This review covers the recent developments in the field of biobased packaging materials. Special emphasis is placed on the barrier properties, which are crucial in terms of food packaging. The state-of-the-art of seve...This review covers the recent developments in the field of biobased packaging materials. Special emphasis is placed on the barrier properties, which are crucial in terms of food packaging. The state-of-the-art of several biopolymers including pectin, starch, chitosan, xylan, galactoglucomannan, lignin and cellulose nanofibrils is discussed. As in most cases the packaging related properties of single layer biopolymer films are inadequate, the thin film coatings, such as sol-gel and ALD (atomic layer deposition), as well as the multilayer coatings are also briefly touched.展开更多
This work was made to investigate how nucleation and growth behavior of the coating film were affected by surface topographies of Mg–Al–Zn alloy substrate during the initial stage of plasma electrolytic oxidation(PE...This work was made to investigate how nucleation and growth behavior of the coating film were affected by surface topographies of Mg–Al–Zn alloy substrate during the initial stage of plasma electrolytic oxidation(PEO).To satisfy this end,a single substrate was prepared by mechanical treatment exhibiting rough and smooth regions with an equal area on the surface.The rough region with prominent hills and grooves induced the breakdown of passive film,which was indicated by an early appearance of plasma discharge on the rough region since nucleation of coating film occurred preferentially around the hills.However,the coating film grown on the grooves was somewhat thicker and more porous than the film grown on the hills and smooth regions.This was due to the fact that the growth of the coating film was found to be localized in the presence of rough region,which was in line with the discharge activities.Herein,the nucleation and growth behavior during the initial stage of PEO will be discussed schematically on the basis of microstructural interpretation.展开更多
This paper puts forward the two methods of weightlessness and alkoxyl group content determination to calculate the amount of cross-linking agent after elaborating the curing essence of silicone paint under the action ...This paper puts forward the two methods of weightlessness and alkoxyl group content determination to calculate the amount of cross-linking agent after elaborating the curing essence of silicone paint under the action of catalysis , and provides the theoretical basis of fixing the amoount of cross-linking agent accurately and quantitatively. At the same time, the structure of coating film is studied by the use of photoelectronic spectromenter and some other modern technology, and verified in theory. At last, this paper analyses the layer structure and the relationship between it and the coating properties.展开更多
The onset of instability with respect to the spatio-temporally growing disturbance in a viscosity-stratified two-layer liquid film flow is analyzed. The known results obtained from the temporal theory of instability s...The onset of instability with respect to the spatio-temporally growing disturbance in a viscosity-stratified two-layer liquid film flow is analyzed. The known results obtained from the temporal theory of instability show that the flow is unstable in the limit of zero Reynolds numbers. The present theory predicts the neutral stability in the same limit. The discrepancy is explained. Based on the mechanical energy equation, a new mechanism of instability is found. The new mechanism is associated with the convective nature of the disturbance that is not Galilei invariant.展开更多
A simple method of carbon film coating used in CdZnTe crystal growth was developed. The optimum parameters were selected. Breakdown of carbon film was commonly seen if Cd reservoir was not used in the crystal growth. ...A simple method of carbon film coating used in CdZnTe crystal growth was developed. The optimum parameters were selected. Breakdown of carbon film was commonly seen if Cd reservoir was not used in the crystal growth. The carbon film was in good condition when the vapor pressure of Cd was kept around 0.1 MPa during crystal growth.展开更多
Film coating is an important unit operation to produce solid dosage forms,thereby,the monitoring of this process is helpful to find problems in time and improve the quality of coated products.Traditional methods adopt...Film coating is an important unit operation to produce solid dosage forms,thereby,the monitoring of this process is helpful to find problems in time and improve the quality of coated products.Traditional methods adopted to monitor this process include measurement of coating weight gain,performance of disintegration and dissolution test,etc.However,not only do these methods cause destruction to the samples,but also consume time and energy.There have recently emerged the applications of process analytical technologies(PAT)on film coating,especially some novel spectroscopic and imaging technologies,which have the potential to real-time track the progress in film coating and optimize production efficiency.This article gives an overview on the application of such technologies for film coating,with the goal to provide a reference for the further researches.展开更多
