Ramadan M A, Tawashi R
Faculté de Pharmacie, Université de Montréal, Québec, Canada.
J Pharm Sci. 1990 Oct;79(10):929-33. doi: 10.1002/jps.2600791018.
In this paper we present a study on the effect of surface ruggedness of microspheres on the rheological behavior of their suspensions. For this purpose, different types of ragweed pollen grains were selected as models of natural microspheres. A computer-image processing system based on Fourier and fractal analysis of the contour was used to quantitate the micromorphology and surface roughness. The viscosity of suspensions, prepared by the dispersion of the different types of microspheres in heavy liquid paraffin, was determined. It was found that an increase in surface roughness causes an increase in the viscosity of the suspension. Additional resistance to flow could be attributed to internal friction within the suspension due to an increase in the area of contact (during collision or aggregation) among the microspheres, and between microspheres and liquid environment. These findings suggest that the surface geometry of solid particles (e.g., microcapsules, beads, and microspheres) could have a significant effect on the performance of these microparticles in suspension.
在本文中，我们展示了一项关于微球表面粗糙度对其悬浮液流变行为影响的研究。为此，选择了不同类型的豚草花粉粒作为天然微球的模型。使用基于轮廓的傅里叶和分形分析的计算机图像处理系统来定量微观形态和表面粗糙度。测定了通过将不同类型的微球分散在重质液体石蜡中制备的悬浮液的粘度。发现表面粗糙度的增加会导致悬浮液粘度的增加。额外的流动阻力可归因于微球之间以及微球与液体环境之间接触面积的增加（在碰撞或聚集期间）导致的悬浮液内部摩擦。这些发现表明，固体颗粒（例如微胶囊、珠子和微球）的表面几何形状可能对这些微粒在悬浮液中的性能产生重大影响。
