Ti O2-organic multilayered nanocomposite films were deposited on a self-assembled monolayer-coated silicon substrate based on layer-by-layer technique and chemical bath deposition method by a hydrolysis of Ti Cl4 in a...Ti O2-organic multilayered nanocomposite films were deposited on a self-assembled monolayer-coated silicon substrate based on layer-by-layer technique and chemical bath deposition method by a hydrolysis of Ti Cl4 in an acid aqueous solution. The chemical compositions, surface morphologies and mechanical properties of the films were investigated by X-ray photoelectron spectrometer(XPS), scanning electron microscopy(SEM) and nanoindentation depth-sensing technique, respectively. The results indicate that the major chemical compositions of the films are Ti and O. The principal mechanism for the nucleation and growth of the films is homogeneous nucleation, and the layer number of films has great influence on the surface morphology and roughness of the films. In addition, mechanical nanoindentation testing presents a significant increase in hardness and fracture toughness of titanium dioxide multilayered films compared with single-layer titanium dioxide thin film.展开更多
杭白菊由于易受潮、变色、发霉及虫蛀而引起货架期较短,影响着市场的供应和销售量的增加。本研究表明:1)杭白菊的货架期受包装材料的影响较大,采用复合薄膜袋 A 或 B 包装贮藏300天以上的杭白菊仍能保持原有的色、香、味;2)选择适宜的...杭白菊由于易受潮、变色、发霉及虫蛀而引起货架期较短,影响着市场的供应和销售量的增加。本研究表明:1)杭白菊的货架期受包装材料的影响较大,采用复合薄膜袋 A 或 B 包装贮藏300天以上的杭白菊仍能保持原有的色、香、味;2)选择适宜的辐照剂量是杭白菊综合保藏技术的关键之一,其中以3KGy~5KGy 的效果最佳。用10KGyr 射线处理杭白菊对其主要品质指标无明照影响:3)辐照剂最率不影响处理效果。展开更多
Titanium oxide thin films were prepared on self-assembled monolayers-coated silicon substrate using layer-by-layer self-assembly method and chemical bath deposition from an aqueous solution. The effects of temperature...Titanium oxide thin films were prepared on self-assembled monolayers-coated silicon substrate using layer-by-layer self-assembly method and chemical bath deposition from an aqueous solution. The effects of temperature on structural properties, thickness and morphologies of titanium oxide thin films were investigated. The results show that the absorption peak of peroxo complexes of titanium at 410 nm decreases gradually with increasing the temperature. The deposited films consisting of titanium oxide nanocrystals are believed to be fully amorphous by XRD. Titanium oxide thin films fabricated at 60 °C for 2 h are continuous, dense and homogeneous with a size in the range of 20-40 nm by SEM. The chemical compositions of deposited thin films were studied by EDS, and the mole ratio of O to Ti is 2.2:1.展开更多
An experiment on retail film packaging system was conducted to compare the atmospheric composition within sealed packs containing rambutan fruits. This research was done in order to study the effect of packaging films...An experiment on retail film packaging system was conducted to compare the atmospheric composition within sealed packs containing rambutan fruits. This research was done in order to study the effect of packaging films with different permeability on the some of physicochemical properties of rambutan during storage at 10℃. The films used were 0.090 mm low density polyethylene (LDPE), 0.040 mm polyprophylene and 0.057 mm LDPE compared unwrapped fruits. Fruits were evaluated every 5 days for changes in moisture content, total sugars, vitamin C, hardness and color. Unwrapped rambutan had severe browning after 10 days. Sealed packages especially the LDPE had delayed the development of the browning for 20 days of storage and had the lowest weight loss.展开更多
Interface characteristics possess very important influence on the performance of thin film devices. ITO/ PTCDA/p-Si thin film device was set up with vacuum evaporation and sputter deposition method. The surface and in...Interface characteristics possess very important influence on the performance of thin film devices. ITO/ PTCDA/p-Si thin film device was set up with vacuum evaporation and sputter deposition method. The surface and interface electron states of ITO/PTCDA/p-Si were investigated by X-ray photoelectron spectroscopy (XPS) and argon ion beam etch techniques. Results indicate that at the interface of ITO/PTODA/p- Si,not only ITO/PTCDA-Si but also PDCDA-Si can produce diffusion. Moreover, the XPS spectra of each atom appear chemical shifts, and the chemical shifts of C1s and O1s are more remarkable.展开更多
