Development Of Ultrafiltration Membranes Research Articles

Development of Ultrafiltration Membrane from Polyethylene Terephthalate (Pet) Bottle Waste

Polyethylene Terephthalate (PET) bottle is used as beverage packaging, which is very convenient as one time use packaging. However, the huge amount of PET bottle waste has been becoming a serious problem for the environment. The utilization of PET bottle waste is very important to reduce the environmental problem. In this work, PET bottle waste was used a raw material to develop an ultrafiltration (UF) membrane. The membrane was prepared by using a phase inversion technique. The effect of the type of solvent, additive, and non-solvent on the microstructure and ultrafiltration performance of the membrane was studied. Different type of solvent, phenol, m-cresol, and DMSO were used to dissolve PET bottle as the source of membrane polymer. Two different additives, Polyethylene Glycol (PEG) and Polyvinyl Pyrrolidone (PVP) were used. Membrane 3 with the composition of PET, phenol as solvent, and PEG as additive was prepared successfully. The variation of aqueous alcohol solutions as non-solvent resulted in different microstructures of the membranes as shown by the scanning electron microscopy (SEM). The permeation experiment result using pure water as the feed showed that membrane 3 using aqueous butanol as non-solvent (membrane 3-ButOH) exhibited the highest permeate flux compared to that of membrane 3 using aqueous propanol (membrane 3-PrOH) or ethanol as non-solvent (membrane 3-EtOH). The ultrafiltration experiment was carried out using a feed solution of water containing polyethylene glycol (PEG) 20,000. The membrane 3-EtOH showed the lowest permeate flux of 3.24 kg/m h, but the highest rejection of PEG 20,000 of 65.87%. The membrane 3-PrOH had a permeate flux of 11.57 kg/m h and a rejection of 64.73%. Whereas the membrane 3-ButOH showed the highest permeate flux of 27.78 kg/m h, but the lowest rejection 16.93%. This result was obtained due to the different membrane microstructures which were strongly affected by the type of non-solvent.

Development of ultrafiltration membrane via in-situ grafting of nano-GO/PSF with anti-biofouling properties

The antibacterial PSF nanohybrid ultrafiltration membrane was fabricated based on the phase inversion method by incorporation of hydrophilic GO nanoparticles, as a pre-filter. The various weights of GO nanoparticles have been applied to the polymer matrix to improve the hydrophilicity, antifouling property and nitrate rejection of the prepared ultrafiltration membrane. OPEN-MX software has been employed to estimate the optimal percentage of GO embedding on the PSF polymer surface. Among the different percentage of GO loading, 0.75% wt. GO reveals the most stable state, which further affirmed in the experimental tests. The collections of analyzing methods have been employed for the comprehensive study of prepared membranes. The supplement of GO on the PSF surface has been inferred by FTIR, SEM, AFM, contact angle analyses. The GO-modified membranes showed amended antifouling performance on the basis of inhibition zone test and SEM study of bacterial suspension experiment.

Development of ultrafiltration membrane by stacking of silver nanoparticles stabilized with oppositely charged polyelectrolytes

We have developed a nanoparticle (NP)-stacked ultrafiltration membrane with a very thin active separation layer, by using electrostatic interaction of polyelectrolyte-stabilized NPs. Oppositely charged Ag NPs were prepared by the seed-growth method using either cationic or anionic polyelectrolytes as stabilizing agents. The Ag NPs were stacked onto an inorganic supporting membrane using layer-by-layer (LbL) deposition. By controlling the ionic strength of the NP dispersion and increasing the number of LbL dipping cycles, a stacked layer of NPs was successfully formed onto the supporting membrane. The membrane fabricated with 30 cycles of LbL dipping had a water permeability of 9.5m3m−2day−1atm−1 and a molecular weight cutoff of 500kDa for dextran. This value was comparable to commercial membranes, suggesting applications for water treatment and solute separation.

Development of ultrafiltration membranes from acrylonitrile co-polymers

Hydrophobic polymer surfaces show higher tendency to protein adsorption and bacteria attachment, thus hydrophobic polymeric membranes foul rapidly in water purification operations. A change in membrane surface properties can reduce fouling; this may be accomplished by increasing the hydrophilicity of the membrane surface, and by using a membrane with smaller pore size. The ultrafiltration membranes were prepared via phase inversion process in our laboratory. Negatively charged hydrophilic ultrafiltration membranes were prepared from acrylonitrile-vinyl acetate (CP16)/Acrylonitrile-vinyl acetate-sodium p-sulfophenyl methallyl ether (CP24). Scanning electron microscopy (SEM) revealed the asymmetric structure of these membranes. The roughness of the surface was measured by atomic force microscopy (AFM). The basic characteristics of these membranes like water permeability, water content and membrane selectivity were also measured.