The Effects of Calcium Ion, pH Value on the Rheological Properties of Sodium Alginate Solution
Chen, Zong-Qi~* WANG, NING-HUA Han, En-San Chen, Juan Wang, Guang-Xin (Department of Applied Chemistry, Qingdao Institute of Chemical Technology, Qingdao, 266042)
The trend of change in viscosity with change in the rate of shear for sodium alginate solutions has been studied. High viscosity sodium alginate has been found to exhibit non-Newtonian behaviour, a characteristic properties of pseudo-plastic materials. The formation of sodium alginate solution is described as a function of shearing gradient, temperature, pH value and concentration is attributed to causes of macromolecular nature. Bizarre rheological effects, thixotropy-negative thixotropy, e. g. shear thinning-shear thickening occurs. Some rheological properties of shear thickening complexes of sodium alginate and calcium chloride are described. Time dependent shear thickening behavior is also observed with some complexes.