Wastewater, spent solvent, spent process solutions, and sludge are the major waste streams generated in large volumes daily in electroplating industries. These waste streams can be significantly minimized through process modification and operational improvement. Waste minimization methods have been implemented in some of the electroplating industries. Suggestions such as practicing source reduction approaches, reduction in drag out and waste, process modification and environmental benefits, have also been adopted. In this endeavor, extensive knowledge covering various disciplines has been studied, which makes problem solving extremely easy. Moreover, available process data pertaining to waste minimization (WM) is usually imprecise, incomplete, and uncertain due to the lack of sensors, the difficulty of measurement, and process variations. In this article waste minimization techniques and its advantages on the improvement of working atmosphere and reduction in operating cost have been discussed.
Thermoplastic polyurethane (TPU)/single-walled carbon nanotube (SWCNT) nanocomposite films were prepared using 1,6-hexane diisocyanate and hydroxyl-terminated polybutadiene (HTPB) in tetrahydrofuran with various concentrations of SWCNTs. The interaction between polyurethane (PU) and SWCNTs in nanocomposite was studied using different methods. The film turns yellowish to grayish-black in colour upon increasing the concentration of SWCNTs in PU matrix. This may be due to the formation of p-p interaction between polyurethane amide functional group and SWCNTs. Differential scanning calorimetric results show that the soft segment of nanocomposite interacts much stronger than hard segment, which results in lowering melting transition temperature of soft segments. The activation energy and thermal stability parameters were determined from thermogravimetric and differential scanning calorimetric analyses. The x-ray photoelectron spectroscopic results show the intermolecular interaction between HTPB-based PU and SWCNT. Mesoporous morphology of the nanocomposites was observed by scanning electron microscopy. The average diameter of the pores was calculated using Gaussian method. The TPU films exhibit about 3.5 times greater resistivity than nanocomposite films. All the analysed data prove that the SWCNTs were well distributed in PU matrix and exhibited as tough films with low electrical resistivity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.