The Experts below are selected from a list of 36411 Experts worldwide ranked by ideXlab platform
Yi Huang - One of the best experts on this subject based on the ideXlab platform.
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rapid and efficient polymer graphene based multichannel self Healing Material via diels alder reaction
Carbon, 2019Co-Authors: Peishuang Xiao, Shengyue Hou, Yi HuangAbstract:Abstract It is a challenge to manufacture self-Healing Material that possesses rapid, efficient and multichannel self-Healing capability. Herein, we design and synthesize a polymer/graphene based self-Healing Material with a cross-linking network structure via Diels-Alder (D-A) reaction. The as-prepared Material can be healed after damage under the stimuli of heat, infrared light, and microwave with controlling the formation and cleavage of D-A bonds. And it exhibits rapid (IR light-5 s, Heat/Microwave-60 s), efficient (efficiencies are 90% after heat-healed, 106% after IR-healed, and 133% after microwave-healed, respectively), and multichannel self-Healing ability (i.e. can be self-healed in multiple ways). Furthermore, functionalized graphene oxide (FGO) has high grafting rate of 47.5% for GO-FA (graphene oxide (GO) was functionalized by Furfurylamine, FA), and 85.3% for GO-MDA (GO was functionalized by 6-Maleimidocaproic acid, MDA). In addition, photo-thermal conversion efficiency of the self-Healing Material was calculated with the average value reached up to 59.8%. The outstanding self-Healing performances suggest that this self-Healing Material has huge promising potential applications in military equipment, protective coating and building Materials, etc.
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Rapid and efficient polymer/graphene based multichannel self-Healing Material via Diels-Alder reaction
Carbon, 2019Co-Authors: Guanghao Li, Peishuang Xiao, Shengyue Hou, Yi HuangAbstract:It is a challenge to manufacture self-Healing Material that possesses rapid, efficient and multichannel self-Healing capability. Herein, we design and synthesize a polymer/graphene based self-Healing Material with a cross-linking network structure via Diels-Alder (D-A) reaction. The as-prepared Material can be healed after damage under the stimuli of heat, infrared light, and microwave with controlling the formation and cleavage of D-A bonds. And it exhibits rapid (IR light-5 s, Heat/Microwave-60 s), efficient (efficiencies are 90% after heat-healed, 106% after IR-healed, and 133% after microwave-healed, respectively), and multichannel self-Healing ability (i.e. can be self-healed in multiple ways). Furthermore, functionalized graphene oxide (FGO) has high grafting rate of 47.5% for GO-FA (graphene oxide (GO) was functionalized by Furfurylamine, FA), and 85.3% for GO-MDA (GO was functionalized by 6-Maleimidocaproic acid, MDA). In addition, photo-thermal conversion efficiency of the self-Healing Material was calculated with the average value reached up to 59.8%. The outstanding self-Healing performances suggest that this self-Healing Material has huge promising potential applications in military equipment, protective coating and building Materials, etc.
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Multichannel and Repeatable Self‐Healing of Mechanical Enhanced Graphene‐Thermoplastic Polyurethane Composites
Advanced Materials, 2013Co-Authors: Lu Huang, Yingpeng Wu, Ningbo Yi, Yanfeng Ma, Qian Bo-zhang, Yi Huang, Yi Zhang, Yongsheng ChenAbstract:A novel self-Healing Material, which was fabricated using few-layered graphene (FG) and thermoplastic polyurethane (TPU) via a facile method, not only exhibits a mechanical enhanced property, but also can be repeatedly healed by various methods including infrared (IR) light, electricity and electromagnetic wave with Healing efficiencies higher than 98%.
