Flocculation of Titanium Dioxide with Functionalized Citrus Pectin

Modified polysaccharides were prepared by the reaction of citrus pectin with a cationic monomer, (1,2-epoxypropyl)triethylammonium chloride, in alkaline medium and under the action of microwave radiation in the reactor system microwave–ultrasonic–UV-induced synthesis. Organic hybrids were prepared by mixing aqueous solutions of natural polysaccharides (pectin and modified pectin with chitosan) under ambient conditions in 1 : 1 ratio. The influence of the concentration of citrus pectin, its modified samples, chitosan, and their organic hybrids on the flocculating properties was studied for a model disperse system, a suspension of titanium dioxide in water and aqueous salt solutions, under the conditions of free (unrestricted) sedimentation. The influence of the ionic strength on the conformational state of polysaccharide macromolecules and on the aggregation of titanium dioxide particles was analyzed.