Effect of pH on the rheological properties of a silica hydrosol

摘要: Abstract The viscosity of a silica hydrosol is studied as function the volume fraction for pHs from 2 to 11 using capillary flow viscometer. experimental curves depend on pH sol and exhibit discrepancy with behaviour predicted theoretical expressions. An adsorbed layer must exist these colloidal particles (equivalent spherical radius 87–88 A) which increases dispersed phase. hydrodynamic r H including thickness calculated viscometric data. values obtained at 9·7 are 94–98 110–115 A respectively. These analyses used explain previously reported results variation gel packing density pH. also determined measurements dilute sols quasi-elastic light scattering. At 9·7, measured value, 120 A, close that calculated. highest , 130 2. explanation proposed account difference value.