Co-reporter:Lie Shen, Wenlian Qiu, Wen Wang, Guohua Xiao, Qipeng Guo
Composites Science and Technology 2015 Volume 117() pp:39-45
Publication Date(Web):29 September 2015
DOI:10.1016/j.compscitech.2015.05.016
The fabrication of superhydrophobic surfaces with mechanical durability is challenging because the surface microstructure is easily damaged. Herein, we report superhydrophobic conductive graphite nanoplatelet (GNP)/vapor-grown carbon fiber (VGCF)/polypropylene (PP) composite coatings with mechanical durability by a hot-pressing method. The as-prepared GNP/VGCF/PP composite coatings showed water contact angle (WCA) above 150° and sliding angle (SA) less than 5°. The superhydrophobicity was improved with the increase of VGCF content in the hybrid GNP and VGCF fillers. The more VGCFs added in the GNP/VGCF/PP composite coating, the higher porosity on the surface was formed. Compared to the GNP/PP and VGCF/PP composite coatings, the GNP and VGCF hybrid fillers exhibited more remarkable synergistic effect on the electrical conductivity of the GNP/VGCF/PP composite coatings. The GNP/VGCF/PP composite coating with GNP:VGCF = 2:1 possessed a sheet resistance of 1 Ω/sq. After abrasion test, the rough microstructure of the GNP/VGCF/PP (2:1) composite coating was mostly restored and the composite coating retained superhydrophobicity, but not for the VGCF/PP composite coating. When the superhydrophobic surface is mechanically damaged with a loss of superhydrophobicity, it can be easily repaired by a simple way with adhesive tapes. Moreover, the oil-fouled composite surface can regenerate superhydrophobicity by wetting the surface with alcohol and subsequently burning off alcohol.
Co-reporter:Wenlian Qiu, Du Xu, Bin Liu, Lie Shen and Qipeng Guo
RSC Advances 2015 vol. 5(Issue 87) pp:71329-71335
Publication Date(Web):12 Aug 2015
DOI:10.1039/C5RA12287B
Utilizing the smoke emitted by discarded silicone combustion, a simple method of smoke deposition is presented for fabricating a superhydrophobic surface with outstanding water repellence, which exhibited a water contact angle of 164 ± 0.8° and a sliding angle of lower than 1°. In addition, the as-prepared surface possesses favourable heat, water impact and water immersion stabilities. Oil leakages seriously endanger both the environment and the social economy. By this simple smoke deposition method, a selective-wettability copper mesh has been fabricated to separate oil–water mixtures. The smoke-deposited mesh achieved a high separation efficiency of over 93% for various oils, and showed excellent reusability, maintaining a high separation efficiency over 10 cycles. The water repellence of the used mesh can be refreshed by recoating with silicone and smoke deposition. This work provides a new strategy to utilize discarded silicone to fabricate superhydrophobic surfaces and oil–water separation meshes.
Co-reporter:Lie Shen, Wenlian Qiu, Bin Liu and Qipeng Guo
RSC Advances 2014 vol. 4(Issue 99) pp:56259-56262
Publication Date(Web):14 Oct 2014
DOI:10.1039/C4RA10838H
Discarded silicone products can be recycled to prepare superhydrophobic powder by simply burning and smashing. The powder can be used to fabricate a superhydrophobic surface with mechanical durability such that the superhydrophobicity was kept after 50 abrasion cycles. A robust electroconductive superhydrophobic surface can also be obtained by this simple method.
Co-reporter:Lie Shen, Wen Wang, Hongliang Ding, Qipeng Guo
Applied Surface Science 2013 Volume 284() pp:651-656
Publication Date(Web):1 November 2013
DOI:10.1016/j.apsusc.2013.07.149
Highlights
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We report a superhydrophobic surface of flame soot deposited silicone coating.
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Structure of tree branch-like network with micro and nanoscale roughness is formed.
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Superhydrophobic 20 s deposited silicone coating possesses good transmittance.
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Flame soot can stably deposit on the silicone coating during water-flow impact.
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The deposited silicone coating can keep superhydrophobic after heating at 200 °C.
