By means of changing the detection angle, the molecular conformation of a new type of polymer surfactant, acrylamide-poly(oxyethykene alkyl ether)acrylate-anionic monomer random copolymer, was studied by x-ray photoel...By means of changing the detection angle, the molecular conformation of a new type of polymer surfactant, acrylamide-poly(oxyethykene alkyl ether)acrylate-anionic monomer random copolymer, was studied by x-ray photoelectron spectroscopy(XPS) in detail.展开更多
Biaxially oriented polypropylene(BOPP)is one of the most commonly used commercial capacitor films,but its upper operating temperature is below 105℃due to the sharply increased electrical conduction loss at high tempe...Biaxially oriented polypropylene(BOPP)is one of the most commonly used commercial capacitor films,but its upper operating temperature is below 105℃due to the sharply increased electrical conduction loss at high temperature.In this study,growing an inorganic nanoscale coating layer onto the BOPP film's surface is proposed to suppress electrical conduction loss at high temperature,as well as increase its upper operating temperature.Four kinds of inorganic coating layers that have different energy band structure and dielectric property are grown onto the both surface of BOPP films,respectively.The effect of inorganic coating layer on the high-temperature energy storage performance has been systematically investigated.The favorable coating layer materials and appropriate thickness enable the BOPP films to have a significant improvement in high-temperature energy storage performance.Specifically,when the aluminum nitride(AIN)acts as a coating layer,the AIN-BOPP-AIN sandwich-structured films possess a discharged energy density of 1.5 J cm^(-3)with an efficiency of 90%at 125℃,accompanying an outstandingly cyclic property.Both the discharged energy density and operation temperature are significantly enhanced,indicating that this efficient and facile method provides an important reference to improve the high-temperature energy storage performance of polymer-based dielectric films.展开更多
Three major types of protective coating of wood and wood-based materials have been considered. These three types include the coatings based on carboxyl-containing water-soluble polymers which are easily cross-linked b...Three major types of protective coating of wood and wood-based materials have been considered. These three types include the coatings based on carboxyl-containing water-soluble polymers which are easily cross-linked by inorganic salts or OH-containing compounds, pH-sensitive coatings and polymer multi-layer structures. First of three mentioned approaches allows affecting permeability and enhancing the prevention the loss of water from the surface of wood to its surrounding. The advantage of the second approach is its ability to vary and purposely adjust the polymer composition and the number and distribution of -COOH groups in the chain which make the originally water-soluble polymers completely insoluble. The strong feature of the third approach which includes broad use of hydrogen-bonded films produced by layer-by-layer self-assembly is the possibility of manipulation of coatings stability after construction.展开更多
This study reports on the tribological performance of aromatic thermosetting co-polyester(ATSP)and polyether ether ketone(PEEK)-based polymer composite coatings mixed with PTFE filler.The coatings were tested across a...This study reports on the tribological performance of aromatic thermosetting co-polyester(ATSP)and polyether ether ketone(PEEK)-based polymer composite coatings mixed with PTFE filler.The coatings were tested across a wide temperature range from−180 to 110℃ to simulate the environmental temperatures on Titan,Moon,and Mars,which are of particular interest for NASA’s future exploratory missions.An experimental setup was developed to conduct the pin-on-disk experiments under dry sliding conditions and extreme temperature and contact pressure.Transfer film formation and its characteristics were found to play significant roles in the tribological performance,and the characteristics of the film were temperature-dependent.The XPS and SEM analysis indicated the increase of the PTFE content in the transfer film as the temperature decreased to cryogenic conditions.The coefficient of friction did not follow a linear trend with temperature and was minimum at 110℃ and maximum at−180℃.ATSP coating showed superior performance with lower friction and unmeasurable wear at all temperatures,whereas PEEK coating exhibited maximum wear at 25℃ followed by−180,and 110℃.展开更多
文摘By means of changing the detection angle, the molecular conformation of a new type of polymer surfactant, acrylamide-poly(oxyethykene alkyl ether)acrylate-anionic monomer random copolymer, was studied by x-ray photoelectron spectroscopy(XPS) in detail.
基金supported by the National Natural Science Foundation of China(Nos.52277024,U20A20308)Natural Science Foundation of Heilongjiang Province(No.YQ2020E031)+3 种基金China Postdoctoral Science Foundation(Nos.2021T140166,2018M640303)Heilongjiang Province Postdoctoral Science Foundation(No.LBH-Z18099)University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2020178)the support from the China Scholarship Council(CSC)
文摘Biaxially oriented polypropylene(BOPP)is one of the most commonly used commercial capacitor films,but its upper operating temperature is below 105℃due to the sharply increased electrical conduction loss at high temperature.In this study,growing an inorganic nanoscale coating layer onto the BOPP film's surface is proposed to suppress electrical conduction loss at high temperature,as well as increase its upper operating temperature.Four kinds of inorganic coating layers that have different energy band structure and dielectric property are grown onto the both surface of BOPP films,respectively.The effect of inorganic coating layer on the high-temperature energy storage performance has been systematically investigated.The favorable coating layer materials and appropriate thickness enable the BOPP films to have a significant improvement in high-temperature energy storage performance.Specifically,when the aluminum nitride(AIN)acts as a coating layer,the AIN-BOPP-AIN sandwich-structured films possess a discharged energy density of 1.5 J cm^(-3)with an efficiency of 90%at 125℃,accompanying an outstandingly cyclic property.Both the discharged energy density and operation temperature are significantly enhanced,indicating that this efficient and facile method provides an important reference to improve the high-temperature energy storage performance of polymer-based dielectric films.
文摘Three major types of protective coating of wood and wood-based materials have been considered. These three types include the coatings based on carboxyl-containing water-soluble polymers which are easily cross-linked by inorganic salts or OH-containing compounds, pH-sensitive coatings and polymer multi-layer structures. First of three mentioned approaches allows affecting permeability and enhancing the prevention the loss of water from the surface of wood to its surrounding. The advantage of the second approach is its ability to vary and purposely adjust the polymer composition and the number and distribution of -COOH groups in the chain which make the originally water-soluble polymers completely insoluble. The strong feature of the third approach which includes broad use of hydrogen-bonded films produced by layer-by-layer self-assembly is the possibility of manipulation of coatings stability after construction.
基金supported by Small Business Innovation Research(SBIR)Phase II contract No.#80NSSC20C0180.
文摘This study reports on the tribological performance of aromatic thermosetting co-polyester(ATSP)and polyether ether ketone(PEEK)-based polymer composite coatings mixed with PTFE filler.The coatings were tested across a wide temperature range from−180 to 110℃ to simulate the environmental temperatures on Titan,Moon,and Mars,which are of particular interest for NASA’s future exploratory missions.An experimental setup was developed to conduct the pin-on-disk experiments under dry sliding conditions and extreme temperature and contact pressure.Transfer film formation and its characteristics were found to play significant roles in the tribological performance,and the characteristics of the film were temperature-dependent.The XPS and SEM analysis indicated the increase of the PTFE content in the transfer film as the temperature decreased to cryogenic conditions.The coefficient of friction did not follow a linear trend with temperature and was minimum at 110℃ and maximum at−180℃.ATSP coating showed superior performance with lower friction and unmeasurable wear at all temperatures,whereas PEEK coating exhibited maximum wear at 25℃ followed by−180,and 110℃.
