Heat-Induced Self-Assembling of Thermosensitive Block Copolymer. Rheology and Dynamic Light Scattering Study
Heat-Induced Self-Assembling of Thermosensitive Block Copolymer. Rheology and Dynamic Light Scattering Study
复制标题
热敏嵌段共聚物的热诱导自组装。
DOI：
10.1021/ma030066p
复制
发表时间：
2003
期刊：
影响因子：
5.5
通讯作者：
M. Shibayama
中科院分区：
文献类型：
--
作者：
S. Okabe;S. Sugihara;S. Aoshima;M. Shibayama
用动态光散射（DLS）和流变学方法研究了聚（2-乙氧基乙基乙烯基醚）-b-聚（2-羟乙基乙烯基醚）（PEOVE-b-PHOVE）在水溶液中热可逆形态转变的动力学过程。这里采用的样本位置相关的DLS研究使我们能够解决两个转换，即，(1)分子分散到胶束转变和（2）胶束到宏观晶格转变，这在以前的工作中没有被小角中子散射研究清楚地解决。这些转变的特征在于（1）散射强度的突然增加和（2）斑点图案的出现。观察到强度突然增加的温度比散斑图案出现的温度低几度。流变行为也支持两种转变：（1）牛顿-非牛顿转变和（2）非牛顿-塑性转变。结果表明，该体系存在假溶胶-凝胶转变。
The dynamic aspects of the thermoreversible morphological transition of poly(2-ethoxyethyl vinyl ether)-b-poly(2-hydroxyethyl vinyl ether) (PEOVE-b-PHOVE) in aqueous solutions have been investigated by dynamic light scattering (DLS) and rheological measurements. A sample-position-dependent DLS study, employed here, allowed us to resolve two transitions, i.e., (1) molecular dispersion-to-micelle transition and (2) micelle-to-macrolattice transition, which were not clearly resolved by small-angle neutron scattering studies in the previous work. These transitions are characterized by (1) an abrupt increase in the scattered intensity and (2) an appearance of speckle patterns. The temperature where the abrupt increase in intensity was observed was a few degrees lower than that the speckle pattern appeared. Rheological behaviors also supported the two transitions as (1) Newtonian-to-non-Newtonian transition and (2) non-Newtonian-to-plastic flow transition. It is concluded that a pseudo-sol-to-gel transition wit...