Microstructure, electric, and thermal properties of the Ta-Cu composite is evaluated for the application in electric contact materials. This material has the potential to be used in a medium for a high current range of current conditions, replacing Ag-MO, W, and WC containing materials. The optimized SPS process conditions are a temperature of 900°C for a 5 min holding time under a 30 MPa mechanical pressure. Comparative research is carried out for the calculated and actual values of the thermal and electric properties. The range of actual thermal and electric properties of the Ta-Cu composite are 50~300W/mk and 10~90 %IACS, respectively, according to the compositional change of the 90 to 10 wt% Ta-Cu system. The results related to the electric contact properties, suggest that less than 50 wt% of Ta compositions are possible in applications of electric contact materials.

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• Formation mechanism, microstructural features and dry-sliding behaviour of “Bronze/WC carbide” composite synthesised by atmospheric pulsed-plasma deposition
  V.G. Efremenko, Yu.G. Chabak, V.I. Fedun, K. Shimizu, T.V. Pastukhova, I. Petryshynets, A.M. Zusin, E.V. Kudinova, B.V. Efremenko
  Vacuum.2021; 185: 110031.     CrossRef

High-quality colloidal CdSe/ZnS (core/shell) is synthesized using a continuous microreactor. The particle size of the synthesized quantum dots (QDs) is a function of the precursor flow rate; as the precursor flow rate increases, the size of the QDs decreases and the band gap energy increases. The photoluminescence properties are found to depend strongly on the flow rate of the CdSe precursor owing to the change in the core size. In addition, a gradual shift in the maximum luminescent wave (λ_max) to shorter wavelengths (blue shift) is found owing to the decrease in the QD size in accordance with the quantum confinement effect. The ZnS shell decreases the surface defect concentration of CdSe. It also lowers the thermal energy dissipation by increasing the concentration of recombination. Thus, a relatively high emission and quantum yield occur because of an increase in the optical energy emitted at equal concentration. In addition, the maximum quantum yield is derived for process conditions of 0.35 ml/min and is related to the optimum thickness of the shell material.

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• Quantum materials made in microfluidics - critical review and perspective
  M. Wojnicki, V. Hessel
  Chemical Engineering Journal.2022; 438: 135616.     CrossRef
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  Doyeon Kim, So-Yeong Joo, Chan Gi Lee, Bum-Sung Kim, Woo-Byoung Kim
  Journal of Photochemistry and Photobiology A: Chemistry.2019; 376: 206.     CrossRef
• Multimodal luminescence properties of surface-treated ZnSe quantum dots by Eu
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