of Initial Synthesis Gel and Precursors2012In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, ISSN 0897-4756, Vol. 24, no 14, p. 2733-2738Article in journal (Refereed)
    Abstract [en]

    Zeolite beta with a mesopore-micropore hierarchy is hydrothermally synthesized here using various surfactants that can function as a hierarchical structure-directing agent at both the meso- and microstructural levels. Tetraethoxysilane and diatomaceous earth were tested as the silica sources. The pore size distribution of the zeolite was analyzed by N2 adsorption and electron microscopy. The result was related to the surfactant structure, silica source, and Na+ concentration. The zeolite showed quite uniform mesopores corresponding to the surfactant micelles, in addition to zeolitic micropores generated by the surfactant head groups. Furthermore, an additional level of large pores (≥20 nm) could be obtained as a result of the retaining of pores from the initial synthesis gel or the zeolite precursor. The large pores were fully retained when the silica source was transformed into a crystalline zeolite via pseudomorphic transformation without migration into the solution phase. The transformation could be controlled by the choice of the synthesis conditions and surfactants. The resultant zeolite with a macropore-mesopore-micropore hierarchy shows potential applicability where facile diffusion is required.

  • 5. Corma, Averlino
    et al.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Hovmöller, Sven
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Jansson, Kjell
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Zhang, Daliang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Jordá, José L.
    Díaz Cabañas, María J.
    Cantín, Ángel
    Moliner, Manuel
    Synthesis and structure of polymorph B of zeolite Beta2008In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 20, no 9, p. 3218-3223Article in journal (Refereed)
    Abstract [en]

    It was found that either polymorph B or polymorph C of zeolite beta can be obtained from the same structure directing agent: 4,4-dimethyl-4-azonia-tricyclo[5.2.2.02,6]undec-8-ene hydroxide. The synthesis occurs through a consecutive process where polymorph B is first formed and then transformed into polymorph C. It is possible to produce a zeolite highly enriched in polymorph B, provided that the transformation of this phase into polymorph C is slowed down up to the point where polymorph C is only detected at trace levels. The structure of polymorph B was determined for the first time by electron crystallography with SAED and HRTEM from areas of unfaulted polymorph B crystals.

  • 6.
    Gao, Chuanbo
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Formation Mechanism of Anionic Surfactant-Templated Mesoporous Silica2006In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 18, p. 3904-3914Article in journal (Refereed)
    Abstract [en]

    The synthesis mechanism of anionic surfactant-templated mesoporous silica (AMS) is described. A family of highly ordered mesoporous silica structures have been synthesized via an approach based on the self-assembly of anionic surfactants and inorganic precursors by using aminopropylsiloxane or quaternized aminopropylsiloxane as the co-structure-directing agent (CSDA), which is a different route from previous pathways. Mesophases with differing surface curvatures, varying from cage type (tetragonal P42/mnm; cubic Pm-3n with modulations; cubic Fd-3m) to cylindrical (two-dimensional hexagonal p6mm), bicontinuous (cubic Ia-3d and Pn-3m), and lamellar have been obtained by controlling the charge density of the micelle surfaces by varying the degree of ionization of the carboxylate surfactants. Changing the degree of ionization of the surfactant results in changes of the surfactant packing parameter g, which leads to different mesostructures. Furthermore, variation of the charge density of positively charged amino groups of the CSDA also gives rise to different values of g. Mesoporous silicas, functionalized with amino and quaternary ammonium groups and with the various structures given above, have been obtained by extraction of the surfactant. This report leads to a deeper understanding of the interactions between the surfactant anions and the CSDA and provides a feasible and facile approach to the mesophase design of AMS materials.

  • 7. Gu, Dong
    et al.
    Bongard, Hans
    Meng, Yan
    Miyasaka, Keiichi
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zhang, Fuqiang
    Deng, Yonghui
    Wu, Zhangxiong
    Feng, Dan
    Fang, Yin
    Tu, Bo
    Schueth, Ferdi
    Zhao, Dongyuan
    Growth of Single-Crystal Mesoporous Carbons with Im(3)over-barm Symmetry2010In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 22, no 16, p. 4828-4833Article in journal (Refereed)
    Abstract [en]

    Highly ordered mesoporous carbon FDU-16 rhombic dodecahedral single crystals with body-centered cubic structure (space group Im (3) over barm) have been successfully synthesized by employing an organic-organic assembly of triblock copolymer Pluronic F127 (EO106PO70EO106) and phenol/formaldehyde resol in basic aqueous solution. Synthetic factors (including reaction time, temperature, and stirring rate) are explored for controlling the formation of rhombic dodecahedral single crystals. The optimal stirring rate and the reaction temperature are 300 +/- 10 rpm and similar to 66 degrees C, respectively. High-resolution scanning electron microscopy (HRSEM), scanning transmission electron microscopy (STEM), and ultramicrotomy are applied to study the fine structures of the carbon single crystals. The mesopores are arranged in body-centered cubic symmetry throughout the entire particle. Surface steps are clearly observed in the {110} surface, which suggests a layer-by-layer growth of the mesoporous carbon FDU-16 single crystals. Cryo-SEM results from the reactant solution confirm the formation of resol/F127 unit micelles, further supporting the layer-by-layer growth process. The mesoporous carbon FDU-16 single crystals grow up to the final size of 2-4 mu m within 2 days. These findings may have consequences for the growth mechanism of other carbon materials in aqueous solution; moreover, the high-quality single crystals also have potential applications in nanodevice technologies.

  • 8.
    Gustafsson, Mikaela
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Bartoszewicz, Agnieszka
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Martín-Matute, Belén
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Grins, Jekabs
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zhao, Tony
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Li, Zhongyue
    Zhu, Guangshan
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    A family of highly stable lanthanide metal-organic frameworks: structural evolution and catalytic activity2010In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 22, no 11, p. 3316-3322Article in journal (Refereed)
    Abstract [en]

    A family of homeotypic porous lanthanide metal−organic frameworks (MOFs), [Ln(btc)(H2O)]·guest (Nd (1), Sm (2), Eu (3), Gd (4), Tb (5), Ho (6), Er (7), and Yb (8); guest: DMF or H2O) was synthesized. The structures of the as-synthesized compounds are tetragonal and contain 1D channels with accessible lanthanide ions. In situ single crystal X-ray diffraction shows that 1 undergoes a single-crystal to polycrystalline to single-crystal transformation from room temperature to 180 °C. During the release of DMF and water molecules from the channels by evacuation and subsequent heating, the structures of 1 and 7 transformed from tetragonal to monoclinic, and then to tetragonal, while the structure of 8 remained tetragonal. The transformation between the monoclinic and the low temperature tetragonal phases is reversible. The Ln(btc) MOFs are stable to at least 480 °C and are among the most thermally stable MOFs. The Ln(btc) MOFs act as efficient Lewis acid catalysts for the cyanosilylation of aldehydes yielding cyanohydrins in high yields within short reaction times. 1 also catalyzes the cyanosilylation of less reactive substrates, such as ketones at room temperature. The Ln(btc) MOFs could be recycled and reused without loss of their crystallinity and activity.

