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液晶模板机理合成新一代介孔分子筛
(2007-10-31 20:17:54)
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Abstract: The synthesis, characterization,
and proposed mechanism of formation of a new family of
silicatelaluminosilicate mesoporous molecular sieves designated as
M41S is described. MCM-41, one member of this family, exhibits a
hexagonal arrangement of uniform mesopores whose dimensions may be
engineered in the range of - 15 A to greater than 100 A. Other
members of this family, including a material exhibiting cubic
symmetry, have ken synthesized. The larger pore M41S materials
typically have surface areas above 700 m2/g and hydrocarbon
sorption capacities of 0.7 cc/g and greater. A templating mechanism
(liquid crystal templating-LCT) in which surfactant liquid crystal
structures serve as organic templates is proposed
for the formation of these materials. In support of this templating
mechanism, it was demonstrated that the structure and pore
dimensions of MCM-41 materials are intimately linked to the
properties of the surfactant, including surfactant chain length and
solution chemistry. The presence of variable pore size MCM-41,
cubic material, and other phases indicates that M41S is an
extensive
family of materials.
family of materials.
摘要：本文报道了新一代的M41S家族系列介孔硅-硅铝分子筛的合成，表征，并提出形成机理。作为新一代介孔材料家族一员，MCM-41具有呈六方排列的均匀介孔，孔径在1.5-10 nm可调。这一家族的其他介孔材料也已合成，包括呈立方对称的。因为M41S具有较大的孔径，一般比表面积可达700m/g，对碳氢化合物的吸收孔容可达0.7cc/g或更高。提出的液晶模板机理，是指以表面活性剂的液晶结构作为有机模板剂。为了论证该模板机理，已有前人报道MCM-41的结构和孔维与表面活性剂的性质密切相关,包括表面活性剂的疏水链的长℃，溶液化学性质。具有不同孔径的MCM-41，呈立方对称以及其他相态的材料都表明M41S家族系列将是具有广阔发展前景的介孔材料.
Conclusion
M41S represents a new family of mesoporous molecular sicve
materials. MCM-41, the hexagonal phase, is characterized as
having a uniform and controllable pore size from - 15 to greater
than 100 A, high surface area, and high hydrocarbon sorption
capacity. These molecular sieves are formed by a mechanism in
which surfactant liquid crystal phases are believed to serve as
templates. In support of this templating mechanism, the structure
and pore dimensions of MCM-41 materials are intimately linked
to the properties of the surfactant, such as surfactant chain length,
solution chemistry and micellar solubilization of trimethylbenzene.
The existence of other phases, including a cubic phase, supports
this LCT mechanism and indicates that M41S is an extensive
family of materials.
M41S represents a new family of mesoporous molecular sicve
materials. MCM-41, the hexagonal phase, is characterized as
having a uniform and controllable pore size from - 15 to greater
than 100 A, high surface area, and high hydrocarbon sorption
capacity. These molecular sieves are formed by a mechanism in
which surfactant liquid crystal phases are believed to serve as
templates. In support of this templating mechanism, the structure
and pore dimensions of MCM-41 materials are intimately linked
to the properties of the surfactant, such as surfactant chain length,
solution chemistry and micellar solubilization of trimethylbenzene.
The existence of other phases, including a cubic phase, supports
this LCT mechanism and indicates that M41S is an extensive
family of materials.
结论
M41S代表了新一代介孔分子筛家族，MCM-41，具有六方相排列，孔道均一规则，在15-100Å孔径范围可调，高的比表面和对有机物的吸附。形成机理：无机前驱体，在表面活性剂溶液形成的液晶结构为模板进行自组装。与此机理相一致的是，表面活性剂的某些特性，如有机链的长度，溶液化学性质，三甲苯的胶束增溶作用与合成的介孔材料维数有密切联系。合成的其它相态的介孔材料，如立方相，也支持LCT机理，表明M41S系列是具有广泛发展前景的介孔材料新家族。
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