Studies on organic-inorganic hybrid ion-exchange materials

Abstract

The thesis comprises of five chapters. First chapter deals with the general introduction of the subject matter of the thesis which describes the critical review of the existing literature on the development of ion exchanger in general and inorganic-organic composite ion exchangers in particular. This also covers the applications of these materials in separation technology and other diverse fields. Separation is basically a pre-treatment method which, usually proceeds any quantitative or qualitative analysis. Separation process has very important role in various fields namely medicine, agriculture and environmental analysis. The general methods of separation include distillation, extraction, precipitation, crystallization, dialysis and diffusion etc. The most advance and versatile technique for the purpose of separation are chromatography, electrophoresis and ion exchange chromatography. Among them ion exchange chromatography emerged as the most versatile and standard analytical tool. Rarely has a particular area of science seen so spectacular and so phenomenal growth as ion exchange chromatography. Ion exchange is basically a process of nature occurring throughout the ages from even before the dawn of human civilization. Aristotle stated that the sea water loses part of its salts content when percolated through certain type of the soil. The earliest of the references were found in the Holy Bible, which says Moses succeeded in preparing drinking water from brackish water by an ion-exchange method. The applications of ion exchange technology have been firmly established with the development of ion exchange resins. The fundamental principle of an ion exchange process is based on the following facts:and#61656; Equivalence of exchange and#61656; Selectivity preference of the exchanger for one ion relative to another and#61656; Donnan exclusion- the ability of the resin to exclude ions under most conditions but not un-dissociated substances and#61656; Screening effect- the inability of very large ions or polymer to be absorbed to an appropriate extent