Coagulation performance of cationic polyelectrolyte/TiO2 nanocomposites prepared under LED irradiation

Abstract

AbstractA series of acrylic‐based cationic polyelectrolyte nanocomposites including water‐soluble monomers acrylamide (AAm) and 2‐acryloyloxyethyltrimethylammonium chloride (DAC) with different mole percent of DAC (30, 40, and 45%) in feed were produced using TiO2 nanoparticles (0.018, 0.037, and 0.11 wt%) as photoinitiator in the aqueous solution of monomers and named as p(ADT)1–9. The LED light at 365 nm was used for photocatalysis activation of TiO2 nanoparticles. Structure and morphology of the synthetic polyelectrolyte were characterized by FT‐IR, NMR, TGA, FESEM‐EDX, and TEM. The other properties of synthetic polyelectrolyte such as molecular weight, viscosity, charge density, AAm/DAC molar ratio in copolymers, reactivity ratio values for the AAm and DAC monomers, and polymerization degree were measured. Furthermore, coagulation performance of these polyelectrolytes was investigated in soil suspension (1,000 ml, initial turbidity = 1,715 NTU). The prepared nanocomposites enhanced the coagulation of soil suspension up to 99.5% in low dosages. The best turbidity removal efficiencies (TRE) between 99.5–99.77% were achieved by p(ADT)3 conatining 30% DAC and 0.11 wt% TiO2. Decreasing the temperature from room temperature to 0°C led to an increase in TRE from 98 to 99.8%. Also, increasing the pH from 4 to 12 led to a decrease in TRE from 99.86 to 94%.