A cyanine dye, 2-[7-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1,3,5-heptatrienyl]-1,3,3-trimethyl-3H-indolium iodide (NK-125), is doped in 4-cyano-4'-pentylbiphenyl (5 CB), and the mixture is sandwiched ...A cyanine dye, 2-[7-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1,3,5-heptatrienyl]-1,3,3-trimethyl-3H-indolium iodide (NK-125), is doped in 4-cyano-4'-pentylbiphenyl (5 CB), and the mixture is sandwiched between two pieces of rubbed glass plates. The third-order nonlinear optical properties of the oriented NK-125-SCB layers are measured by the resonant femtosecond degenerate four-wave mixing (DFWM) technique at 760 nm. The third-order nonlinear optical susceptibility of one of the present samples is 5.5×10^-8 esu. The slow DFWM response of the NK-125-SCB layers due to a population grating is accelerated by the increasing laser power because of amplified spontaneous emission (ASE). On the other hand, we do not observe a similar phenomenon for NK-125- polyethylene glycol (PEG-400). Oriented NK-125 molecules in nematic liquid crystals must have very high ASE efficiency. Hence the population grating in a DFWM signal disappears within about 4 ps. It is expected that NK-125-SCB can be used as a material for very fast all-optical switching.展开更多
Sea bass(Lateolabrax maculatus)is one of the important seafood in China.Its shelf-life under refrigerated storage exponentially deteriorate due to the growth of spoilage microorganisms,protein degradation and lipid ox...Sea bass(Lateolabrax maculatus)is one of the important seafood in China.Its shelf-life under refrigerated storage exponentially deteriorate due to the growth of spoilage microorganisms,protein degradation and lipid oxidation.In this study,4 coating materials namely,konjac glucomannan-whey protein isolate(KGM-WPI)film,chitosan-sweet potato starch(CHI-SPS)film,chitosan-bamboo fungus(CHI-BF)film,and chitosan-boehmite alumina(CHI-BAH)have been explored to enhance the shelf life of sea bass during 8 days of refrigerated storage.Overall,CHI-BF was observed to be best in retaining hardness,gumminess and maintaining total volatile basic nitrogen value.Whereas CHI-SPS was found to retain chewiness and maintain lower values for drip loss and peroxide value.CHI-BAH coating was observed to maintain the lower values for pH and EC values of sea bass under refrigerated storage.However,the least increase in total viable count and minimum change in b^(*)value was observed in the case of sea bass coated with KGM-WPI.The current research fi ndings provide a new practical storage method for the entire fresh fish.The fresh fish can be coated with different coating materials and store on the ice at 4℃without packaging during retailing.These film coated whole fresh fish retains its microbial and sensory quality.展开更多
Premature failure of coated tool often results from a poor adhesion of coating-substrate and shortens the lifetime of the tool. The results of increasing the adhesion strength of thin film coatings on cutting tool ins...Premature failure of coated tool often results from a poor adhesion of coating-substrate and shortens the lifetime of the tool. The results of increasing the adhesion strength of thin film coatings on cutting tool inserts by pretreating the inserts with sandblasting technique to obtain a desirable surface morphology of the inserts are presented. A geometric model representing the ideal surface morphology is established to enhance the nucleation density and adhesion strength of coating-substrate. Thin film coating experiment is conducted on the substrates of four different sample groups. Indentation and wear tests are performed on coated inserts to evaluate the effect of sandblasting on the adhesion strength of the coatings. A theoretical analysis is provided on the formation and growth of atom clusters in terms of the contact angle and the thermodynamic barrier of a substrate to predict thin film nucleation.展开更多
In this study,heat-denatured and alcalase-hydrolyzed whey and soy protein films/coatings containing marjoram essential oil(MEO)and thyme extract(TE)were investigated comparatively in terms of physicochemical and funct...In this study,heat-denatured and alcalase-hydrolyzed whey and soy protein films/coatings containing marjoram essential oil(MEO)and thyme extract(TE)were investigated comparatively in terms of physicochemical and functional properties.Heat-denaturated high protein solutions produced self-standing,smooth,transparent and viscoelastic films in the presence of glycerol.Enzymatic hydrolysis provided transparency,elasticity and extensibility to the films of low protein solutions.The addition of MEO and TE triggered hardness and brittleness especially in hydrolyzed high protein films and remarkably changed film color,thickness and viscosity possibly affecting surface adherence of films.Heat denatured films exhibited higher water vapor permeability(WVP)than alcalase-hydrolyzed ones.The lowest hardness was obtained in hydrolyzed low protein films with considerable adhesiveness.Hydrolyzed protein solutions coated to cheese provided better protection against moisture loss and MEO added films caused elevated hardening of cheese.MEO and TE incorporated in film matrices were seemed to suppress mycelial growth and sporulation of Aspergillus niger.This study presented valuable new findings on functional protein films produced by enzymatic hydrolysis as an alternative to heat treatment.展开更多
