Multi-walled carbon nanotubes (MWCNTs) mixed polyacrylonitrile (PAN) ultrafiltration membranes

Abstract

Hydroxyl functionalized multi-walled carbon nanotubes (MWCNTs) were blended with Polyacrylonitrile (PAN) to prepare ultrafiltration membranes by a phase inversion process. Three different concentrations of MWCNTs were used in PAN, i.e. 0.5, 1 and 2 wt%. The water flux of the membranes increased by 63% at 0.5 wt% loading of MWCNTs compared to neat PAN membranes. The water flux decreased upon further increase in the concentration of MWCNTs, but at 2 wt% loading it was still higher compared to pure PAN membranes. The surface hydrophilicity of the membranes was enhanced upon the addition of MWCNTs, as observed by contact angle measurements. The increased hydrophilicity might have an impact on the improved water flux. All the membranes showed a molecular weight cut off (MWCO) of approximately 50 Kg/mol. Surface pore size analysis by scanning electron microscopy (SEM) showed no significant difference in the mean pore size of the nanocomposite membranes compared to the neat membranes. The cross section morphology was influenced by the introduction of MWCNTs where less but enlarged macrovoids were observed, particularly prominent at a loading of 2 wt% MWCNTs. The membranes containing 2wt% MWCNTs showed 36% improvement in resistance against compaction compared to neat membranes. Furthermore, the tensile strength of the membranes at 2wt% MWCNTs loading increased over 97% compared to neat ones.

Hollow mesoporous silica spheres/polyethersulfone composite ultrafiltration membrane with enhanced antifouling property

“…Nonetheless, with more HMSS, high viscosity slowed down the demixing rate during NIPS process leading to the suppression of macrovoids. A similar phenomenon was found when adding hydrophilic carbon nanotubes into polymer membranes [37][38][39][40]. Moreover, the macrovoids in the PES-MSS membrane matrix was also suppressed as compared with PES-1.5.…”

Enhanced gas permeability by fabricating mixed matrix membranes of functionalized multiwalled carbon nanotubes and polymers of intrinsic microporosity (PIM)

“…Table 5 polymer chain with different mobility [53]. These results suggest that the presence of fMWCNTs increases the specific uptake (relative sorption) of gases in the MMM at higher fMWCNTs content, and beyond the optimum the decrement may be countered by constrained polymer chain packing at f-MWCNTs/polymer interface.…”

“…The addition of small amounts of CNTs to a polymer matrix is expected to enhance the mechanical properties significantly [53,59]. The summary of mechanical properties obtained from the films of PIM-1 and f-MWCNTs /PIM-1 MMM, in terms of Young's modulus (E), tensile strength (σ M ), and elongation at break (ε) with standard deviations is reported in Table 7.…”

Novel anti-microbial membrane for desalination pretreatment: A silver nanoparticle-doped carbon nanotube membrane

“…The higher transport of molecules is possible through the smooth and friction-less graphitic walls of CNTs [27][28]. CNTs were used as direct filter and appealing membrane fillers to enhance thermal, mechanical and electrical properties of polymeric composite materials [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. The permeate flux through CNTs has been estimated to be 3-4 orders of magnitude faster than predicted by the Hagen-Poiseuille equation [30][31][32][33].…”