Ice accumulation on transmission lines often leads to great damage to power systems.Super-hydrophobic surfaces are proposed to inhibit ice accumulation on electrical power equipment.A novel anti-icing method was prese...Ice accumulation on transmission lines often leads to great damage to power systems.Super-hydrophobic surfaces are proposed to inhibit ice accumulation on electrical power equipment.A novel anti-icing method was presented for conductors with super-hydrophobic sleeves.The super-hydrophobic sleeves were prepared by applying polydimethylsiloxane(PDMS) and nano-silica hybrid coating on the outer surface of polyethylen terephthalate(PET) sleeves.Hydrophobicity and ice adhesion strength of the super-hydrophobic surface were investigated.Ice accumulation experiments were carried out on ordinary conductors,super-hydrophobic coated conductors,PET sleeve-covered conductors,and super-hydrophobic PET sleeve-covered conductors.Ice accumulation morphology,accumulated ice weight,and the icicle length of these four types of conductors were studied and analyzed.At the end of the 3 h ice accumulation experiment,the ice weight and icicle length on the conductor with super-hydrophobic PET sleeve was only approximately one tenth and one seventh of that on the untreated conductor respectively.Furthermore,the water contact angles of super-hydrophobic coated aluminum surface and super-hydrophobic coated PET sleeve were about 163o in average.The results indicate that the super-hydrophobic coating is effective in inhibiting ice accumulation on conductors.However,the use of a super-hydrophobic PET sleeve is a significantly more effective method,comparing with the application of a super-hydrophobic coating directly on the conductor.展开更多
The hydrophobic aggregation of ultrafine kaolinite in cationic surfactant suspension was investigated by sedimentation test,zeta potential measurement and SEM observation. SEM images reveal that kaolinite particles sh...The hydrophobic aggregation of ultrafine kaolinite in cationic surfactant suspension was investigated by sedimentation test,zeta potential measurement and SEM observation. SEM images reveal that kaolinite particles show the self-aggregation of edge-face in acidic media,the aggregation of edge-face and edge-edge in neutral media,and the dispersion in alkaline media due to electrostatic repulsion. In the presence of the dodecylammonium acetate cationic surfactant and in neutral and alkaline suspension,the hydrophobic aggregation of face-face is demonstrated. The zeta potential of kaolinite increases with increasing the concentration of cationic surfactant. The small and loose aggregation at a low concentration but big and tight aggregation at a high concentration is presented. At pH=7 alkyl quarterly amine salt CTAB has the best hydrophobic aggregation among three cationic surfactants,namely,dodecylammonium acetate,alkyl quarterly amine salts 1227 and CTAB.展开更多
In order to improve the surface hydrophobicity, silicone rubber （SIR） samples were exposed to CF4 radio frequency （RF） capacitively coupled plasma （CCP）. Attenuated total reflection Fourier transform infrared （...In order to improve the surface hydrophobicity, silicone rubber （SIR） samples were exposed to CF4 radio frequency （RF） capacitively coupled plasma （CCP）. Attenuated total reflection Fourier transform infrared （ATR-FTIR） spectrum and X-ray photoelectron spectroscopy （XPS） were used to observe the variation of the functional groups of the modified SIR. Static contact angle （SCA） was employed to estimate the change of hydrophobicity of the modified SIR. The surface energy of SIR is reduced largely from 27.37 mJ/m^2 of original SIR sample to 2.94 mJ/m^2 of SIR sample treated by CF4 CCP modification at RF power of 200 W for a treatment time of 5 rnin. According to the XPS, ATR-FTIR and surface energy analysis, it is suggested that the improvement of hydrophobicity on the modified SIR surface is mainly ascribed to the decrease of surface energy, which is caused by the cooperation of the fluosilicic structure of Si--F or Si--F2 and the fluoric groups of C--CFn induced by the methyl replacement reaction and residual methyl groups of SIR surface.展开更多
Some polarity terms of two groups of nitrogen-containing surfactants （six alkanolamides and nine polyoxyethylenated long chain amines） are measured through gas chromatography. The apparent methanol carbon number (CM...Some polarity terms of two groups of nitrogen-containing surfactants （six alkanolamides and nine polyoxyethylenated long chain amines） are measured through gas chromatography. The apparent methanol carbon number (CMeOH) and polarity index （IP） values are determined on the investigated surfactants as stationary phases in packed columns. Similarly, CMeOH and IP values are determined on simulated hydrophobic tail （SHT） models. The obtained results reveal that the introduction of SHT approach permits the distinction between the polarities of different surfactants and their head groups. The measured polarity terms are discussed as related to hydrophile-lipophile balance （HLB） number and the hydrophobic group carbon number （RCN）. Some equations relating the measured polarity values and these variable have been developed.展开更多
Araldite S-HCEP,a new cost-efficient alternative housing material for composite insulators is briefly presented.Main topics of this paper are the results of two new studies on this material:①UV-weathering resistanc...Araldite S-HCEP,a new cost-efficient alternative housing material for composite insulators is briefly presented.Main topics of this paper are the results of two new studies on this material:①UV-weathering resistance in terms of hydrophobicity,roughness increase,surface resistance and flexibility.②Leakage current behavior under salt fog conditions in comparison to other materials.展开更多
基金Project supported by National Natural Science Foundation of China（51107152）, Ftmd for Innovation Research Groups（51021005）, Key Science and Technology Project of Chongqing Eleelric Power Company （2012 Yu Electricity Science and Technoloyg 18）.
