Exploring the characteristics, performance, and modification of Matrimid for development of thin‐film composite and thin‐film nanocomposite reverse osmosis membranes

Abstract

Reverse osmosis (RO) membrane technology is widely employed to address the demands for freshwater. In this study, fabrication and performance evaluation of customized RO membranes comprised of Matrimid and polyacrylonitrile (PAN) is carried out. While exploring adoption of slip coating procedure, the effects of various modification techniques including incorporation of TiO2 nanoparticles and polyethylene glycol (PEG) into the skin layer as well as cross‐linking were investigated. The individual and combined effects of parameters on membrane morphology, surface characteristics and performance were also examined. Despite the distinctive characteristics of involved materials, delamination‐free composite membranes were successfully formed with an intimate contact at the interface of two layers. The results also indicated that increasing concentration of Matrimid in dope solution led to increase in membrane thickness and consequently decline in water flux. In the best case, membrane prepared using 1 wt.% Matrimid in dope exhibited water flux of 0.98 LMH and NaCl rejection of 95.7%. Also, incorporation of 3 wt.% TiO2 nanoparticles offered membranes with improved water flux of 1.37 LMH and salt rejection of 95.8%. On the other hand, water flux and salt rejection in membranes containing 5 wt.% PEG were 1.18 LMH and 96.2%, respectively. The co‐presence of both nanoparticles and PEG provided more insights about the contributing factors in tuned membranes. Modification of skin layer by cross‐linking significantly improved salt rejection at the expense of water flux. The results are scientifically interpreted and compared to the values reported in literature.

Advances in surface modification and functionalization for tailoring the characteristics of thin films and membranes via chemical vapor deposition techniques

“…In this process, high pressure is exerted on the saline water to overcome the osmotic pressure upon which the water molecules pass through the semi‐permeable membrane 273 . This process is more established than other techniques of desalination for large scale applications though challenges associated to the large energy consumption per unit volume of the produced water has recently diverted attentions to other more energy‐efficient membrane‐based methods 274–277 …”

“…Nowadays, the ever‐increasing demand for the consumption of fossil fuels has contributed to the large production of CO 2 as the main cause of global warming and climate change. To mitigate these problems, there is a need to limit the amount of CO 2 emission to the atmosphere by either preventing its excessive production or by removing it from the effluent streams 277,342,343 . Various technologies have been used for CO 2 separation and capture from the rich or low content streams such as membrane separation processes, absorption and adsorption 344 .…”

“…273 This process is more established than other techniques of desalination for large scale applications though challenges associated to the large energy consumption per unit volume of the produced water has recently diverted attentions to other more energy-efficient membrane-based methods. [274][275][276][277] Since RO membranes are prone to organic fouling, biofouling, and scaling, the surface of such membranes must be modified by appropriate techniques among which CVD techniques are attractive due to providing a high-quality coating. Therefore, several studies have been conducted in this field.…”

“…To mitigate these problems, there is a need to limit the amount of CO 2 emission to the atmosphere by either preventing its excessive production or by removing it from the effluent streams. 277,342,343 Various technologies have been used for CO 2 separation and capture from the rich or low content streams such as membrane separation processes, absorption and adsorption. 344 Among these techniques, membrane processes are highly favorable thanks to their tremendous benefits including low operational cost, high effective surface area, high efficiency and their green and energy saving merits.…”

Development of a superhydrophilic nanofiber membrane for oil/water emulsion separation via modification of polyacrylonitrile/polyaniline composite

“…Today, membrane filtration is considered as a superior process due to its high efficiency, reasonable price and environmental friendliness 12‐14 . The major membranes for the separation of water and oil are microfiltration (MF) and ultrafiltration (UF).…”