Co-reporter:Lie Shen, Hongliang Ding, Wen Wang, Qipeng Guo
Applied Surface Science 2013 Volume 268() pp:297-301
Publication Date(Web):1 March 2013
DOI:10.1016/j.apsusc.2012.12.081
Abstract
Superhydrophobic conductive Ketjen black-polybenzoxazine (KB-PBZ) composite coatings were prepared by a simple drop casting method with high static water contact angle (∼160°), low sliding angle (∼3°), and low sheet resistance (103 Ω/sq). The relationship between Ketjen black amounts and the structure and properties of the composite coatings was investigated. Under appropriate conditions, the composite coatings showed hierarchically structured roughness and possessed superhydrophobicity over the whole range of pH values. These coatings exhibited excellent thermal and environmental stability. Moreover, the superhydrophobic conductive composite coatings also can be obtained on various substrates such as wood, aluminum foil, paper, polyethylene terephthalate film and fabric.
Co-reporter:Lie Shen, Hongliang Ding, Qinghua Cao, Weican Jia, Wen Wang, Qipeng Guo
Carbon 2012 Volume 50(Issue 11) pp:4284-4290
Publication Date(Web):September 2012
DOI:10.1016/j.carbon.2012.05.018
A Ketjen black-high density polyethylene (HDPE) superhydrophobic conductive surface was prepared by a single-step pressing method in which the Ketjen black was pressed into the HDPE leaving it partially exposed to form a superhydrophobic coating with high static water contact angle (∼160o), low sliding angle (∼2.5o), and low sheet resistance (100–102 Ω/sq). The preparation conditions such as the pressing time and the amount of Ketjen black greatly influence the superhydrophobicity and conductivity. The simple pressing of Ketjen black onto the HDPE substrate provides hierarchically structured roughness, leading to the superhydrophobicity of the surface. The superhydrophobic conductive surface also can be obtained with other carbonaceous materials, such as other carbon blacks and nanotubes, and the superhydrophobicity is decided by whether it can produce hierarchically structure roughness.
Co-reporter:Lie Shen;Fangquan Wang;Weican Jia ;Hui Yang
Polymer International 2012 Volume 61( Issue 2) pp:163-168
Publication Date(Web):
DOI:10.1002/pi.3163
Abstract
By calculating the surface tensions of the components, composites with innovative thermodynamically induced self-assembled electrically conductive networks were designed, prepared and investigated. Carbon black (CB) was added into a ternary blend system comprised of poly(methyl methacrylate) (PMMA), ethylene–acrylic acid copolymer (EAA) and polypropylene (PP). Scanning electron microscopy images show that the PMMA/EAA/PP ternary blend forms a tri-continuous phase structure like a sandwich, in which PMMA and PP form a co-continuous phase while EAA spreads at the interface of the PMMA and PP phases as a sheath. The micrographs and resistivity–temperature characteristic curve results indicate that CB fillers are selectively located at the interface of the PMMA and PP phases, namely the EAA phase. The percolation threshold of PMMA/EAA-CB/PP composites is 0.2 vol%, which is only one-fifth of that of PP/CB composites. Copyright © 2011 Society of Chemical Industry
Co-reporter:L. Shen, F.Q. Wang, H. Yang, Q.R. Meng
Polymer Testing 2011 Volume 30(Issue 4) pp:442-448
Publication Date(Web):June 2011
DOI:10.1016/j.polymertesting.2011.03.007
Composites were prepared of high-density polyethylene (HDPE) with carbon black (CB) and carbon fiber (CF) (HDPE/CB/CF), and of polymer blends of HDPE and polypropylene (PP) with CB and CF fillers (HDPE/PP/CB/CF). The combined effects of CB and CF on the conductivity and resistivity-temperature behavior of the two composites were investigated. The volume resistivities of HDPE/CB/CF and HDPE/PP/CB/CF (2 wt% CF) composites were, respectively, lower than those of HDPE/CB and HDPE/PP/CB composites at the same total filler content. In both composites, electrons are transported over long distances by CFs with little loss of energy, whereas CB particles improve the interfiber contact by forming CB particle bridges. Scanning electron microscopy revealed two network structures that can both increase the density of conducting paths, which reduces the resistivity of the composites. The intensity of the positive temperature coefficient (PTC) and the temperature coefficient of resistivity of both the HDPE/CB/CF and HDPE/PP/CB/CF composites increase appreciably with increasing CF loading. This finding indicates that adding a mixture of CB and CF is a promising way to improve the performance of PTC composites.
