水分在中药原料中的扩散行为研究

Moisture Diffusivity in Chinese Herbal Medicine Ingredients

目的:研究中药原料在不同温湿度条件下的吸湿行为。方法:应用膜扩散传质模型和菲克第二定律传质模型模拟和分析水分在中药原料中的扩散行为。结果:在25℃,相对湿度为50%时研究的13种中药原料的扩散系数最大,且扩散符合膜扩散传质过程。在其他温湿度环境下可能同时存在两种扩散机制。结论:水分在中药原料中的扩散可能存在多种扩散机制,并受环境因素影响明显。

This paper was aimed to study the moisture adsorption of Chinese herbal medicine ingredients at different environment. The film mass transfer model and Fick＇s second law were applied to evaluate the moisture diffusion for Chinese herbal medicine ingredients. The results showed that under the temperature of 25℃ and 50% relative humidity, the diffusion coefficient of 13 medicine ingredients reached the highest. The diffusivity was controlled by film mass transfer. However, both film mass transfer and Fick＇s second law can be existed at the same time under different temperature and humidity. It was concluded that the diffusion of water in the traditional Chinese medicine might have been driven by a variety of diffusion mechanism, which was obviously affected by environmental factors.