G. Scheltjens - One of the best experts on this subject based on the ideXlab platform.
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A remendable polymer network based on reversible covalent bonding for coating applications
2013Co-Authors: G. Scheltjens, M.m. Diaz, Joost Brancart, B Van MeleAbstract:An extrinsic self-Healing Material was synthesized based on the reversible DielsAlder (DA) reaction between furan and maleimide functional groups, designed for coating applications. At elevated temperatures, the DA/retro-DA equilibrium is shifted towards the initial building blocks. This shift in equilibrium allows a temporary increase in local mobility, which is essential in order to seal any sustained damages to the coating. The actual recovery of initial properties takes place in a subsequent cooling, where recombination of covalent bonds through the exothermic DA reaction occurs. The advantage of this particular self-Healing system lies in its flexible network design. Changing the spacer length in the furan functionalized compound leads to tailormade properties, such as cross-link density and glass transition temperature (Tg). Based on the Tg analysis performed by differential scanning calorimetry (DSC), a model system was chosen to evaluate the kinetic parameters of the reversible DA reaction by Fourier transform infrared spectroscopy (FTIR). A methodology to study self-Healing properties was developed in a well-defined temperature windo w based on the kinetics and equilibrium of the reversible networks. In a first step, a maximum sealing temperature of 120 °C was determined to avoid an irreversible homopolymerization of maleimide functional groups [1]. Secondly, the flow behavior at elevated temperatures was characterized by dynamic rheometry. Frequency sweeps were performed in equilibrium conditions at various isothermal temperatures in order to determine the gelation temperature (Tgel). It was shown that sealing of microscopic scratches was possible below Tgel, leading to the advantage that mechanical properties remain guaranteed during a thermal Healing procedure. In addition, the exothermic DA reaction was characterized by Modulated DSC at low temperatures, proving the Healing capacity at low temperatures and showing the repeatability of Healing procedures.
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A generic methodology to study self-Healing properties of thermo-reversible polymer networks
2013Co-Authors: B Van Mele, G. Scheltjens, M.m. Diaz, Joost BrancartAbstract:Based on the reversible Diels-Alder (DA) reaction between furan and maleimide functional groups, an extrinsic self-Healing Material was synthesized for coating applications [1]. At elevated temperatures, the DA/retro-DA equilibrium is shifted towards the initial building blocks. This shift in equilibrium allows a temporary increase in local mobility, which is essential to seal damage. The recovery of initial properties takes place in a subsequent cooling by recombination of covalent bonds through the exothermic DA reaction. Changing the spacer length in the furan functionalized compound leads to a flexible network design and tailor-made network properties with a variable cross-link density and glass transition temperature [1]. Based on these systems, a generic methodology was developed to study the self-Healing properties of thermo-reversible networks. The effect of temperature on kinetics and equilibrium of the reversible DA/retro-DA reaction, and also the effect of diffusion-control was measured (and modeled) by means of Fourier transform infrared spectroscopy, microcalorimetry and Modulated DSC. Both elastomeric and thermosetting reversible networks were investigated. A maximum sealing temperature was determined to avoid unwanted side-reactions. In case of the DA networks studied, an irreversible homopolymerization of maleimide functional groups occurs above 120 °C. The flow behavior at elevated temperatures was characterized by dynamic rheometry in order to determine the gelation temperature (Tgel) of the reversible networks. It was shown that sealing of microscopic scratches is possible below Tgel, leading to the advantage for coatings that sufficient mechanical properties remain guaranteed during a thermal sealing/Healing procedure. At low temperatures, the exothermic DA reaction was characterized by microcalorimetry and Modulated DSC proving the Healing capacity of the networks and showing the repeatability of sealing/Healing cycles in an acceptable temperature window. The mechanical properties in this temperature window were studied with dynamic mechanical analysis. REFERENCES
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Self-Healing property characterization of reversible thermoset coatings
Journal of Thermal Analysis and Calorimetry, 2011Co-Authors: G. Scheltjens, B Van Mele, Joost Brancart, Iris De Graeve, Herman Terryn, Gilles Van AsscheAbstract:A self-Healing Material for coating applications was synthesized using the DielsAlder (DA) reaction as cross-linking reaction. The built-in reversibility allows local mobility and rearrangements in the polymeric network, which is composed of a furan functionalized epoxy-amine and a bismaleimide. The self-Healing Material was characterized by physicalchemical means using Fourier Transform Infrared spectroscopy, thermogravimetric analysis (TG) and rapid heat-cool differential scanning calorimetry. It has been shown that the reversibility, as a result of a change in DA/retro-DA equilibrium, occurs in a temperature window ranging from ca. 80 to 150 C. The repeatability of the non-autonomous Healing was checked by TG, showing no evaporation or degradation of the components involved in the temperature window of interest.
