关键词: 胶囊, 褶皱, 聚酰胺, 剪切力, 聚合

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