TiZrV film is mainly applied in the ultra-high vacuum pipes of storage rings. Thin fihn coatings of palladium, which are added onto the TiZrV film to increase the service life of nonevaporable getters and enhance H2 p...TiZrV film is mainly applied in the ultra-high vacuum pipes of storage rings. Thin fihn coatings of palladium, which are added onto the TiZrV film to increase the service life of nonevaporable getters and enhance H2 pumping speed, were deposited on the inner face of stainless steel pipes by dc magnetron sputtering using argon gas as the sputtering gas. The TiZrV-Pd film properties were investigated by atomic force microscope (AFM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and X-Ray Diffraction (XRD). The grain size of TiZrV and Pd films were about 0.42 1.3 nm and 8.5-18.25 nm respectively. It was found that the roughness of TiZrV films is small, about 2 4 nm, but for Pd film it is large, about 17 19 nm. The PP At. % of Pd in TiZrV/Pd films varied from 86.84 to 87.56 according to the XPS test results.展开更多
The scaling relationships of elastic-perfectly plastic film/coating materials during sharp indentation have been obtained using dimensional analysis and finite-element modeling. Besides the bulk substrate materials, a...The scaling relationships of elastic-perfectly plastic film/coating materials during sharp indentation have been obtained using dimensional analysis and finite-element modeling. Besides the bulk substrate materials, a wide range of film/coating materials with different ratios in term of the Young’s modulus and yield strength were examined, namely different values of Ef/Esand Yf/Es.Based on these scaling relationships, the substrate effects on indentation response and deformed surface profile of residual imprint are given. Furthermore, the scaling relationship among the work of indentation, reduced elastic modulus and hardness has been found. It is found that the ratio of the indentation hardness to measurement of substrate elastic modulus could be used to characterize the wear resistance of film/coating materials. In addition, a novel method to acquire the intrinsic hardness and elastic modulus of film/coating materials is proposed combined with the well-known 10% critical indentation depth rule, which avoids the error caused by estimating the contact area. This work could be contributed for characterizing the mechanical properties of film/coating materials at micro-and nanoscale.展开更多
A nanostructured ternary coating of Ti/(Ru + Ti + Ce)O2 was prepared by the conventional electrodeposition on the titanium substrate as the cathode with different numbers of coating layers. The main objective of t...A nanostructured ternary coating of Ti/(Ru + Ti + Ce)O2 was prepared by the conventional electrodeposition on the titanium substrate as the cathode with different numbers of coating layers. The main objective of this work was to study nanostructured coatings of ceramic materials. For this purpose, the amount of precursor materials in the electrolyte was a variable parameter. Furthermore, the salt of TiCl4/RuCl3·xH2 O/Ce(NO3)3·6 H2 O with different amounts, hydrogen peroxide, methanol, and distilled water were used as an aqueousunaqueous bath. In addition, the coated samples were put to heat at 300, 450, 650, and 850℃ in an electric furnace for1 h. The crystalline phase of the coating was characterized by X-ray diffraction(XRD). The chemical composition and microstructure of the coating were studied using energydispersive spectroscopy(EDS) and scanning electron microscopy analysis(SEM). Moreover, the electrochemical measurement of Ti/(Ru + Ti + Ce)O2 coatings was carried out. Results show that with the increase in the number of coating layers, the quality of morphology is improved.Then, the best quality of coatings is obtained at six layers on the titanium substrate with electrolyte including TiO2/RuO2/CeO2 with the molar ratio of 70:5:25 after heat treatment at 450 ℃ for 1 h. Besides,with the increase in Ce02 content from 5 wt% to 25 wt% and the number of coating layers, higher thickness of about(20.0±0.1) μm and minimum over potential for chlorine evolution were obtained.展开更多