Novel composites were synthesized using AEPTES (3-(2-aminoethylamino)propyltriethoxysilane), which behaves as an excellent dispersant for MWCNTs (multiwall carbon nanotubes) in polymer film matrices. The thickne...Novel composites were synthesized using AEPTES (3-(2-aminoethylamino)propyltriethoxysilane), which behaves as an excellent dispersant for MWCNTs (multiwall carbon nanotubes) in polymer film matrices. The thickness of the synthesized nanocomposite films ranged from 50 to 70 lam, having well-dispersed MWCNTs. Increasing the AEPTES concentration from 0.0196 to 0.0300 M, increased the amine content and the dispersion of MWCNTs. The film synthesized at 0.0300 M AETPES exhibited the greatest degree of dispersion among the three samples, which is consistent with a self-assembled silane group interacting with the MWCNT surface.展开更多
As instrument technology is needed for rapid determination of the smaller,thinner and lighter specimens,more stringent demands are related to thin films such as micro-electro-mechanical systems(MEMS),dielectric coatin...As instrument technology is needed for rapid determination of the smaller,thinner and lighter specimens,more stringent demands are related to thin films such as micro-electro-mechanical systems(MEMS),dielectric coatings and electronic packaging.Therefore,the requirement for testing platforms for rapidly determine the mechanical properties of thin films is increasing.Buckling of a film/substrate system could offer a variety of applications,ranging from stretchable electronics to micro-nanoscale metrology.In this paper,a fatigue-loading device has been designed to make the cyclic loading available for investigating the cumulative propagation of thin film buckling.The straight side buckling of thin compressed titanium film with the thickness of 50 nm deposited on organic glass substrates is investigated by using an optical microscope.The cumulative buckling propagation under the cyclic loading of a sequence of peak compression with the frequency 1 Hz is recorded by CCD camera.The buckling extension lengths are calculated by digital image measurement technology.展开更多
A cobalt-based catalyst was directly photo-deposited on the surface of a widely used n-type nano-structured semiconductor(TiO_(2)).Different thicknesses of the TiO 2 films as well as different time of photo-deposition...A cobalt-based catalyst was directly photo-deposited on the surface of a widely used n-type nano-structured semiconductor(TiO_(2)).Different thicknesses of the TiO 2 films as well as different time of photo-deposition of the Co-based catalyst on TiO_(2) films have been optimized.It was found that the electrode with 3 layers of TiO_(2) film(in 8 m thickness) and 1 hour photo-deposition of the cobalt-based catalyst by light irradiation from a 500 W Xenon lamp gave the highest current density(~5 mA/cm^(2)).Using this cobalt-modified TiO_(2) film as a working electrode in an electrochemical device,highly efficient water oxidation has been demonstrated in a pH 7.0 aqueous solution with low overpotential.展开更多
A novel arc-shaped piezoelectric generator based on flexible PVDF thin film is presented and systemically studied.With a periodical external force,the generator can produce peak voltage of 45.6 V and peak power of 30....A novel arc-shaped piezoelectric generator based on flexible PVDF thin film is presented and systemically studied.With a periodical external force,the generator can produce peak voltage of 45.6 V and peak power of 30.7μW.The maximum power density reaches 38.4μW/cm3with a 4 cm×2 cm×100μm device,at the optimum load resistance of 33.33 MOhm.The influence of frequency,size dimension and load resistance are investigated through experimental measurements.With this high output arc-shaped generator,capacitors can be effectively charged and three commercial LEDs have been directly lighted without any energy storage unit.展开更多
