The effect of SiO2 nanoparticles and surfactant on the wetting properties of an enzyme-based nanofluid as a liquid binder in the enzyme granulation process

This study investigated the effect of SiO2 nanoparticles and SDS surfactant on the wetting properties of an enzyme-based liquid binder and granule size distribution in a fluidized bed granulation process. The nanofluids were prepared by adding different SiO2 and SDS concentrations to the alkaline protease enzyme liquor with sodium carboxymethylcellulose as the granulating binder. The surface tension (ST) and contact angle (CA) of nanofluids with powder compact were measured by the pendant and sessile drop methods. A new correlation was also proposed for the ST of nanofluids. Furthermore, the influence of the nanoparticle and surfactant on the enzyme activity of nanofluids was evaluated. The results showed that nanoparticles increased both ST and CA of the base fluid, while the SDS had the opposite effect. The granulation results revealed the granule size was increased by increasing the adhesion tension of the binder, whereas the size distribution became narrower and more uniform.