Beckett R, Giddings JC
Water Studies Centre, Department of Chemistry, Monash University, Caulfield East, Vic., 3145, Australia
J Colloid Interface Sci. 1997 Feb 1;186(1):53-9. doi: 10.1006/jcis.1996.4612.
In this paper the effect of particle shape on the entropy of nonspherical particles adjacent to a plane surface is considered. The subsequent influence on particle retention in field-flow fractionation (FFF) has been estimated. New retention equations for thin rod and disc shaped particles have been derived to cover this steric-entropic region of FFF. As particle size increases relative to the mean cloud thickness, the retention ratio for nonspherical particles is predicted to increase compared to small spherical particles of the same mass. This could result in a significant underestimation of the calculated equivalent spherical diameter (d) by FFF methods. The steric-entropic FFF equations could be used to calculate accurate d values if the large particle dimension is estimated independently (e.g., by microscopy). Alternatively, run conditions could be designed to minimize steric-entropic perturbations to the ideal retention equation.
本文考虑了颗粒形状对与平面相邻的非球形颗粒熵的影响。并估计了其对场流分级法（FFF）中颗粒保留的后续影响。已推导了细棒状和盘状颗粒的新保留方程，以涵盖FFF的这种空间熵区域。随着颗粒尺寸相对于平均云厚度增加，预计非球形颗粒的保留率与相同质量的小球形颗粒相比会增加。这可能导致FFF方法对计算的等效球形直径（d）产生显著低估。如果通过独立方法（例如显微镜）估计大颗粒尺寸，则空间熵FFF方程可用于计算准确的d值。或者，可以设计运行条件以最小化对理想保留方程的空间熵扰动。
