International Journal of Membrane Science and Technology, 2015, 2, 39-46 39 E-ISSN: 2410-1869/15 © 2015 Cosmos Scholars Publishing House Recycling of Polysulfone: Study Properties of Membranes Mayank Saxena 1 , Saroj Sharma 2 and A. Bhattacharya 1,* 1 Reverse Osmosis Division, 2 Electro-Membrane Process Division, CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Council of Scientific & Industrial Research (CSIR), G. B. Marg, Bhavnagar- 364 002, (Gujarat), INDIA. Abstract: Many significant developments regarding membranes have been taken place in past few decades. The wet phase inversion is a simple method to prepare asymmetric polysulfone membranes. Membranes were fabricated from polysulfone using N,N dimethyl formamide (solvent) and water (non-solvent) and permeation properties were investigated. We have explored the differences in performances of the membranes prepared from consecutive phase inversion of polysulfone. The effect of addition of sodium lauryl sulphate and their multi stage phase inversion were also studied. Functional group ruination/formation, Morphology, hydrophobicity, MWCO were analysed from different analytical instruments (viz. SEM, FTIR-ATR, TGA, contact angle, GPC). Fourier Transform Infrared (FTIR-ATR) spectra of polysulfone membranes were analysed to identify the variations of the bonds. The results obtained from water permeation experiments showed that consecutive phase separation of polysulfone increased the water permeability of the membranes. The polysulfone membranes resulted from multistage phase separation showed decreasing trend in separation for polyethylene oxide (PEO, 200kDa) as well as Bovine Serum Albumin (BSA, 66 kDa). Keywords: Polysulfone, N,N dimethyl formamide, Wet phase separation, Bovine Serum Albumin. INTRODUCTION Polysulfones (PSf) are well-known high temperature amorphous engineering thermoplastic materials. The PSf has attracted the polymer scientists for its excellent characteristics, such as good solubility in a wide range of aprotic polar solvents, high thermal resistance (150- 170 o C), good chemical resistance over a wide range of pH, good oxidative resistivity, high mechanical resistance of the films (fracture, flexure, torsion), moderate reactivity in aromatic electrophilic substitutions reactions (sulfonation, nitration, chlorome- thylation, acylation, etc.) [1, 2]. The PSf can be molded, extruded, and thermoformed into a wide variety of shapes for different applications. Due to all these features, PSf and it derivatives have been widely used as new functional materials in various fields such as; biochemical, industrial and medical applications, as a high performance technological/biomedical material, but mostly in membranes for separation technologies (ultra filtration, reverse osmosis, or gas separation) [3- 10]. It has been found that mostly the modification of polysulfone has been achieved chemically (by chloromethylation, suphonation, grafting of suitable monomers on to membrane surface etc.) to get the polymer of desired properties for its specific applications viz. fuel cell, pH responsive membrane * Address correspondence to this author at the Reverse Osmosis Division CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Council of Scientific & Industrial Research (CSIR), G. B. Marg, Bhavnagar- 364 002, (Gujarat), INDIA; Tel: 91-0278-2567760-7610; Fax: 91-0278-2567762; E-mail: bhattacharyaamit1@rediffmail.com etc. [11-16]. Apart from its functionality, the formation of controlled pores is another criterion to form better membranes. There are many techniques to form pores on the membranes such as incorporation of porogens in the membrane which can be destructed thermally, leached after particular reaction [17-20]. The porosity in PSf was introduced by embedding calcium carbonate nanoparticles in the bulk polymer [21]. Here in this particular study we have approached simple wet phase inversion technique. The demixing of solvent–non-solvent is the basic mechanism of the formation of pores in polymer membrane. In the present study phase inversion steps are enhanced to study the property profiles of PS membranes from different steps. The present study is conceptualised focusing the justification of reusability of polysulfone, once phase-inversion has done. MATERIALS AND METHODS Materials Polysulfone (PSf) pellet (Udel P-3500, Solvey Advanced Polymers, USA), Non-Woven polyester fabric (Filtration Sciences Corp., USA), N,N dimethyl formamide (Merck, India), Sodium lauryl sulphate (SLS, SD fine chemicals, India) were used for the preparation of membranes. Polyethylene Oxide (Mw 200kDa) (Sigma-Aldrich) was used as markers for the characterization of membranes in terms of separation abilities. Bovine serum albumin (BSA) (Mw 66kDa) (Sigma-Aldrich, USA) was used to study the separation performances of the membrane. Milli-Q water was used in the experiment.