Wai Fen Yong

Xiamen University Malaysia · School of Energy and Chemical Engineering

Material synthesis requires an enormous amount of organic solvents which leads to huge environmental burdens. Being so, the necessity to utilize non-toxic chemicals is of growing interest in the global market. Harnessing a green fabrication strategy could be a sustainable remedy. Herein, life cycle assessment (LCA) and techno-economic assessment (T...

The scarcity of clean water resources combined with other environmental and anthropogenic effects have urged the development of advanced technology for wastewater treatment. Adsorption attracts great attention as a cost-effective technique for the remediation of contaminated water. Despite a broad variety of adsorbents existing in the literature, a...

This analysis integrates life cycle assessment and techno-economic analysis to examine the impacts of solvent selection and synthesis approaches in fabricating 1 m ² of polyimide flat sheet membrane.

Metal-organic frameworks (MOFs) combine the advantages of both organic and inorganic materials. Among the synthesized MOFs, ZIF-8 is promising for CO2 capture, raising the need for its sustainable production. The life cycle assessment (LCA) of various ZIF-8 synthesis methods such as solvothermal (DMF), solvothermal (MeOH), microwave, sonochemical,...

The aggravation of environmental problems such as water scarcity and air pollution has called upon the need for a sustainable solution globally. Membrane technology, owing to its simplicity, sustainability, and cost-effectiveness, has emerged as one of the favorable technologies for water and air purification. Among all of the membrane configuratio...

The virtuous of two-dimensional (2D) nanomaterials in high aspect ratio and tunable surface functionality have geared towards their implementation in mixed matrix membranes (MMMs) for advanced gas separation. In this study, the effects of functionalized 2D nanosheets in the MMMs for gas separation were investigated. The graphitic carbon nitride (g-...

Adsorption has gained much attention as one of the efficient approaches to remediate the contaminants in wastewater. Herein, this critical review focuses on the preparation, modification, application and regeneration of the biosorbents, nanoparticles and magnetic biosorbents for the wastewater treatment in recent 5 years (2017–2021). Among these ma...

The booming of global environmental awareness has driven the scientific community to search for alternative sustainable approaches. This is accentuated in the 13th sustainable development goal (SDG13), climate action, where urgent efforts are salient in combating the drastic effects of climate change. Membrane separation is one of the indispensable...

Polymeric membranes for gas separations often suffer from plasticization, which leads to the swelling of polymer matrices and thus the loss of the separation selectivity and performance. Such intrinsic and detrimental issues remain challenging and unsolved. Here, we report a newly designed polymer, poly trimethyl phenylene ethersulfone (PTPES) that...

The increasing discharge of metal-associated waste not only causes growing concerns on the environment and human health but also accelerates the depletion of natural metal resources. Within this context and...

CO2 capture using membrane technology has received much attention compared to the traditional gas separation technologies such as amine adsorption and cryogenic distillation because of simplicity, scalability, and low carbon. Carbon capture and storage involves two strategies: post-combustion CO2 capture from the flue gas of fossil-fueled power pla...

The increasing challenges in meeting the clean air demand have fuelled growing environmental awareness to secure effective air purification and separation techniques. Membrane separation has drawn interdisciplinary attention and has emerged as an indispensable gas purification technology. Nevertheless, the permeance/selectivity trade-off relationsh...

The emergence of nanomaterial arouses the development of thin film nanocomposite (TFN) in membrane separation technology. The incorporation of nanofillers into the TFN selective layer enhanced the membrane pure water permeability (PWP) with a slight improvement or even deterioration on the salt rejection. This trade-off is mainly due to the agglome...

The application of thin film composite (TFC) has emerged in aqueous and organic solvent-based membrane separation. However, the fabrication of TFC membrane requires abundant toxic and hazardous solvents, resulting in a process that is not completely green. For the first time, we report here using TamiSolve® NxG as a green solvent for the preparatio...

Permselective thin-film composite membranes are gaining a significant role in solvent-based molecular sieving applications. Nevertheless, the lack of desirable substrate materials, which combines high flux, solvent resistance as well as a straightforward fabrication process, is still the biggest bottleneck for large-scale commercial implementation....

Environmental remediation is a worldwide concern to reverse the impact of rapid urbanization. Outstanding porosity, tunable pore structure and unique flexibility render metal-organic frameworks (MOF) and MOF based separation technologies as promising for air and water filtration. In this chapter, we summarize the design of MOF based adsorbents for...

Fossil fuels produced over 80% of the world total energy and at the same time, it contributes to 40% of greenhouse gases emission. Gas separation using polymeric membranes has received great attention in the past decades compared to the conventional gas separation technologies such as amine absorption, adsorption, and cryogenic distillation because...

In this chapter the state of the art of polyhedral oligomeric silsesquioxane (POSS) nanocomposites used in membrane-based separations for water treatment is reviewed, taking into account representative examples in applications. Transport principles and mechanisms of these processes are briefly discussed. Emphasis is placed on the transport properti...

