Modification of natural polymers by graft copolymerization is a promising technique as it functionalizes these biopolymer to their potential, imparting desirable properties onto them. Grafting with vinyl monomers is the route for modifying the properties of the naturally occurring guar-gum for their better industrial exploitation and development of various commercial products. Acrylated guar-gum chain is synthesized and analysed using Fourier transform infrared, differential scanning calorimetry and X-ray diffraction techniques to gain an insight into the particle size and structural features. Chlorpyrifos is then entrapped into the polymer, and its release is studied under various conditions. Critical factors influencing the size, entrapment efficiency and release behaviour of entrapped chlorpyrifos have been studied.

Exciton generation, migration and dissociation are key fundamental processes that dictate the efficiency of optoelectronic devices. Here, we investigate exciton diffusion process of conjugated polymer nanoparticles (PNPs) in the presence of electron and hole scavenger molecules using time-resolved spectroscopy. We found that the exciton diffusion length of hole transporting PNPs, decreases in the presence of hole scavenger molecule and it increases in the presence of electron scavenger molecule. Analysis reveals that the diffusivity of excitons can be controlled by changing the nature of scavenger molecules. Such fundamental study is important for developing devices where lower and higher exciton diffusivities are required depending on the requirement of application mode.