Numerical and experimental investigation of the deviation of microparticles inside the microchannel using the vortices caused by the ICEK phenomenon.

One field of study in microfluidics is the control, trapping, and separation of microparticles suspended in fluid. Some of its applications are related to cell handling, virus detection, and so on. One of the new methods in this field is using ICEK phenomena and dielectrophoresis forces. In the present study, considering the ICEK phenomena, the microparticles inside the fluid are deviated in the desired ratio using a novel ICEK microchip. The deviation is such that after the microparticles reach the floating electrode, they are trapped in the ICEK flow vortex and deviated through a secondary channel that was placed crosswise and noncoplanar above the main channel. For simulation verification, an experimental test is done. The method used for making two noncoplanar channels and separating the particles in the desired ratio with a simple ICEK microchip is an innovation of the present study. Moreover, the adjustment of the percentage of separation of microparticles by adjusting the parameters of the applied voltage and fluid inlet velocity is one of the other innovations of the present experimental study. We observed that for input velocities of 150-1200 µm/s with applied voltages of 10-33 V, 100% of the particles can be directed toward the secondary-channel.

Investigation of Photocatalytic Efficiency of Supported CuO Nanoparticles on Natural Zeolite Particles in Photodegradation of Methyl Orange.

In the current work, CuO nanoparticles were deposited on natural zeolite's particles to resolve the drawbacks of zeolite catalysis. The synthesized composites were characterized by XRD, SEM, BET, and DRS analyses. The results illustrated that in the 15% CuO composite, CuO nanoparticles with a size of 21 nm are deposited on the surface of the zeolite particles. Deposition of CuO nanoparticles on zeolite's particles decreased the specific surface area from 35 m²/g (pure zeolite) to 28 m²/g (20% CuO composite), and causes a red shift in the absorption edge of the sample to 796 nm for 20% CuO composite. In order to compare the samples' performances in eliminating water pollutants, methyl orange dye removal was investigated. The analyses indicated that the optimum efficiency (85% in 120 min) belongs to zeolite-15% CuO composite with a band gap of 1.70 eV.