The dissipation of energy during the process of contact and separation between a tip and a sample is very important for understanding the phase images in the tapping mode of atomic force microscopes（AFMs）. In this s...The dissipation of energy during the process of contact and separation between a tip and a sample is very important for understanding the phase images in the tapping mode of atomic force microscopes（AFMs）. In this study, a method is presented to measure the dissipated energy between a tip and a sample. The experimental results are found to be in good agreement with the theoretical model, which indicates that the method is reliable.Also, this study confirms that liquid bridges are mainly produced by extrusion modes in the tapping mode of AFMs.展开更多
A novel templated LiFePO_4 cathode material was prepared with linear polyacrylamide, which exhibited excellent electrochemical properties, such as a 109.3 mA·h/g capacity at a rate of C/3 and a 120 mA·h/g ca...A novel templated LiFePO_4 cathode material was prepared with linear polyacrylamide, which exhibited excellent electrochemical properties, such as a 109.3 mA·h/g capacity at a rate of C/3 and a 120 mA·h/g capacity at a rate of C/6 as well as a good cycliability. We proposed the templating mechanism based upon the precursors′ TG-DTA curves, X-ray diffraction patterns and FTIR spectra of the samples at different temperatures. A tapping-mode atomic force microscope was used to investigate the surfaces of the end products. We found that the polyacrylamide template produced metal organic compounds in the cross-linked gel precursor, and thereby modified the crystallization and particle surfaces during calcining. The template was “removed” in the end, which was partially pyrolyzed into the spiral carbon to form a conductive network with nanocrys\|talline LiFePO_4 highly monodispersed in it.展开更多
The carbon nanotube (fundamentally Single- walled carbon nanotube, SWCNT) based on 1-Amino-undecanethiol (AUT) were extremely controlled (nano-level) organizing a vertical self-assembled monolayer (SAM) on gold single...The carbon nanotube (fundamentally Single- walled carbon nanotube, SWCNT) based on 1-Amino-undecanethiol (AUT) were extremely controlled (nano-level) organizing a vertical self-assembled monolayer (SAM) on gold single crystal surfaces. The produced nano-surfaces were explored particularly by Fourier Transform Infra-red Spectroscopy (FT-IR), Cyclic Voltammetry (CV), Raman spectroscopy, Electrochemi- cal quartz crystal microbalance (EQCM), and Atomic force microscopy (AFM) techniques. The SWCNTs were initially cut (chemically) into short pipes and thiol-derivatized at the open ends. The vertical aggregation of SWCNT-AUTs on chemically refined Au(111) substrates was made-up by their spontaneous chemical bonding among carboxyl derivatized SWCNT-COOH and AUT SAM on Au(111), via peptide bonds, or directly by synthesized SWCNT-AUT composites. Raman spectroscopy and AFM surface images obviously disclosed that the SWCNT- AUT (dia. 20~40 nm) has been vertically categorized d on gold (111) substrates, shaping a SAM with a perpendicular direction.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11572031 and 11642013the Opening Fund of State Key Laboratory of Nonlinear Mechanics
文摘The dissipation of energy during the process of contact and separation between a tip and a sample is very important for understanding the phase images in the tapping mode of atomic force microscopes（AFMs）. In this study, a method is presented to measure the dissipated energy between a tip and a sample. The experimental results are found to be in good agreement with the theoretical model, which indicates that the method is reliable.Also, this study confirms that liquid bridges are mainly produced by extrusion modes in the tapping mode of AFMs.
文摘A novel templated LiFePO_4 cathode material was prepared with linear polyacrylamide, which exhibited excellent electrochemical properties, such as a 109.3 mA·h/g capacity at a rate of C/3 and a 120 mA·h/g capacity at a rate of C/6 as well as a good cycliability. We proposed the templating mechanism based upon the precursors′ TG-DTA curves, X-ray diffraction patterns and FTIR spectra of the samples at different temperatures. A tapping-mode atomic force microscope was used to investigate the surfaces of the end products. We found that the polyacrylamide template produced metal organic compounds in the cross-linked gel precursor, and thereby modified the crystallization and particle surfaces during calcining. The template was “removed” in the end, which was partially pyrolyzed into the spiral carbon to form a conductive network with nanocrys\|talline LiFePO_4 highly monodispersed in it.
文摘The carbon nanotube (fundamentally Single- walled carbon nanotube, SWCNT) based on 1-Amino-undecanethiol (AUT) were extremely controlled (nano-level) organizing a vertical self-assembled monolayer (SAM) on gold single crystal surfaces. The produced nano-surfaces were explored particularly by Fourier Transform Infra-red Spectroscopy (FT-IR), Cyclic Voltammetry (CV), Raman spectroscopy, Electrochemi- cal quartz crystal microbalance (EQCM), and Atomic force microscopy (AFM) techniques. The SWCNTs were initially cut (chemically) into short pipes and thiol-derivatized at the open ends. The vertical aggregation of SWCNT-AUTs on chemically refined Au(111) substrates was made-up by their spontaneous chemical bonding among carboxyl derivatized SWCNT-COOH and AUT SAM on Au(111), via peptide bonds, or directly by synthesized SWCNT-AUT composites. Raman spectroscopy and AFM surface images obviously disclosed that the SWCNT- AUT (dia. 20~40 nm) has been vertically categorized d on gold (111) substrates, shaping a SAM with a perpendicular direction.
