High-Performance Reverse Osmosis CNT/Polyamide Nanocomposite Membrane by Controlled Interfacial Interactions

Abstract

Polyamide reverse osmosis (RO) membranes with carbon nanotubes (CNTs) are prepared by interfacial polymerization using trimesoyl chloride (TMC) solutions in n-hexane and aqueous solutions of m-phenylenediamine (MPD) containing functionalized CNTs. The functionalized CNTs are prepared by the reactions of pristine CNTs with acid mixture (sulfuric acid and nitric acid of 3:1 volume ratio) by varying amounts of acid, reaction temperature, and reaction time. CNTs prepared by an optimized reaction condition are found to be well-dispersed in the polyamide layer, which is confirmed from atomic force microscopy, scanning electron microscopy, and Raman spectroscopy studies. The polyamide RO membranes containing well-dispersed CNTs exhibit larger water flux values than polyamide membrane prepared without any CNTs, although the salt rejection values of these membranes are close. Furthermore, the durability and chemical resistance against NaCl solutions of the membranes containing CNTs are found to be improved compared with those of the membrane without CNTs. The high membrane performance (high water flux and salt rejection) and the improved stability of the polyamide membranes containing CNTs are ascribed to the hydrophobic nanochannels of CNTs and well-dispersed states in the polyamide layers formed through the interactions between CNTs and polyamide in the active layers.

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

“…Accordingly, with a high concentration of MWCNT in the aqueous phase, it may increase in hydrophilicity of the modified membrane and thus increase in water rate. It is observed here that our results are in agreement with those achieved by other investigators (Kim et al 2014;Zhao et al 2014;Amini et al 2013).…”

“…A black solid mass was attained after filtration. It was washed numerous times with distilled water and dried at 80°C in a vacuum oven for 8 h. The resulting MWCNT mass was found to contain the -COOH group attached to the MWCNT molecule (i.e., MWCNT-COOH), which was detected using various analytical tools by Kim et al (2014).…”

“…The pristine-CNT disperse during the preparation of membrane was carried out by using the procedure from Kim et al (2014 …”

Effects of hydrophilic CuO nanoparticles on properties and performance of PVDF VMD membranes

“…Nanocomposite membranes demonstrated to have great potential in improving the membrane performance in terms of flux, rejection, antifouling characteristics, thermal, mechanical, and chemical stability in membrane water treatment including ultrafiltration [3][4][5], microfiltration [6][7][8], nanofiltration [9][10][11], reverse osmosis [12][13][14], and forward osmosis [15][16][17]. To this end, different nanomaterials such as SiO 2 , carbon nanotubes (CNTs), TiO 2 , Al 2 O 3 , CaCO 3 , Ag, and nanozeolites have been used [5,16,[18][19][20][21][22][23].…”

Exploring the effect of additives on polyamide membrane surface for seawater desalination using density functional tools

“…In a similar way there are several studies [25][26][27][28][29] which use various monomers to prepare membranes through interfacial polymerization and analyze the membrane performance in terms of water flux, salt rejection, resistance to chlorine, anti-fouling properties and hydrophilicity. The alternative way, as mentioned earlier, is by incorporating nano-particles like PA-silica [30], PA-zeolite [31], PA-CNT [32,33], into the active surface of TFC membrane for better performance.…”