Abstract: Wrinkling and deformation of the microcapsule membrane introduced by flow are commonly observed, and have been stuided both experimentally and computationally. However, there are few discussions on the effect of different factors inside the micro-channel on the wrinkling of the microcapsules and on the effect of the wrinkles on the actual microcapsule size and membrane area. To solve this problem, we prepared a series of polyamide microcapsules with wrinkled membrane, and empolyed a solvent soaking method to make the wrinkled membrane outspread, which allows the actual particle size and membrane area to be measurable. We also put forward the concept of wrinkling degree to define different wrinkling situations. During the preparation of microcapsules, we found that the wrinkling degree of the microcapsules increased along with the increase of the fluid viscosity and the continuous phase flow. When these two factors were fixed, the wrinkling degree didn't change with the microcapsule size. The reason is that the change of the wrinkle degree is mainly related to the flow shear. Furthermore, the microcapsules with wrinkle membrane could be used to prepare double layered microcapsules.

Key words: capsule, wrinkle, polyamide, shear force, polymerization

摘要： 流体流动诱导微胶囊膜起皱和变形是一个普遍存在的现象。针对这一现象已有一些模拟和实验研究，但是对于微通道内不同因素对于微胶囊褶皱情况的影响以及褶皱的存在对于微胶囊实际膜面积和粒径的影响等方面却鲜有探讨。针对这一问题，本文制备了具有褶皱膜的聚酰胺微胶囊，并提出通过溶剂浸泡法将微胶囊膜褶皱伸展开，以分析微胶囊的实际膜面积和实际粒径。同时，定义了褶皱度的概念，将抽象的褶皱情况数值化，使分析更为方便。最终，通过研究分析发现，由于与流体剪切力正相关，流体流量和黏度的增大会导致微胶囊褶皱度增加；当这两者固定时，微胶囊粒径的改变对其褶皱度基本无影响。在应用方面，微胶囊壁面褶皱情况的分析为制备单核双壁式微胶囊提供了一种新思路。

关键词: 胶囊, 褶皱, 聚酰胺, 剪切力, 聚合