Super Water Absorbent Polymers (SWAPs)
Radiation grafted Super water absorbent polymers can absorb and retain large amounts of water relative to their own mass and has slow releasing capability of water. These are classified as hydrogels. When cross-linked they absorb water through hydrogen bonding. The total absorbency an d Swelling capacity are
controlled by the type and degree of cross-linking used to make the gel.
Fig 07: Preparation of radiation grafted Super Water Absorbent
The objective of the project is to produce advanced grafted materials for
past and present efforts – Chito Power
Chitin, the second abandon natural polymer n the world, is extracted from shells of crabs, shrimps, and prawns etc and it is used to produce the chitosan.
Chitosan is a long chain polymer and its maximum molecular weight is in the range of 500-800 kDa. Different molecular weights show different properties & features and these features can be applied for different useful applications in the fields of Agriculture, Environmental, and Medical etc. The research and development works are carried out related to Chitosan to develop new products which are oriented to agriculture applications.
The Chito Power, the newly developed Natural Plant Growth Promoter, was
introduced by the Atomic Energy Authority and the Horticultural Research & Development Institute (HORDI), Department of Agriculture for vegetables and leafy vegetable products. The project was implemented by the Atomic Energy Authority in collaboration with the Department of Agriculture under the activities of IAEA/RCA project RAS/8/109, Supporting Radiation Processing of Polymeric Materials for Agricultural Applications and Environmental Remediation. This newly developed alternate product provides healthy plant growth and optimum yield while reducing the usage of existing environmental hazardous chemical fungicides
and growth promoters/elicitors in the market.
Sri Lanka has been facing of air, water and soil pollution problems since past few years due to fast growing industries such as textiles, metal plating, etc. Stringent environmental laws have forced industries to look for cheaper and effective alternatives for controlling pollution. As such, radiation grafted fibrous polymers become one of the best solutions for the treatment of waste water since they have shown selectivity for uptaking of toxic and hazardous materials from water bodies and they have proven to be excellent bio-compatible products.
Radiation grafted polymers play a major role as they perform high chemically
active polymer matrix for adsorption and separation processes. Polymer adsorbents can be easily prepared by direct grafting of the desired functional groups to the polymer. Ionizing radiation creates an active radical which initiate the chain propagation in the trunk polymer.
Under the IAEA project RAS 1014, a radiation grafted heavy metal absorbent
polymer is prepared using both Non-woven Polyethylene/Polypropylene (PE/PP) and Polypropylene (PP) fabric as the trunk polymer and Acrylic acid as the monomer. The Co-60 Gamma cell at Human Tissue Bank is used for the irradiation of the samples.
Further, upon the radiation grafting, the hydrophobic nature of the non woven
PE/PP and PP fabric is converted in to hydrophilic nature and hence the fabric is
wetted by water. These properties can be applied to treat waste water in order to remove metal ions from water bodies.
The re-usability of these radiation grafted samples is also studied by readjustingthe pH of the medium. The efficiency of this radiation grafted metal adsorbent is expected to be increased by using nano particles.
In addition, the efficiency of metal adsorption of grafted chitosan films, surface
characterization and quantitative determination of the heavy metal adsorbent capacity of this modified chitosan films towards different heavy metal ions are expected to be examined