Boron removal and antifouling properties of thin‐film nanocomposite membrane incorporating PECVD‐modified titanate nanotubes

Abstract

BACKGROUND Incorporation of nanofillers into the polyamide (PA) layer of thin‐film composite (TFC) membrane could improve membrane surface properties for enhanced water separation efficiency. However, most nanofillers do not disperse well in organic medium. In this work, the surface of titanate nanotubes (TNTs) was modified via the plasma‐enhanced chemical vapour deposition (PECVD) method in order to promote its dispersion rate (in organic medium) during thin‐film nanocomposite (TFN) membrane fabrication. RESULTS Fourier transform infrared (FTIR) analysis confirmed the surface chemistry of TNTs coated by hexafluorobutyl acrylate (HFBA) or hydroxyethyl methacrylate (HEMA) via PECVD method. The effects of embedding modified TNTs into the PA layer on membrane surface morphology, hydrophilicity and performance were also investigated and the results were further compared with commercial reverse osmosis (RO) membranes. It was found that the incorporation of HFBA‐ and HEMA‐modified TNTs could enhance the membrane water permeability by >25% and >40%, respectively, without compromising their salt rejection. The boron rejections of TFN membranes incorporated with HFBA‐ and HEMA‐modified TNTs meanwhile were recorded at 75.56% and 70.73%, respectively; these values were relatively higher than those for the self‐synthesized TFC (68.57%) and commercial RO membranes (37–39%). The developed TFN membranes also exhibited higher fouling tolerance than the commercial RO membranes, achieving >94% of water flux regeneration as a result of enhanced membrane surface hydrophilicity. CONCLUSION Compared to hydrophilic modification using HEMA, nanofillers modified by hydrophobic HFBA proved more effective at producing a PA layer with better nanofiller distribution, making the resultant TFN membrane more suitable for desalination processes. © 2019 Society of Chemical Industry

Surface modification of anti‐fouling novel cellulose/graphene oxide (GO) nanosheets (NS) microfiltration membranes for seawater desalination applications

“…The continuously growing world population continues to put a massive burden on available freshwater resources. Seawater desalination is one of the feasible options to alleviate this burden . Currently, reverse osmosis (RO) technology is dominating the market of seawater desalination due to its minimal environmental footprint and energy consumption when compared to other desalination technologies .…”

“…There are different methods to reduce membrane biofouling in the pretreatment unit, including membrane modification and integration with other technologies, such as ion‐exchange, coagulation, and others . The modification of membranes with antibacterial nanomaterial via surface coating and blending is considered to be more practical and has shown encouraging results . Graphene oxide nanosheets (GONSs) have shown great potential in this aspect due to their remarkable antibacterial activity and relatively low cost .…”

Functionalization of silica nanoparticles to reduce membrane swelling in CO2 absorption process

“…However, the drawback with silica nanoparticles is their tendency to agglomerate . This poses a major problem as it makes uniform dispersion of nanoparticles inside the polymer matrix difficult, as well as showing poor interfacial compatibility with the polymer .…”

“…However, the drawback with silica nanoparticles is their tendency to agglomerate. 18 This poses a major problem as it makes uniform dispersion of nanoparticles inside the polymer matrix difficult, as well as showing poor interfacial compatibility with the polymer. [19][20][21] Functionalizing these originally hydrophilic silica nanoparticles to change its surface functional groups to hydrophobic could alleviate the problem.…”

In focus: recent development of membrane technology for water and environmental applications

“…In this issue of Journal of Chemical Technology and Biotechnology (JCTB), a collection of 9 contributions that dealt with membrane science and technology, including 1 review and 8 research articles, is presented in this ‘ In Focus ’ section. The major topics of the contributions are synthesis of new nanocomposite membranes incorporated with advanced nanomaterials for both water and gas separation processes; fabrication of membranes using new materials for enhanced chlorine and solvent resistance; as well as development of a mathematical model to characterize the physical aging mechanism of polymeric membrane during oxygen enriched combustion process.…”