Phase relationship and dynamics of anisotropic gelation of carboxymethylcellulose aqueous solution
Phase relationship and dynamics of anisotropic gelation of carboxymethylcellulose aqueous solution
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DOI：
10.1007/s00396-010-2193-y
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发表时间：
2010-04-01
影响因子：
2.4
通讯作者：
Dobashi, Toshiaki
中科院分区：
文献类型：
--
作者：
Lin, S. C.;Minamisawa, Yoshiyuki;Dobashi, Toshiaki
研究了将羧甲基纤维素(CMC)浸泡在CaCl2水溶液中，夹在两块圆形玻璃之间的NaOH溶液中的各向异性凝胶化过程。在透析过程中，凝胶和相分离同时发生，使混浊的条纹呈放射状排列。在低CMC浓度下，基于“移动边界图”的理论所预测的凝胶层宽度的时间过程可以很好地用比例线性图来表示。另一方面，在高CMC浓度下，时间过程表现为两个阶段的动力学。时间过程不依赖于CMC溶液的初始浓度和覆盖玻璃的直径，而凝胶化速度随着CMC浓度的增加而减小。这归因于在此过程中形成凝胶所需的钙离子浓度的变化。讨论了该体系在凝胶动力学中的共性和个性。
Anisotropic gelation of carboxymethylcellulose (CMC) in aqueous NaOH sandwiched between two circular cover glasses by immersing it in aqueous CaCl2 has been studied. In the course of dialysis, gelation and phase separation occurred simultaneously to make turbid stripes arranged radially. The time course of the gel layer width was well expressed in scaled linear plots predicted by a theory based on "moving boundary picture" at low CMC concentrations. On the other hand, at high CMC concentrations, the time course was expressed by a two-stage dynamics. The time course did not depend on the initial thickness of the CMC solution and the diameter of the cover glasses, whereas the rate of gelation decreased with increasing CMC concentration. It was attributed to the change in the calcium cation concentration required for forming the gel in the process. The universality and the individuality of the present system in the gelation dynamics are discussed.