The effects of thermally stable titanium silicon oxide nanoparticles on structure and performance of cellulose acetate ultrafiltration membranes

摘要

The thermal stability of membranes is currently a cause of major concern, keeping their competence for industrial application and high temperature cleaning in perspective. The present study explores the degree of membrane performance enhancement accomplished by the alterations introduced in membrane structure and properties through the inclusion of titanium silicon oxide (TiSiO4) nanoparticles in the cellulose acetate (CA) ultrafiltration membrane matrix. Different techniques such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, contact angle goniometry, molecular weight cutoff (MWCO) and ultrafiltration experiments were employed to characterize the nanocomposite membranes. Significant improvement was observed in hydrophilicity, permeability, fouling properties and thermal stability of these membranes. Additionally, the membrane hydraulic resistance decreased with the incorporation of thermally stable titanium silicon oxide nanoparticles in the CA membranes. Ultrafiltration experiments examined the separation efficiency of dyes at varying operating temperatures. Thus, while the dye permeate flux for membrane M3 (with moderate 15 wt% TiSiO4) increased from about 55 L m~(-2) h~(-1) to 92 L m~(-2) h~(-1) with the corresponding rise in the operation temperature from 20 °C to 90 °C, an almost constant 68% dye rejection was observed over the entire temperature range. These results further affirmed the thermal resistance demonstrated by the as-fabricated nanocomposite membranes in dye-water separation.