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Zinc oxide (ZnO) nanoparticles were immobilized on polyurethane foam (PUF) and employed for the degradation of Acid black 1 dye (AB1). The ZnO/PUF was characterized by x-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive x-ray (EDX) techniques. Process variables i.e., dye concentration, pH, concentration of H2O2, irradiation time were optimized for maximum degradation of dye. ZnO/PUF showed promising efficiency for the degradation of AB1 dye and up to 86% and 65% dye degradation was achieved under UV and solar light irradiation at neutral pH, 4% H2O2, 240 min/sunlight and 75 min/UV irradiation time using 40 mg l−1 dye initial concentration. The optimum conditions were applied for the treatment of textile wastewater and biological oxygen demand (BOD) and total organic carbon (TOC) were reduced up to 70% and 80%, respectively. In view of promising photocatalytic activity (PCA), ZnO/PUF could possibly be used for the treatment of wastewater contains dyes.

The effect of carboxymethylcellulose (CMC) addition on the tensile and absorption properties of alginate fibers had been reported in the previous research. Great increase in absorbency was observed due to addition of CMC to calcium alginate fibers but was not balanced with mechanical strength. By addition of CMC dry and wet strength of composite fibers was reduced, therefore, a balance was needed between the absorbency of the fibers and mechanical strength. The effect to introduce another component i.e. Guar-gum on overall mechanical and absorbency characteristics is reported here. In comparison to CMC/alginate co-spun fibers, it was shown that inclusion of guar-gum improves the tensile strength as well as absorbency of composite fibers. CMC/guar-gum/alginate fibers were extruded through two different coagulation baths. In first step the dope solution was extruded through CaCl2 coagulation bath. The dope of optimized composite fiber formulation with adjusted mechanical property and absorption was extruded, then, through 50:50 CaCl2 and ZnCl2 coagulation bath. The formed CMC/guar-gum/Zn/alginate composite fibers were found excellent for medical applications with their super absorbency along with equivalent mechanical strength and high antibacterial efficacy.

In this systematic study, we describe the influence of various surfactants and polymers on aggregation stability of ZnO nanorods. Triton X-100, PVP and PVA were used to disperse nanorods. The surfactant/polymer stabilizing effect was monitored using the sedimentation study and photographic methods based on the decrease in the height of the interface as a function of time. The dispersion of nanorods when applied to cotton fabric, it exhibited functional properties like antibacterial activity and UV protection. The morphologies of nanorods and functionalized cotton were characterized by using SEM.