Dielectric barrier discharge at atmospheric presure has been applied to prepare hydrocarbon films on large- area glass and silicon substrates. When hydrogen and methane mixture(2:1) is used as discharge gas and the s...Dielectric barrier discharge at atmospheric presure has been applied to prepare hydrocarbon films on large- area glass and silicon substrates. When hydrogen and methane mixture(2:1) is used as discharge gas and the substrate is heated to 300 C, hard hydrogenated amorphous carbon film is deposited. From the IR deconvolution analysis of the C-H stretching absorption for the coating, the hydrocarbon group ration (CH3:CH2:CH) and C-C bond type ratio (sp3c/sp2c) are about 10%: 21%: 69% and 3:1~6:1,respectively. Their Knoop hardness is up to 10Gpa. No film isdeposited when the content of methane in the mixed gases is decreased to 5% at 300 C silicon substrate.展开更多
Relatively well crystallized and high aspect ratio Mg-Al layered double hydroxides（LDHs） were prepared by coprecipitation process in aqueous solution and further rehydrated to an organic modified LDH（OLDH） in the ...Relatively well crystallized and high aspect ratio Mg-Al layered double hydroxides（LDHs） were prepared by coprecipitation process in aqueous solution and further rehydrated to an organic modified LDH（OLDH） in the presence of surfactant. The intercalated structure and high aspect ratio of OLDH were verified by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. A series of poly（propylene carbonate）（PPC）/OLDH composite films with different contents of OLDH were prepared via a melt-blending method. Their cross section morphologies, gas barrier properties and tensile strength were investigated as a function of OLDH contents. SEM results show that OLDH platelets are well dispersed within the composites and oriented parallel to the composite sheet plane. The gas barrier properties and tensile strength are obviously enhanced upon the incorporation of OLDH. Particularly, PPC/2%OLDH film exhibits the best barrier properties among all the composite films. Compared with pure PPC, the oxygen permeability coefficient（OP） and water vapor permeability coefficient（WVP） is reduced by 54% and 17% respectively with 2% OLDH addition. Furthermore, the tensile strength of PPC/2%OLDH is 83% higher than that of pure PPC with only small lose of elongation at break. Therefore, PPC/OLDH composite films show great potential application in packaging materials due to its biodegradable properties, superior oxygen and moisture barrier characteristics.展开更多
文摘Dielectric barrier discharge at atmospheric presure has been applied to prepare hydrocarbon films on large- area glass and silicon substrates. When hydrogen and methane mixture(2:1) is used as discharge gas and the substrate is heated to 300 C, hard hydrogenated amorphous carbon film is deposited. From the IR deconvolution analysis of the C-H stretching absorption for the coating, the hydrocarbon group ration (CH3:CH2:CH) and C-C bond type ratio (sp3c/sp2c) are about 10%: 21%: 69% and 3:1~6:1,respectively. Their Knoop hardness is up to 10Gpa. No film isdeposited when the content of methane in the mixed gases is decreased to 5% at 300 C silicon substrate.
基金financially supported by the National Natural Science Foundation of China(No.21376276)the Specialfunded Program on National Key Scientific Instruments and Equipment Development of China(No.2012YQ230043)+1 种基金Guangdong Province Sci&Tech Bureau(Key Strategic Project No.2008A080800024)the Fundamental Research Funds for the Central Universities
文摘Relatively well crystallized and high aspect ratio Mg-Al layered double hydroxides（LDHs） were prepared by coprecipitation process in aqueous solution and further rehydrated to an organic modified LDH（OLDH） in the presence of surfactant. The intercalated structure and high aspect ratio of OLDH were verified by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. A series of poly（propylene carbonate）（PPC）/OLDH composite films with different contents of OLDH were prepared via a melt-blending method. Their cross section morphologies, gas barrier properties and tensile strength were investigated as a function of OLDH contents. SEM results show that OLDH platelets are well dispersed within the composites and oriented parallel to the composite sheet plane. The gas barrier properties and tensile strength are obviously enhanced upon the incorporation of OLDH. Particularly, PPC/2%OLDH film exhibits the best barrier properties among all the composite films. Compared with pure PPC, the oxygen permeability coefficient（OP） and water vapor permeability coefficient（WVP） is reduced by 54% and 17% respectively with 2% OLDH addition. Furthermore, the tensile strength of PPC/2%OLDH is 83% higher than that of pure PPC with only small lose of elongation at break. Therefore, PPC/OLDH composite films show great potential application in packaging materials due to its biodegradable properties, superior oxygen and moisture barrier characteristics.
