Formation of porous gel morphology by phase separation in gelling alkoxy-derived silica. Phenomenological study
Formation of porous gel morphology by phase separation in gelling alkoxy-derived silica. Phenomenological study
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通过在胶凝烷氧基衍生二氧化硅中相分离形成多孔凝胶形态。
DOI：
10.1016/0022-3093(94)00670-9
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发表时间：
1995
影响因子：
3.5
通讯作者：
N. Soga
中科院分区：
文献类型：
--
作者：
H. Kaji;K. Nakanishi;N. Soga
确定了TMOS：甲酰胺：水= 1：f：r体系在酸催化条件下形成孔结构的机理和凝胶形态。从SEM显微照片，孔径变得更大，凝胶形态从宏观上均匀的凝胶，通过互联结构和颗粒的聚集体，宏观上的两相材料与甲酰胺的增加或与水的减少。特别是，它被发现从Hg孔率和N2吸附-脱附测量，具有互连结构和颗粒聚集体的形态的凝胶具有双重孔结构。从1H NMR测量和低聚烷氧基硅烷体系的相行为，这些结果一致地解释了孔结构和凝胶形态是由相分离的结构发展和凝胶网络形成的结构冻结的竞争决定的。研究还发现，该体系中的相分离不是由溶液组成的变化引起的，而是由聚合度的增加引起的。
The mechanisms for forming pore structures and the gel morphology were determined for the system with TMOS:formamide:water = 1:f:r under an acid-catalyzed condition. From SEM micrographs, the pore sizes became larger and the gel morphologies changed from macroscopically homogeneous gels, through interconnected structures and aggregates of particles, to macroscopic two-phase materials with an increase of formamide or with a decrease of water. In particular, it was found from Hg porosimetry and N2adsorption-desorption measurements that gels with the morphologies of interconnected structures and aggregates of particles had dual pore structures. From1H NMR measurements and the phase behavior for the oligometric alkoxysilane system, these results were consistently explained that the pore structures and gel morphologies were determined by the competition of structure development by phase separation and structure freezing by gel network formation. It is also found that the phase separation in the present system was not induced by the change of solution composition but by the increase of degree of polymerization.
聚合物共混体系中相分离过程的原位观察
DOI：
--
发表时间：
2008
期刊：
影响因子：
--
作者：
Haruko Saito;Masahiro Yoshinaga;Takaaki Mihara;Hiroshi Jinnai;Toshio Nishi
通讯作者：
Toshio Nishi