Ying Yang - One of the best experts on this subject based on the ideXlab platform.
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A homemade self-Healing Material utilized as multi-functional binder for long-lifespan lithium–sulfur batteries
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Zhihao Yu, Trunghieu Le, Wenxuan Wang, Li Wang, Ying YangAbstract:This study reports a supramolecular self-Healing Material as a multi-functional binder for lithium–sulfur batteries. The spontaneously damage repair ability of such a binder can be applied to overcome the short cycle-life issue of lithium–sulfur batteries under low current density with deep galvanostatic cycling. Diamines and polybasic acids are used to synthesize the supramolecular self-Healing Material. 10 wt% amine groups in this designed Material provide a large amount of chemical adsorption sites for polysulfides which can effectively inhibit the shuttling of polysulfides and maintain the content of sulfur species in cathode. This N-rich binder is mixed with the sulfur during preparation, which can improve the effective contacting surface of N function groups and sulfur locally. The cells with pure self-Healing Material binder achieve an initial capacity of 918 mAh g−1, and maintain a reversible capacity of 469 mAh g−1 after 200 cycles at 0.1C, twice higher than the retention capacity of cells with polyvinylidene fluoride binder. After optimization, the cells with a hybrid binder of self-Healing Material and polyvinylidene fluoride (weight ratio of 1:1) with a sulfur loading of 2.65 mg cm−2 achieve an initial capacity of 993 mAh g−1, and remain a reversible capacity of 571 mAh g−1 with a capacity fade of 0.2% per cycle after 200 cycles at 0.1C.
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a homemade self Healing Material utilized as multi functional binder for long lifespan lithium sulfur batteries
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Tianji Gao, Wenxua Wang, Li Wang, Ying YangAbstract:This study reports a supramolecular self-Healing Material as a multi-functional binder for lithium–sulfur batteries. The spontaneously damage repair ability of such a binder can be applied to overcome the short cycle-life issue of lithium–sulfur batteries under low current density with deep galvanostatic cycling. Diamines and polybasic acids are used to synthesize the supramolecular self-Healing Material. 10 wt% amine groups in this designed Material provide a large amount of chemical adsorption sites for polysulfides which can effectively inhibit the shuttling of polysulfides and maintain the content of sulfur species in cathode. This N-rich binder is mixed with the sulfur during preparation, which can improve the effective contacting surface of N function groups and sulfur locally. The cells with pure self-Healing Material binder achieve an initial capacity of 918 mAh g−1, and maintain a reversible capacity of 469 mAh g−1 after 200 cycles at 0.1C, twice higher than the retention capacity of cells with polyvinylidene fluoride binder. After optimization, the cells with a hybrid binder of self-Healing Material and polyvinylidene fluoride (weight ratio of 1:1) with a sulfur loading of 2.65 mg cm−2 achieve an initial capacity of 993 mAh g−1, and remain a reversible capacity of 571 mAh g−1 with a capacity fade of 0.2% per cycle after 200 cycles at 0.1C.
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A Self-Healing and Electrical-Tree-Inhibiting Epoxy Composite with Hydrogen-Bonds and SiO2 Particles
Polymers, 2017Co-Authors: Wancong Bian, Wenxuan Wang, Ying YangAbstract:Electrical tree growth in the insulation Material is a main factor limiting the lifespan of insulation. A new method of increasing the durability and reliability of polymer dielectrics has been proposed by designing a three-phase electrical self-Healing composite. SiO2 micro and nano particles were loaded in the sample which can improve the resistance to electrical tree breakdown. Materials with hydrogen bonds were synthesized and added into epoxy matrix to make the composite self-healable. It is found that both SiO2 and hydrogen-bonding self-Healing Material (HSM) can inhibit the electrical trees. Besides the self-Healing behavior at the macro level, the incorporation of HSM can also make the micro defects such as electrical tree channel self-healable. The electrical self-Healing composite will find a wide application in the field of electronic and electrical engineering.
