Natural organic matters (NOMs) have been found to be the major foulant in the application of ultrafiltration (UF) for treating surface water. Against this background, although hydrophilicity has been demonstrated to aid fouling mitigation, other parameters such as membrane surface morphology may contribute equally to improved fouling resistance. In this work, with humic acid solution as the model substance, the effects of titanium dioxides (TiO2) types (PC-20, P25, and X500) on membrane anti-fouling and defouling properties were comparatively analysed. The aims are (1) to determine the correlation between membrane surface morphology and membrane fouling and (2) to investigate the anti-fouling and UV-cleaning abilities of PVDF/TiO2 mixed-matrix membranes with different membrane topographies and surface energy conditions. The mixed-matrix membrane with P25 TiO2 exhibited the most significant UV-defouling ability, with a high irreversible flux recovery ratio (IFRR(UV)) of 16.56 after 6 h of UV irradiation, whereas that with X500 TiO2 exhibited both superior anti-fouling and defouling properties due to its smoother surface and its highly reactive surface layer.

Tissue engineering products have grown rapidly as an alternative solution available for chronic wound and burn treatment. However, some drawbacks include additional procedures and a lack of antibacterial properties that can impair wound healing, which are issues that need to be tackled effectively for better wound recovery. This study aimed to develop a functionalized dual-layered hybrid biomatrix composed of collagen sponge (bottom layer) to facilitate cell proliferation and adhesion and gelatin/cellulose hydrogel (outer layer) incorporated with graphene oxide and silver nanoparticles (GC-GO/AgNP) to prevent possible external infections post-implantation. The bilayer hybrid scaffold was crosslinked with 0.1% (w/v) genipin for 6 h followed by advanced freeze-drying technology. Various characterisation parameters were employed to investigate the microstructure, biodegradability, surface wettability, nanoparticles antibacterial activity, mechanical strength, and biocompatibility of the bilayer bioscaffold towards human skin cells. The bilayer bioscaffold exhibited favourable results for wound healing applications as it demonstrated good water uptake (1702.12 ± 161.11%), slow rate of biodegradation (0.13 ± 0.12 mg/h), and reasonable water vapour transmission rate (800.00 ± 65.85 gm−2 h−1) due to its porosity (84.83 ± 4.48%). The biomatrix was also found to possess hydrophobic properties (48.97 ± 3.68°), ideal for cell attachment and high mechanical strength. Moreover, the hybrid GO-AgNP promoted antibacterial properties via the disk diffusion method. Finally, biomatrix unravelled good cellular compatibility with human dermal fibroblasts (>90%). Therefore, the fabricated bilayer scaffold could be a potential candidate for skin wound healing application.

Different types of titanium dioxide (TiO 2) nanoparticles (NPs) (PC-20, P25 and X500), with various particle sizes in coagulation bath were incorporated as an nanofiller into membrane matrix. The NPs were added to the polyvinylidene (PVDF) ultrafiltration (UF) membranes via phase inversion and colloidal precipitation method. A series of test, such as surface field emission scanning electron microscopy (FESEM) images, energy-dispersive X-ray spectroscopy (EDX) mapping and pore size measurement were performed to characterize the modified mixed-matrix membranes. FESEM was applied to observe the distribution pattern of TiO 2 NPs in the membrane matrix and its distribution was examined using (EDX). The size and distribution of TiO 2 NPs on the membrane surface was affected to a very great extent by the size of TiO 2 prepared in the coagulation bath. Conversely, the presence of TiO 2 on membrane surface does not provide any significant changes on the membrane pore size distribution, suggesting that in situ precipitation method is suitable to prepare mixed-matrix membrane without scarifying the membrane rejection ability. The performance of the UF membranes fabricated from the nano-sized TiO 2 particles were evaluated by measuring the membrane permeates flux and humic acid (HA) rejection. The experiment demonstrated that the flux improvements of the membranes were improved due to the pore enlargement (defect) as well as increasing membrane hydrophilicity. The flux of the mixed-matrix membrane prepared by adding X500 nanofiller was the greatest (44.06 L/m 2 • h), which was determine as the optimum TiO 2 type without scarified the membrane rejection (98.44%) compared to PC-20 and P25. This is due to the relatively small size of X500 which provides better dispersibility in the membrane matrix whereby flux was enhanced due to improve of hydrophilicity without the expense of poor humic acid rejection.

is currently pursuing a master's degree at Universiti Kebangsaan Malaysia (UKM). Her research focuses on the antimicrobial of nanoparticles for application in the industry. Dr. Teow Yeit Haan is a senior lecturer at UKM. Her expertise includes membrane synthesis and characterization, membrane application for water purification and wastewater treatment, membrane fouling, water disinfection technology, and adsorption. She had published more than 44 research articles, 22 conference proceedings, and 3 book chapters. Dr. Ebrahim Mahmoudi is working as a senior lecturer at UKM. He is researching separation and purification using polymeric membranes and membrane bioreactors. Current Approaches for the Exploration of Antimicrobial Activities of NanoparticlesInfectious diseases of bacterial and viral origins contribute to substantial mortality worldwide. Collaborative efforts have been underway between academia and the industry to develop technologies for a more effective treatment for such diseases. With their utility in various industrial applications, nanoparticles (NPs) offer promising potential as antimicrobial agents against bacterial and viral infections. NPs have been established to possess potent antimicrobial activities against various types of pathogens due to their unique characteristics and cell-damaging ability through several mechanisms. The recent accepted antimicrobial mechanisms possess by NPs include metal ion release, oxidative stress induction, and non-oxidative mechanisms. Another merit of NPs lies in the low likelihood of the development of microbial tolerance towards NPs,given the multiple simultaneous mechanisms of action against the pathogens targeting numerous gene mutations in those pathogens. Moreover, NPs provide a fascinating opportunity to curb microbial growth before infections: this outstanding feature has led to their utilization as active antimicrobial agents in different industrial applications, e.g. the coating of medical devices, incorporation in food packaging, promoting wound healing, and encapsulation with other potential materials for wastewater treatment. This review discusses the progress and achievements in the antimicrobial applications of NPs, factors contributing to their actions, mechanisms underlying their efficiency, and risks of their applications, including the antimicrobial action of metal nanoclusters (NCs).The review concludes with a discussion of the restrictions in present studies and future prospects of nanotechnology-based NPs development.

Membrane fouling is the major challenges that hinders the widespread application of membrane bioreactor (MBR). Recently, application of electricity in electrically-enhanced MBR (EMBR) to suppress membrane fouling has gained much attention among research communities. This paper presents an overview of developments on EMBR for fouling suppression in wastewater treatment. The flow of electricity has stimulated several electrokinetic processes including electrophoresis/electrochemical process, and electrocoagulation which are the major fouling suppression mechanisms employed in EMBR. In electrophoresis, the membrane fouling is suppressed by the increased electrorepulsive force between negatively-charged foulants and cathode membrane under the influence of an electric field. Besides, electric field also induces simultaneous electrochemical oxidation and reduction which generate chemicals to degrade pollutant in wastewater. On top of that, use of active anode is reminiscent of electrocoagulation which produces cation coagulants in EMBR that capable to neutralize charge of the foulants and promotes flocs formation. This increases flocs size and sedimentation rate thereafter reduces adhesion of foulants on the membrane surface. Lastly, bioelectricity generation of microbial fuel cell (MFC) integrated with MBR to attain self-sustained EMBR has been studied. Self-sustained EMBR combines the advantages of MFC and MBR in treating wastewater and energy recovery simultaneously. Overall, it is evidenced that MBR and electrokinetic processes have a synergetic enhancement effect in EMBR system.