Change in Surface Microstructure and Properties of PTFE after Solar Radiation and its Mechanism
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摘要
A series of solar radiation tests for the polytetrafluoroethylene(PTFE) bulk and film samples were carried out using Q-SUN XE-3-HSC type Solar Radiation Simulator, with the test parameters as follows: radiation intensity is 1 120 W/m~2, temperature is 55 ℃ and humidity is 70% RH. Surface morphology, composition and microstructure of the PTFE samples before and after radiation tests were characterized contrastively. Effect of solar radiation on the tribology and wetting properties of PTFE were also studied by tribometer and contact angle tester, respectively. The results show that, for radiated PTFE, surface roughness, the relative content of C element, the friction coefficients and the contact angle with water increased in varying degrees. In conclusion, the obvious change in PTFE samples can be mainly attributed to break of(CFx)-C bonds after bombardment of high energy UV photons, which causes the loss of F-rich groups, oxidation, crosslinking and restructuring of active unsaturated groups.
A series of solar radiation tests for the polytetrafluoroethylene(PTFE) bulk and film samples were carried out using Q-SUN XE-3-HSC type Solar Radiation Simulator, with the test parameters as follows: radiation intensity is 1 120 W/m~2, temperature is 55 ℃ and humidity is 70% RH. Surface morphology, composition and microstructure of the PTFE samples before and after radiation tests were characterized contrastively. Effect of solar radiation on the tribology and wetting properties of PTFE were also studied by tribometer and contact angle tester, respectively. The results show that, for radiated PTFE, surface roughness, the relative content of C element, the friction coefficients and the contact angle with water increased in varying degrees. In conclusion, the obvious change in PTFE samples can be mainly attributed to break of(CFx)-C bonds after bombardment of high energy UV photons, which causes the loss of F-rich groups, oxidation, crosslinking and restructuring of active unsaturated groups.
A series of solar radiation tests for the polytetrafluoroethylene(PTFE) bulk and film samples were carried out using Q-SUN XE-3-HSC type Solar Radiation Simulator, with the test parameters as follows: radiation intensity is 1 120 W/m~2, temperature is 55 ℃ and humidity is 70% RH. Surface morphology, composition and microstructure of the PTFE samples before and after radiation tests were characterized contrastively. Effect of solar radiation on the tribology and wetting properties of PTFE were also studied by tribometer and contact angle tester, respectively. The results show that, for radiated PTFE, surface roughness, the relative content of C element, the friction coefficients and the contact angle with water increased in varying degrees. In conclusion, the obvious change in PTFE samples can be mainly attributed to break of(CFx)-C bonds after bombardment of high energy UV photons, which causes the loss of F-rich groups, oxidation, crosslinking and restructuring of active unsaturated groups.
引文
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[12]Iwamori S, Hasegawa N, Uemura A, et al. Friction and Adhesion PropertiesofFluorocarbon Polymer ThinFilms Prepared byMagnetron Sputtering[J]. Vacuum, 2009, 84(5):592-596
[13]Feng L, Li S H, Jiang L, et al. Super-hydrophobic Surfaces from Natural to Artificial[J]. Advanced Materials, 2002, 14(24):1 857-1 860
[14]Hitchcock S J, Carrol N T, Nicholas M J. Some Effect of Substrate Roughness on Wettability[J]. Journal of Materials Science, 1981,16(3):714-732
[15]Nakae H, Inui R, Hirata Y, et al. Effects of Surface Roughness on Wettability[J]. Acta Materialia, 1998, 46(7):2 313-2 318
[16]Rado C, Kalogeropoulou S, Eustathopoulos N. Wetting and Adhesion inMetal-silicon Carbide System:TheEffectofSurface Polarityof SiC[J]. Scripta Materialia, 1999, 42(2):203-208
[2]Dhillo R K, Singh S, Kumar R. 150 MeV Nickel Ion Beam Irradiation Effects on Polytetrafluoroethylene(PTFE)Polymer[J]. Nuclear Instruments&Methods in Physics Research, 2010, 268(11-12):2 189-2 192
[3]Ikeda S, Tabata Y, Suzuki H, et al. Radiation-induced Synthesis of Low Molecular Weight of PTFE and Their Crosslinking in Acetone Medium[J]. Radiation Physics&Chemistry, 2008, 77(9):1 050-1 056
[4]Cezeaux J L, Romoser C E, Benson R S, et al. VUV Modification Promotes Endothelial Cell Proliferation on PTFE Vascular Grafts[J].Nuclear Instruments&Methods in Physics Research, 1998, 141(1-4):193-196
[5]Ikeda S, Suzuki H, Miyoshi T, et al. Formation of Crosslinked PTFE by Radiation-induced Solid-state Polymerization of Tetrafluoroethylene at Low Temperatures[J]. Radiation Physics&Chemistry, 2008, 77(4):401-408
[6]Zhao X H, Shen Z G, Xing Y S, et al. An Experimental Study of Low Earth Orbit Atomic Oxygen and Ultraviolet Radiation Effects on a Spacecraft Material-polytetrafluoroethylene[J]. Polymer Degradation&Stability, 2005, 88(2):275-285
[7]Oya T, Kusano E. Characterization of Organic Polymer Thin Films Deposited by RF Magnetron Sputtering[J]. Vacuum, 2008, 83(3):564-568
[8]Rae P J, Brown E N. The Properties of Polytetrafluoroethylene(PTFE)in Tension[J]. Polymer, 2005, 46(19):8 128-8 140
[9]Brown E N, Dattelbaum D M. The Role of Crystalline Phase on Fracture and Microstructure Evolution of Polytetrafluoroethylene(PTFE)[J].Polymer, 2005, 46(9):3 056-3 068
[10]Oshima A, Tabata Y, Kudoh H, et al. Modification of Polytetrafluoroethylene and Polyethylene Surfaces Downstream from Helium Microwave Plasmas[J]. Polymer Degradation&Stability, 1990, 30(3):293-308
[11]Oshima A, Ikeda S, Katoh E, et al. Chemical Structure and Physical Properties of Radiation-induced Crosslinking of Polytetrafluoroethylene[J]. Radiation Physics&Chemistry, 2001, 62(1):39-45
[12]Iwamori S, Hasegawa N, Uemura A, et al. Friction and Adhesion PropertiesofFluorocarbon Polymer ThinFilms Prepared byMagnetron Sputtering[J]. Vacuum, 2009, 84(5):592-596
[13]Feng L, Li S H, Jiang L, et al. Super-hydrophobic Surfaces from Natural to Artificial[J]. Advanced Materials, 2002, 14(24):1 857-1 860
[14]Hitchcock S J, Carrol N T, Nicholas M J. Some Effect of Substrate Roughness on Wettability[J]. Journal of Materials Science, 1981,16(3):714-732
[15]Nakae H, Inui R, Hirata Y, et al. Effects of Surface Roughness on Wettability[J]. Acta Materialia, 1998, 46(7):2 313-2 318
[16]Rado C, Kalogeropoulou S, Eustathopoulos N. Wetting and Adhesion inMetal-silicon Carbide System:TheEffectofSurface Polarityof SiC[J]. Scripta Materialia, 1999, 42(2):203-208