1. Synthesis of Nanoparticles
Nanoparticles are attracting interests from various disciplines because of their unique electronic, optical, magnetic, chemical and mechanical properties that are different from both their constituent molecules/atoms and their corresponding bulk materials. Controlled synthesis and assembly of nanoparticles provide a powerful route to build nanodevices. We have developed a compact and low-cost atmospheric dc mini-arc plasma reactor to produce aerosol nanoparticles through direct vaporization of solid precursors followed by a rapid quenching. Our research focuses on understanding and control of the nanoparticle production process for tailored nanoparticle properties.
2. Nanoparticle Assembly
There is a tremendous gap between nanoparticle synthesis and nanodevice engineering stage, especially related to facile incorporation of a small number of nanoparticles into high performance devices and systems. New routes for precise, parallel, hierarchical, and low-cost assembly of nanoparticles are needed. We have developed an electrostatic force directed assembly technique to assemble nanoparticles onto a variety of semiconducting and conducting substrates including carbon nanotubes (CNTs) with considerable control. We are currently trying to understand the nanoparticle assembly process and to achieve better control over the assembly process.
3. Fabrication of Nanoparticle-Based Technological Devices
Nanoparticle-based devices that take advantage of unique properties of nanoparticles often exhibit superior performance compared to their conventional counterparts. In collaboration with UWM Physics Department, Electrical Engineering Department, and Argonne National Laboratory (ANL), we are developing an artificial electronic nose using tin oxide nanoparticles synthesized from the mini-arc plasma source. We have successfully fabricated a functional gas sensor based on tin oxide nanoparticles. Current research focuses on detailed characterization of the sensor, optimization of the fabrication process, and scale-up of the process for multi-sensor fabrication.
4. Corona Discharge and Ozone Production
Atmospheric direct current (dc) corona discharge has been widely used in many indoor devices, such as photocopiers, laser printers, and electronic air cleaners. Production of detrimental ozone has been plaguing these devices. We have been developing a first-principle numerical model to predict the ozone production from corona discharges and to guide the design of indoor corona devices to meet federal regulations. The model consists of a corona plasma module, an ozone chemistry module, and a transport module. The computation is implemented on the IBM pSeries 690 supercomputer housed in the NCSA at UIUC. Recently, we are extending the model to nanoscale regime.