Highly effective surface modification using plasma technologies toward green coloration of polyester fabrics.

This study is anchored on the use of an eco-friendly effective plasma technique and cationization treatment to improve the hydrophobic nature of polyester (PET) fabric by incorporating hydrophilic functional groups onto the PET surface. The PET surface was initially treated with three different plasma gases prior to cationization treatment with quaternary ammonium salt (Quat 188). Madder roots were used, to produce natural dyes for the green coloration of PET fabrics in both dyeing and printing processes. The color strength (K/S) was measured to study the influence of both plasma gases and the cationization treatment on the coloration of PET fabric. Exposure to nitrogen plasma gases prior to the cationization treatment showed promising results for efficient PET coloration, resulting in the selection of nitrogen as a working gas at a flow rate of 3 l/min. The results also demonstrated that by combining the nitrogen plasma technique and cationization treatment, PET fabric with a highly effective surface was obtained, resulting in improved coloration, wettability, tensile strength, and roughness properties.

Equilibrium and kinetic models on the adsorption of Reactive Black 5 from aqueous solution using Eichhornia crassipes/chitosan composite.

New natural biopolymer composite was prepared using extracted cellulose from an environmentally problematic water hyacinth Eichhornia crassipes (EC). The extracted cellulose was functionalized by chitosan and TiO2 nanoparticles to form EC/Chitosan (EC/Cs) composite network. Surface characterization of EC/Cs natural biopolymer composite was examined by spectrum analysis FT-IR, specific surface area, micropore volume, pore width and SEM. Furthermore, the sorption experiments were carried out as a function of pH, various initial dye concentration and contact time. Experiment results showed that the EC/Cs composite have high ability to remove C.I. Reactive Black 5 from its dye-bath effluent. The equilibrium sorption evaluation of RB5 conformed and fitted well to Langmuir adsorption isotherm models and the maximum sorption capacity was 0.606 mg/g. The kinetic adsorption models followed pseudo-second order model and the dye intra-particle diffusion may suggesting a chemical reaction mechanism. Further, it was obvious from the investigation that this composite could be applied as a promising low cost adsorbent for anionic dye removal from aqueous solutions.