Abstract A brief overview is presented in the light emitting diodes (LEDs) based on purely organic materials. Organic LEDs are of great interest to the research community because of their outstanding properties and flexibility. Comparison between devices made using different organic materials and their derivatives with respect to synthetic protocols, characterizations, quantum efficiencies, sensitivity, specificity and their applications in various fields have been discussed. This review also discusses the essential requirement and scientific issues that arise in synthesizing cost-effective and environmental friendly organic LEDs diodes based on purely organic materials. This mini review aims to capture and convey some of the key current developments in phosphors formed by purely organic materials and highlights some possible future applications. Hence, this study comes up with a widespread discussion on the various contents in a single platform. Also, it offers avenues for new researchers for futuristic development in the area.

Abstract Poly(acrylamide-aniline)-grafted gum ghatti [Gg-cl-poly(AAm)] conducting hydrogel was prepared via 60 Co γ-irradiation using N, N′-methylene-bis-acrylamide as a cross linker. The effects of the reaction conditions (viz. gamma dose, monomer, solvent and cross linker concentration) were investigated on the degree of swelling of Gg-cl-poly(AAm). Results showed that optimum reaction conditions for maximum percentage swelling were 10 ml of solvent, 1.08 mol/L of monomer concentration, 0.324 × 10 −1  mol L −1 of crosslinker concentration and 1.5 kGy of total dose. The semi-interpenetrating network (Semi-IPN) was converted into an IPN through the impregnation of poly(aniline) chains followed by doping with HCl. The influence of dopant concentration on the conductivity of synthesized hydrogel was investigated. Different physical properties of the synthesized hydrogel were also studied. The candidate polymers were characterized using different techniques such as X-ray diffraction and thermogravemetric analysis techniques. The mechanism of graft copolymerization via 60 Co irradiation was discussed. Biodegradation studies of the synthesized hydrogels were carried out using a soil burial test. IPN showed better degradation efficiency than semi-IPN. Weight loss of semi-IPN and IPN was 68% and 78%, respectively, in 60 days. Different degradation stages were studied using FTIR and SEM techniques.

Abstract The scarcity of water is a serious problem in the agricultural production, leading to decrease in crop yield. The solution to this problem can be generated by inducing the production of synthetic materials based on natural polysaccharide with good water absorption and retention capacities. The present work aimed at preparing an acrylic acid grafted over agar and gum Arabic based hydrogels for sustainable moisture retention capacity in agricultural land. The graft copolymer based biodegradable hydrogel has been synthesized by using microwave irradiation under the best conditions to get the maximum percentage swelling. The synthesized product has been characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The effects of hydrogel treatment on water retention capacity of eight different soil samples collected from various regions of Punjab were evaluated. The synthesized hydrogel showed great potential as a soil conditioning material to be used in agriculture purposes. Highlights • Green synthesis of agar/gum Arabic based superabsorbent. • Optimization of various reaction parameters. • Swelling behavior of the synthesize hydrogels. • Alternative for irrigation in agriculture.

Abstract Investigation on water retention and dye adsorption behavior of Gg-cl-poly(acrylic acid-aniline) conducting hydrogel has been studied. In this study, a novel poly(acrylic acid-aniline)-grafted gum ghatti based conducting hydrogel were synthesized by a simple two-step method. Initially, superabsorbent copolymers based on acrylic acid and gum ghatti was prepared using N,N′-methylene-bis-acrylamide and ammonium persulfate as a cross linker-initiator system under microwave irradiation. Optimum reaction conditions affording maximum percentage swelling were: solvent = 10 ml, acrylamide = 0.291 × 10 − 3 mol L –1 , ammonium peroxydisulfate = 0.291 × 10 − 3 mol L –1 , N, N′-methylene bisacrylamide = 0.324 × 10 − 1 mol L − 1 , reaction time = 55 s, microwave power = 100% and pH = 7.0. The effect of different reaction parameters on the swelling capacity was investigated. In the final step, polyaniline was entrapped within a crosslinked hydrogel followed by doping with hydrochloric acid (HCl), which led to the formation of conducting hydrogel. The IPN has been observed to exhibit as much as 2032% swelling in aqueous solution. Synthesized hydrogels were analyzed using FTIR, XRD, SEM and TGA. Application of hydrogels to improve the water retention properties of different soils was studied and found that the IPN hydrogel can improve the moisture retention capacity of soil for cultivation. Finally, synthesized hydrogels was studied for dye removal from waste water. It has been found that IPN hydrogel shows better adsorption behavior than semi-IPN. Highlights • A novel gum ghatti based conducting hydrogel were synthesized. • Application of hydrogels to improve the water retention of different soils was studied. • IPN hydrogel improved the moisture retention capacity of soils. • IPN hydrogel shows better adsorption behavior than semi-IPN.

