Kar Chun Wong

Bio: Kar Chun Wong is an academic researcher from Universiti Teknologi Malaysia. The author has contributed to research in topics: Membrane & Thin-film composite membrane. The author has an hindex of 9, co-authored 26 publications receiving 295 citations.

Graphene oxide/polysulfone hollow fiber mixed matrix membranes for gas separation

Abstract: Hollow fiber mixed matrix membranes (MMM) were fabricated by embedding graphene oxide (GO) into a polysulfone (PSf) polymer matrix to investigate the gas permeation properties of CO2, N2, and CH4 in the membrane. The properties of the neat membrane and MMM loaded with 0.25% of GO were investigated. The transmission electron microscopy (TEM) and atomic force microscopy (AFM) analysis confirmed the synthesized GO was in the nanosheet form. The prepared MMM exhibited an improvement in mechanical and thermal stability. Field emission scanning electron microscopy (FESEM) analysis showed that the addition of GO into the polymer developed a well integrated skin layer as well as change in the formation of a membrane substructure layer which lead to better gas separation performance properties. The unique characteristics of GO which showed a strong affinity towards CO2 has contributed to the increment of CO2 permeance by 14%. Besides, GO created a path for small molecule gases (CO2) and restricted large molecule gases (N2 and CH4) to pass through the membrane. Both CO2/N2 and CO2/CH4 selectivity of MMM were enhanced by 158% and 74% respectively as compared to that of the neat PSf membrane.

Strategies in forward osmosis membrane substrate fabrication and modification: A review

Abstract: Forward osmosis (FO) has been recognized as the preferred alternative membrane-based separation technology for conventional water treatment technologies due to its high energy efficiency and promising separation performances. FO has been widely explored in the fields of wastewater treatment, desalination, food industry and bio-products, and energy generation. The substrate of the typically used FO thin film composite membranes serves as a support for selective layer formation and can significantly affect the structural and physicochemical properties of the resultant selective layer. This signifies the importance of substrate exploration to fine-tune proper fabrication and modification in obtaining optimized substrate structure with regards to thickness, tortuosity, and porosity on the two sides. The ultimate goal of substrate modification is to obtain a thin and highly selective membrane with enhanced hydrophilicity, antifouling propensity, as well as long duration stability. This review focuses on the various strategies used for FO membrane substrate fabrication and modification. An overview of FO membranes is first presented. The extant strategies applied in FO membrane substrate fabrications and modifications in addition to efforts made to mitigate membrane fouling are extensively reviewed. Lastly, the future perspective regarding the strategies on different FO substrate layers in water treatment are highlighted.