[en] Super absorbent hydrogels based on the natural polymer chitosan and acrylic acid (CS/AAc) was prepared using 60 Co gamma radiation as a source of initiation and crosslinking, The factors, which affect the preparation of CS/AAc hydrogels such as irradiation dose, CS/AAc ratios, and acrylic acid monomer concentrations, to get the best optimum conditions, were investigated, The kinetic studies of the swelling of CS/AAc hydrogel showed that it follows a Fickian type of water diffusion, The Fickian constant value 'n' was more than 0.5 with a high swelling capacity of 300 gig as super absorbent hydrogel. In addition, the suitability of CS/AAc hydrogel as carrier material for the drug Chlortetracycline-H CI has been investigated by adsorption isotherm studies. The performance of drug release from hydrogel systems, influenced by acrylic acid ratio and the effect of ph of the medium was studied

[en] Super absorbent hydrogels based on the natural polymer chitosan and acrylic acid (CS/AAc) was prepared using 60 Co gamma radiation as a source of initiation and crosslinking, The factors, which affect the preparation of CS/AAc hydrogels such as irradiation dose, CS/AAc ratios, and acrylic acid monomer concentrations, to get the best optimum conditions, were investigated, The kinetic studies of the swelling of CS/AAc hydrogel showed that it follows a Fickian type of water diffusion, The Fickian constant value 'n' was more than 0.5 with a high swelling capacity of 300 gig as super absorbent hydrogel. In addition, the suitability of CS/AAc hydrogel as carrier material for the drug Chlortetracycline-HCl has been investigated by adsorption isotherm studies. The performance of drug release from hydrogel systems, influenced by acrylic acid ratio and the effect of Ph of the medium was studied

[en] Radiation sensitive indicators based on dyed poly(vinyl alcohol) (PVA) containing acid sensitive dye chromeazurol S (CAS) and chloral hydrate (CH) have been developed. These plastic film dosimeters undergo colour change from orange to yellow colour, useful dose ranges are between 2 to 40 kGy. In presence of different concentrations of CH the colour change from orange to red indicating acid formation and the useful dose range from 100 Gy to 5 kGy. The radiation chemical yield G(value) was calculated. The films have the advantage of negligible humidity effects on response in the intermediate range of relative humidity from 10 to 50% and good stability before and after irradiation under different storage conditions.

[en] In this work, phenol/formaldehyde nano composites were synthesized using reactive rubber nano-particles (RRNP) and cloisite 30B nano clay with different percentages and were fully investigated. A little amount of these nano materials enhanced the mechanical properties of the produced composites. This enhancement is attributed to the interaction of these nano materials with the bakelite matrix. In bakelite/RRNP, the mechanical properties enhancement is due to the chemical connection of RRNP to the bakelite matrix while in bakelite/Cloisite 30B, this enhancement is due to polar/polar interaction. It was observed that the composites exhibited an intercalated disordered structure by means of X-ray diffraction (XRD) and transmission electronic microscopy. The crosslinking density of the bakelite network was greatly influenced by the presence and type of nano material that was added to the resin. The thermal stability was investigated with TGA/DSC which proved that these nano composite are (10-20)% more thermally stable than neat Bakelite resin

[en] The sorption of radio cobalt onto low cost materials (such as soil and clay) in the presence of environmentally available organic ligands (such as humic acid, phenol and gallic acid) is investigated. The organic matter was eliminated from the soil and clay and they are characterized by FT-IR, Textural analysis, X- ray diffraction (XRD) and Energy dispersive X- ray (EDX). The investigations were carried out as a function of ph, metal ion concentration and weight of sorbent, using the batch technique. The results showed that the pseudo 2nd-order equation tailored the kinetic sorption well. The sorption of Co(II) on both soil and clay is powerfully dependent on ph. A positive effect of humic acid on the sorption of Co(II) is found, whereas a negative effect is observed for phenol and gallic acid. The presence of HA, together with the other ligands, enhances the sorption in all cases. Generally, the sorption of Co(II) is higher for soil than for clay