Myung Hwan Hong

Recycling of waste automotive laminated glass and valorization of polyvinyl butyral through mechanochemical separation.

Due to strong binding, optical clarity, adhesion to many surfaces, toughness and flexibility polyvinyl butyral (PVB) resin films are commonly used in the automotive and architectural application as a protective interlayer in the laminated glass. Worldwide million tons of PVB waste generated from end-of-life automotive associated with various environmental issues. Stringent environmental directive, higher land cost eliminates land filling option, needs a study, we have developed a mechanochemical separation process to separate PVB resins from glass and characterized the separated PVB through various techniques, i.e., scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Commercial nonionic surfactants D201 used for the mechanochemical separation purpose. Through parameter optimization following conditions are considered to be the optimum condition; 30v ol% D201, stirring speed of 400 rpm, 35 °C temperature, operation time 1h, and dilute D201 volume to waste automotive laminated glass weight ratio of ≈25. The technology developed in our laboratory is sustainable, environmentally friendly, techno-economical feasible process, capable of mass production (recycling).

Synthesis and analysis CdSe Quantum dot with a Microfluidic Reactor Using a Combinatorial Synthesis System

A microfluidic reactor with computer-controlled programmable isocratic pumps and online detectors is employed as a combinatorial synthesis system to synthesize and analyze materials for fabricating CdSe quantum dots for various applications. Four reaction condition parameters, namely, the reaction temperature, reaction time, Cd/Se compositional ratio, and precursor concentration, are combined in synthesis condition sets, and the size of the synthesized CdSe quantum dots is determined for each condition. The average time corresponding to each reaction condition for obtaining the ultraviolet-visible absorbance and photoluminescence spectra is approximately 10 min. Using the data from the combinatorial synthesis system, the effects of the reaction conditions on the synthesized CdSe quantum dots are determined. Further, the data is used to determine the relationships between the reaction conditions and the CdSe particle size. This method should aid in determining and selecting the optimal conditions for synthesizing nanoparticles for diverse applications.

Indium ion cementation onto aluminum plates in hydrochloric acid solutions: a kinetic perspective

Abstract The cementation of indium on an aluminum plate in indium-bearing concentrated hydrochloric acid solutions has been performed over a period of 2 hr at 278, 298, 318, 328 and 338 K. Aluminum was selected for two reasons: (1) aluminum has significantly higher oxidation potential compared to indium and (2) the leaching of waste plasma display panels produces a significant concentration of aluminum ions in solution. The effect of the cementation variables was comprehensively investigated, and a preliminary kinetic analysis was made using first order kinetics with pertinent Arrhenius-type plots. The cementation process was highly temperature sensitive for the range of 298–338 K, and more than 96% of the indium was recovered at 338 K. For morphology and purity analysis, indium powders obtained from the cementation process were examined using various analytical tools, such as X-ray diffraction and scanning electron microscopy–energy dispersive X-ray spectrometry.