Preparation, Characterization, and Separation Performances of Novel Surface Modified LbL Composite Membranes from Polyelectrolyte Blends and MWCNT

Abstract

Here, it was aimed to modify the surface of NF90 with layer by layer (LbL) blended poly(allylamine hydrochloride) (PAH)‐chitosan (CHI) and poly(acrylic acid) (PAA) with/without functionalized multiwalled carbon nanotube (fMWCNT) for reverse‐osmosis applications. Using Quartz Crystal Microbalance Dissipation monitoring, it was observed that PAH‐CHI/PAA LbL films grew linearly after a few bilayers and no LbL film degradation occurred during synthetic seawater treatment. Thermal degradation of all LbL blended membranes was similar. NF90 had a heterogeneous surface while the surface of LbL blend membranes exhibited some agglomerations due to the polyelectrolyte (PE) complex formation and fibrillary appearance depending on the use of fMWCNT. [(PAH50‐CHI50/(PAA‐fMWCNT)]30 indicated the highest flux with 14.5 L m2 h−1 at 40 bar. The sodium and chlorine ion rejections were 75% and 87%, respectively, for the same membrane. The use of fMWCNT led to a significant enhancement in flux with a slight decay in ion rejections. On the other hand, chlorine ion rejection of [(PAH50‐CHI50/(PAA‐fMWCNT)]30 decreased by 25% at 40 bar while 60 and 90 bilayers of [(PAH50‐CHI50/(PAA‐fMWCNT)] disintegrated after NaOCl treatment. Briefly, the flux and ion rejections of the LbL blended membranes can be controlled depending on the use of fMWCNT and different PE couples without multilayer decomposition against synthetic seawater. POLYM. ENG. SCI., 60: 341–351, 2019. © 2019 Society of Plastics Engineers

Experimental design of Al 2 O 3 /MWCNT/HDPE hybrid nanocomposites for hip joint replacement

“…Carbon nanotubes or single layers of graphene rolled into a cylinder shape, have been commonly applied and evolved into diverse research directions including medical applications. CNT usually exists in 2 phases, single-walled and multiwalled, with different characteristics properties [28][29][30][31][32][33]. There are different types of techniques that have been improved for synthesizing CNT which mainly involve vapor phase routes.…”

Monitoring the Salt Stability of Layer‐by‐Layer Self‐Assembled Films From Polyelectrolyte Blends by Quartz Crystal Microbalance‐Dissipation and Their Ion Separation Performances

“…Considering the significant improvement in separation and ion rejection of LbL blend structured membranes in the presence or absence of multiwall carbon nanotubes (MWCNT) [47] compared to ones prepared from single anionic and cationic PE couples [33], we assembled membranes from anionic blend PEs in the study. Apart from the using of two different negatively charged PE solutions, one solution comprising of anionic PE blends was used.…”

Experimental Design of AL2O3/MWCNT/HDPE Hybrid Nanocomposites for Hip Joint Replacement

“…Carbon nanotubes or single layers of graphene rolled into a cylinder shape, have been commonly applied and evolved into diverse research directions: mechanics, and even medical applications. CNT usually exists in 2 phases, single-walled and multiwalled, with different characteristics properties [6][7][8][9][10][11]. There are different types of techniques that have been improved for synthesizing CNT which mainly involve vapor phase routes.…”