Influence of observation temperature on light scattering of poly-N-isopropylacrylamide hydrogels
Influence of observation temperature on light scattering of poly-N-isopropylacrylamide hydrogels
复制标题
观察温度对聚N-异丙基丙烯酰胺水凝胶光散射的影响
DOI：
10.1039/c2sm07316a
复制
发表时间：
2012
期刊：
影响因子：
3.4
通讯作者：
W. Oppermann
中科院分区：
文献类型：
--
作者：
S. Dogu;W. Oppermann
采用静态和动态光散射方法对N-异丙基丙烯酰胺交联共聚凝胶的微观结构进行了表征，重点研究了测量温度对凝胶微观结构的影响。总散射强度分为两部分：由于布朗运动的热散射和由于拓扑或空间不均匀性的静态散射。不同的数据评估方法，即非遍历和部分外差方法，进行了仔细比较。我们获得了一致的结果，清楚地表明，当观察温度从10 ° C增加到27.5 °C时，散射的两个部分显著上升，从而接近下临界溶解温度。虽然热散射组分的温度依赖性是很好的理解，我们属性的静态组件的上升，以建立局部溶胀平衡的凝胶，其交联密度具有一定的不均匀性。这意味着随着温度的升高，交联密度更高的区域会以交联密度较低的区域为代价而解膨胀。结果，散射对比度增强，从而导致更大的静态散射强度。
Static and dynamic light scattering methods were applied to characterize the microstructure of gels synthesized by cross-linking copolymerization of N-isopropylacrylamide, with particular emphasis on the influence of measurement temperature. The total scattering intensity was divided into two parts: thermal scattering due to Brownian motion and static scattering due to topological or spatial inhomogeneity. Different methods of data evaluation, i.e. the non-ergodic and the partial heterodyne approaches, were carefully compared. We obtained consistent results clearly demonstrating that both parts of the scattering rise markedly upon increasing the observation temperature from 10 to 27.5 °C thus approaching the lower critical solution temperature. While the temperature dependence of the thermal scattering component is well understood, we attribute the rise of the static component to the establishment of local swelling equilibrium in a gel whose cross-link density features some inhomogeneity. This means that with rising temperature the more densely cross-linked regions deswell at the expense of the less densely cross-linked ones. As a result, the scattering contrast is enhanced thus leading to a larger static scattering intensity.
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影响因子：
--
作者：
Ikkai, F;Shibayama, M
通讯作者：
Shibayama, M
压力对环境敏感聚合物凝胶不均匀性的影响
DOI：
--
发表时间：
2004
期刊：
影响因子：
--
作者：
M. Shibayama;S. Takata;C. Nakamoto
通讯作者：
C. Nakamoto
影响因子：
5.5
作者：
Hecht, AM;Horkay, F;Geissler, E
通讯作者：
Geissler, E
影响因子：
3.3
作者：
Kawaguchi, Tomoaki;Kobayashi, Kunihiko;Yoshizaki, Takenao
通讯作者：
Yoshizaki, Takenao
溶胀和反应器批次聚合物凝胶的静态不均匀性和动力学
影响因子：
4.4
作者：
M. Shibayama;Y. Shirotani;Y. Shiwa
通讯作者：
Y. Shiwa