Electric Birefringence Relaxation Method for the Analysis of Polyelectrolyte Gel.

近年来，多糖热可逆凝胶因其凝胶化机理的物理化学和作为智能材料的应用而备受关注。卡拉胶作为多糖凝胶的一种模型，其溶胶凝胶转变已被广泛研究。然而，由于缺乏合适的方法，关于凝胶网络结构的报道很少，在本研究中，我们应用电双折射弛豫法研究了多糖凝胶的网络结构。到目前为止，电双折射方法主要用于研究聚合物溶液的性质，但其在凝胶中的应用从未被研究过，我们建造该设备是为了观察凝胶结构组分取向运动的微弱信号。当矩形电脉冲作用于克尔池时，观察到来自凝胶的电双折射信号。首次观察到凝胶的电双折射信号。该信号由两个过程组成，分别对应于结合区的取向运动和整个凝胶网络结构的变形。通过分析电双折射信号的驰豫过程，可以估计结区的大小。这些结果表明用电双折射方法研究凝胶的网络结构是可能的。

Recently, much interest has been focused on the thermoreversible gel of polysaccharides because of its physicochemical aspect of the gelation mechanism and the application as intelligent materials. Sol-gel transition of k-carrageenan has been studied extensively as a model of polysaccharide gel. However, there are few reports concerning the network structure of the gel because of the lack of appropriate method.In this study, we applied the electric birefringence relaxation method to investigate the network structure of the polysaccharide gel. So far, the electric birefringence method has been mainly used for properties of polymer solutions, but its application to gel has never been examined.We construct the equipment in order to observe the weak signal of the orientational motion of the structural component of the gel. When the rectangular electric pulse is applied to the Kerr cell, the electric birefringence signal from the gel was observed. The observation of the electric birefringence signal from the gel was the first time. The signal was found to consist of two processes, which correspond to the orientational motion of the junction zone and the deformation of the whole network structure of the gel. The size of the junction zone can be estimated by analyzing the relaxation process of the electric birefringence signal. These results indicate the possibility of the electric birefringence method to investigate the network structure of the gel.