Recent interest in developing high performance polymeric membranes has evolved the molecular transport performance in gas separation and pervaporation. The synthesis of polymer with novel structures may improve the separation performance of a membrane. However, it always accompanies undeterminable risk such as economic costs and development duratio...

Compared to polysulfone (PSF), the effects of chemical structure on gas separation performance of polyethersulfone (PES) are rarely in-depth studied. To explore the potential of various PES polymers as gas separation membranes, PES containing four different backbone structures have been synthesized. They are polyphenylsulfone (PPSU), poly trimethyl...

Polymers containing ethylene oxide groups have gained significant interest as the ethylene oxide groups have favorable interactions with polar molecules such as H2O, quadrupolar molecules such as CO2 and metal ions. However, the main challenges of poly(ethylene oxide) (PEO) membranes are their weak mechanical properties and high crystallinity natur...

Severe air pollution has become a global concern and there is a pressing need to develop effective and efficient air filters for removing airborne particulate matters (PMs). In this work, a highly permeable polyethersulfone (PES) based hollow fiber membrane was developed via a one-step dry-jet wet spinning. For the first time, a hollow fiber membra...

A defect-free membrane with a very high gas permeance is greatly attractive to both academia and industry. Thin film composite (TFC) membranes are promising candidates. However, it is always challenging to have a reproducible and up-scalable method to fulfill the needs. Herein, we report a novel and straightforward strategy to fabricate a high-perf...

Air conditioning systems consume a large portion of energy to remove the latent heat of moisture to reach the indoor comfort level in Southeast Asia due to the high relative humidity. The worsening air pollution causes significant health concerns in recent years. Therefore, an efficient strategy to simultaneously remove both haze particles and exce...

This study reveals as the first attempt to apply hollow fibers for air filtration of ultrafine particles. Different from symmetric nano-fiber filters and non-woven fabrics, asymmetric polyvinylidene fluoride - polyethylene glycol (PVDF-PEG) hollow fibers with high gas permeances have been developed by the dry-jet wet-spinning process. The addition...

A systematic strategy to molecularly design flexible tough hydrolyzed polymers of intrinsic microporosity (hPIM-1) films from the PIM-1 polymer is explored in this study. Flexible films can be fabricated from N-methyl-2-pyrrolidone (NMP) by appropriate hydrolysis conditions. The optimal weight ratio of NaOH/H 2 O/EtOH in the base-catalyzed reaction...

Polymers of intrinsic microporosity, specifically PIM-1, have attracted significant attention for gas separation due to its relatively high permeability and reasonably good selectivity. Although few studies evaluated the potential of PIM-1 in pervaporation, their dehydration performance was not impressive because of low selectivity. In this work, w...

Polyphenylenesulfone (PPSU) and sulfonated polyphenylenesulfone (sPPSU) are widely used for liquid separations in the medical and food industries. However, their potential applications for gas separation have not been studied extensively owing to their low intrinsic gas permeability. We report here for the first time that blending with sPPSU can si...

In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeatin...

Polymers of intrinsic microporosity, specifically PIM-1, have emerged as promising materials for gas separation due their high gas permeability. However, its insolubility in common polar aprotic solvents like N-Methyl-2-pyrrolidone (NMP) limits its full potential and possible industrial applications. In this study, the solubility of PIM-1 in such s...

Polymer-based membrane separation technology has become attractive due to its environmentally benign, small footprint, easy processability, and cost competitiveness. Polymers of intrinsic microporosity, e.g., PIM-1, has emerged as an attractive material for gas separation and energy development because of its high permeability. Three approaches in...

Polymers of intrinsic microporosity (PIM-1) have received worldwide attention as new polymer type for gas separation but most PIM-1 researches have been conducted on dense flat membranes. For the first time, we have fabricated PIM-1/Matrimid membranes in a useful form of hollow fibers with promising separation performance. The newly developed hollo...

Polymers of intrinsic microporosity, e.g. PIM-1, are attractive materials for gas separation and energy development, which is ascribed mainly to their superior permeability. The H2 and CO2 permeability of PIM-1 is about 1300–4000 Barrer and 3000–8000 Barrer, respectively. However, it has a relatively low H2/CO2 selectivity of 0.4–0.8. Different fro...

The polymers of intrinsic microporosity have gained the attention as one of the potential materials for membrane gas separation. The contorted ladder-like structure in polymers of intrinsic microporosity, specifically PIM-1 possesses high permeability but with moderate selectivity for O2/N2, CO2/N2 and CO2/CH4 separation. We report here the most co...

Owing to the cost competitiveness and ease of processing of polymeric membranes, polymers have been widely used as the material for the fabrication of gas separation membranes in both research development and industrial applications. Recently, the polymers of intrinsic microporosity have gained the attention as one of the potential materials for me...