Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 90-93). Also available via the Internet.

Thesis (M.S.Ch.E.)--University of Toledo, 2007. / Typescript. "Submitted as partial fulfillment of the requirements for The Masters of Science Degree in Chemical Engineering." Bibliography: leaves 76-77.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 230-235). Also available via the Internet.

Thesis (M.S.)--University of North Texas, May, 2008. / Title from title page display. Includes bibliographical references.

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 175-181).

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (p. 73-75).

Advancing contact angles formed by water and aqueous ethanol solutions were measured on both bare surfaces and film-covered surfaces of acrylic, glass, hydrophilic and hydrophobic silicon, polycarbonate, polyester, and stainless steel. Each bare surface was initially characterized with respect to its hydrophilic - hydrophobic balance. Both protein films and milk films were prepared on each surface; the adsorbed mass comprising each film was measured with ellipsometry. Contact angle methods proved useful in detecting the presence of a protein film on sufficiently hydrophilic or sufficiently hydrophobic surfaces. Contact angle methods were also found to be useful for detecting the presence of a milk film on sufficiently hydrophilic solid surfaces. The results also indicated that the type of diagnostic liquid chosen for the analysis becomes an important factor for films of increasing complexity. In any event, contact angle analysis is inappropriate to quantify the actual mass of soil remaining on a solid surface. / Graduation date: 1991

Three alkyldihydrochlorosilanes were synthesized; ethyldihydrochlorosilane, octyldihydrochlorosilane and octadecyldihydrosilane. Ethyldihydrochlorosilane was produced by the reaction of ethylsilane with mercuric chloride and the other two chlorosilanes were produced by the reaction of the alkyl Grignard reagent with dichlorosilane. Each alkyldihydrochlorosilane was reacted with porous silica in an attempt to discover the extent of reaction or the highest surface concentration of bonded groups attainable. The reaction between these alkydihydrochlorosilanes and porous silica was compared to the reaction between silica and the analogous alkyldimethylchlorosilane. The rate of reaction of both type of chlorosilane was found to be essentially the same. The maximum surface concentration of bonded surface groups attainable by alkyldihydrochlorosilanes was found to be approximately 1.3 #moles/m² greater than that attainable by alkyldimethylchlorosilanes. This increased surface coverage seemed to depend very little on the chain length of the alkyl group and was attributed to the decrease in steric hindrance of the bonding silicon atom of the silane. Surface bound silyl hydrides could be oxidized selectively and sequentially to form silane silanols. Surface silanes also appeared to reduce chloroplatinic acid, but were not observed to add efficiently to olefins. The chromatographic properties of silica modified with alkyldihydrochlorosilanes were compared to those of equivalent silicas modified with alkyldimethylchlorosilanes and alkyltrichlorosilanes before and after the surface silanes were oxidized. Both normal and reversed-phase liquid chromatographic studies were conducted. In general, it was found that alkyldihydrochlorosilanes yielded the most polar modified silicas. This greater surface polarity was attributed to an increase in the activity of water in the near surface region of the bonded phase.

Superhydrophobic (SH) surfaces equipped on the skins of natural living beings give them trumps of self-cleaning, anti-bacterial, water harvest, and directional liquid transport, etc., to survive in harsh environments. Bioinspired Superhydrophobic (SH) surfaces have developed many emerging functions, such as self-cleaning, anti-bacterial, water harvest, anti-icing, anti-corrosion, oil-water separation, and many other fascinating functions. However, the implementations of SH coating in real world are still in its infancy, due to (i) the poor performance in the harsh real-world environment and industrial process application, where a multi-level robustness including the mechanical, chemical, and thermal robustness, as well as the strong adherent strength to substrates, is strictly required; (ii) the lack of a technology for facile and mass production. In the light of that any non-perfluorinated component in the formula of an SH coating inevitably generates vulnerable points to the external invasions and the functional applications of SH coatings require control surface topography, we here propose an SH coating entirely made of perfluorinated materials (referred to as Teflon). To achieve this goal, we developed a complete strategy involving material, fabrication, and applications. Firstly, we developed a feasible dynamic soft molding method for the fabrication of three-dimensional (3D) structures. This method paves a road not only to the fabrication of whole-Teflon SH coatings but also to the practical adoption of many other important technologies based on 3D structures. Secondly, we generated whole-Teflon and multi-resist SH coatings by using this method and tightly attached them to different substrates with superior adhering strength surpassing the conventional work. Thirdly, we performed a proof-of-concept demonstration of a roll-to-roll (R2R) hot molding process, which has the potential of translating the lab-scale and plate-to-plate fabrication to industrial mass production. Finally, some fundamental mechanisms and problems of the multifunctional applications in self-cleaning, anti-bacterial fouling, and anti-icing are studied. The outcomes are expected to provide insight understandings on the multifunctional SH coating and move SH coatings toward real-world application.

Polymer samples of polytetrafluoroethylene (PTFE) and a PTFE-glass weave (RF- 35P) are exposed to low pressure, non-equilibrium glow discharge plasmas for enhanced wettability as measured by static contact angles. Plasma treatments are performed in two parallel plate RF plasma systems, a downstream microwave plasma and a barrel etcher using feed gases composed of H₂, N₂, Ar, He, and 0₂. Surface analysis of the topography and chemical composition of treated samples is performed by atomic force microscopy (AFM), attenuated total reflection infrared (ATR-IR) spectroscopy, x-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectroscopy (ToF SIMS). Optical emission spectroscopy is used to correlate wettability to reactive species in the plasma, and plasma parameters to species emission. In the parallel plate plasma systems, the contact angle can change from approximately 95° to 5° with treatment while treatments in the downstream and barrel etcher systems do not result in a contact angle change. The difference in plasma performance is attributed to ion bombardment. Plasmas composed of 20 to 80% H₂O in (H₂ + N₂) give the best wettability improvement. Plasma exposure significantly reduces the surface fluorine content followed by incorporation of nitrogen, oxygen and hydrogen, apparently as amino, hydroxyl and carbonyl functional groups with evidence of an amide. The incorporation of oxygen likely originates through peroxy radicals subsequent to plasma exposure. It is proposed that using a higher applied power creates a more reactive surface. A larger percentage of H₂ in the plasma tends to passivate the surface, leading to a smaller wettability improvement which is correlated to the atomic hydrogen concentration in the plasma. The addition of He or Ar into the H₂/N₂ plasma tends to dilute or weaken the plasma effect on wettability. To a much greater extent, the addition of oxygen also decreases the wettability. This latter effect is attributed to etching reactions which result in a more hydrophobic surface. An etch rate of approximately 0.2 μ/min is observed, and this is the first report of PTFE etching with 0₂/H₂/N₂. The distance between the parallel plate electrodes (gap) is a significant factor for the wettability of treated polymers, while power, pressure and flow rate are not. The optimal storage conditions to retain the wettability of H₂/N₂ plasma-treated RF-35P are low pressure and low temperature. The following model of PTFE surface modification is proposed. Ion bombardment creates reactive sites that initiate surface reactions. Reactive species from the H₂/N₂ plasma modify the surface through incorporation of amino, hydroxyl and carbonyl surface groups. These new groups increase the polymer wettability. Atomic hydrogen in the mixture is required to improve the wettability, but too high of a concentration will passivate the surface and lessen the wettability improvement. If oxygen is present, the modified surface is etched away leaving a refreshed, more hydrophobic surface. / Graduation date:2006