Controlled metal loading on poly(2-acrylamido-2-methyl-propane-sulfonic acid) membranes by an ion-exchange process to improve electrodialytic separation performance for mono-/bi-valent ions

Abstract

Highly cross-linked poly(2-acrylamido-2-methyl-propane-sulfonic acid) (PMPS) based cation-exchange membranes (CEMs) were prepared and the mono-valent selectivity of the membranes was significantly improved using the pore-sieving strategy by metal (copper) loading by the ion-exchange process. The prepared membranes were characterized for their morphological, physicochemical, electrochemical, and electrodialytic properties. Metal (Cu) loading in the PMPS membrane matrix improved thermal, mechanical, oxidative and hydrolytic stabilities. The results demonstrated that fine control over membrane permselectivity is possible and can be effectively tuned. Metal modification on the CEM surface improved the blocking behaviour and restricted the transport (leakage) of bi-valent metal cations (Ni 2+ and Zn 2+ ) during electrodialytic separation of mono-and bi-valent ions. However, partial deterioration in membrane ionic conductivity showed a slight adverse effect on the electrodialytic performance of the modified membranes. Extremely low Zn 2+ leakage for the prepared PMPS-3 membrane in comparison with other state-of-the-art CEMs was attributed to the excellent pore-size sieving effect. The metal loaded PMPS-3 membrane showed improved surface compactness, which hindered the easy accessibility of bulky counter-ions (Ni 2+ /Zn 2+ ) to fixed charge and thus quite low transport (leakage) of bi-valent ions was observed.

Physically crosslinked KOH impregnated polyvinyl alcohol based alkaline membrane for direct methanol fuel cell

“…Generally, a high IEC is correlated to higher conductivity. The IEC is an important parameter to assess the ionic charge nature of the membrane in terms of equivalent of ionic functional groups present in the per unit dry weight . Figure shows the IEC of the physically crosslinked membrane as a function of KOH concentration.…”

Intercalated Poly (2-acrylamido-2-methyl-1-propanesulfonic Acid) into Sulfonated Poly (1,4-phenylene ether-ether-sulfone) Based Proton Exchange Membrane: Improved Ionic Conductivity

“…The final weight loss observed at ~500 °C is due to the polymer backbone degradation. Thermal study of PMPS also shows a similar trend in which initial degradation starts from 80–100 °C due to absorbed moisture while high weight loss in the region 200–250 °C is due to the presence of sulfonic acid groups and backbone degradation starts at 325–500 °C [ 20 , 21 ]. Thus, this study reveals the durability of membranes over a high temperature range which could fit these membranes to various electrochemical applications which could be operated at high temperature.…”

Enhancement of alkaline conductivity and chemical stability of quaternized poly(2,6-dimethyl-1,4-phenylene oxide) alkaline electrolyte membrane by mild temperature benzyl bromination

“…3,4 there have been numerous studies on the development of alkaline electrolyte membranes (AEMs). [5][6][7][8][9][10][11] Even though several types of AEMs have already been commercialized, there are still some criticisms against them in association with the poor chemical and mechanical stability along with low alkaline conductivity. It is noticed that those cons are mostly caused by the nature and location of ion conductive groups such as quaternized ammonium in their synthesis.…”

“…Nowadays as a base material, PPO has been extensively studied for their versatile electrochemical applications such as electro-dialysis, fuel cells, batteries, diffusion dialysis, electrolysis and electro deionization due to its easily modiable structure with robust stability. [5][6][7][8][9][10][11] The present work reects the characterization of a new class of PPO based alkaline membrane synthesized at the mild bromination temperature using NBS. This bromination process is expected to improve not only the chemical and mechanical stability of the membrane but also its IEC and conductivity along with controllable water uptake.…”