Modification of thin-film polyamide membrane with multi-walled carbon nanotubes by interfacial polymerization

Abstract

Polyamide thin-film composite (TFC) was fabricated on polysulfone (PS-20) base by interfacial polymerization of aqueous m-phenylenediamine (MPD) solution and 1,3,5-benzenetricarbonyl trichloride (TMC) in hexane organic solution. Multi-wall carbon nanotubes (MWCNT) were carboxylated by heating MWCNT powder in a mixture of HNO 3 and H 2 SO 4 (1:3 v/v) at 70°C under constant sonication for different periods. Polyamide nanocomposites were prepared by incorporating MWCNT and the carboxylated MWCNT (MWCNT-COOH) at different concentrations (0.001-0.009 wt%). The developed composites were analyzed by Fourier transform infrared spectroscopy-attenuated total reflection, scanning electron microscopy, transmission electron microscopy, contact angle measurement, determination of salt rejection and water permeate flux capabilities. The surface morphological studies displayed that the amalgamation of MWCNT considerably changed the surface properties of modified membranes. The surface hydrophilicity was increased as observed in the enhancement in water flux and pure water permeance, due to the presence of hydrophilic nanotubes. Salt rejection was obtained between 94 and 99% and varied water flux values for TFC-reference membrane, pristine-MWCNT in MPD, pristine-MWCNT in TMC and MWCNT-COOH in MPD were 20.5, 38, 40 and 43 L/m 2 h. The water flux and salt rejection performances revealed that the MWCNT-COOH membrane was superior membrane as compared to the other prepared membranes.

Flexible high dielectric thin films based on cellulose nanofibrils and acid oxidized multi-walled carbon nanotubes

“…3), demonstrating that more COOH groups are introduced by the acid oxidation. 39 Additionally, the peaks at 1624 cm À1 , 1383 cm À1 and 1122 cm À1 shis to 1633 cm À1 , 1384 cm À1 , and 1125 cm À1 , respectively, it also reveals the structure changes of MWCNT upon carboxylation.…”

“…The FTIR spectrum of pristine MWCNT displays not only C]C peaks at 1383 cm À1 and 1122 cm À1 , but also many other small peaks, namely, O-H peak at 3434 cm À1 , C-H peaks at 2925 cm À1 and 2850 cm À1 , and C]O peak at 1624 cm À1 , indicating the presence of hydroxyl and carboxyl groups. [38][39][40] These hydroxyl and carboxyl groups in as-received MWCNT could be attributed to the purication process by the manufacturer. 41 On acid treatment, two characteristic peaks of the carboxyl group are seen at 1705 cm À1 and 1579 cm À1 , respectively (as shown in the dashed circle of Fig.…”

Anti-biofouling effect of a thin film nanocomposite membrane with a functionalized-carbon-nanotube-blended polymeric support for the pressure-retarded osmosis process

“…[17][18][19][20] In this purpose, the functionalized CNT was embedded in the polyamide thin lm during interfacial polymerization or additional coating. [22][23][24] Nevertheless, few studies have described carbon nanotubes employed in the TFC membrane for PRO process. In this study, the CNTs incorporated in the support layer of TFN membranes was analyzed to determine their anti-biofouling ability in the PRO mode for potential applications of the PRO process.…”

Investigation of characteristic and performance of polyvinyl chloride ultrafiltration membranes modified with silica‐oriented multi walled carbon nanotubes

“…Moreover, the tubular shape of MWCNT nanoparticles can offer fast transport for passing water molecules through, thereby facilitating mass transfer in the process of membrane formation which gives the membrane a better pore structure. [13,14] Choi et al fabricated MCWNT/PSf nanocomposite membranes using the phase inversion method. They reported that the addition of MWCNT nanoparticles enhanced the filtration performance of the PSf membranes by altering morphology and controlling the hydrophilicity of the membrane surface.…”

“…However, because of the Van der Waals interactions among the tubes, the uniform dispersion of CNT nanoparticles in a polymer matrix is very difficult, which greatly limits their application. [14,16] To overcome the obstacles to CNT application, some functionalized CNT such as carboxylic acid-functionalized CNT, sulfonated CNT and phosphonated CNT have been subjected to the chemical modification approach followed by sonication and, therefore, have been used to facilitate the dispersion of CNT nanoparticles. [13,16] For example, Sianipar et al improved the dispersion of MWCNT to provide an antifouling behavior by coating CNT with polydopamine (Pdop).…”