Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Koganei, Tokyo 184-8588, Japan.
Komaba Institute for Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro, Tokyo 153-8902, Japan.
Langmuir. 2020 May 19;36(19):5186-5191. doi: 10.1021/acs.langmuir.0c00428. Epub 2020 May 7.
Gelatin microgels prepared inside lipid droplets have a much higher elasticity than that of bulk gels because of their differences in nanostructure. This nanostructural difference in gelatin microgels is expected to provide the microgels with unique viscoelastic properties that differ from the bulk gels. To clarify this hypothesis, here we evaluated the frequency-dependent viscoelasticity of gelatin gels by developing a cyclic micropipette aspiration. The frequency-dependent relationship between storage modulus ' (reflecting elasticity) and loss modulus ″ (reflecting viscosity) was compared between the microgels and the bulk gels. The microgels have a smaller ″/' than that of the bulk gels. Because the ratio ″/' of the bulk gels is constant regardless of the concentration, the microgel viscoelasticity cannot be achieved for the bulk gels with a different concentration. These findings mean that preparing biopolymer gels inside droplets is useful to change the viscoelasticity nanostructural transition through the interaction with the droplet interface.
内部制备的明胶微凝胶由于其纳米结构的不同，其弹性要比块状凝胶高得多。明胶微凝胶的这种纳米结构差异预计会赋予微凝胶独特的粘弹性，与块状凝胶不同。为了验证这一假设，我们通过开发循环微管吸吮法来评估明胶凝胶的频率依赖性粘弹性。比较了微凝胶和块状凝胶之间储能模量 '（反映弹性）和损耗模量 ″（反映粘性）随频率的关系。微凝胶的 ″/' 小于块状凝胶。由于块状凝胶的 ″/' 比值与浓度无关，因此对于不同浓度的块状凝胶，无法实现微凝胶的粘弹性。这些发现意味着通过与液滴界面的相互作用，在液滴内部制备生物聚合物凝胶有助于改变粘弹性和纳米结构转变。