文摘Ice accumulation on transmission lines often leads to great damage to power systems.Super-hydrophobic surfaces are proposed to inhibit ice accumulation on electrical power equipment.A novel anti-icing method was presented for conductors with super-hydrophobic sleeves.The super-hydrophobic sleeves were prepared by applying polydimethylsiloxane(PDMS) and nano-silica hybrid coating on the outer surface of polyethylen terephthalate(PET) sleeves.Hydrophobicity and ice adhesion strength of the super-hydrophobic surface were investigated.Ice accumulation experiments were carried out on ordinary conductors,super-hydrophobic coated conductors,PET sleeve-covered conductors,and super-hydrophobic PET sleeve-covered conductors.Ice accumulation morphology,accumulated ice weight,and the icicle length of these four types of conductors were studied and analyzed.At the end of the 3 h ice accumulation experiment,the ice weight and icicle length on the conductor with super-hydrophobic PET sleeve was only approximately one tenth and one seventh of that on the untreated conductor respectively.Furthermore,the water contact angles of super-hydrophobic coated aluminum surface and super-hydrophobic coated PET sleeve were about 163o in average.The results indicate that the super-hydrophobic coating is effective in inhibiting ice accumulation on conductors.However,the use of a super-hydrophobic PET sleeve is a significantly more effective method,comparing with the application of a super-hydrophobic coating directly on the conductor.
基金Project(2005CB623701) supported by the Major State Basic Research Development Program of China
文摘The hydrophobic aggregation of ultrafine kaolinite in cationic surfactant suspension was investigated by sedimentation test,zeta potential measurement and SEM observation. SEM images reveal that kaolinite particles show the self-aggregation of edge-face in acidic media,the aggregation of edge-face and edge-edge in neutral media,and the dispersion in alkaline media due to electrostatic repulsion. In the presence of the dodecylammonium acetate cationic surfactant and in neutral and alkaline suspension,the hydrophobic aggregation of face-face is demonstrated. The zeta potential of kaolinite increases with increasing the concentration of cationic surfactant. The small and loose aggregation at a low concentration but big and tight aggregation at a high concentration is presented. At pH=7 alkyl quarterly amine salt CTAB has the best hydrophobic aggregation among three cationic surfactants,namely,dodecylammonium acetate,alkyl quarterly amine salts 1227 and CTAB.
基金Project(05JT1034) supported by the Plan of Science and Technology Bureau of Hunan Province,China
文摘In order to improve the surface hydrophobicity, silicone rubber （SIR） samples were exposed to CF4 radio frequency （RF） capacitively coupled plasma （CCP）. Attenuated total reflection Fourier transform infrared （ATR-FTIR） spectrum and X-ray photoelectron spectroscopy （XPS） were used to observe the variation of the functional groups of the modified SIR. Static contact angle （SCA） was employed to estimate the change of hydrophobicity of the modified SIR. The surface energy of SIR is reduced largely from 27.37 mJ/m^2 of original SIR sample to 2.94 mJ/m^2 of SIR sample treated by CF4 CCP modification at RF power of 200 W for a treatment time of 5 rnin. According to the XPS, ATR-FTIR and surface energy analysis, it is suggested that the improvement of hydrophobicity on the modified SIR surface is mainly ascribed to the decrease of surface energy, which is caused by the cooperation of the fluosilicic structure of Si--F or Si--F2 and the fluoric groups of C--CFn induced by the methyl replacement reaction and residual methyl groups of SIR surface.
文摘Some polarity terms of two groups of nitrogen-containing surfactants （six alkanolamides and nine polyoxyethylenated long chain amines） are measured through gas chromatography. The apparent methanol carbon number (CMeOH) and polarity index （IP） values are determined on the investigated surfactants as stationary phases in packed columns. Similarly, CMeOH and IP values are determined on simulated hydrophobic tail （SHT） models. The obtained results reveal that the introduction of SHT approach permits the distinction between the polarities of different surfactants and their head groups. The measured polarity terms are discussed as related to hydrophile-lipophile balance （HLB） number and the hydrophobic group carbon number （RCN）. Some equations relating the measured polarity values and these variable have been developed.
文摘Araldite S-HCEP,a new cost-efficient alternative housing material for composite insulators is briefly presented.Main topics of this paper are the results of two new studies on this material:①UV-weathering resistance in terms of hydrophobicity,roughness increase,surface resistance and flexibility.②Leakage current behavior under salt fog conditions in comparison to other materials.
