Research on the Influence of Dispersants on Coating of TiO₂

With a pH value of 9.0 to 10.0,Zeta potential of rutile titanium dioxide slurry reaches the maximum value,and the titanium dioxide has the best dispersion property in water.In this paper,the changes of viscosity in the coating process were studied as sodium silicate,sodium hexametaphosphate, sodium pyrophosphate,or ammonium dihydrogen were used as dispersants respectively.The results show that the slurry has lowest viscosity by taking sodium silicate or sodium hexametaphosphate as dispersant, and when sodium silicate is added at an amount of 0.15% all at once,the slurry's viscosity is the lowest in coating process.Moreover,BET and SEM-EDS analyses on surface compositions of coated titanium dioxide indicate that with lower slurry viscosity during the coating process,coating agents will deposit more evenly and compactly on the surface of TiO₂.