Gilles Van Assche - One of the best experts on this subject based on the ideXlab platform.
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Self-Healing property characterization of reversible thermoset coatings
Journal of Thermal Analysis and Calorimetry, 2011Co-Authors: G. Scheltjens, B Van Mele, Joost Brancart, Iris De Graeve, Herman Terryn, Gilles Van AsscheAbstract:A self-Healing Material for coating applications was synthesized using the DielsAlder (DA) reaction as cross-linking reaction. The built-in reversibility allows local mobility and rearrangements in the polymeric network, which is composed of a furan functionalized epoxy-amine and a bismaleimide. The self-Healing Material was characterized by physicalchemical means using Fourier Transform Infrared spectroscopy, thermogravimetric analysis (TG) and rapid heat-cool differential scanning calorimetry. It has been shown that the reversibility, as a result of a change in DA/retro-DA equilibrium, occurs in a temperature window ranging from ca. 80 to 150 C. The repeatability of the non-autonomous Healing was checked by TG, showing no evaporation or degradation of the components involved in the temperature window of interest.
Wai Prathumpai - One of the best experts on this subject based on the ideXlab platform.
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Exobiopolymer production of Ophiocordyceps dipterigenaBCC 2073: optimization, production in bioreactor and characterization
BMC Biotechnology, 2010Co-Authors: Kanokarn Kocharin, Pranee Rachathewee, Jean-jacques Sanglier, Wai PrathumpaiAbstract:Background Biopolymers have various applications in medicine, food and petroleum industries. The ascomycetous fungus Ophiocordyceps dipterigena BCC 2073 produces an exobiopolymer, a (1→3)-β- D -glucan, in low quantity under screening conditions. Optimization of O. dipterigena BCC 2073 exobiopolymer production using experimental designs, a scale-up in 5 liter bioreactor, analysis of molecular weight at different cultivation times, and levels of induction of interleukin-8 synthesis are described in this study. Results In order to improve and certify the productivity of this strain, a sequential approach of 4 steps was followed. The first step was the qualitative selection of the most appropriate carbon and nitrogen sources (general factorial design) and the second step was quantitative optimization of 5 physiological factors (fractional factorial design). The best carbon and nitrogen source was glucose and malt extract respectively. From an initial production of 2.53 g·L^-1, over 13 g·L^-1 could be obtained in flasks under the improved conditions (5-fold increase). The third step was cultivation in a 5 L bioreactor, which produced a specific growth rate, biomass yield, exobiopolymer yield and exobiopolymer production rate of 0.014 h^-1, 0.32 g·g^-1 glucose, 2.95 g·g biomass^-1 (1.31 g·g^-1 sugar), and 0.65 g.(L·d)^-1, respectively. A maximum yield of 41.2 g·L^-1 was obtained after 377 h, a dramatic improvement in comparison to the initial production. In the last step, the basic characteristics of the biopolymer were determined. The molecular weight of the polymer was in the range of 6.3 × 10^5 - 7.7 × 10^5 Da. The exobiopolymer, at 50 and 100. μg·mL^-1, induced synthesis in normal dermal human fibroblasts of 2227 and 3363 pg·mL^-1 interleukin-8 respectively. Conclusions High exobiopolymer yield produced by O. dipterigena BCC 2073 after optimization by qualitative and quantitative methods is attractive for various applications. It induced high IL-8 production by normal dermal fibroblasts, which makes it promising for application as wound Healing Material. However, there are still other possible applications for this biopolymer, such as an alternative source of biopolymer substitute for hyaluronic acid, which is costly, as a thickening agent in the cosmetic industry due to its high viscosity property, as a moisturizer, and in encapsulation.
