Engineering Commons^™

Plasma Treatment Of Polyethylene And Polydimethylsiloxane By Air, Oxygen, And Carbon Tetrafluoride And Their Characterization, Osman Polat

USF Tampa Graduate Theses and Dissertations

In this thesis, low density polyethylene (LDPE) and polydimethylsiloxane (silicone/PDMS) were treated with oxygen (O2) , air and carbon tetrafluoride (CF4) low pressure 13.56 MHz radiofrequency plasma. An experimental setup was used to determine process power and irradiation time for improved modification, the validation was done by measuring the contact angle of the treated samples immediately after treatment. The modification used commercially available sheets to imitate its use in the industry and various applications. The treatment aims to increase/decrease the surface free energy, making it possible to modify the intrinsic inert materials without affecting the bulk. Increased wettability, adhesion, and …

Corrosion Characteristics Of Magnesium Under Varying Surface Roughness Conditions, Yahya Efe Yayoglu

USF Tampa Graduate Theses and Dissertations

The biggest challenge with magnesium alloy biodegradable implants is the rapid corrosion at the earlier stages of the healing process after implantation. In this research, the impact of surface roughness generated by different means on the corrosion rate of AZ31 magnesium alloy in a simulated biologic environment is investigated. In order to perform accurate experimentation, an in vitro setup is assembled that simulates the human body environment accurately has been prepared using Schinhammer’s in vitro immersion testing setup and Kokubo’s Simulated Body Fluid (SBF). For the immersion test of Mg in SBF, several surface texture groups of Mg have been …

Static And Dynamic Components Of Droplet Friction, Peter Robert Griffiths

USF Tampa Graduate Theses and Dissertations

As digital microfluidics has continued to mature since its advent in the early 1980's, an increase in new and novel applications of this technology have been developed. However, even as this technology has become more common place, a consensus on the physics and force models of the motion of the contact line between the fluid, substrate, and ambient has not been reached. This uncertainty along with the dependence of the droplet geometry on the force to cause its motion has directed much of the research at specific geometries and droplet actuation methods.

The goal of this thesis is to help …