دانلود رایگان مقاله افزایش خواص ضدرسوبی سطح غشا اولترافیلتراسیون هموفان

Abstract

To improve the hydrophilicity and antifouling properties of polysulfone (PS) ultrafiltration membranes, we studied the use of salicylate-alumoxane (SA) nanoparticles as a novel hydrophilic additive. The effects of SA nanoparticles on the membrane characteristics and performance were investigated in terms of membrane structure, permeation flux, solute rejection, hydrophilicity, and antifouling ability. The new mixed-matrix membranes (MMMs) possess asymmetric structures. They have smaller finger-like pores and smoother surfaces than the neat PS membranes. The embedment of SA nanoparticles in the polymer matrix and the improvement of surface hydrophilicity were investigated. Ultrafiltration experiments indicated that the pure-water flux of the new MMMs initially increases with SA nanoparticles loading followed by a decrease at high loadings. Higher BSA solution flux was achieved for the MMMs compared to the neat PS membranes. Membranes with 1 wt.% SA nanoparticles exhibit the highest flux recovery ratio of 87% and the lowest irreversible fouling of 13%

4. Conclusions

To investigate the influence of SA nanoparticles on the morphology and performance of PS membranes, SA nanoparticles were synthesized and PS/SA nanocomposite ultrafiltration membranes were successfully fabricated via phase inversioninduced by immersion precipitation. FTIR and EDAX analyses confirmed the presence of SA nanoparticles in the membrane structures. FESEM images showed that the addition of the nanoparticles reduces the sizes of the membrane surface and sub-layer pores, and increases the interconnectivity of the pores across the thickness of MMMs. The nanocomposite membranes have a higher hydrophilicity than neat PS membranes due to the presence of extra hydroxyl groups on the surface of SA nanoparticles. The ultrafiltration results showed that the water flux increases at low concentration of nanoparticles, and then decreases with a further increase in the nanoparticles concentration, due to the agglomeration of the nanoparticles in the membrane pores. Because of the reduction of the size of pores on the membrane surface, the protein rejection of the MMMs is higher. This study showed that the addition of SA nanoparticles to the PS casting solution improves the antifouling properties of PS membranes significantly.