  • 9.
    Han, Lu
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Ruan, Juanfang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Li, Yongsheng
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Che, Shunai
    Synthesis and Characterization of the Amphoteric Amino Acid Bifunctional Mesoporous Silica2007In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 19, no 11, p. 2860-2867Article in journal (Refereed)
  • 10. Hertzberg, Benjamin J.
    et al.
    Huang, An
    Hsieh, Andrew
    Chamoun, Mylad
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Davies, Greg
    Seo, Joon Kyo
    Zhong, Zhong
    Croft, Mark
    Erdonmez, Can
    Meng, Ying Shirley
    Steingart, Dan
    Effect of Multiple Cation Electrolyte Mixtures on Rechargeable Zn-MnO2 Alkaline Battery2016In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 28, no 13, p. 4536-4545Article in journal (Refereed)
    Abstract [en]

    A Bi2O3 in beta-MnO2 composite cathode material has been synthesized using a simple hydrothermal method and cycled in a mixed KOH-LiOH electrolyte with a range of concentrations. We show that, at a KOH:LiOH molar ratio of 1:3, both proton insertion and lithium insertion occur, allowing access to a higher fraction of the theoretical capacity of the MnO2 while preventing the formation of ZnMn2O4. This enables a capacity of 360 mAh/g for over 60 cycles, with cycling limited more by anode properties than traditional cathodic failure mechanisms. The structural changes occurring during cycling are characterized using electron microscopy and in situ synchrotron energy-dispersive X-ray diffraction (EDXRD) techniques. This mixed electrolyte shows exceptional cyclability and capacity and can be used as a drop-in replacement for current alkaline batteries, potentially drastically improving their cycle life and creating a wide range of new applications for this energy storage technology.

  • 11. Hmadeh, Mohamad
    et al.
    Lu, Zheng
    Liu, Zheng
    Gandara, Felipe
    Furukawa, Hiroyasu
    Wan, Shun
    Augustyn, Veronica
    Chang, Rui
    Liao, Lei
    Zhou, Fei
    Perre, Emilie
    Ozolins, Vidvuds
    Suenaga, Kazu
    Duan, Xiangfeng
    Dunn, Bruce
    Yamamto, Yasuaki
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Yaghi, Omar M.
    New porous crystals of extended metal catecholates2012In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 24, no 18, p. 3511-3513Article in journal (Refereed)
  • 12.
    Hu, Shichao
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Lemmens, Peter
    Schmid, Daniel
    Menzel, Dirk
    Tapp, Joshua
    Moeller, Angela
    Acentric Pseudo-Kagome Structures: The Solid Solution (Co1-xNix)(3)Sb4O6F62014In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 26, no 12, p. 3631-3636Article in journal (Refereed)
    Abstract [en]

    Compounds within the solid solution (Co1-xNix)(3)Sb4O6F6 were prepared by the hydrothermal method. The compounds crystallize in the noncentrosymmetric cubic space group I (4) over bar 3m with unit cell parameters a = 8.176(1) angstrom for M = Co and a = 8.0778(1) angstrom for M = Ni. The crystal structure is made up by corner sharing [MO2F4] octahedra via the fluorine atoms. [Sb4O6E4] supertetrahedra (T2) consisting of four [SbO3E] groups (E being the stereo-chemically active lone-pair on Sb) that share O atoms with the [MO2F2](n) network. Magnetic ordering phenomena are observed with two characteristic temperatures, T-N and T*, in the range from 67 to 170 K, that evolve gradually with composition and collapse for M = Co (x = 0) to one transition. T-N is assigned to a transition into a long-range ordered antiferromagnetic phase, and T* marks a temperature in the range of 45 to 65 K where field cooled (FC) and zero field cooled (ZFC) susceptibility splits. The latter is tentatively attributed to a canting of the spin moments.

  • 13. Izquierdo-Barba, Isabel
    et al.
    Arcos, Daniel
    Sakamoto, Yasuhiro
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Lopez-Noriega, Adolfo
    Vallet-Regi, Maria
    High-performance mesoporous bioceramics mimicking bone mineralization2008In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 20, no 9, p. 3191-3198Article in journal (Refereed)
    Abstract [en]

    The preparation of bioceramics with ordered mesoporous structures is of importance for biomedical technology, for the design of bone and dental grafts with regeneration purposes. Here we demonstrate that hexagonal mesoporous SiO2-CaO-P2O5 bioglasses (MBG) with high calcium content are the first known bioceramics that exhibit amorphous calcium phosphate (ACP)-octacalcium phosphate (OCP)-calcium deficient carbonatehydroxyapatite (CDHA) maturation as biomineralization governing mechanism in simulated body fluid (SBF), similarly to the in vivo biomineralization process. The unique characteristics of hexagonal MBGs lead to a local acid pH at the bioceramic surface that allows the formation of metastable OCP. Besides, 3D cubic MBG has been also synthesized, exhibiting higher surface area and porosity. The 3D reconstruction carried out by electron microscopy evidence a 3D bicontinuous network comprising a pair of rods mutually intertwined, creating the pore system available in three dimensions. This 3D pore system provides not only high surface area and porosity but also easier interchange of ions, increasing mass transport and diffusion processes. The final result is that 3D cubic MBGs exhibit an accelerated bioactivity behavior, forming a bonelike apatite phase on the surface, I h after coming into contact with SBF.

  • 14. Kang, Jong Hun
    et al.
    Xie, Dan
    Zones, Stacey I.
    Smeets, Stef
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    McCusker, Lynne B.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). ETH Zurich, Switzerland.
    Davis, Mark E.
    Synthesis and Characterization of CIT-13, a Germanosilicate Molecular Sieve with Extra-Large Pore Openings2016In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 28, no 17, p. 6250-6259Article in journal (Refereed)
    Abstract [en]

    The synthesis of the germanosilicate CIT-13, a molecular sieve that is the first to have a two-dimensional (2D) pore system possessing pores that are bounded by 14- and 10-rings, is accomplished using a family of monoquaternary, benzyl-imidazolium organic structure-directing agents (OSDAs) in aqueous media containing fluoride. CIT-13 is prepared using either hydrogen fluoride (HF) or ammonium fluoride (NH4F). The structure refinement suggests that most of the Ge atoms are located in the d4r(double-4-rings) units, and that there are framework disorders in the arrangement of those d4r units. Other characterizations of CIT-13 such as Si-29 MAS NMR spectra, Ar-adsorption isotherms, and so forth are presented and compared to those of IM-12 (UTL), a previously reported germanosilicate with 14- and 12-ring pores.

