Cross Linked Thin PolyVinyl Alcohol Membranes Supported On Polysulfone And Their Application In Separation Science

Abstract

Membrane separation is the most advanced filtration technology utilized to clarify, newlineconcentrate and separate continuously molecular or ionic compounds from their newlinesolutions. This process is potentially interesting for water processing, in particular in newlinethe treatment or recycling of water polluted by micron, submicron and/ or ionic species. newlineThere are several membrane separation techniques based on the variation of driving newlineforces. These driving forces include concentration gradient, applied pressure and newlineelectrical potential. The principal advantages of membrane processes compared to newlineother separation processes are low energy consumption, simplicity and environmental newlinefriendliness. The membrane process generally does not require a phase change to newlinemake a separation (except pervaporation), as a result, energy requirements are low newlinecompared to other separation processes. Thus, no additive is required essentially to newlineproceed with the separation. That is why; membrane technology is termed clean newlinetechnology. Pressure driven membrane process is highly effective with high newlineseparation efficiency, low energy consumption, economic cost, and avoidance or newlinereduced use of organic solvent. All of the polymer membranes developed till now are newlineeither integrally skinned asymmetric or thin-film-composite membranes. The history of newlinereverse osmosis began in the 1950s. Srinivasa Sourirajan and Sidney Loeb prepared newlinean asymmetric cellulose acetate membrane capable of desalting seawater through a newlinepressure-driven technique. As cellulose acetate the membrane is natural, and it has newlinesome limitations in chemical and mechanical stabilities. Considering the limitations, newlinethe research was directed to find different membranes from synthetic materials (viz. newlinepolysulfone, polyethersulfone, polyvinylidene fluoride, polyvinyl alcohol). All of the newlinemembranes have their limitations. To search for the better one, John Cadotte from newlineMidwest Research Institute in the 1970s succeeded in polyamide composite newlinemembranes. There are several attempts to