Preparation of nano-TiO_2 microcapsule by complex coacervation

The nano-TiO2 microcapsule was prepared by complex coacervation with nano-TiO2 as the core and gelatin and arabic gum as the wall.The average particle size,embedding rate,and particle size distribution variance of the microcapsules were used to evaluate the process of preparation.The impact of pH value,reaction temperature,mass fraction of wall material and stirring speed on the result of microcapsules were investigated by orthogonal experiment.The optimal process conditions were determined as follows: pH value 4.2,mass fraction of wall material 2%,reaction temperature 50 ℃,and stirring with a speed of 750 r/min.Under the above conditions,the resulting microcapsules′ average particle size was 90.1 μm,embedding rate was over 85% and particle size distribution variance was 12.1.