  • 15. Karlsson, Maths
    et al.
    Engberg, Dennis
    Bjorketun, Marten E.
    Matic, Aleksandar
    Wahnstrom, Goran
    Sundell, Per G.
    Berastegui, Pedro
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Ahmed, Istaq
    Falus, Peter
    Farago, Bela
    Borjesson, Lars
    Eriksson, Sten
    Using Neutron Spin-Echo To Investigate Proton Dynamics in Proton-Conducting Perovskites2010In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 22, no 3, p. 740-742Article in journal (Refereed)
  • 16. Kjellman, Tomas
    et al.
    Asahina, Shunsuke
    Schmitt, Julien
    Imperor-Clerc, Marianne
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). Korea Advanced Institute of Science & Technology (KAIST), South Korea.
    Alfredsson, Viveka
    Direct Observation of Plugs and Intrawall Pores in SBA-15 Using Low Voltage High Resolution Scanning Electron Microscopy and the Influence of Solvent Properties on Plug-Formation2013In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 25, no 20, p. 4105-4112Article in journal (Refereed)
    Abstract [en]

    Through the use of low voltage high resolution scanning electron microscopy (LV-HRSEM) we have studied the fine details of the intricate pore structure of SBA-15. Intrawall pores and deviations from the ideal and uniform cylindrical pores are clearly observed, and we report for the first time the direct observation of plugs in the pores. N-2-sorption measurements confirm their existence. LV-HRSEM provides an opportunity to quantify the frequency of occurrence of plugs within the pore structure. The rate of mesophase formation, followed with in situ small angle X-ray scattering (SAXS) under different solvent conditions, is shown to have a significant influence on the development of plugs and how frequently they occur. We suggest a mechanism explaining the existence of the plugs, providing means for a better understanding and control over material properties.

  • 17.
    Konar, Sumit
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Häusserman, Ulrich
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Svensson, Gunnar
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Intercalation Compounds from LiH and Graphite: Relative Stability of Metastable Stages and Thermodynamic Stability of Dilute Stage I-d2015In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 27, no 7, p. 2566-2575Article in journal (Refereed)
    Abstract [en]

    The intercalation of lithium into graphite was studied at temperatures between 400 and 550 degrees C by heating mixtures of LiH and graphite powders with molar ratios 4:1, 1:1, and 1:6 under dynamic vacuum for periods between 1 and 72 h. These conditions probe the formation and thermal stability of metastable staged Ligraphite intercalation compounds (Li-GICs) close to the competing formation of the thermodynamically stable carbide Li(2)C2. Li-GICs of stages I (LiC6, A alpha), IIa (Li0.5C6, A alpha A), IIb (Li similar to C-0.33(6), A alpha AB beta B), III (Li similar to C-0.22(6), A alpha AB), IV (Li similar to C-0.167(6)), and dilute stage lithium Id have been identified and characterized by powder X-ray diffraction and Raman spectroscopy. The rate and extent of intercalation (i.e., the achieved stage of Li-GIC) depends on LiH activity and temperature. Stage I was only observed for temperatures above 500 degrees C. At 400 degrees C, the highest intercalation corresponded to stage IIb, which was obtained after 2 and 24 h for 4:1 and 1:1 reaction mixtures, respectively. Lower-staged Li-GICs attained at temperatures below 500 degrees C deintercalate upon prolonged dwelling with the exception of stage IIa, which can be maintained for very long periods (several days) in the presence of LiH. At temperatures above 500 degrees C, the kinetically controlled formation of Li-GICs is followed by Li2C2 carbide formation. It is shown that the Li-GIC I-d coexists with Li2C2 at temperatures up to 800 degrees C and that the Li content of I-d (solubility of Li in graphite) increases between 550 and 800 degrees C. Consequently, I-d with a temperature-dependent homogeneity range should be added as a stable phase in the Li-C phase diagram. A sketch of a revised Li-C phase diagram is provided.

  • 18. Lee, Hwajun
    et al.
    Shin, Jiho
    Choi, Wanuk
    Choi, Hyun June
    Yang, Taimin
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Hong, Suk Bong
    PST-29: A Missing Member of the RHO family of Embedded Isoreticular Zeolites2018In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 30, no 19, p. 6619-6623Article in journal (Refereed)
  • 19. Luo, Zhong-Zhen
    et al.
    Lin, Chen-Sheng
    Cui, Hong-Hua
    Zhang, Wei-Long
    Zhang, Hao
    Chen, Hong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    He, Zhang-Zhen
    Cheng, Wen-Dan
    PbGa2MSe6 (M = Si, Ge): Two Exceptional Infrared Nonlinear Optical Crystals2015In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 27, no 3, p. 914-922Article in journal (Refereed)
    Abstract [en]

    Two noncentrosymmetric (NCS) quaternary selenides, PbGa2SiSe6 (<bold>1</bold>) and PbGa2GeSe6 (<bold>2</bold>), with second-order nonlinear optical (NLO) responses, were synthesized by a conventional high-temperature solid-state reaction method. Compounds <bold>1</bold> and <bold>2</bold> are constructed by three NCS chromophores, [PbSe4], [GaSe4], and [Ga/SiSe4] or [Ga/GeSe4], with the covalent interactions between the X and Se atoms (X = Pb, Ga, Ga/Si, or Ga/Ge). They crystallize in the polar space groups Cc and Fdd2, respectively. Inspiringly, compound <bold>2</bold> is phase-matchable (PM) and shows high laser-induced damage threshold (LIDT) of 3.7 x AgGaS2 and wide transparent region (0.6325 mu m) in the mid-infrared (MIR) region. Most importantly, it presents extraordinary strong second harmonic generation (SHG) at 2.05 mu m radiation of about 12 x AgGaS2 at the particle size of 2545 mu m, which represents the strongest SHG among PM chalcogenides to date. The calculated major SHG tensor elements of compounds <bold>1</bold> and <bold>2</bold> are d31 = 224.7 and d12 = 222.1 pm/V, respectively, while the calculated d36 of AgGaS2 is only 21.2 pm/V.

  • 20. López-Noriega, Adolfo
    et al.
    Ruiz-Hernández, Eduardo
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Stevens, Sam M.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Mesoporous Microspheres with Doubly Ordered Core-Shell Structure2009In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 21, no 1, p. 18-20Article in journal (Refereed)
  • 21.
    Ma, Yanhang
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Han, Lu
    Miyasaka, Keiichi
    Oleynikov, Peter
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Che, Shunai
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry. Graduate School of EEWS, WCU, KAIST, Republic of Korea.
    Structural Study of Hexagonal Close-Packed Silica Mesoporous Crystal2013In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 25, no 10, p. 2184-2191Article in journal (Refereed)
    Abstract [en]

    Close-packed spheres can be stacked into two crystalline structures: cubic close-packed (ccp) and hexagonal close-packed (hcp). Both of these structures were found in silica mesoporous crystals (SMCs). Herein, pure hcp mesostructure with P6(3)/mmc symmetry of silica mesoporous crystals (SMCs) has been obtained in the synthetic system of cationic gemini surfactant as template and the N-[(3-trimethoxysilyl)propyl]ethylenediamine triacetix acid trisodium salt (EDTA-silyl) as the costructure directing agent (CSDA), which gives rise to the three-dimensional (3D) hexagonal structure and hexagonal plate morphology. The formation of the pure hcp structure was controlled by organic/inorganic interface curvature induced by charge matching between carboxylate groups of the CSDA and quaternary ammonium head groups of surfactant. Electrostatic potential distribution 3D map was reconstructed using Fourier analysis of HRTEM images based on electron crystallography, which showed characteristic features of the shape and connectivity of mesopores in the hcp structure. Small windows for connecting cages can be found only between layers, which determine the symmetry and local curvature of structures. As a result, the point group symmetry of mesopores becomes (6) over bar m2, instead of the m (3) over barm symmetry observed for perfect spheres in the ccp. The mechanism of stabilization and favorable growth of the pure hcp structure in mesoscale has been proposed based on synthesis strategy and symmetry support. This work provides people a better understanding of the priority of two sphere close-packed forms by comparing hcp and ccp structures.

