|
KMID : 0381920010310020117
|
|
Korean Journal of Microscopy
2001 Volume.31 No. 2 p.117 ~ p.128
|
|
|
A Scanning Electron Microscopic Study on the Phase Demixing of PVA Gel
|
|
Hong Sung-Goo
Sohn Jeong-In
Lee Ihn-Chong
Kim Soo-Jin
|
|
|
Abstract
|
|
|
|
DMF is not a good solvent for PVA. There is no solvent-PVA interaction such as H-bonding. DMF/PVA makes a UCST system. DMF/PVA makes a gel through crystallization-induced gelation. X-ray, thermal analysis, and other experimental proofs are presented. The gelation rate was faster at low temperature. Small addition of PEG increased the rate of gelation, but urea decreased the rate. SEM showed the phase demixing process very clearly. In the early stage of gelation, only phase demixing was occurring at a low rate. Hence, no holes appear in the early stage photographs. As demixing proceeded further, the holes began to appear and the sizes became bigger. DMF phase remains many holes after vaporization and PVA phase constitute the matrix phase.
|
|
|
KEYWORD
|
|
|
Gel, Phase demixing, PVA
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
|
|