The interface properties of Fe(101)/zinc silicate modified by organo-siloxane(KH-570)was studied by using the method of molecular dynamics simulation.By calculating the temperature and energy fluctuation of equilibriu...The interface properties of Fe(101)/zinc silicate modified by organo-siloxane(KH-570)was studied by using the method of molecular dynamics simulation.By calculating the temperature and energy fluctuation of equilibrium state,equilibrium concentration distribution,MSD of layer and different groups,and interaction energy of two interface models,the influencing mechanism on the interface properties of adding organosiloxane into coating system was studied at the atomic scale.It shows that the temperature and energy of interface oscillated in a small range and it was exited in a state of dynamic equilibrium within the initial simulation stage(t<20 ps).It can be seen from the multiple peak states of concentration distribution that the iron substrate,organo-siloxane and zinc silicate are distributed in the form of a concentration gradient in the real environment.The rapid diffusion of free zinc powder in zinc silicate coating was the essential reason that affected the comprehensive properties of coating.The interface thickness decreased from 7.45 to 6.82Å,the MSD of free zinc powder was effectively reduced,and the interfacial energy was increased from 104.667 to 347.158 kcal/mol after being modified by organo-siloxane.展开更多
One of the most widely used and well-established atomic oxygen(AO)protection solutions for low Earth orbit(LEO)satellites is the deposition of protective coatings on polymeric materials.However,manufacturing extensive...One of the most widely used and well-established atomic oxygen(AO)protection solutions for low Earth orbit(LEO)satellites is the deposition of protective coatings on polymeric materials.However,manufacturing extensive expanses of these coating materials with good transparency,flexibility,smoothness,ultra-thinness,and exceptional AO resistance remains a critical issue.Herein,we successfully deposited a 400 nm thick polyorgansiloxane(SiO_(x)C_(y)H_(z))coating with high optical transparency and uniform good adherence on to a 1.2 m wide polyimide surface,by optimizing the distribution of hexamethyldisiloxane and oxygen as precursors in the roll-to-roll compatible plasmaenhanced chemical vapor deposition process.After AO irradiation with the fluence of 7.9×10^(20)atoms·cm^(–2),the erosion yield of the SiO_(x)C_(y)H_(z)-coated Kapton was less than 2.30×10^(–26)cm^3·atom^(–1),which was less than 0.77%of that of the Kapton.It indicates that the SiO_(x)C_(y)H_(z)coating can well prevent the erosion of Kapton by AO.In addition,it was also clarified that a SiO_(2) passivation layer was formed on the surface of the SiO_(x)C_(y)H_(z)coating during AO irradiation,which exhibited a‘self-reinforcing’defense mechanism.The entire preparation process of the SiO_(x)C_(y)H_(z)coating was highly efficient and low-cost,and it has shown great potential for applications in LEO.展开更多
Copper thin films were deposited by plasma-enhanced atomic layer deposition at low temperature,using copper(I)-N,N′-di-sec-butylacetamidinate as a precursor and hydrogen as a reductive gas.The influence of temperatur...Copper thin films were deposited by plasma-enhanced atomic layer deposition at low temperature,using copper(I)-N,N′-di-sec-butylacetamidinate as a precursor and hydrogen as a reductive gas.The influence of temperature,plasma power,mode of plasma,and pulse time,on the deposition rate of copper thin film,the purity of the film and the step coverage were studied.The feasibility of copper film deposition on the inner wall of a carbon fibre reinforced plastic waveguide with high aspect ratio was also studied.The morphology and composition of the thin film were studied by atomic force microscopy and x-ray photoelectron spectroscopy,respectively.The square resistance of the thin film was also tested by a four-probe technique.On the basis of on-line diagnosis,a growth mechanism of copper thin film was put forward,and it was considered that surface functional group played an important role in the process of nucleation and in determining the properties of thin films.A high density of plasma and high free-radical content were helpful for the deposition of copper thin films.展开更多
基金supported by the National Science Fundation of China(No.U1937601),and the National Natural Science Foundation of China(Grant No.NSFC51905471).
文摘The interface properties of Fe(101)/zinc silicate modified by organo-siloxane(KH-570)was studied by using the method of molecular dynamics simulation.By calculating the temperature and energy fluctuation of equilibrium state,equilibrium concentration distribution,MSD of layer and different groups,and interaction energy of two interface models,the influencing mechanism on the interface properties of adding organosiloxane into coating system was studied at the atomic scale.It shows that the temperature and energy of interface oscillated in a small range and it was exited in a state of dynamic equilibrium within the initial simulation stage(t<20 ps).It can be seen from the multiple peak states of concentration distribution that the iron substrate,organo-siloxane and zinc silicate are distributed in the form of a concentration gradient in the real environment.The rapid diffusion of free zinc powder in zinc silicate coating was the essential reason that affected the comprehensive properties of coating.The interface thickness decreased from 7.45 to 6.82Å,the MSD of free zinc powder was effectively reduced,and the interfacial energy was increased from 104.667 to 347.158 kcal/mol after being modified by organo-siloxane.
基金financially supported by National Natural Science Foundation of China (No.U1937601)the Industrial Technology Development Program of China(No.JCKY 2020203B019).
文摘One of the most widely used and well-established atomic oxygen(AO)protection solutions for low Earth orbit(LEO)satellites is the deposition of protective coatings on polymeric materials.However,manufacturing extensive expanses of these coating materials with good transparency,flexibility,smoothness,ultra-thinness,and exceptional AO resistance remains a critical issue.Herein,we successfully deposited a 400 nm thick polyorgansiloxane(SiO_(x)C_(y)H_(z))coating with high optical transparency and uniform good adherence on to a 1.2 m wide polyimide surface,by optimizing the distribution of hexamethyldisiloxane and oxygen as precursors in the roll-to-roll compatible plasmaenhanced chemical vapor deposition process.After AO irradiation with the fluence of 7.9×10^(20)atoms·cm^(–2),the erosion yield of the SiO_(x)C_(y)H_(z)-coated Kapton was less than 2.30×10^(–26)cm^3·atom^(–1),which was less than 0.77%of that of the Kapton.It indicates that the SiO_(x)C_(y)H_(z)coating can well prevent the erosion of Kapton by AO.In addition,it was also clarified that a SiO_(2) passivation layer was formed on the surface of the SiO_(x)C_(y)H_(z)coating during AO irradiation,which exhibited a‘self-reinforcing’defense mechanism.The entire preparation process of the SiO_(x)C_(y)H_(z)coating was highly efficient and low-cost,and it has shown great potential for applications in LEO.
文摘Copper thin films were deposited by plasma-enhanced atomic layer deposition at low temperature,using copper(I)-N,N′-di-sec-butylacetamidinate as a precursor and hydrogen as a reductive gas.The influence of temperature,plasma power,mode of plasma,and pulse time,on the deposition rate of copper thin film,the purity of the film and the step coverage were studied.The feasibility of copper film deposition on the inner wall of a carbon fibre reinforced plastic waveguide with high aspect ratio was also studied.The morphology and composition of the thin film were studied by atomic force microscopy and x-ray photoelectron spectroscopy,respectively.The square resistance of the thin film was also tested by a four-probe technique.On the basis of on-line diagnosis,a growth mechanism of copper thin film was put forward,and it was considered that surface functional group played an important role in the process of nucleation and in determining the properties of thin films.A high density of plasma and high free-radical content were helpful for the deposition of copper thin films.