A practical approach to synthesize polyamide thin film nanocomposite (TFN) membranes with improved separation properties for water/wastewater treatment

Abstract

Thin film nanocomposite (TFN) membranes containing 0.05 or 0.10 w/v% functionalized titanate nanotubes (TNTs) in polyamide selective layer were prepared via interfacial polymerization of piperazine (PIP) and trimesoyl chloride (TMC) monomers. Nanomaterials were dispersed into the monomer solution using two different approaches. In the first one, the functionalized TNTs were dispersed into the amine aqueous solution, while in the second approach the same nanomaterials were dispersed in TMC organic solution. The TFN membranes were characterized and compared with a control thin film composite (TFC) membrane to investigate the effect of nanofiller loadings and the fabrication approach on membrane properties. Results showed that introducing nanofillers into the organic phase was more effective to synthesize a TFN membrane of greater separation performance as the use of rubber roller to remove aqueous solution from the substrate surface could cause the loss of a significant amount of nanofillers, which further affected the polyamide layer integrity. It was also found that incorporation of high nanofiller loading tended to interfere with interfacial polymerization and weaken the bonds between monomers blocks, resulting in poor polyamide-nanotubes integrity. Compared to the TFC membrane, the TFN membrane made of 2% PIP and 0.15% TMC with 0.5% nanofiller incorporation could achieve greater water flux (7.5 vs 5.4 L/m 2 .h.bar) and Na2SO4 rejection (96.4% vs 86%) while exhibiting higher resistance against the fouling by protein and dye.

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

“…Instead, the absence of the peak for CO stretching for both T‐HFBA and T‐HEMA could imply that plasma polymerization takes place at the CO bonding. However, the morphological change on the surface of the modified TNTs is hardly distinguishable when compared to the pristine TNTs reported in our previous work (see Fig. A.1).…”

“…These properties are essential in overcoming the major challenge of TFN RO membrane fabrication – the agglomeration of nanomaterials that affects PA integrity and reduces its separation efficiency . However, because of the hydrophilic nature of TNTs, a perfect dispersion of TNTs in nonpolar solvent during the IP process is difficult to achieve …”

Fabrication and characterization of novel antimicrobial thin film nano‐composite membranes based on copper nanoparticles

“…As presented in Table 3, the best performances in our work were attributed to TFN1 where a higher water permeability was achieved (8.84 m −2 h −1 bar −1 ) while keeping a relatively high rejection of Na 2 SO 4 (93.3 %) compared with other TFN membranes reported in the literature. 24,[39][40][41][42][43] The present TFN membrane exhibits good equilibrium between water permeability and salt rejection, which can be associated with its stability after the introduction of CuNPs into the PA layer via simple IP.…”

La‐modified vermiculites for efficient adsorption of Congo red

“…Considerable efforts have been made to treat dye‐containing effluents, including membrane separation, flocculation/coagulation, ion exchange, biological treatment and photocatalytic degradation . Adsorption has been considered as an effective technique of choice, which is superior to others in terms of several advantages, such as low cost, easy operation, suitability in removing different colouring materials, insensitivity to other toxic pollutants and formation of non‐harmful by‐products .…”

“…Considerable efforts have been made to treat dyecontaining effluents, including membrane separation, flocculation/coagulation, ion exchange, biological treatment and photocatalytic degradation. [6][7][8][9][10][11] Adsorption has been considered as an effective technique of choice, which is superior to others in terms of several advantages, such as low cost, easy operation, suitability in removing different colouring materials, insensitivity to other toxic pollutants and formation of non-harmful by-products. [12] So far, various materials, including natural and modified clays, [13,14] metal oxides, [15] calcined and uncalcined layered double hydroxides [16] and biomaterials [17,18] have been developed in order to achieve high-performance removal of dyes from water.…”