- 著者
- Takeshi HIGUCHI Haruna OIZUMI Tatsuya SASAKI Tadahiro AITA
- 出版者
- The Ceramic Society of Japan
- 雑誌
- Journal of the Ceramic Society of Japan (ISSN:18820743)
- 巻号頁・発行日
- vol.117, no.1368, pp.873-877, 2009 (Released:2009-08-01)
- 参考文献数
- 25
A silica-polymer composite with oriented macropores was fabricated from tetraethoxysilane (TEOS) incorporated with poly(ethylene glycol) (PEG) via a sol-gel method. The solution mixture containing PEG and TEOS after hydrolysis was subjected to shear stress so that the macroporous structure generated by spinodal decomposition during the process of polycondensation to a silica-PEG-rich phase and a solvent-rich phase was elongated and oriented toward the shear flow direction. It was found that shear flow is effective for macropore elongation after the solution mixture becomes turbid. The optimum PEG content for macropore elongation was also revealed. The elongation ratio of the macropores was dependent to a certain extent on the shear rate.
- 著者
- Takeshi Higuchi Yusuke Yano Tadahiro Aita Seiichi Takami Tadafumi Adschiri
- 出版者
- 公益社団法人 化学工学会
- 雑誌
- JOURNAL OF CHEMICAL ENGINEERING OF JAPAN (ISSN:00219592)
- 巻号頁・発行日
- vol.46, no.10, pp.709-715, 2013-10-20 (Released:2013-10-20)
- 参考文献数
- 17
- 被引用文献数
- 2 3
Simulation of polymerization-induced phase separation of a polymer gel from a multifunctional monomer was carried out using the phase field method. To describe the driving force for phase separation, the interfacial energy between the polymeric phase and the aqueous phase was assumed to depend positively on the degree of polymerization, while the thickness of the interface at equilibrium and the mobility were assumed to depend negatively on it. The mobility was also assumed to depend negatively on the volume fraction of the polymer. A sigmoidal function was introduced to describe the nonlinear dependence of the mobility on the volume fraction. The wavelength of phase separation became finer as the polymerization rate increased when the rate of the reaction had a time scale similar to that of diffusion. When a nonreactive polymer coexists in the phase separation, the wavelength of phase separation shrinks because of suppression of diffusion caused by the coexisting polymer. These results qualitatively agreed with the experimental results for macroporous silica prepared via polymerization-induced phase separation.