  • 22. Ma, Yue
    et al.
    Tai, Cheuk-Wai
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Younesi, Reza
    Gustafsson, Torbjörn
    Lee, Jim Yang
    Edström, Kristina
    Iron Doping in Spinel NiMn2O4: Stabilization of the Mesoporous Cubic Phase and Kinetics Activation toward Highly Reversible Li+ Storage2015In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 27, no 22, p. 7698-7709Article in journal (Refereed)
    Abstract [en]

    Quaternary oxide structures with a three-dimensional macro/mesoporous network are synthesized via a facile nanocasting method followed by a calcination process. Structural engineering integrates multiscale pores by using a hydrophilic membrane with tunable-porosity as the sacrificial template. Through tailoring the metal precursor ratio, the tetragonal sites of spinel oxide are preferentially occupied by iron, resulting in a stabilized mesoporous cubic phase. Crystal field theory together with compositional characterizations from energy-dispersive spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), Mossbauer, and electron energy loss spectroscopy (EELS) direct our detailed analysis of the cation distribution in the spinel structures. Galvanostatic tests based on the best performing electrode exhibits a robust cycle life stable for 1200 cycles at a high current density of 1500 mA g(-1). This good Li+ storage performance could be attributed to the mutually beneficial synergy of the optimal level of iron doping which improves the electrical conductivity and structural robustness, as well as the presence of extended, hierarchical macro/mesoporous network. Finally, we demonstrate three feasible surface modification strategies for the oxide anodes toward better reversibility of Li+ storage.

  • 23.
    Mathew, Renny
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Physical Chemistry.
    Turdean-Ionescu, Claudia
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Materials Chemistry.
    Stevensson, Baltzar
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Physical Chemistry.
    Izquierdo-Barba, Isabel
    Garcia, Ana
    Arcos, Daniel
    Vallet-Regi, Maria
    Eden, Mattias
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Physical Chemistry.
    Direct Probing of the Phosphate-Ion Distribution in Bioactive Silicate Glasses by Solid-State NMR: Evidence for Transitions between Random/Clustered Scenarios2013In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 25, no 9, p. 1877-1885Article in journal (Refereed)
    Abstract [en]

    By employing P-31 multiple-quantum coherence-based solid-state nuclear magnetic resonance spectroscopy, we present the first comprehensive experimental assessment of the nature of the orthophosphate ion distributions in silicate based bioactive glasses (BGs). Results are provided both from melt prepared BG and evaporation-induced self-assembly-derived mesoporous bioactive glass (MEBG) structures of distinct compositions. The phosphate species are randomly dispersed in melt-derived BGs (comprising 44-55 mol % SiO2) of the Na2O-CaO-SiO2-P2O5 system, whereas a Si-rich (86 mol % SiO2) and Ca-poor ordered MBG structure exhibits nanometer-sized amorphous calcium phosphate clusters, conservatively estimated to comprise at least nine orthophosphate groups. A Ca-richer MBG (58 mol % SiO2) reveals a less pronounced phosphate clustering. We rationalize the variable structural role of P in these amorphous biomatetials.

  • 24. Norberg, Stefan T.
    et al.
    Hull, Stephen
    Eriksson, Sten G.
    Ahmed, Istaq
    Kinyanjui, Francis
    Biendicho, Jordi Jacas
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Pyrochlore to fluorite transition: the y 2(ti1 xzrx)(2)o 7 (0.0 <= x <= 1.0) system2012In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 24, no 22, p. 4294-4300Article in journal (Refereed)
    Abstract [en]

    The structural properties of the system Y-2(Ti1-xZrx)(2)O-7 have been investigated using the neutron powder diffraction technique, including a detailed analysis of the total scattering using reverse Monte Carlo modeling to probe the short-range ion-ion correlations over sample range 0.0 <= x <= 1.0. The average crystal structure shows a continuous transformation from the long-range ordered pyrochlore structure (Fd (3) over barm, a = 10.0967(1) angstrom, Z = 8, for x = 0.00, Y2Ti2O7) to a disordered fluorite structure (Fm (3) over barm, a = 5.2042(1) angstrom, Z = 1, for x = 1.00, Zr2Y2O7) in agreement with previous reports. However, on increasing x the disordering of both the cation and the anion sublattices occurs in stages, with the Zr4+ initially only substituting onto the Ti4+ site and adopting a cubic, rather than octahedral, local anion environment. At concentrations in excess of x approximate to 0.4 there is a gradual disordering of the Y3+, Ti4+, and Zr4+ species over all the cation sites, coupled with a redistribution of the O2- which initially only involves those anions on the O1 sites. The relationship between the composition dependences of the structure properties and the ionic conductivity is discussed.

  • 25. Pedersen, Birgitte L.
    et al.
    Yin, Hao
    Birkedal, Henrik
    Nygren, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Iversen, Bo B.
    Substitution in MxZn4-xSb3: Effect on Thermal Stability, Crystal Structure, Phase Transitions, and Thermoelectric Performance2010In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 22, no 7, p. 2375-2383Article in journal (Refereed)
    Abstract [en]

    The effects of Cd substitution in MxZn4-xSb3 on the high-temperature thermal stability, low-temperature phase transitions and thermoelectric properties have been studied on three samples with a substitution degree of 0.1, 1, and 2 at % Cd (x = 0.004, 0.04, 0.08). The high-temperature thermal stability in atmospheric air of a I % substituted sample is compared with an unsubstituted Zn4Sb3 sample. Multitemperature synchrotron powder diffraction data reveals that while only similar to 42 wt % of the original Zn4Sb3 phase remains in the unsubstituted sample after three heating cycles to 625 K, 78 wt % is preserved in the Cd-substituted sample. Thus, Cd-substitution provides a significant improvement of the thermal stability of Zn4Sb3. Multitemperature synchrotron powder diffraction data measured between 90 and 300 K reveal that Cd substitution has a suppressing effect on the alpha'-alpha-beta phase transitions. With increasing substitution, there is also a significant change in the individual Zn site occupancies. Differential scanning calorimetry shows an apparent correlation between Cd content and phase transition temperature. Thermoelectric properties have been measured from 2 to 400 K for all samples, and although some physical properties are significantly affected by doping, no immediate improvement of ZT was achieved.

