Abstract

Alginic acid, also called algin or alginate, is an anionic polysaccharide distributed widely in the cell walls of brown algae, where it, through binding water, forms a viscous gum. In extracted form it absorbs water quickly; it is capable of absorbing 200-300 times its own weight in water.^[1] Its colour ranges from white to yellowish-brown. It is sold in filamentous, granular or powdered forms. It is a linear copolymer with homopolymeric blocks of (1-4)-linked β-D-mannuronate (M) and its C-5 epimer α-L-guluronate (G) residues, respectively, covalently linked together in different sequences or blocks. The monomers can appear in homopolymeric blocks of consecutive G-residues (G-blocks), consecutive M-residues (M-blocks) or alternating M and G-residues (MG-blocks). Alginate is used extensively as an impression-making material in dentistry, prosthetics, life casting and occasionally for creating positives for small-scale casting. It is also used in the food industry, for thickening soups and jellies. In this paper, explains about the applications of alginates in different industries.

A8  APPLICATION OF ALGINATE IN VARIOUS INDUSTRIES  pdf

Abstract

Alginates are cell-wall constituents of brown algae (Phaeophyceae). They are chain-forming heteropolysaccharides made up of blocks of mannuronic acid and guluronic acid (picture left shows high manuronic acid gel, standard gel and high guluronic gel, giving different consistencies). Composition of the blocks depends on the species being used for extraction and the part of the thallus from which extraction is made. Calcium alginate is insoluble in water and this led to the development of fibres that could be woven into various textiles or parts of textiles, and their use in bandages, particularly for large wounds and burns, became widespread. The bandage could be removed much more easily than cellulose-based bandages, as the calcium alginate was soluble in a simple salt solution, and wound disruption was reduced. Modifications of the same principle also allows these fibres to form an important part of firemen’s fire-proof clothing and as part of the fluxes now used in welding rods. . Good quality stable fibers have been produced from mixed salts of sodium and calcium alginate, and processed into non-woven fabric that is used in wound dressings. They have very good wound healing and haemostatic properties and can be absorbed by body fluids because the calcium in the fibre is exchanged for sodium from the body fluid to give a soluble sodium alginate. This also makes it easy to remove these dressings from large open wounds or burns since they do not adhere to the wound.

A6 SEAWEEDS USED AS A SOURCE OF ALGINATE IN TEXTILE INDUSTRYpdf

Abstract

Poly aniline is the oldest and potentially one of the most useful conducting polymer because of its facile synthesis, environmental stability and simple acid or base doping chemistry. Because Nano form of this polymer could offer new properties or enhanced performance, nanostructure poly aniline has attracted a great deal of interest during the past few years. Poly aniline is a conducting polymer which has been used for decades, however only within the past few years has it become a process able material with the development of poly aniline Nano fibers and dispersions. The Nano fibrillar morphology allows one to use poly aniline easily. The process ability and high surface area allow efficient use in applications such as sensors, artificial muscles, metal nanoparticle scaffolds, bistable memory devices, electro chromic, water purification, capacitors and many other areas. Improved control of the synthesis of poly aniline, its derivatives, and other conducting polymers promise an even greater enhancement of the application range for these lightweight and inexpensive materials. This account summarizes our recent research on the synthesis, processing, properties and applications of poly aniline Nano fibers.

A4POLYANILINE NANOFIBERS AND THEIR APPLICATION pdf