Fluid Dynamics of Complex Biosystems, School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany.
Carbohydr Polym. 2020 Oct 15;246:116615. doi: 10.1016/j.carbpol.2020.116615. Epub 2020 Jun 12.
There is a growing interest in the in situ gelation of the alginate-Ca system due to its remarkable applications. In this work, we record and evaluate the fast gelation kinetics of alginate-Ca using a custom-made rheometric setup. This enables us to inject CaCl into the alginate while we perform the rheological measurements. We successfully measure the in situ gelation reaction from the early stages. As the alginate concentration is increased up to 3 wt.%, we observe a systematic increase of the elastic modulus, G'. Similarly, higher concentrations and injected volumes of CaCl increase the magnitude and initial growth rate of G'. At longer times, the growth rate of G' is lower. It decreases further very slowly, indicating that the chemical reaction requires quite a considerable amount of time to be completed. Finally, from the rheometric data, we estimate the average rates of the elastic modulus during the initial and quasi-steady-state stages.
由于其显著的应用，人们对海藻酸钠-Ca 体系的原位凝胶化越来越感兴趣。在这项工作中，我们使用定制的流变仪设备记录和评估了海藻酸钠-Ca 的快速凝胶化动力学。这使我们能够在进行流变测量的同时将 CaCl2 注入海藻酸钠中。我们成功地从早期阶段测量了原位凝胶化反应。随着海藻酸钠浓度增加到 3wt.%，我们观察到弹性模量 G'的系统性增加。同样，更高浓度和注入体积的 CaCl2 增加了 G'的幅度和初始增长率。在更长的时间内，G'的增长率较低。它进一步缓慢下降，表明化学反应需要相当长的时间才能完成。最后，从流变数据中，我们估计了初始和准稳态阶段弹性模量的平均速率。
