凝胶形成动态过程在线监测方法的比较

以醋酸介质中戊二醛（Ｇｌｕ）交联壳聚糖（ＣＳ）水凝胶的形成为例，研究比较了粘度法，电导法，光度法和荧光探针法用于监测凝胶形成动态过程的可行性性和特点，结果表明：粘度法具有简单、直观等优点，但粘度法不能够跟踪凝胶点（ｇｅｌｌｉｎｇｐｏｉｎｔｓ）后体系的进一步变化，旋转粘度法在测定时对体系的扰动不容忽视。电导法和光度法跟踪的是引起凝胶化的交联反应过程，但溶液到凝胶的转化往往发生在交联反应完成之前，因此所得结果未必与宏观观察结果相一致，荧光探针法具有适用面宽，可供选用的探针种类多、方法灵活等特点，对于研究凝胶形成动态过程具有普适性，该法还可用于凝胶性质的研究。

A Comparative Study of the Methods for in Situ Monitoring of Gelation Dynamics

The usefulness and characteristics of some methods for in situ monitoring gelation dynamics have been studied, taking glutaraldehyde(Glu) crosslinked chitosan(CS) in acetic acid medium as a model system. It has been shown that the viscosity method is simple and direct. But it is unlikely to monitor the changes occurring after the gelling point of a gelation system. In addition, there is a perturbation to the gelling process from the rotationary visco- sity measurements. The electroconductivity and photometric methods monitor the crosslin- king reaction, rather than the rheological changes. Therefore, the results may not be in consistent with that perceived through the senses. Among the methods tested, fluorescence probe method appears the first choice to monitor the gelation dynamics of various gelling systems due to the great number of probes and related fluorescence properties.