Co-reporter:Hui Liu, Ping’an Song, Zhengping Fang, Lie Shen, Mao Peng
Thermochimica Acta 2010 Volume 506(1–2) pp:98-101
Publication Date(Web):10 July 2010
DOI:10.1016/j.tca.2010.04.029
The thermal and flame retardancy properties of high-density polyethylene (HDPE)/ethylene vinyl-acetate copolymer (EVA)/fullerene (C60) nanocomposites were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and cone calorimetry with C60 loading varied from 0.5 to 2% by mass fraction. Dispersion of C60 in HDPE/EVA blend was characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). TGA and DSC results showed that the presence of C60 could remarkably enhance the thermal stability, and cone calorimeter measurements indicated that incorporating C60 could result in a significant reduction in the peak heat release rate and a much longer time to ignition of the HDPE/EVA blend. Furthermore, the larger the C60 loading level, the better the flame retardancy of HDPE/EVA/C60 nanocomposites.
Co-reporter:Lie Shen;Hui Yang;Jia Ying;Fei Qiao
Journal of Materials Science: Materials in Medicine 2009 Volume 20( Issue 11) pp:2259-2265
Publication Date(Web):2009 November
DOI:10.1007/s10856-009-3785-2
A novel biocomposite of carbon fiber (CF) reinforced hydroxyapatite (HA)/polylactide (PLA) was prepared by hot pressing a prepreg which consisting of PLA, HA and CF. The prepreg was manufactured by solvent impregnation process. Polymer resin PLA dissolved with chloroform was mixed with HA. After reinforcement CF bundle was impregnated in the mixture, the solvent was dried completely and subsequently hot-pressed uniaxially under a pressure of 40 MPa at 170°C for 20 min. A study was carried out to investigate change in mechanical properties of CF/HA/PLA composites before and after degradation in vitro. The composites have excellent mechanical properties. A peak showed in flexural strength, flexural modulus and shear strength aspects, reaching up 430 MPa, 22 GPa, 212 MPa, respectively, as the HA content increased. Degraded in vitro for 3 months, the flexural strength and flexural modulus of the CF/HA/PLA fell 13.2% and 5.4%, respectively, while the shear strength of the CF/HA/PLA composites remains at the 190 MPa level. The SEM photos showed that there were gaps between the PLA matrix and CF after degradation. Water uptake increased to 5%, but the mass loss rate was only 1.6%. The pH values of the PBS dropped less than 0.1. That’s because the alkaline of HA neutralize the acid degrades from PLA, which can prevent the body from the acidity harm.
Co-reporter:L. Shen;Z. D. Lou;Y. J. Qian
Journal of Polymer Science Part B: Polymer Physics 2007 Volume 45(Issue 22) pp:3078-3083
Publication Date(Web):9 OCT 2007
DOI:10.1002/polb.21307
Polymeric positive temperature coefficient (PTC) materials have been prepared by incorporating carbon black (CB) into two different polymer matrices, crystalline high density polyethylene (HDPE) and amorphous polystyrene (PS). The effects of thermal volume expansion on the electrical properties of conductive polymer composites were studied. The volume fraction of conductive particles behaves like a switch from insulator to conductor in the polymeric PTC composite. Our mathematical model and experimental model have proved that the abrupt resistivity increase at PTC transition range and at the percolation curve close to the critical volume fraction for both polymeric PTC composites have the same conductive mechanism. The thermal expansion is one of the key factors responsible for the PTC effect and can be seen by comparing the PTC transition curves from model predictions and experiment. Furthermore, the model predicts PTC curves of CB/PS composite more successfully than it does for the CB/HDPE composite, and the reasons for this are also discussed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3078–3083, 2007