  • 26. Prashar, Atul K.
    et al.
    Hodgkins, Robert P.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Chandran, Jima N.
    Rajamohanan, P. R.
    Devi, R. Nandini
    In situ Encapsulation of Pt Nanoarchitectures of Varying Morphologies in Mesoporous Compounds2010In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 22, no 5, p. 1633-1639Article in journal (Refereed)
    Abstract [en]

    Nanoparticle morphology could be engineered and fine-tuned based on a novel in situ template method Different shapes of platinum nanoparticles were obtained from very low concentrations of precursors and could be isolated exclusively inside the mesochannels of SBA-15 This was achieved by dispersing a platinum precursor in surfactant modified polymer to different extents and using these composite materials as templates for the formation of mesoporous silica [PtCl6](2-) interacts with the cationic headgroup of the surfactant and facilitates the isolation of precursors within the composite template leading to the formation of nanoparticles molded by the walls of the mesochannels when calcined When this [PtCl6](2-)-surfactant-polymer micelle composite is aged for different duration, Pt nanoparticles of various morphologies like spheroids, nano rugby balls, and nanorods are obtained.

  • 27. Renman, Viktor
    et al.
    Hu, Shichao
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Eriksson, Rickard
    Maibach, Julia
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Gómez, Cesar Pay
    Edström, Kristina
    Ni3Sb4O6F6 and Its Electrochemical Behavior toward Lithium-A Combination of Conversion and Alloying Reactions2016In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 28, no 18, p. 6520-6527Article in journal (Refereed)
    Abstract [en]

    A group of oxohalides, where Ni3Sb4O6F6 is one example, has been investigated with respect to its electrochemical reactions toward Li+/Li. In situ and ex situ XRD measurements reveal that the original structure collapses and the material becomes amorphous upon insertion of Li at low potentials versus Li+/Li. With continued cycling, a nanocrystalline phase of NiSb, which reacts reversibly with Li, appears and steadily grows more stable. Electrochemical experiments (i.e., chronopotentiometry and cyclic voltammetry) show that multiple reactions of both conversion- and alloying-type are active in the system. High storage capacities are achieved initially but with rapid fading as a consequence of a limited reversibility of the Ni2+/Ni redox process, as shown by X-ray absorption spectroscopy of the first discharge/charge cycle. Stable cycling can be achieved by optimizing the cutoff potentials (i.e., excluding poorly reversible reactions at high and low voltages, respectively), yielding long-term cycling with a practical gravimetric capacity of similar to 200 mAh g(-1).

  • 28.
    Ruan, Juanfang
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry, Structural Chemistry.
    Wu, Peng
    Slater, Ben
    Zhao, Zhonglin
    Wu, Leilei
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Structural Characterization of Interlayer Expanded Zeolite Prepared From Ferrierite Lamellar Precursor2009In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 21, no 13, p. 2904-2911Article in journal (Refereed)
    Abstract [en]

    A novel methodology was successfully developed to expand the structure of zeolitic lamellar precursors through molecular alkoxysilylation. The method has been applied to PREFER (lamellar precursor of ferrierite). As a result, a novel crystalline interlayer expanded zeolite named as IEZ-FER (IEZ is the abbreviation of interlayer expanded zeolite) with enlarged distance perpendicular to the layer was synthesized through interlayer molecular alkoxysilylation. In this paper, the structure of IEZ- FER has been comprehensively studied by various means such as electron diffraction, high-resolution electron microscopy (HREM) and structure modeling. Our studies provide evidence that IEZ-FER preserves the pentasil layers corresponding to that found in the known three-dimensional (3D) FER zeolite, but it also shows a distinct expansion of the layer spacing (?5 A ? ). The newly formed channel system is distinct from that of the known 3D FER structure,which has 8-membered ring (MR) and 10MR pores along the [010] and [001] directions, respectively; IEZ-FER exhibits 10MR and 12MR pores along the [010] and [001] directions, respectively, in the interlayer space, which can be shown to explain the expansion in between layers. Furthermore, the formation of the large pores could be realized by the insertion of monolayer of Si species between the layers, and it explains the unique interlayer cross-linkages (Si(OH)(SiO2)3 and Si(OH)2(SiO2)2) present in the interlayer.

  • 29.
    Sakamoto, Yasuhiro
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Han, Lu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Che, Shunai
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Structural Analyses of Intergrowth and Stacking Fault in Cage-Type Mesoporous Crystals2009In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 21, no 2, p. 223-229Article in journal (Refereed)
  • 30. Sobkowiak, Adam
    et al.
    Roberts, Matthew R.
    Younesi, Reza
    Ericsson, Tore
    Häggström, Lennart
    Tai, Cheuk-Wai
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Anderssor, Anna M.
    Edström, Kristina
    Gustafsson, Torbjörn
    Björefors, Fredrik
    Understanding and Controlling the Surface Chemistry of LiFeSO4F for an Enhanced Cathode Functionality2013In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 25, no 15, p. 3020-3029Article in journal (Refereed)
    Abstract [en]

    The tavorite polymorph of LiFeSO4F has recently attracted a lot of interest as a cathode material for lithium ion batteries stimulated by its competitive specific capacity, high potential for the Fe2+/Fe3+ redox couple, and low-temperature synthesis. However, the synthesis routes explored to date have resulted in notably varied electrochemical performance. This inconsistency is difficult to understand given the excellent purity, crystallinity, and similar morphologies achieved via all known methods. In this work, we examine the role of the interfacial chemistry on the electrochemical functionality of LiFeSO4F. We demonstrate that particularly poor electrochemical performance may be obtained for pristine materials synthesized in tetraethylene glycol (TEG), which represents one of the most economically viable production methods. By careful surface characterization, we show that this restricted performance can be largely attributed to residual traces of TEG remaining on the surface of pristine materials, inhibiting the electrochemical reactions. Moreover, we show that optimized cycling performance of LiFeSO4F can be achieved by removing the unwanted residues and applying a conducting polymer coating, which increases the electronic contact area between the electrode components and creates a highly percolating network for efficient electron transport throughout the composite material. This coating is produced using a simple and scalable method designed to intrinsically favor the functionality of the final product.

  • 31.
    Sun, Junliang
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zhang, Daliang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Extensive inspection of an unconventional mesoporous material at all length scales2010In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 23, no 2, p. 229-238Article in journal (Refereed)
    Abstract [en]

    The structure of an unconventional mesoporous material, formed by the packing of silica coated spherical micelles as hard spheres, has been uniquely determined through a series of advanced characterization techniques. The synchrotron-based small-angle X-ray scattering (SAXS) analysis confirms that the bulk material assembled via the hard sphere packing (HSP) route exhibits a strong 200 reflection and a relatively weaker 111 reflection, which is the first example in all reported mesostructured materials with the same symmetry. At the morphological macroscale, high-resolution scanning electron microscopy (SEM) images directly show that the hexagonal platelike micrometer-sized particles consist of nanospheres (20 nm in diameters) in a close packing mode. The intrinsic pore structure of calcined HSP material has been reconstructed using both electron crystallography (EC) and electron tomography (ET) techniques, which can be simply viewed as a face-centered cubic (fcc) packing of monodispersed hollow silica nanospheres. The EC technique provides a three-dimensional visualization of the pore organization and demonstrates the existence and crystallographic positions of the cagelike mesopores, octahedral and tetrahedral cavities. The ET method directly and accurately determines the sizes of the mesopores and octahedral cavity and offers nanometer-scale structural information at any given local area, which cannot be obtained by conventional transmission electron microscopy (TEM). To our knowledge, this is the first time that the EC and ET techniques are simultaneously employed and provide complementary information for the mesostructure determination. More importantly, the structural details collected from the synchrotron SAXS, high resolution SEM, EC and ET techniques are consistent and support the HSP mechanism, different from the well-understood liquid crystal templating or cooperative self-assembly pathways. The complex pore structure and the existence of octahedral and tetrahedral cavities are responsible for the unusual indexation of the SAXS, which is further validated by the structural simulation. Our work provides both a comparative and comprehensive case study to show the strength and limitation of individual techniques and demonstrates the need for the careful characterization of novel structures by a selection of complementary, state-of-the-art methods which provide selective structural information at different length scales.

