Silica self-assembly and the synthesis of microporous and mesoporous silicates

被引:79
作者
Rimer, JD [1 ]
Fedeyko, JM [1 ]
Vlachos, DG [1 ]
Lobo, RF [1 ]
机构
[1] Univ Delaware, Ctr Catalyt Sci & Technol, Dept Chem Engn, Newark, DE 19716 USA
关键词
aggregation; self-assembly; silicon; zeolites;
D O I
10.1002/chem.200500684
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The microstructure of silica in basic aqueous solutions containing organic cations and prepared from monomeric precursors is reviewed and interpreted within the context of classical ideas of self-assembly of molecular aggregates. The solution properties can be understood by using the pseudo-phase separation approach coupled to the acid-base chemistry of silanol groups and the Poisson-Boltzmann equation. The silica nanoparticles frequently observed in these systems have a core-shell structure with silica in the core and the organic cations at the shell. Individual particles are observed when the forces between particles are repulsive-as is the case for small cations such as tetramethylammonium or tetrapropylammonium-and ex-tended structures such as M41S materials are formed when the forces are attractive-as is the case for surfactants such as cetyltrimethylammonium. These ideas are useful to understand the evolution of zeolite synthesis gels from nucleation to crystal growth. Although at room temperature the silica and the organic cations are segregated, upon heating the organic cations are embedded within the particles. This transformation signals the onset of structure direction whereby the size and geometry of the organic cation induce changes in the structure of silica that may lead to zeolite nuclei.
引用
收藏
页码:2926 / 2934
页数:9
相关论文
共 61 条
  • [21] Spontaneous formation of silica nanoparticles in basic solutions of small tetraalkylammonium cations
    Fedeyko, JM
    Rimer, JD
    Lobo, RF
    Vlachos, DG
    [J]. JOURNAL OF PHYSICAL CHEMISTRY B, 2004, 108 (33) : 12271 - 12275
  • [22] FEDEYKO JM, 2005, IN PRESS MICROPOR ME
  • [23] HEANEY PJ, 1994, SILICA PHYSL BEHAV G
  • [24] Controlling the preferred orientation in silicalite-1 films synthesized by seeding
    Hedlund, J
    Mintova, S
    Sterte, J
    [J]. MICROPOROUS AND MESOPOROUS MATERIALS, 1999, 28 (01) : 185 - 194
  • [25] Hiemenz P.C., 1997, PRINCIPLES COLLOID S, V3rd
  • [26] Iler R.K., 1979, The chemistry of silica
  • [27] Israelachvili JN, 2011, INTERMOLECULAR AND SURFACE FORCES, 3RD EDITION, P1
  • [28] JORGE M, 2005, IN PRESS J AM CHEM S, P127
  • [29] On the TEM and AFM evidence of zeosil nanoslabs present during the synthesis of silicalite-1 - Reply
    Kirschhock, CEA
    Liang, DD
    Aerts, A
    Aerts, CA
    Kremer, SPB
    Jacobs, PA
    Van Tendeloo, G
    Martens, JA
    [J]. ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 2004, 43 (35) : 4562 - 4564
  • [30] KIRSCHHOCK CEA, 2004, ANGEW CHEM, V116, P4662