Preparation and electrochemical characterization of cation- and anion-exchange/polyaniline composite membranes

Electrochemical membrane reactor: Synthesis of quaternary ammonium hydroxide from its halide by in situ ion substitution

“…Thus, J values were estimated from OH − concentration in the catholyte. Considering negligible mass (water) transport through AEM, as in this case, J may be defined as [13,34]:…”

Synthesis of a monovalent selective cation exchange membrane to concentrate reverse osmosis brines by electrodialysis

“…A very simple procedure was performed to carry out the surface polymerization by modifying described procedures [18,24]. The membranes were immersed in 5 % aniline and 0.1 M H 2 SO 4 for 1 h while the solution was stirring with a low rate shaking.…”

“…For this reason, surface modification was done in the synthesized membranes by polyaniline (PANi) surface polymerization. PANi has been used for surface modification of CEMs and also anion exchange membranes previously [17,18]. PANi is an electrically conducting polymer, which is easy to synthesize and has high chemical stability [19].…”

Electrochemical membrane reactor: In situ separation and recovery of chromic acid and metal ions

“…The amount of H + or OH − ions liberated was estimated by acid-base titration [29]. Counter-ion transport numbers across the membranes (t m i )were estimated from membrane potential measurements in equilibration with NaCl solutions of 0.10 and 0.01 M concentrations according to methodology reported earlier [30] using Eq. (2): where R is the universal gas constant, T the absolute temperature, n the electrovalence (1 in this case), a 1 and a 2 are the activities of the NaCl solutions used.…”

“…The chromate ion flux from central compartment to anolyte or the rate of formation of chromic acid in the anolyte (J), in the case of negligible volume change can be defined as [30,36]: Fig. 7(A) and (B) as a function of electric quantity passed, respectively.…”