Cation-Exchange Membranes With Polyaniline Surface Layer for Water Treatment

Abstract

Ion-exchange membranes are widely used in modern technologies, particularly in the field of water treatment and make it possible to considerably reduce expenses for wastewater treatment and ensure high degree of purification. Currently, perfluorinated sulfated proton-conducting membranes are often used, such as NAFION and its Russian analogue, MF-4SK based on co-polymerization product of a perfluorinated vinyl ether with tetrafluoroethylene. However, with development of the industry, materials with improved properties and lower cost are required. The aim is to obtain ion-exchange membranes for water treatment from metal ions and to study physico-chemical properties of obtained membranes. In this study, cation exchange composite membranes with modified polyaniline surface layer on nylon and PTFE substrate have been obtained. Changes in the structure of membranes were recorded using a microscope. Throughput capacity of the membranes was determined by passing a certain volume of distilled water through the membrane. The experiment intended to determine electivity of membranes was performed by passing a certain volume of metal salt solutions of a known concentration, after which the filtrate was collected. Concentrations of the studied metal ions in the original solution and in the filtrate were determined by the method of atomic adsorptive spectrometry with electro thermal atomization "Quantum Z.ETA". Prepared highly selective ion exchange membranes. Properties of modified membranes, such as selective permeability and ion-exchange capacity have been determined. The membranes feature high selectivity for heavy metal ions. Moisture-retaining power and swelling ability of the membranes have been studied. Selectivity of the membrane to heavy metal ions is between 70 and 99%. Ion-exchange capacity of the obtained nylon polyaniline membrane is not inferior to some commercially available cation-exchange membranes. Use of the modified membranes in the stage of tertiary wastewater treatment will ensure achieving established standards.

Infrared Spectroscopic Studies of the PTFE and Nylon Membranes Modified Polyaniline

“…In this work (Fazullin et al, 2014), we obtained ion-selective membranes with polyaniline (PANI) as a working layer. Studies were performed on a laboratory membrane separation installation.…”

Research Trends in the Use of Polyaniline Membrane for Water Treatment Applications: A Scientometric Analysis

“…The use of PANI as a component in water filtration and treatment membranes has been completed either in the form of blends/composites with one or more components (mainly polymers) or as coating/laminates on a base polymeric membrane [4]. When acting as a cation-exchanger, the extent of doping of PANI and the feasibility of the interfacial transfer of charge between PANI and a second component is of extreme importance, and the latter is governed by the area of contact and the interaction between the two phases [10]. In this regard, coating/lamination provides a better scenario as it results in higher surface coverage of PANI, often with high interfacial strength, and the coating/laminating layer of PANI acts as a physical barrier to facilitate restrictive movement of moieties across the membrane [11].…”

Development of thermoplastic polyurethane/polyaniline-doped membranes for the separation of glycine through electrodialysis

“…At a pH greater than 4, the electroactivity of PANI is lost because the conductive form of PANI (emeraldine salt) does not exist [5]. No doubt, PANI possesses fantastic properties and that is why it is used in electrodialysis, nanofiltration, pervaporation, and fuel cells [6][7][8]. Instead of remarkable properties, pristine PANI exhibits poor mechanical properties, which are due to the chemical nature of PANI; it is intractable and brittle.…”