  • 32.
    Tang, Liqiu
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Dadachov, Mike, S.
    Zou, Xiaodong
    SU-12: a silicon-substituted ASU- 16 with circular 24-rings and templated by a monoamine2005In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 17, no 10, p. 2530-2536Article in journal (Refereed)
    Abstract [en]

    A new silicogermanate, SU-12, |(CH3CH2CH2NH3)3(H2O)2.5|[(Ge6.44Si0.56)O14.5F2], with 24-ring channel systems was synthesized under hydro/solvothermal conditions, and its structure was determined by single-crystal X-ray diffraction. It is the first silicogermanate with extra-large 24-rings templated by a primary monoamine. Crystallographic data: tetragonal, space group I2m, unit cell parameters a = 27.6460(22) Å and c = 17.0885(14) Å, V = 13060.8(17) Å3, Z = 16, ρcalcd = 1.797 g/cm3, R1 = 0.0512 [5471 observed reflections with I > 2σ(I)], wR2 = 0.1487, S (goodness-of-fit on F2) = 1.08. SU-12 has a structure topology similar to that of the pure germanate ASU-16. However, the symmetry of SU-12 is higher than that of ASU-16, and the 24-rings become more circular than those in ASU-16. The interaction between the templates and framework is compared for ASU-16 and SU-12, and their thermal stabilities are studied. The orthorhombic ASU-16 is thermally less stable than the tetragonal SU-12 and transformed to SU-12 by heating. The ion-exchange property of SU-12 is also studied.

  • 33.
    Tengå, Andreas
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    García-García, Javier
    Max-Planck Institute for Solid State Research.
    Mikhaylushkin, Arkady S
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Espinosa-Arronte, Beatriz
    Solid State Physics, IMIT, Royal Institute of Technology, KTH.
    Andersson, Magnus
    Solid State Physics, IMIT, Royal Institute of Technology, KTH.
    Häussermann, Ulrich
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Sphalerite-Chalcopyrite Polymorphism in Semimetallic ZnSnSb22005In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 17, no 24, p. 6080-6085Article in journal (Refereed)
    Abstract [en]

    We have investigated the system ZnSnSb2 in the course of our attempts to modify thermoelectricZn-Sb frameworks. ZnSnSb2 is only accessible when employing Sn as reactive flux in the synthesis.The material shows an order-disorder transition in the temperature interval between 225 and 240 °Cand decomposes peritectically at about 360 °C. The high-temperature form of ZnSnSb2 adopts the Zn/Sndisordered cubic sphalerite-type structure. Electron microscopy investigations reveal that samples quenchedfrom 350 °C already contain domains of the low-temperature form, which has the Zn/Sn ordered tetragonalchalcopyrite structure. The c/a ratio of the tetragonal structure is, within experimental errors, identical tothe ideal value 2. This gives rise to intricate microtwinning in the low-temperature chalcopyrite form ofZnSnSb2 as obtained in samples quenched from 250 °C. First principles electronic structure calculationsdemonstrate that the tetragonal low-temperature form of ZnSnSb2 has a narrow band gap of about 0.2eV. This is in agreement with the semimetallic behavior of the material found from resistivity measurement.The shape of the electronic density of states for ZnSnSb2 is similar to thermoelectric binary Zn-Sbframeworks. However, the thermopower of ZnSnSb2 is rather low with room-temperature values rangingfrom 10 to 30 íV/K.

  • 34.
    Vasiliev, Petr O.
    et al.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Shen, Z. J.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Hodgkins, R. P.
    Bergström, L.
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Meso/macroporous, mechanically stable silica monoliths of complex shape by controlled fusion of mesoporous spherical particles2006In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 18, p. 4933-4938Article in journal (Refereed)
  • 35. Wang, Hongjing
    et al.
    Wang, Liang
    Sato, Takaaki
    Sakamoto, Yasuhiro
    Tominaka, Satoshi
    Miyasaka, Keiichi
    Miyamoto, Nobuyoshi
    Nemoto, Yoshihiro
    Terasaki, Osamu
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Yamauchi, Yusuke
    Synthesis of Mesoporous Pt Films with Tunable Pore Sizes from Aqueous Surfactant Solutions2012In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 24, no 9, p. 1591-1598Article in journal (Refereed)
    Abstract [en]

    Platinum (Pt) is widely used as battery electrodes, catalysts for chemicals, and catalysts for exhaust gas decomposition in industries. Increasing need and very limited supply of rare Pt is a serious problem in the world. Here, we propose new synthetic way for reducing the use of Pt in a catalytic system by increasing the surface area and modifying the Pt surface structure. Several types of mesoporous Pt films with different pore sizes ranging from 5 to 30 nm are prepared by electrochemical plating in aqueous surfactant solutions. The mesopore walls are composed of connected Pt nanoparticles with around 3 nm in diameter. The Pt atomic crystallinity is coherently extending across over several Pt nanoparticles, showing a large number of atomic steps, which can accelerate methanol oxidation reaction. As a result of a high surface area and unique Pt surface, our mesoporous Pt film exhibits high potentiality as a superior electrocatalyst.

  • 36.
    Wicklein, Bernd
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Kocjan, Darko
    Carosio, Federico
    Camino, Giovanni
    Bergström, Lennart
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Tuning the Nanocellulose-Borate Interaction To Achieve Highly Flame Retardant Hybrid Materials2016In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 28, no 7, p. 1985-1989Article in journal (Refereed)
  • 37. Wu, Xiaowei
    et al.
    Ruan, Juanfang
    Stockholm University, Faculty of Science, Department of Physical, Inorganic and Structural Chemistry.
    Ohsuna, Tetsu
    Terasaki, Osamu
    Che, Shunai
    A Novel Route for Synthesizing Silica Nanotubes with Chiral Mesoporous Wall Structures2007In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 19, no 7, p. 1577-1583Article in journal (Refereed)
    Abstract [en]

    Right- and left-handed excess chiral mesoporous silica nanotubes with a helical channel in the wall have been formed by the self-assembly of an achiral surfactant sodium dodecyl sulfate (SDS) in the presence of (R)-(+)- and (S)-(-)- 2-amino-3-phenyl-1-propanol ((R)-(+)- and (S)-(-)-APP) chiral molecules. Transmission electron microscopy combined with computer simulations confirmed the presence of ordered chiral channels winding around the central axis of the tubes of similar to 100 nm inner diameter. Furthermore, it has been found that these have been produced through a specific crystallization route that hollows out the chiral mesoporous silica rod, which is different from the tube synthesis pathways reported previously. The enantiomeric excess ee of chiral mesoporous silica has been increased from 0 to a maximum value of 32% with increasing (R)-(+)-APP/SDS molar ratios from 0 to 0.8.

