Grafting from polymerization was used to synthesize nano-titania/polyurethane (nTiO(2)/polyurethane) composite coatings, where nTiO(2) was chemically attached to the backbone of the polyurethane polymer matrix with a bifunctional monomer, 2,2-bis(hydroxymethyl) propionic acid (DMPA). This bifunctional monomer can coordinate to nTiO(2) through an available -COOH group, with two available hydroxyl groups that can react with diisocyanate terminated pre-polyurethane through step-growth polymerization. The coordination reaction was monitored by FTIR and TGA, with the coordination reaction found to follow first order kinetics. After step-growth polymerization, the polyurethane nanocomposites were found to be stable on standing with excellent distribution of Ti in the polymer matrix without any significant agglomeration compared to simple physical mixtures of nTiO(2) in the polyurethane coatings. The functionalized nTiO(2)-polyurethane composite coatings showed excellent antibacterial activity against gram-negative bacteria Escherichia coli; 99% of E. coli were killed within less than one hour under solar irradiation. Self-cleaning was also demonstrated using stearic acid as a model for 'dirt'.

Aza-Michael addition is one of the most exploited reactions in organic chemistry. It is regarded as one of the most popular and efficient methods for the creation of the carbon-nitrogen bond, which is a key feature of many bioactive molecules. Herein, we report the synthesis of CuO nanoparticles by an alkaline hydrolysis process in the presence of the flower extract of Lantana camara, an invasive weed, followed by calcination in air at 400 C. Microscopic results indicated that the plant extract played an important role in the modulation of the size and shape of the product. In the presence of extract, porous CuO nanostructures are formed. While mostly aggregated rod-shaped CuO nanostructures are formed in the absence of extract. The products are pure and highly crystalline possessing the monoclinic phase. The CuO nanoparticles have been used as a catalyst in the aza-Michael addition reaction in aqueous medium under ultrasound vibration. The product yield is excellent and the catalyst is reusable up to the fifth cycle. The catalyst system can be extended to various substituted substrates with excellent to moderate yields.

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Herein, we report the synthesis of SnO2 nanostructures by alkaline hydrolysis of the corresponding metal ions in presence of biopolymer additive such as carboxy methylcellulose at 65 °C. X‐ray diffraction studies confirmed the formation of pure crystalline tetragonal SnO2 nanostructures. Microscopic results revealed that addition of biopolymer results in the formation of hollow nanostructures. The sizes of such hollow nanostructures are controllable by varying the concentration of the biopolymer. The hollow nanostructures are further characterized by other spectroscopic techniques such as UV‐vis spectroscopy, photoluminescence spectroscopy, X‐ray photoelectron spectroscopy and energy dispersive X‐ray spectroscopy. These hollow SnO2 nanostructures are porous and show excellent adsorption capability in removal of organic dye, methylene blue from its aqueous solution at room temperature. The recovered SnO2 nanostructures can be reused in successive batches for dye adsorption without much losing its adsorption capacities.