Event Details
Nanostructured Multifunctional Thin Film prepared from Nanogrinding technique.
Presenter: Raju Sapkota
Supervisor:
Date: Fri, January 7, 2022
Time: 11:00:00 - 00:00:00
Place: ZOOM - Please see below.
ABSTRACT
Zoom link Details: https://uvic.zoom.us/j/82530567964?pwd=VVVrMURzTTdhbTV5VW1sUTBCVnJudz09
Meeting ID: 825 3056 7964
Password: 404492
Summary: Planetary ball milling (PBM) or colloidal grinding is a distinctive top-down approach for fabricating nanomaterials. The alteration of grinding parameters (grinding speed, grinding time and solvents) creates different nanostructured materials with multifunctional properties. The nanoparticles of silicon (both high and low purity types), titanium disilicide (TiSi2) and Zinc Oxide (ZnO) grounded with different solvents (DI water/ Ethylene Glycol/ IPA) are coated on various substrates (SiO2/Si, Silicon, glass and other flexible substrates) via drop-casting, doctor blading or dip coating. Next, these films are thermally treated, and their properties such as wettability, conductivity and gas sensing behavior are studied. The fabricated film properties can be straightforwardly tuned depending on a combination of choice of materials, grinding parameters and resulting nanoparticle size/geometry. The results show that Si and TiSi2 film are easily altered into hydrophobic or hydrophilic and metallic to insulating over the wide range depending upon the grinding condition. Similarly, to study the gas sensing performance, we tested ZnO sensors by using dry air/oxygen against hydrogen, argon and methane target gases, in addition to different temperatures and different relative humidity, under ambient light conditions. The results show that at room temperature, the gas sensor response of a thin-film sample reaches the peak for nano inks milled at 400 rpm and 30 min. Additionally, the research also indicates that the sensor response and dynamic behavior improves with temperature increasing, reaching a peak value between 100-150 ºC. The experimentation and research work presented using the nano grinding technique are promising, straightforward and effective. In future, the low-cost PBM inks could be used as active material in many other applications such as optoelectronics, environmental, energy storage and biomedical.