  • 38. Yang, Tao
    et al.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Yeon, Jeongho
    Halasyamani, Shiv
    Huang, Shiliang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Hemberger, Joachim
    Greenblatt, Martha
    Cd1−xBix(Cd1+xIn1−x)VO6 (0 ≤ x ≤ 0.14): A New Polar Oxide with Second-Harmonic Generation2010In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 22, no 16, p. 4814-4820Article in journal (Refereed)
    Abstract [en]

    The structure of the new polar oxide, Cd2InVO6, was determined by powder X-ray diffraction. Cd2InVO6 crystallizes in space group P31 with the unit cell parameters: a = 12.21896(4), c = 9.25675(4) Å. The Cd2+ and In3+ ions are statistically disordered in nine independent positions (M1−M9) with a certain level of site preference. M1−M3 form highly asymmetric oxygen-coordination polyhedra, which are similar to those formed by alkali or alkali-earth cations. M4−M9 are in distorted octahedral cavities. It is shown that M1−M3 are likely occupied mostly by Cd2+ while M4−M9 are extensively mixed by Cd2+ and In3+. The structure is best described as a framework of interconnected M4−M9 distorted octahedra with the M1−M3 polyhedra off-framework and the three independent VO4 tetrahedra filling the channels of the framework structure by corner-sharing with the MO6 octahedra. The polar framework is composed of M4O6M9O6 octahedra in a five-connected net with the topology nomination (33, 63, 94). The Bi3+-substituted compounds were also investigated with the rationale that the lone pair electrons of Bi3+ might enhance ferroelectricity. Single phase Cd1−xBix(Cd1+xIn1−x)VO6 forms limited solid solutions (0.02 ≤ x ≤ 0.14). Ferroelectricity was observed for neither the parent nor the Bi3+-substituted compounds, which suggest that the dipole moments are not switchable or too insignificant in magnitude. The powder second-harmonic generation measurements with 1064 nm radiation established that Cd1−xBix(Cd1+xIn1−x)VO6 are type-1 phase-matchable materials for x = 0, 0.14 with 70 and 90 times the efficiency of α-SiO2, respectively.

  • 39.
    Yao, Qingxia
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Bermejo Gómez, Antonio
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Su, Jie
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Pascanu, Vlad
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Yun, Yifeng
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zheng, Haoquan
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Chen, Hong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Liu, Leifeng
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Abdelhamid, Hani Nasser
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Martin-Matute, Belén
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Series of Highly Stable Isoreticular Lanthanide Metal-Organic Frameworks with Expanding Pore Size and Tunable Luminescent Properties2015In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 27, no 15, p. 5332-5339Article in journal (Refereed)
    Abstract [en]

    A series of highly porous isoreticular lanthanide-based metal organic frameworks (LnMOFs) denoted as SUMOE-7I to SUMOE-7IV (SU = Stockholm University; Ln = La, Ce, Pr, Nd, Sm, Eu, and Gd) have been synthesized using tritopic carboxylates as the organic linkers. The SUMOF-7 materials display one-dimensional pseudohexagonal channels with the pore diameter gradually enlarged from 8.4 to 23.9 angstrom, as a result of increasing sizes of the organic linkers. The structures have been solved by single crystal X-ray diffraction or rotation electron diffraction (RED) combined with powder X-ray diffraction (PXRD). The SUMOF-7 materials exhibit robust architectures with permanent porosity. More importantly, they exhibit exceptionally high thermal and chemical stability. We show that, by inclusion of organic dye molecules, the luminescence properties of the MOFs can be elaborated and modulated, leading to promising applications in sensing and optics.

  • 40.
    Yu, Zheng-Bao
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Han, Yu
    Zhao, Lan
    Huang, Shiliang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zheng, Qi-Yu
    Lin, Shuangzheng
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Córdova, Armando
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Intergrown New Zeolite Beta Polymorphs with Interconnected 12-Ring Channels Solved by Combining Electron Crystallography and Single-Crystal X-ray Diffraction2012In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 24, no 19, p. 3701-3706Article in journal (Refereed)
    Abstract [en]

    Two new polymorphs of zeolite beta, denoted as SU-78A and SU-78B, were synthesized by employing dicyclohexylammonium hydroxides as organic structuredirecting agents. The structure was solved by combining transmission electron microscopy and single-crystal X-ray diffraction. SU-78 is an intergrowth of SU-78A and SU-78B and contains interconnected 12-ring channels in three directions. The two polymorphs are built from the same building layer, similar to that for the zeolite beta family. The layer stacking in SU-78, however, is different from those in zeolite beta polymorph A, B, and C, showing new zeolite framework topologies. SU-78 is thermally stable up to 600°C.

  • 41. Zeilinger, Michael
    et al.
    Baran, Volodymyr
    van Wuellen, Leo
    Häussermann, Ulrich
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Faessler, Thomas F.
    Stabilizing the Phase Li15Si4 through Lithium-Aluminum Substitution in Li15-xAlxSi4 (0.4 <= x <= 0.8)-Single Crystal X-ray Structure Determination of Li15Si4 and Li14.37Al0.63Si42013In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 25, no 20, p. 4113-4121Article in journal (Refereed)
    Abstract [en]

    Single crystals of Li15Si4 and Li15-xAlxSi4 (x = 0.63(1)) were obtained from equilibrated melts with compositions Li100-xSix (x = 10, 15) and Li83Al13Si4, respectively, and isolated by isothermal centrifugation. Li15Si4 and Li14.37(1)Al0.63(1)Si4 crystallize with the Cu15Si4 structure type (I (4) over bar 3d, a(x=0) = 10.6322(9) angstrom, a(x=0.63(1)) = 10.6172(4) angstrom, Z = 4, T = 123 K). The incorporation of Al equally affects both crystallographically distinguished Li positions in the Li15Si4 structure. The replacement of about 4% of Li is firmly established by the refinement of single crystal diffraction data and NMR spectroscopy. The homogeneity range of Li15-xAlxSi4 was assessed as 0.4 < x < 0.8 from synthesis experiments using stoichiometric proportions of the elements. Differential scanning calorimetry studies confirm the metastable character of Li15Si4, decomposing exothermally at temperatures around 200 degrees C. However, the decomposition process of Li15Si4, is sluggish and appreciable rates are not observed before temperatures reach 400 degrees C. In contrast Li15-xAlxSi4 is thermodynamically stable. The decomposition temperature is at about 700 degrees C. It is speculated that the thermodynamic stability of Li15-xAlxSi4 is a consequence of the increased electron concentration, shifting the Fermi level to a pseudo-gap in the electronic density of states. Since metastable Li15Si4 plays an important role during electrochemical lithiation of a silicon anode, thermodynamically stable Li15-xAlxSi4 may have interesting properties as anode material in lithium ion batteries.