Highlights • Two steps electrochemical synthesis for the fabrication of Ag-polypyrrole composite films. • Surface modifications by swift heavy ion beam. • SEM image shows the formation of craters and humps after irradiation. • Detailed structural analysis by Raman spectroscopy. Abstract The general aim of this work was to study the effects of swift heavy ions on the properties of electrochemically synthesized Ag-polypyrrole composite thin films. Initially, polypyrrole (PPy) films were electrochemically synthesized on indium tin oxide coated glass surfaces using a chronopotentiometery technique, at optimized process conditions. The prepared PPy films have functioned as working electrodes for the decoration of submicron Ag particles on the surface of the PPy films through a cyclicvoltammetry technique. Towards probing the effect of swift heavy ion irradiation on the structural and morphological properties, the composite films were subjected to a 40 MeV Li 3+ ion beam irradiation for various fluences (1 × 10 11 , 1 × 10 12 and 1 × 10 13 ions/cm 2 ). Comparative microstructural investigations were carried out after the different ion fluences using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy and micro-Raman spectroscopy techniques. Raman and SEM studies revealed that the structure of the films became disordered after irradiation. The SEM studies of irradiated composite films show significant changes in their surface morphologies. The surface was smoother at lower fluence but craters were observed at higher fluence.

Abstract A natural polysaccharide, Gum ghatti (Gg), was modified to prepare cross-linked hydrogels using the grafting method initiated by gamma-radiation. Acrylic acid (AA) and aniline monomers were used as the grafted monomers. Grafted copolymer based on Gg and AA was synthesized using N, N′-methylene-bis-acrylamide as a cross linker. The effects of monomer and cross linker concentration, gamma dose and the amount of solvent on the grafting percentage and percentage swelling were investigated. The degree of grafting and percentage swelling were found to be greatly dependent on the reaction parameters. Whereas, aniline monomer was absorbed into the network of Gg-cl-poly(AA), followed by a polymerization reaction between aniline monomer initiated by gamma-radiation. Biodegradation of synthesized hydrogels was also investigated using a composting soil method and Gg-cl-poly(AA-ipn-aniline) showed better degradation efficiency in comparison to Gg-cl-poly(AA). Furthermore, the degraded sample was characterized by FT-IR and surface morphology by SEM. Our results showed that Gg-cl-poly(AA) degraded at a rate of ∼6.1% after 6 days, whereas the degradation rate for Gg-cl-poly(AA-IPN-aniline) was ∼10%. Application of hydrogels to improve the water retention properties of different soils was studied for agricultural purposes and found that the IPN hydrogel can improve the moisture retention capacity of soil for cultivation.

Abstract A systematic comparative study was carried out for the induced changes in the chemical, structural, morphological and thermal properties of poly(methacrylic acid) grafted gum ghatti i.e. [Gg-cl-poly(MAA)] material by irradiation of 120 MeV Ni 9+ and Au 8+ ions at various fluences ranging from 3×10 11 to 3×10 12 ions/cm 2 . The degradation of the material was observed after ion irradiation. A significant loss of crystallinity and change in the crystallite size was observed in irradiated samples of Gg-cl-poly(MAA). The changes in chemical properties and surface morphology were observed by Fourier transform infrared spectroscopy and scanning electron microscopy respectively. The magnitude of the effect of the irradiation was observed to be greater in the case of Au 8+ ions irradiation than those of Ni 9+ ions irradiation due to the high electronic energy loss of the Au 8+ ions in the grafted samples. Highlights • The effect of 120 MeV Ni 9+ and Au 8+ ion beams irradiation on grafted hydrogel was studied. • XRD pattern shows a decrease in intensity of peak position with increase in ions fluence. • FTIR spectrum shows an overall reduction in intensity of typical bands. • The decrease in IDT and FDT shows thermal changes in the grafted hydrogel.