Hone John H E, Howe Andrew M
Research & Development, Kodak Limited, Headstone Drive, Harrow, Middlesex, HA1 4TY, United Kingdom.
J Colloid Interface Sci. 2002 Jul 1;251(1):193-9. doi: 10.1006/jcis.2002.8374.
The low-shear viscosity eta(0) of colloidal suspensions of acrylic latex or silica in aqueous gelatin has been measured at a temperature above the sol-gel transition. Measurements were made on dilution of a concentrated suspension with water or a gelatin solution. Thus, either the gelatin : colloid ratio was maintained or it was varied at constant aqueous gelatin concentration. Systems were studied with four lime-processed gelatins of different molecular weights at two concentrations of added salt. In addition, the latex particle size and the thickness of the adsorbed gelatin layer were measured by photon correlation spectroscopy (PCS) under dilute conditions. The dependence of the low-shear viscosity eta(0) on particle concentration was exponential and did not follow the well-established Krieger-Dougherty model for simple hard-sphere suspensions over the concentration range studied. A simple phenomenological model, eta(0)=eta(o)10(phi(e)/phi(s)), was found to predict the behavior well. Here, eta(o) is the viscosity of a gelatin solution of the corresponding solution concentration, phi(e) is proportional to the volume fraction of the particles, and phi(s) is a scaling factor, which was determined to have a value of 0.85. With this value of phi(s), the dimensions determined from PCS could be used to predict the viscosity values.
在高于溶胶-凝胶转变温度的条件下，对丙烯酸乳胶或二氧化硅在水性明胶中的胶体悬浮液的低剪切粘度η(0)进行了测量。测量是在用水或明胶溶液稀释浓悬浮液时进行的。因此，要么保持明胶与胶体的比例，要么在恒定的水性明胶浓度下改变该比例。研究了在两种盐添加浓度下，四种不同分子量的石灰处理明胶体系。此外，在稀溶液条件下，通过光子相关光谱法（PCS）测量了乳胶粒径和吸附明胶层的厚度。在所研究的浓度范围内，低剪切粘度η(0)对颗粒浓度的依赖性呈指数关系，并不遵循适用于简单硬球悬浮液的成熟的克里格-多尔蒂模型。发现一个简单的唯象模型η(0)=η(o)10(φ(e)/φ(s))能很好地预测该行为。这里，η(o)是相应溶液浓度的明胶溶液的粘度，φ(e)与颗粒的体积分数成正比，φ(s)是一个标度因子，其值确定为0.85。利用这个φ(s)值，由PCS确定的尺寸可用于预测粘度值。