  • 42. Zeilinger, Michael
    et al.
    Benson, Daryn
    Haussermann, Ulrich
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Faessler, Thomas F.
    Single Crystal Growth and Thermodynamic Stability of Li17Si42013In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 25, no 9, p. 1960-1967Article in journal (Refereed)
    Abstract [en]

    Single crystals of Li17Si4 were synthesized from melts LixSi100-x (x > 85) at various temperatures and isolated by isothermal centrifugation. Li17Si4 crystallizes in the space group F (4) over bar 3m (a = 18.7259(1) angstrom, Z = 20). The highly air and moisture sensitive compound is isotypic with Li17Si4. represents a new compound and thus the lithium-richest phase in the binary system Li-Si superseding known Li21Si5 (Li16.8Si4). As previously shown Li22Si5 (Li17.6Si4) has been determined incorrectly. The findings are supported by theoretical calculations of the electronic structure, total energies, and structural optimizations using first-principles methods. Results from melt equilibration experiments and differential scanning calorimetry investigations suggest that Li17Si4 decomposes peritectically at 481 +/- 2 degrees C to Li4Si and melt. In addition a detailed investigation of the Li-Si phase system at the Li rich side by thermal analysis using differential scanning calorimetry is given.

  • 43. Zeilinger, Michael
    et al.
    Jantke, Laura-Alice
    Scherf, Lavinia M.
    Kiefer, Florian J.
    Neubueser, Gero
    Kienle, Lorenz
    Karttunen, Antti J.
    Konar, Sumit
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Häussermann, Ulrich
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Faessler, Thomas F.
    Alkali Metals Extraction Reactions with the Silicides Li15Si4 and Li3NaSi6: Amorphous Si versus allo-Si2014In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 26, no 22, p. 6603-6612Article in journal (Refereed)
    Abstract [en]

    The silicides Li15Si4 and Li3NaSi6 were subjected to chemical extraction of the alkali metal component by liquid ammonia and ethanol, respectively, which after washing yielded black powders of amorphous silicon. The investigated reactions are interesting with respect to both the formation of novel Si modifications and the delithiation process in Si anode materials. The products termed a-Si (from Li15Si4) and a-allo-Si (from Li3NaSi6) were characterized by a combination of methodologies (X-ray diffraction, transmission electron microscopy, differential thermal analysis, Raman, atomic absorption, and energy-dispersive X-ray spectroscopy) which revealed (i) a porous microstructure for a-Si built from spherically shaped particles with sizes around 10 nm, (ii) partial surface oxidation of both materials and (iii) the presence of nanocrystalline Si in both materials. The result of the protic oxidation of Li3NaSi6 is at variance with earlier findings reporting the formation of a crystalline bulk allotrope of silicon (allo-Si) from the topotactic combination of silicon layers present as polyanions in Li3NaSi6. Additionally, quantum chemical calculations show that silicon layers in Li3NaSi6 cannot combine to energetically favorable allotropic forms of Si. This is different from Li7Ge12, where polyanionic germanium layers topotactically convert to the germanium allotrope m-allo-Ge upon oxidation.

  • 44. Zeilinger, Michael
    et al.
    Kurylyshyn, Iryna M.
    Häussermann, Ulrich
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Faessler, Thomas F.
    Revision of the Li-Si Phase Diagram: Discovery and Single-Crystal X-ray Structure Determination of the High-Temperature Phase Li4.11Si2013In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 25, no 22, p. 4623-4632Article in journal (Refereed)
    Abstract [en]

    Silicon has been regarded as a promising anode material for future lithium-ion batteries, and Li-Si phases play an important role. A detailed reinvestigation of the Li-rich part of the binary Li-Si phase diagram revealed the existence of a new phase, Li4.106(2)Si (Li16.42Si4). Li16.42Si4 forms through the peritectic decomposition of the Li-richest phase Li17Si4 at 481-486 degrees C and was characterized by single-crystal X-ray diffraction (a = 4.5246(2) angstrom, b = 21.944(1) angstrom, c = 13.2001(6) angstrom, space group Cmcm, Z = 16), differential scanning calorimetry, and theoretical calculations. Li16.42Si4 represents a high-temperature phase that is thermodynamically stable above similar to 480 degrees C and decomposes peritectically at 618 +/- 2 degrees C to Li13Si4 and a melt. Li16.42Si4 can be retained at room temperature. The structure consists of 3 and 10 different kinds of Si and Li atoms, respectively. Two Li positions show occupational disorder. Si atoms are well-separated from each other and have only Li atoms as nearest neighbors. This is similar to Li17Si4 and Li15Si4 compositionally embracing Li16.42Si4. The SiLin coordination polyhedra in the series Li15Si4, Li16.42Si4, and Li17Si4 are compared. Li15Si4 exclusively features coordination numbers of 12, Li16.42Si4 of 12 and 13, and Li17Si4 reveals 13- and 14-coordinated Si atoms. The band structure and density of states of Li16.42Si4 were calculated on the basis of two ordered model structures with nominal compositions Li16Si4 (a hypothetical Zintl phase) and Li16.5Si4. Both reveal a metallic character that is analogous to Li17Si4. In contrast, the electronic structure of Li15Si4 is characteristic of a p-doped semiconductor.

  • 45. Zhao, Yunfeng
    et al.
    Zhang, Daliang
    Zhao, Lan
    Wang, Guangchao
    Zhu, Yihan
    Cairns, Amy
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Han, Yu
    Controlled Synthesis of the Tricontinuous Mesoporous Material IBN-9 and Its Carbon and Platinum Derivatives2011In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 23, no 16, p. 3775-3786Article in journal (Refereed)
    Abstract [en]

    Controlled synthesis of mesoporous materials with ultracomplicated pore configurations is of great importance for both fundamental research of nanostructures and the development of novel applications. IBN-9, which is the only tricontinuous mesoporous silica with three sets of interpenetrating three-dimensional channel systems, appears to be an excellent model mesophase for such study. The extensive study of synthesis space diagrams proves mesophase transition among the cylindrical MCM-41, tricontinuous IBN-9 and bicontinuous MCM-48, and also allows a more precise control of phase-pure synthesis. On the other hand, rational design of structure-directing agents offers a possibility to extend the synthesis conditions of IBN-9, as well as tailor its pore size. Moreover, an unprecedented helical,-structure consisting of twisted 3-fold interwoven mesoporous channels is reported here for the first time. The unique tricontinuous mesostructure of IBN-9 has been well-replicated by other functional materials (e.g., carbon and platinum) via a hard-templating synthesis route. The obtained carbon material possesses large surface area (similar to 1900 m(2)/g), high pore volume (1.56 cm(3)/g), and remarkable gas adsorption capability at both cryogenic temperatures and room temperature. The platinum material has an ordered mesostructure composed of highly oriented nanocrystals.

1 - 45 of 45
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf