Abstract

In this work, solutions of low molecular weight chitosan with the concentration of 4 and 5 wt.% were subjected to electrohydrodynamic forming at the feed rate of 0.1 and 0.2 ml/h. Using a statistical analysis of the electron scanning microscopy data, it was shown that at the concentration of 4 wt.%, spherical particles of two types are formed: most of the particles are with the average diameter about of 260 nm, and particles with a larger diameter of about 480 nm. A transition through the particle-to-fiber threshold was observed with an increase in the concentration of the solution to 5 wt.%. This led to the formation of both spherical particles with a monomodal distribution and average diameter of 207 nm and elongated particles of a fiber-like shape with diameter of 157 nm and length of 1401 nm. At the same time, an increase in the solution feed rate resulted in a strong decrease in the average diameter of spherical particles to 150 nm and an elongation of fiber-like objects by 1.5 times. The particle-to-fiber threshold can be observed when the dynamic viscosity of the solution changes in the range of about 10–14 cP.

摘要

在这项工作中，浓度为 4 和 5 重量％的低分子量壳聚糖溶液以 0.1 和 0.2 毫升/小时的进料速率进行电流体动力学成型。对电子扫描显微镜数据进行统计分析，表明在 4 wt.% 的浓度下，形成两种类型的球形颗粒：大多数颗粒的平均直径约为 260 nm，颗粒的平均直径为较大的直径约为 480 nm。随着溶液浓度增加到 5 重量％，观察到通过颗粒到纤维阈值的转变。这导致形成具有单峰分布和平均直径为 207 nm 的球形颗粒和直径为 157 nm 和长度为 1401 nm 的纤维状细长颗粒。同时，溶液进料速率的增加导致球形颗粒的平均直径显着降低至 150 nm，纤维状物体的伸长率增加了 1.5 倍。当溶液的动态粘度在大约 10-14 cP 的范围内变化时，可以观察到颗粒到纤维的阈值。