Abstract-A series of poly(acrylamide-co-acrylic acid) (poly(AAm-co-AAc))-based super-absorbent hydrogels (SAHs) was prepared by gamma radiation at the dose rate of 15 kGy. The amount of AAm was varied in the range of 30-70% (mol of total monomer) in feed. The co-polymers were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, nuclear magnetic resonance and network parameters, such as average molar mass between cross-links and cross-link density, were determined to explain the swelling behaviour. The experimental results indicated that an increase in the AAm content present in the hydrogels varied from 38.87% to 64.02%, equilibrium water absorbency decreased from 872 to 402 g H 2 O/g sample. The equilibrium water absorbency of various SAHs was investigated in different concentration of saline solutions. The effect of synthesized co-polymer on growth of seeds of ladyfinger is reported.

Poly (acrylamide-co-acrylic acid) [poly (AAm-co-AAc)]-based hydrogels were prepared by varying the cross-linking agent concentration (NMBA) in the range of 0.0077% to 0.077%. The effect of the NMBA content on swelling parameters, such as water absorbency, swelling ratio on the hydrogel was studied by keeping two monomers content, that is, AAm and AAc constant. The effect of KPS as an initiator in the range of 0.1% to 0.5% on the water absorbency of the hydrogels was also studied. The swelling value could be modulated in a great range by varying the cross-linking agent (NMBA) or initiator (KPS) concentration at fi xed monomer concentration. The synthesized hydrogels were characterized by FTIR, SEM and network parameters, such as average molecular weight between cross-links (Mc), cross-link density (q) and mesh size (ξ). The experimental results showed that the equilibrium water absorbency decreases from 707.23 to 389 with increasing the NMBA content from 0.0096 % to 0.0385%. The network parameters, such as average molecular weight between cross-links (Mc) were decreased from 2.33 x 10 12 to 2.30 x 10 11 and cross-link density (q) decreased from 3.07 x 10 -11 to3.09 x 10 -11 ; although mesh size (ξ) increased from 3.00 x 10 6 to 8.89 x 10 6 with increase in percentage of NMBA content from 0.009265% to 0.077%. The equilibrium water absorbency of various hydrogels were studied in distilled water and different types of saline solutions, which exhibited that hydrogels have higher equilibrium water absorbency in 0.009% saline (NaCl) solution than in 0.09% and 0.9% saline solutions. From the results it was clear that water absorbency increased from 302 to 573 g water/g sample with increasing the KPS content from 0.1 to 0.5%.

Poly(acrylamide-co-butyl methacrylate-co-acrylic acid) hydrogels were prepared in various concentrations of a dioxane/water mixture as polymerization media using different percentages of cross-linker and by varying the amount of acrylamide over 4-fold in order to study the effect of acrylamide content on swelling behaviour of hydrogels. It was found that hydrogels prepared in 50% aqueous dioxane solution exhibited the highest swelling. The results also indicated that with increasing acrylamide content, swelling increased initially. And when acrylamide content further increased to 66% (based on total monomer), the swelling decreased gradually. Detailed swelling kinetics, such as swelling ratio, transport exponent n and diffusion coefficient D, were studied and the effect of pH on equilibrium swelling was also studied. The hydrogels were also characterized by network parameters, such as molecular weight between cross-links (M c ) and cross-link density (q), that were determined to explain the swelling behaviour. The hydrogels were also characterized by Fourier transform infrared spectroscopy, elemental analysis, differential scanning calorimetry and scanning electron microscopy.

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Now-a-days, the thrust area of materials’ research is to develop multifunctional materials, which have multiple properties in a single functional material. We are interested to develop multifunctional polysilanes having special functional properties such as optical activity and photoluminescence (PL) properties. In this investigation, poly(methyl phenyl silane) (PMPS) was integrated with a chiral unit and a photoactive unit by in situ photopolymerization of  (R)-N-(1-phenyl ethyl) methacrylamide (R-NPEMAM) and disperse red 1 methacrylate (DR1MA) monomer in the presence of PMPS. PMPS acted as a macrophotoinitiator and by UV exposure it produced macroradicals which initiated polymerization of chiral and photoactive monomers. Thus a block copolymer of PMPS-b-(R-NPEMAM-ran-DR1MA) was synthesized.The synthesized multifunctional organic inorganic hybrid polymer samples were characterized by FTIR and NMR spectroscopy. The molecular weights of the samples were measured by GPC analysis. The optical, chiroptical and photoluminescence properties were studied. The narrow band at about 1638 cm-1 is due to C=O stretching vibration of -CONH- of the chiral unit.  A wide absorption peaks at 3444 cm-1 is the characteristic of NH trans stretching vibration of secondary amide group. The asymmetric stretching of NO2 group appeared at 1481 cm-1 and the characteristic peak at 1427 cm-1 was observed due to azo (-N=N-) group stretching of DR1MA unit. The Si-Si band of PMPS appeared at about 462 cm-1 in FTIR spectra. The optical absorbance observed at 272 nm is due to π-π* transition of aromatic ring and at 330 nm corresponds to σ-σ* transition of Si-Si bond. The other electronic absorption observed in the visible region at 475 nm corresponds to the combined contribution of n-π* and π-π* transition of DR1MA unit. The photoluminescence properties of such polymers were studied for the variation of concentration of the polymer solution and variation with excitation energy such as 275 nm, 325 nm and 475 nm in THF solvent. Such synthesized multifunctional photoactive organic-inorganic polymers having unusual optical, chiroptical and photoluminescence property may find novel optoelectronic (friend foe identification and secretive code identification) applications.