Although remarkable progress has been witnessed in mimicking the nacre-like architecture in laboratory,it remains a great challenge for understanding the unique balancing mechanism of toughness and strength in biologi...Although remarkable progress has been witnessed in mimicking the nacre-like architecture in laboratory,it remains a great challenge for understanding the unique balancing mechanism of toughness and strength in biological materials. Here,taking advantage of the synergistic effect of different dimensional nanoscale building blocks,we fabricate nacre-like films that reconcile high strength and toughness.The obtained ternary lamellar composite films are constructed by one-dimensional xonotlite nanowires and two-dimensional montmorillonite nanosheets with the assistance of poly(vinyl alcohol). The ternary composite films show high strength((241.8±10.2)MPa) and toughness((5.85±0.46) MJ m^-3),both of which are higher than that of the single nanofibrillar xonotlite network films or the binary montmorillonite/poly(vinyl alcohol) composite films. The excellent mechanical properties of the nacre-like ternary composite films are aroused by the synergistic toughening mechanism of the different dimensional building blocks. This strategy provides a facile approach to integrate the nacre-like composite films with potential applications in tissue engineering scaffold,strong air barrier coatings,and fire-retardant packing materials.展开更多
Many technological applications require templates with nanoscale patterns.Block copolymer self-assembly is a method of choice for obtaining a large variety of such patterns,with greatest flexibility achieved when comb...Many technological applications require templates with nanoscale patterns.Block copolymer self-assembly is a method of choice for obtaining a large variety of such patterns,with greatest flexibility achieved when combined with a supramolecular approach.One of the ways to fabricate block copolymer templates is the Langmuir-Blodgett (LB) technique.Here,we briefly summarize recent work with LB films of polystyrene-poly(4-vinyl pyridine) (PS-P4VP) mixed with 3-n-pentade cylphenol (PDP),illustrating the different types of patterns possible and the principles governing them.One interesting pattern that can be easily achieved with this system is the so-called "nanostrand network",which,when used as a template for gold deposition,can produce double striped lines of gold.Here,we show how this pattern can be modified by acetone swelling to give rise to gold monolayer ribbons with internal structure.The results also suggest new insights into the early stages of morphology formation at the air/water interface.展开更多
基金Projects(51204036,51234009)supported by the National Natural Science Foundation of ChinaProject(2014CB643405)supported by the National Basic Research Program of China
文摘Ti O2-organic multilayered nanocomposite films were deposited on a self-assembled monolayer-coated silicon substrate based on layer-by-layer technique and chemical bath deposition method by a hydrolysis of Ti Cl4 in an acid aqueous solution. The chemical compositions, surface morphologies and mechanical properties of the films were investigated by X-ray photoelectron spectrometer(XPS), scanning electron microscopy(SEM) and nanoindentation depth-sensing technique, respectively. The results indicate that the major chemical compositions of the films are Ti and O. The principal mechanism for the nucleation and growth of the films is homogeneous nucleation, and the layer number of films has great influence on the surface morphology and roughness of the films. In addition, mechanical nanoindentation testing presents a significant increase in hardness and fracture toughness of titanium dioxide multilayered films compared with single-layer titanium dioxide thin film.
