Fabrication of high-performance ultrafiltration membranes using zwitterionic carbon nanotubes and polyethersulfone

Abstract

Novel and functionalized multiwalled carbon nanotubes (MWCNTs) were successfully synthesized using zwitterionic structure, consisting of quaternary amine and sulfonic acid groups. The zwitterionic MWCNTs were introduced into a polyethersulfone (PES) matrix to prepare ultrafiltration membranes, via the phase inversion method. The acidfunctionalized MWCNTs were then mixed with the membrane matrix as reference. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy validated the introduction of quaternary amine and sulfonic acid groups into the MWCNTs. For example, the hydrophilicity of the composite membranes, especially of zwitterionic MWCNTs/ PES composite membranes, was obviously improved, as compared with that of the pristine PES membrane. Also, the morphologies of the membranes were studied by field emission scanning electron microscopy (FESEM) and their permeability and antifouling properties were thoroughly investigated. The results show that the water flux of the composite membrane, containing 0.2 wt% of zwitterionic MWCNTs, was twice more than that of the pure PES membrane, and its flux recovery ratio was as high as 85%.

Antibiofouling Performance by Polyethersulfone Membranes Cast with Oxidized Multiwalled Carbon Nanotubes and Arabic Gum

“…The subtle decrease in pore size calculated for M8 (Figure 5b) which had the highest OMWCNT loading correlates with previous studies which indicated that beyond a certain loading threshold; the casting solution becomes too viscous causing a delayed demixing process between the solvent and non-solvent in the coagulation bath during membrane casting [41,51].…”

Antibacterial Properties of Polysulfone Membranes Blended with Arabic Gum

“…The addition of AG clearly enhances membrane flux (over 100% increase from neat M1 samples to M4 samples). Flux enhancement due to hydrophilic additives has been widely reported in the literature [ 30 , 43 , 45 , 47 , 48 ]. The improvement in flux readings for the PS/AG membranes can be explained by two main reasons.…”

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

“…[44] Membrane porosity is dependent on the phase inversion kinetics and solvent-nonsolvent interactions. [43] Table 2 shows significantly increased porosity values with the increase of Si-MWCNTs loading. The porosity of the pristine PVC membrane is 78.1% and increased with the addition of Si-MWCNT nanoparticles.…”

“…However, when the nanoparticle loading was increased beyond 0.5%, they started to aggregate in the pore walls of the blended membrane due to their strong Van der Waals interaction, which consequently resulted in blockage of the fingerlike pores and hence, decreased membrane permeability. [43] According to the cross-sectional EDX mapping ( Figure S3), the yellow dots represent silica nanoparticles, which were dispersed in the cross-section of polymer matrices. No silica nanoparticles are present in the pristine PVC membrane matrix.…”