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Design equation for the lip opening of a film extrusion dieJones, Andrea Cecil, January 2008 (has links)
Thesis (M.S.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 51).
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Equation of state for polytetrafluoroethylene (PTFE) and mixtures with PTFEWu, Zhibo. January 2009 (has links)
Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Hanagud,Sathya; Committee Member: Apetre, Nicoleta; Committee Member: Kardomateas, George; Committee Member: McDowell, David L.; Committee Member: Ruzzene, Massimo. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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The effect of teflon on the condensation of benzene on a horizontal copper tube /McCutchen, Gary Duane, January 1966 (has links)
Thesis (B.S.)--Virginia Polytechnic Institute, 1966. / Vita. Abstract. Includes bibliographical references (leaves 36-37). Also available via the Internet.
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The kinetics of a methyl methacrylate polymerization initiated by the stable free radicals in irradiated polytetrafluoroethylene and properties of the resultant graft polymerDonato, Karen Ann Ehnot. January 1987 (has links)
Thesis (Ph. D.)--Ohio University, June, 1987. / Title from PDF t.p.
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Characterizing fluoropolymeric materials for microelectronics and MEMS packagingWillis, Oral R. January 2007 (has links)
Thesis (M.S.)--State University of New York at Binghamton, Dept. of Mechanical Engineering, 2007. / Includes bibliographical references.
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Monte Carlo simulations of systems of light alcohols + water + n-dodecane and water solubility and structures in polytetrafluoroethylene.Lasich, Matthew. January 2011 (has links)
Polytetrafluoroethylene (Teflon®) is encountered in many environments – frying pans, clothing,
osmotic distillation membranes, to name a few – yet the solubility and clustering behaviour of water with
this material was not found in the open literature. This information may be useful in applications where an
absence of water is desired, such as in clothing and textiles. Previous work on polyethylene + water has
shown that small water clusters form in the amorphous portion of the polymer. This work investigated this
phenomenon for the case of polytetrafluoroethylene + water.
Initially, a test system of light alcohols + water + n-dodecane was investigated using Gibbs
Ensemble Monte Carlo simulations and compared to previous laboratory experiments. This test system
was investigated in order to gain expertise in the methodologies and theory behind Monte Carlo
simulation, as well as to gain experience with using the necessary software. For this test system, it was
found that the TraPPE parameters representing the interactions between the alcohols and the n-dodecane
were not adequate and lead to increasing deviations with increasing carbon number in the alcohol.
To replicate the conditions of the amorphous polymer matrix, liquid-liquid equilibrium between
water and the polymer was investigated. Gibbs Ensemble Monte Carlo simulations have been performed
for systems of perfluoroalkanes and water to determine the influence of temperature and carbon number
on the solubility and clustering behaviour of water within the perfluoroalkanes. The temperature range in
this study was from 450 K to 600 K, and the perfluoroalkane carbon number range was from 8 to 300
carbon atoms. With increasing carbon number, it was found that there was an asymptotic value of 98.0
mole percent water in the polymer phase. With increasing temperatures it was found that there were
exponential increases in solubility of water into the polymer matrix. Previous work on clustering and
supramolecular structure of perfluoroalkanes described the rigidity of the perfluoroalkane chains in
comparison to alkane chains, thus explaining the large increases in free volume with increasing
temperature in the polymer matrix observed in this work. A discontinuity with regard to both solubility
and clustering behavior was observed for a polymer carbon number of 10 to 12 carbon atoms. Prior work
on the energy contributions towards the helical structure of perfluoroalkanes showed a shift in the energy
contribution regime for carbon numbers larger than ~10 carbon atoms, which may explain this
discontinuity. It was found that linear water clusters accounted for up to ~90 percent of the water clusters,
concurring with previous work on water clustering in polyethylene. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.
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Plasma-induced modification of films containing polytetrafluoroethylene (PTFE)Jones, Hyrum E. 08 June 2005 (has links)
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
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Numerical analysis of transient Teflon ablation in pulsed plasma thrustersStechmann, David Paul. January 2007 (has links)
Thesis (M.S.) -- Worcester Polytechnic Institute. / Keywords: Teflon ablation; pulsed plasma thrusters; numerical analysis; PPT; depolymerization. Includes bibliographical references (p.102-105).
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Development and implementation of an apparatus for polymeric piston-ring performance tests in controlled environmentEsmaili, Mahyar. January 1993 (has links)
Thesis (M.S.)--Ohio University, August, 1993. / Title from PDF t.p.
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Membrane separation in supercritical antisolvent process for nanoparticle productionOno, Kayoko, Gupta, Ram B. January 2006 (has links) (PDF)
Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.89-92).
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