Investigation of platelet adhesion, platelet activation, and platelet morphology was performed on Hexafluoroethane coated glass coverslips, Fluorinated Ethylene Propylene (FEP), and Polymethyl Methacrylate (PMMA) thin film polymers. Hexafluoroethane was coated on glass coverslips using Radio Frequency Glow Discharge (RFGD) polymer deposition and was supplied by researchers at the University of Washington in Seattle. For several years now, analogously prepared Fluoropolymer surfaces have been reported to exhibit unique protein adsorption properties and reduced adherent platelet concentrations compared to standard fluoropolymers and non-fluorinated polymers (Kiaei, 1995). Platelet interactions were assessed using a novel, dynamic, and physiologically relevant experimental system. In-vitro tests were performed on polymer surfaces mounted in a light transparent flow cell by pumping whole blood through the apparatus to deposit platelets over the polymer surface. Red blood cells were rinsed from the flow cell with plasma immediately after platelet deposition to permit observation of adherent cells. Dynamic, real time single cell morphology observation was made under low flowing plasma conditions using light microscopy and recorded using a computer image acquisition system. Physiologic conditions were maintained using a low plasma flow rate which ensured available nutrients for platelets as tests were performed for up to 90 minutes. Compared to PMMA and FEP, Hexafluoroethane surfaces exhibited the lowest platelet surface concentrations with overall mean adherent platelet concentrations of 8165, 6895, and 4387 platelets per mm², respectively. PMMA is a more activating surface compared to the fluoropolymers tested, however, the rate of progress of platelet activation and morphological trends are similar between the Hexafluoroethane and FEP polymer surfaces. Activation parameters, a quantification of the state of platelet activation, support experimental observations made concerning morphological change information on Hexafluoroetbane, FEP, and PMMA. A Scanning Electron Microscopy study involving all three test surfaces, fixed after 60 or 90 minute plasma flow maintained experiments, support the hypothesis that the pancake platelet evolves from a spreading platelet. Routinely observed, pancake platelets are circular, 3-5 μm in diameter, and have round raised protuberances at the periphery of the cell membrane. Images showing several stages of spread cell retraction on Fluoropolymers tested without added thrombin stimulant give greater detail of peripheral fragmentation and further support a mechanism for polymer surface induced platelet microparticle formation. / Thesis / Master of Engineering (ME)

No description available.

Thesis (Ph. D.)--Ohio University, June, 2003. / Title from PDF t.p. Includes bibliographical references (leaves 96-101).

No description available.

This thesis describes studies directed to the ring opening metathesis polymerisation (ROMP) of some fluorinated compounds using a range of well-defined initiators. Chapter 1 reviews some general aspects of olefin metathesis and ring opening metathesis polymerisation of relevance to the work described in this thesis. Topics such as piezo- and pyro-electricity and optical and electrical properties of conjugated polymers are introduced and these receive more detailed attention later in the thesis. Chapter 2 describes the synthesis, characterisation and properties of . poly(bis(trifluororaethyl)norbomadiene) in detail. The use of various initiating systems that have been used previously and the effect they have on the tacticity of the resulting polymer raicrostructure are discussed. The latter part of this chapter reviews some of the current thinking concerning the detailed mechanistic aspects of this polymerisation. Chapter 3 reviews attempts directed to an improvement in tacticity control in the synthesis of poly(bis(trifluoromethyl)norbomadiene). The synthesis and activity of the new well-defined initiators used in these studies are reported. It is shown that varying the nature of the ancillary Ligands surrounding the metal centre can have a dramatic influence on the tacticity of the resulting polymer. Chapter 4 reports studies directed to an examination of the limits of the well controlled synthesis of poly(bis(trifluoromethyl)norbornadiene). The syntheses of high trans and high cis, highly tactic poly(bis(trifluoromethyl)norbornadiene samples using well-defined initiating systems are described. It is shown that by varying the monomerinitiator ratio, samples with a wide range of molecular weights can be achieved and these are reported. Chapter 5 describes experiments concerning the ROMP of fluorinated monomers containing six membered rings. In particular ROMP studies of the monomers, 2,3-bis(trifluoromethyl)bicyclo[2.2.2]octa-2,5-diene . and 2,3- (tetrafluorobenzo)bicyclo[2.2.2]octatriene are described finally, Chapter 6 provides a summary of the work reported and outlines some ideas for future studies.

Thesis (M.S.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 52-54).

No description available.

The overall emphasis of this doctoral dissertation is on the design, synthesis, detailed characterization and application of amphiphilic hyperbranched fluoropolymers (HBFPs) crosslinked with poly(ethylene glycols) (PEGs) in complex polymer coatings as anti-biofouling surfaces. This dissertation bridges synthetic polymer chemistry, materials science and biology to produce functional coatings capable of fouling prevention, demonstrating thermo-controlled healing and acting as a benchmark surface to understand component:property relationships prior to increasing formulation complexities. A two-dimensional array of HBFP-PEG coatings was produced by the co-deposition of uniquely composed HBFPs with varying weight percentages of PEG. Bulk and surface properties were evaluated and assigned to formulation trends. Based on these findings, the most viable candidates were replicated and their fouling responses were assessed against three marine fouling organisms. An active mode of biofouling resistance was covalently grafted onto the surface of HBFP-PEG. The presentation of the settlement-deterrent molecule noradrenaline (NA) works in tandem with the highly-complex surface, to act as a dual-mode, anti-biofouling coating NA-HBFP-PEG. Secondary ion mass spectrometry (SIMS) was employed to quantify the extent of NA substitution. Biological assays against oyster hemocytes confirmed the activity of the grafted NA and cyprid settlement assays supported that the overall anti-biofouling ability of NA-HBFP-PEG was increased by 75%. Thermally-reversible crosslinks were installed as healable units throughout the framework of the networks, with the goal of generating coatings that could possess a greater resistance to mechanical failure. Small molecule and linear polymer models were probed by nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) to demonstrate the controlled reversibility of the crosslinks. Optical microscopy was employed to visualize surface scratch healing and fluorescence microscopy was used to identify the adsorption behavior of fluorescently-labeled proteins. A benchmark, anti-biofouling surface was generated through thiol-ene crosslinking of a linear fluoropolymer with pendant alkenes (LFPene) with pentaerythritol tetrakis(3-mercaptopropionate) (PETMP). Core constituents were evaluated spectroscopically and surfaces of LFPene-PETMP, along with two model surfaces that largely expressed a single component, were analyzed to understand how individual elements and blending contributed to the physical, mechanical and anti-biofouling properties to generate a performance baseline to compare against future generations.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 75-82). Also available on the Internet.

Thesis (Ph.D.)--University of Melbourne, School of Chemistry, 2010. / Typescript. Includes bibliographical references.