An overview of the advances in studies on tribology of molecular deposition （MD） films is presented here to summarize the studies of nanofrictional properties, adhesion, wear and mechanical behavior, as well as the ...An overview of the advances in studies on tribology of molecular deposition （MD） films is presented here to summarize the studies of nanofrictional properties, adhesion, wear and mechanical behavior, as well as the molecular dynamics simulation of nanotribological properties of the film in the last decade. Some key research topics which need to be investigate further are addressed.展开更多
Experiment of the molecular deposition (MD) films with and without alkyl terminal de-posited on the silicon wafer were conducted by using nanoindentation. It was found that MD filmsand alkyl terminated MD films exhibi...Experiment of the molecular deposition (MD) films with and without alkyl terminal de-posited on the silicon wafer were conducted by using nanoindentation. It was found that MD filmsand alkyl terminated MD films exhibit higher critical load (scratch resistance or adhesive strength)and lower coefficient of friction compared with the silicon substrate. Critical load (scratch resis-tance) increases with the number of layers, and coefficients of friction of those MD film with alkylterminal are still best for the same layer of MD film.展开更多
The result of UV-Vis adsorbance indicates that phthalocyanine copper cation and anion monolayers are alternately deposited, and dimmer is the major form. Through analyzing the 20th phthalocyanine MD film AFM image, we...The result of UV-Vis adsorbance indicates that phthalocyanine copper cation and anion monolayers are alternately deposited, and dimmer is the major form. Through analyzing the 20th phthalocyanine MD film AFM image, we know that the surface of MD film is flat and compact. The physical-chemical properties of molecular end-group have influence on the MD films surface character notably. The contact angles of water on the odd and even layer MD films vary greatly complying with "odd-even" regularity, and the value increases slightly with the increment of MD film layers due to the decrease of van der Waals force reinforced by substrate through MD films.展开更多
The nanofriction properties of Au substrate and monolayer molecular deposition film and multilayer molecular deposition films on Au substrate and the molecular deposition films modified with alkyl-terminal molecule ha...The nanofriction properties of Au substrate and monolayer molecular deposition film and multilayer molecular deposition films on Au substrate and the molecular deposition films modified with alkyl-terminal molecule have been investigated by using an atomic force microscope. It is concluded that (i) the deposition of molecular deposition films on Au substrate and the modification of alkyl-terminal molecule to the molecular deposition films can reduce the frictional force; (ii) the molecular deposition films with the same terminal exhibit similar nanofriction properties, which has nothing to do with the molecular chain-length and the layer number; (iii) the unstable nanofriction properties of molecular deposition films are contributed to the active terminal of the molecular deposition film, which can be eliminated by decorating the active molecular deposition film with alkyl-terminal molecule, moreover, the decoration of alkyl-terminal molecule can lower the frictional force conspicuously; (iv) the relative humidity affects the frictional force; the higher the RH, the lower the frictional force.展开更多
基金the National Natural Science Foundation of China(Grant No.50575171)the National Basic Research Program of China(Grant No.2007CB607604)the Open Financial Fund of the State Key Laboratory of Tribology of Tsinghua University(Grant No.SKLT05-02).
文摘An overview of the advances in studies on tribology of molecular deposition （MD） films is presented here to summarize the studies of nanofrictional properties, adhesion, wear and mechanical behavior, as well as the molecular dynamics simulation of nanotribological properties of the film in the last decade. Some key research topics which need to be investigate further are addressed.
基金Project supported by the National Natural Science Foundation of China(Grant No.59735110)and the Institute of high Education Science Foundation established by the State Education Commission(Grant No.97042510)
文摘Experiment of the molecular deposition (MD) films with and without alkyl terminal de-posited on the silicon wafer were conducted by using nanoindentation. It was found that MD filmsand alkyl terminated MD films exhibit higher critical load (scratch resistance or adhesive strength)and lower coefficient of friction compared with the silicon substrate. Critical load (scratch resis-tance) increases with the number of layers, and coefficients of friction of those MD film with alkylterminal are still best for the same layer of MD film.
文摘The result of UV-Vis adsorbance indicates that phthalocyanine copper cation and anion monolayers are alternately deposited, and dimmer is the major form. Through analyzing the 20th phthalocyanine MD film AFM image, we know that the surface of MD film is flat and compact. The physical-chemical properties of molecular end-group have influence on the MD films surface character notably. The contact angles of water on the odd and even layer MD films vary greatly complying with "odd-even" regularity, and the value increases slightly with the increment of MD film layers due to the decrease of van der Waals force reinforced by substrate through MD films.
基金This work was supported by the National Natural Science Foundation of China(Grant No.59735110).The authors thank Associate Profs.Wang Deguo for his helpful discussions and Lin Li for his help in the experiment.
文摘The nanofriction properties of Au substrate and monolayer molecular deposition film and multilayer molecular deposition films on Au substrate and the molecular deposition films modified with alkyl-terminal molecule have been investigated by using an atomic force microscope. It is concluded that (i) the deposition of molecular deposition films on Au substrate and the modification of alkyl-terminal molecule to the molecular deposition films can reduce the frictional force; (ii) the molecular deposition films with the same terminal exhibit similar nanofriction properties, which has nothing to do with the molecular chain-length and the layer number; (iii) the unstable nanofriction properties of molecular deposition films are contributed to the active terminal of the molecular deposition film, which can be eliminated by decorating the active molecular deposition film with alkyl-terminal molecule, moreover, the decoration of alkyl-terminal molecule can lower the frictional force conspicuously; (iv) the relative humidity affects the frictional force; the higher the RH, the lower the frictional force.