文摘杭白菊由于易受潮、变色、发霉及虫蛀而引起货架期较短,影响着市场的供应和销售量的增加。本研究表明:1)杭白菊的货架期受包装材料的影响较大,采用复合薄膜袋 A 或 B 包装贮藏300天以上的杭白菊仍能保持原有的色、香、味;2)选择适宜的辐照剂量是杭白菊综合保藏技术的关键之一,其中以3KGy~5KGy 的效果最佳。用10KGyr 射线处理杭白菊对其主要品质指标无明照影响:3)辐照剂最率不影响处理效果。
基金Projects(51204036,51234009)supported by the National Natural Science Foundation of ChinaProject(20110042120014)supported by the Research Fund for the Doctoral Program of Higher Education,China
文摘Titanium oxide thin films were prepared on self-assembled monolayers-coated silicon substrate using layer-by-layer self-assembly method and chemical bath deposition from an aqueous solution. The effects of temperature on structural properties, thickness and morphologies of titanium oxide thin films were investigated. The results show that the absorption peak of peroxo complexes of titanium at 410 nm decreases gradually with increasing the temperature. The deposited films consisting of titanium oxide nanocrystals are believed to be fully amorphous by XRD. Titanium oxide thin films fabricated at 60 °C for 2 h are continuous, dense and homogeneous with a size in the range of 20-40 nm by SEM. The chemical compositions of deposited thin films were studied by EDS, and the mole ratio of O to Ti is 2.2:1.
文摘An experiment on retail film packaging system was conducted to compare the atmospheric composition within sealed packs containing rambutan fruits. This research was done in order to study the effect of packaging films with different permeability on the some of physicochemical properties of rambutan during storage at 10℃. The films used were 0.090 mm low density polyethylene (LDPE), 0.040 mm polyprophylene and 0.057 mm LDPE compared unwrapped fruits. Fruits were evaluated every 5 days for changes in moisture content, total sugars, vitamin C, hardness and color. Unwrapped rambutan had severe browning after 10 days. Sealed packages especially the LDPE had delayed the development of the browning for 20 days of storage and had the lowest weight loss.
基金Project is supported by the National Natural Science Foundationof China (Grant No 60076023)
文摘Interface characteristics possess very important influence on the performance of thin film devices. ITO/ PTCDA/p-Si thin film device was set up with vacuum evaporation and sputter deposition method. The surface and interface electron states of ITO/PTCDA/p-Si were investigated by X-ray photoelectron spectroscopy (XPS) and argon ion beam etch techniques. Results indicate that at the interface of ITO/PTODA/p- Si,not only ITO/PTCDA-Si but also PDCDA-Si can produce diffusion. Moreover, the XPS spectra of each atom appear chemical shifts, and the chemical shifts of C1s and O1s are more remarkable.
文摘Novel composites were synthesized using AEPTES (3-(2-aminoethylamino)propyltriethoxysilane), which behaves as an excellent dispersant for MWCNTs (multiwall carbon nanotubes) in polymer film matrices. The thickness of the synthesized nanocomposite films ranged from 50 to 70 lam, having well-dispersed MWCNTs. Increasing the AEPTES concentration from 0.0196 to 0.0300 M, increased the amine content and the dispersion of MWCNTs. The film synthesized at 0.0300 M AETPES exhibited the greatest degree of dispersion among the three samples, which is consistent with a self-assembled silane group interacting with the MWCNT surface.
基金supported by the National Natural Science Foundation of China (Grant Nos 10372069, 10732080, 11072174 and 10672120)the Tianjin Natural Science Foundation (Grant No 06YFJZJC00700)
文摘As instrument technology is needed for rapid determination of the smaller,thinner and lighter specimens,more stringent demands are related to thin films such as micro-electro-mechanical systems(MEMS),dielectric coatings and electronic packaging.Therefore,the requirement for testing platforms for rapidly determine the mechanical properties of thin films is increasing.Buckling of a film/substrate system could offer a variety of applications,ranging from stretchable electronics to micro-nanoscale metrology.In this paper,a fatigue-loading device has been designed to make the cyclic loading available for investigating the cumulative propagation of thin film buckling.The straight side buckling of thin compressed titanium film with the thickness of 50 nm deposited on organic glass substrates is investigated by using an optical microscope.The cumulative buckling propagation under the cyclic loading of a sequence of peak compression with the frequency 1 Hz is recorded by CCD camera.The buckling extension lengths are calculated by digital image measurement technology.
