Development of polymer inclusion membranes for palladium recovery: Effect of base polymer, carriers, and plasticizers on structure and performance

Recently, palladium is widely used in electronics, catalysis, electroplating, and fuel cells. The recovery of precious metals has become very important due to their scarcity and high price. The adsorption method which is generally used in polymer inclusion membranes is both effective and simple because, for that reason, the retention and mechanism of chemicals were shown to be significantly influenced by precious metal adsorption on the membrane. In this study, polymer inclusion membranes were produced and characterized by using different base polymers, carriers (Aliquat 336, trioctylamine (TOA)), and plasticizers (2-nitrophenyl octyl ether (NPOE)). The palladium adsorption capacities of the membranes were examined in detail in terms of different pHs, temperatures, contact times, and membrane contents. The optimum pH was determined as 2 for all membranes. In addition, the temperatures and contact times of the membranes containing cellulose triacetate (CTA), polyvinyl chloride (PVC), and polyvinylidene fluoride (PVDF) were 35 degrees C-240 min, 55 degrees C-90 min, and 35 degrees C-180 min, respectively. According to the effect of membrane type, the best results were obtained for 40 % CTA-20 % Aliquat-40 % TOA, 40 % PVC-20 % Aliquat-40 % TOA, and 40 % PVDF-40 % Aliquat-20 % NPOE for each base polymer.