Biofouling impedes the performance of membrane bioreactors. In this study, we investigated the antifouling effects of polysulfone membranes that were modified by 1,2,3-triazole and palladium (Pd) nanoparticles. The modified membranes were evaluated for antibacterial and antifouling efficacy in a monoculture species biofilm (i.e., drip flow biofilm reactor, DFR) and mixed species biofilm experiment (i.e., aerobic membrane reactor, AeMBR). 1,2,3-triazole and Pd nanoparticles inhibited growth of Pseudomonas aeruginosa in both aerobic and anaerobic conditions. The decrease in bacterial growth was observed along with a decrease in the amount of total polysaccharide within the monoculture species biofilm matrix. When the modified membranes were connected to AeMBR, the increase in transmembrane pressure was lower than that of the non-modified membranes. This was accompanied by a decrease in protein and polysaccharide concentrations within the mixed species biofilm matrix. Biomass amount in the biofilm layer was also lower in the presence of modified membranes, and there was no detrimental effect on the performance of the reactor as evaluated from the nutrient removal rates. 16S rRNA analysis further attributed the delay in membrane fouling to the decrease in relative abundance of selected bacterial groups. These observations collectively point to a lower fouling occurrence achieved by the modified membranes.Membrane bioreactors (MBR) are increasingly used as a preferred biotechnology for wastewater treatment because the coupling of a membrane separation process would achieve an improved effluent quality. Membranes can also be used to retain catalytic metals (e.g. manganese oxide, palladium) within the bioreactors. The catalytic metals in turn achieve reductive hydrodehalogenation of contaminants (e.g. pharmaceutical and personal care products, biocides and organic micropollutants) that are otherwise not easily biodegraded in a conventional activated sludge process. To demonstrate, palladium (Pd) has been used as a catalytic metal to achieve reductive removal of pharmaceuticals, biocides and iodinated contrast media 1 . Similarly, Pd was used in a continuous plate membrane reactor to achieve a complete, efficient and rapid removal of trichloroethene (TCE) 2 . In both instances, Pd was either physically retained in the MBR through the use of hollow-fiber nanofiltration membranes or recirculated throughout the reactor system in the form of suspension. However, the lack of a support material for these nanoparticles can result in the agglomeration and growth of nanoparticles, which will cause a subsequent decrease in the catalytic effect 3,4 . Alternatively, Pd particles can be embedded onto membrane surfaces so as to achieve an even distribution of this catalyst throughout the reactive surface area. For example, Hennebel and coworkers encapsulated Pd particles in polyvinylidene fluoride membranes and demonstrated that such modified membrane contactors can be used

For the first time, self-assembly and non-solvent induced phase separation was applied to polysulfone-based linear block copolymers, reaching mechanical stability much higher than other block copolymer membranes used in this method, which were mainly based on polystyrene blocks.

Hydrophilic surfaces are known to be less prone to fouling. Ultrafiltration membranes are frequently prepared from rather hydrophobic polymers like polysulfone (PSU). Strategies to keep the good pore forming characteristics of PSU, but with improved hydrophilicity are proposed here. PSU functionalized with 1,2,3‐triazole ring substituents containing OH groups was successfully synthesized through click chemistry reaction. The structures of the polymers were confirmed using NMR spectroscopy and Fourier transform infrared spectroscopy (FTIR). High thermal stability (>280°C) was observed by thermal gravimetric analysis. Elemental analysis showed the presence of nitrogen containing triazole group with different degrees of functionalization (23%, 49%, 56%, and 94%). The glass transition temperature shifted with the introduction of triazole pendant groups from 190°C (unmodified) to 171°C. Ultrafiltration membranes were prepared via phase inversion by immersion in different coagulation baths (NMP/water mixtures with volume ratios from 0/100 to 40/60). The morphologies of these membranes were studied by field emission scanning electron microscopy (FESEM). The optimized PSU bearing triazole functions membranes exhibited water permeability up to 187 L m−2 h−1 bar−1, which is 23 times higher than those prepared under the same conditions but with unmodified polysulfone (PSU; 8 L m−2 h−1 bar−1). Results of bovine serum albumin protein rejection test indicated that susceptibility to fouling decreased with the modification, due to the increased hydrophilicity, while keeping high protein rejection ratio (>99%). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41549.

Drug delivery systems are designed to control the release rate and location of therapeutic agents in the body to achieve enhanced drug efficacy and to mitigate adverse side effects. In particular, drug-releasing implants provide sustained and localized release. We report nanostructured polymer monoliths synthesized by polymerization-induced microphase separation (PIMS) as potential implantable delivery devices. As a model system, free poly­(ethylene oxide) homopolymers were incorporated into the nanoscopic poly­(ethylene oxide) domains contained within a cross-linked polystyrene matrix. The in vitro release of these poly­(ethylene oxide) molecules from monoliths was investigated as a function of poly­(ethylene oxide) loading and molar mass as well as the molar mass and weight fraction of poly­(ethylene oxide) macro-chain transfer agent used in the PIMS process for forming the monoliths. We also developed nanostructured microneedles targeting efficient and long-term transdermal drug delivery by combining PIMS and microfabrication techniques. Finally, given the prominence of poly­(lactide) in drug delivery devices, the degradation rate of microphase-separated poly­(lactide) in PIMS monoliths was evaluated and compared with bulk poly­(lactide).

We combine self-assembly in solution, complexation with metallic salts and phase separation induced by solvent-non-solvent exchange to prepare nanostructured membranes for separation in the nanofiltration range. This method was applied to prepare membranes from newly synthesized poly(acrylic acid)-b-polysulfone-b-poly(acrylic acid) copolymers dissolved in a selective solvent mixture and immersed in aqueous Cu or Ag solutions.