基金supported by Swedish Energy Agency,the Knutand Alice Wallenberg Foundation,China Scholarship Council (CSC)the Natural Natural Science Foundation of China (21120102036)the National Basic Research Program of China (2009CB220009)
文摘A cobalt-based catalyst was directly photo-deposited on the surface of a widely used n-type nano-structured semiconductor(TiO_(2)).Different thicknesses of the TiO 2 films as well as different time of photo-deposition of the Co-based catalyst on TiO_(2) films have been optimized.It was found that the electrode with 3 layers of TiO_(2) film(in 8 m thickness) and 1 hour photo-deposition of the cobalt-based catalyst by light irradiation from a 500 W Xenon lamp gave the highest current density(~5 mA/cm^(2)).Using this cobalt-modified TiO_(2) film as a working electrode in an electrochemical device,highly efficient water oxidation has been demonstrated in a pH 7.0 aqueous solution with low overpotential.
基金supported by the National Natural Science Foundation of China(Grant Nos.61176103,91023045)the National Hi-Tech Research and Development Program("863" Project)(Grant No.2013AA041102)the National Ph.D.Foundation Project(Grant No.20110001110103)
文摘A novel arc-shaped piezoelectric generator based on flexible PVDF thin film is presented and systemically studied.With a periodical external force,the generator can produce peak voltage of 45.6 V and peak power of 30.7μW.The maximum power density reaches 38.4μW/cm3with a 4 cm×2 cm×100μm device,at the optimum load resistance of 33.33 MOhm.The influence of frequency,size dimension and load resistance are investigated through experimental measurements.With this high output arc-shaped generator,capacitors can be effectively charged and three commercial LEDs have been directly lighted without any energy storage unit.
基金supported by the National Natural Science Foundation of China (51732011 and 21431006)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (21521001)+1 种基金the National Basic Research Program of China (2014CB931800)the Users with Excellence and Scientific Research Grant of Hefei Science Center of Chinese Academy of Sciences (2015HSC-UE007 and 2015SRG-HSC038)
文摘Although remarkable progress has been witnessed in mimicking the nacre-like architecture in laboratory,it remains a great challenge for understanding the unique balancing mechanism of toughness and strength in biological materials. Here,taking advantage of the synergistic effect of different dimensional nanoscale building blocks,we fabricate nacre-like films that reconcile high strength and toughness.The obtained ternary lamellar composite films are constructed by one-dimensional xonotlite nanowires and two-dimensional montmorillonite nanosheets with the assistance of poly(vinyl alcohol). The ternary composite films show high strength((241.8±10.2)MPa) and toughness((5.85±0.46) MJ m^-3),both of which are higher than that of the single nanofibrillar xonotlite network films or the binary montmorillonite/poly(vinyl alcohol) composite films. The excellent mechanical properties of the nacre-like ternary composite films are aroused by the synergistic toughening mechanism of the different dimensional building blocks. This strategy provides a facile approach to integrate the nacre-like composite films with potential applications in tissue engineering scaffold,strong air barrier coatings,and fire-retardant packing materials.
基金supported by the Natural Sciences and Engineering Council of Canada (NSERC)the Fonds de recherches du Québec-Nature et Technologies (FQRNT)
文摘Many technological applications require templates with nanoscale patterns.Block copolymer self-assembly is a method of choice for obtaining a large variety of such patterns,with greatest flexibility achieved when combined with a supramolecular approach.One of the ways to fabricate block copolymer templates is the Langmuir-Blodgett (LB) technique.Here,we briefly summarize recent work with LB films of polystyrene-poly(4-vinyl pyridine) (PS-P4VP) mixed with 3-n-pentade cylphenol (PDP),illustrating the different types of patterns possible and the principles governing them.One interesting pattern that can be easily achieved with this system is the so-called "nanostrand network",which,when used as a template for gold deposition,can produce double striped lines of gold.Here,we show how this pattern can be modified by acetone swelling to give rise to gold monolayer ribbons with internal structure.The results also suggest new insights into the early stages of morphology formation at the air/water interface.