Silica is one of the most commonly used materials for dielectric layer in organic thin-film transistors due to its excellent stability, excellent electrical properties, mature preparation process, and good compatibili...Silica is one of the most commonly used materials for dielectric layer in organic thin-film transistors due to its excellent stability, excellent electrical properties, mature preparation process, and good compatibility with organic semiconductors. However, most of conventional preparation methods for silica film are generally performed at high temperature and/or high vacuum. In this paper, we introduce a simple solution spin-coating method to fabricate silica thin film from precursor route, which possesses a low leakage current, high capacitance, and low surface roughness. The silica thin film can be produced in the condition of low temperature and atmospheric environment. To meet various demands, the thickness of film can be adjusted by means of preparation conditions such as the speed of spin-coating and the concentration of solution. The p-type and n-type organic field effect transistors fabricated by using this film as gate electrodes exhibit excellent electrical performance including low voltage and high performance. This method shows great potential for industrialization owing to its characteristic of low consumption and energy saving, time-saving and easy to operate.展开更多
Aluminum borate whiskers (9Al 2O 3·2B 2O 3) can be used to reinforce aluminum alloys to produce light and strong composites. However, the adverse interfacial reactions between the whiskers and the aluminum al...Aluminum borate whiskers (9Al 2O 3·2B 2O 3) can be used to reinforce aluminum alloys to produce light and strong composites. However, the adverse interfacial reactions between the whiskers and the aluminum alloys inhibit their practical uses; therefore, a protective coating is needed on whiskers. In this work, aluminum borate whiskers were coated with chromium coating deposits in a hydrothermal solution containing CrCl 3, Na 2C 4H 4O 6, NaPH 2O 2, and H 3BO 3. The presence of the impurity P in the hydrothermal deposits can be avoided by reducing the amount of NaPH 2O 2 in the coating solution. Thermodynamic analysis was used to discuss the behavior of ions in the coating process. The subsequent heating of the hydrothermal products in air at 800 ℃ yielded smooth Cr 2O 3 films with a thickness of 0.060.07 μm.展开更多
The lifetime of orthopaedic implants can be extended by coating the softer Ti6Al4V alloy with harder biocompatible thin films.In this work,thin films of Ti_((1-x))Au_((x))are grown on Ti_(6)Al_(4)V and glass substrate...The lifetime of orthopaedic implants can be extended by coating the softer Ti6Al4V alloy with harder biocompatible thin films.In this work,thin films of Ti_((1-x))Au_((x))are grown on Ti_(6)Al_(4)V and glass substrates by magnetron sputtering in the entire x=0-1 range,before their key biomechanical properties are performance tuned by thermal activation.For the first time,we explore the effect of in-situ substrate heating versus ex-situ post-deposition heat-treatment,on development of mechanical and biocompatibility performance in Ti-Au films.A~250% increase in hardness is achieved for Ti-Au films compared to bulk Ti6Al4V and a~40%improvement from 8.8 GPa as-grown to 11.9 and 12.3 GPa with in-situ and ex-situ heat-treatment respectively,is corelated to changes in structural,morphological and chemical properties,providing insights into the origins of super-hardness in the Ti rich regions of these materials.X-ray diffraction reveals that as-grown films are in nanocrystalline states of Ti-Au intermetallic phases and thermal activation leads to emergence of mechanically hard Ti-Au intermetallics,with films prepared by in-situ substrate heating having enhanced crystalline quality.Surface morphology images show clear changes in grain size,shape and surface roughness following thermal activation,while elemental analysis reveals that in-situ substrate heating is better for development of oxide free Ti3Auβ-phases.All tested Ti-Au films are non-cytotoxic against L929 mouse fibroblast cells,while extremely low leached ion concentrations confirm their biocompatibility.With peak hardness performance tuned to>12 GPa and excellent biocompatibility,Ti-Au films have potential as a future coating technology for load bearing medical implants.展开更多
ZnO films coated with reduced graphene oxide(RGO-ZnO) were prepared by a simple chemical approach. The graphene oxide(GO) films transferred onto ZnO films by spin coating were reduced to RGO films by two steps(ex...ZnO films coated with reduced graphene oxide(RGO-ZnO) were prepared by a simple chemical approach. The graphene oxide(GO) films transferred onto ZnO films by spin coating were reduced to RGO films by two steps(exposed to hydrazine vapor for 12 h and annealed at 600 °C). The crystal structures, electrical and photoluminescence properties of RGO-ZnO films on quartz substrates were systematically studied. The SEM images illustrated that RGO layers have successfully been coated on the ZnO films very tightly. The PL properties of RGO-ZnO were studied. PL spectra show two sharp peaks at 390 nm and a broad visible emission around 490 nm.The resistivity of RGO-ZnO films was measured by a Hall measurement system, RGO as nanofiller considerably decrease the resistivity of ZnO films. An electrode was fabricated, using RGO-ZnO films deposited on Si substrate as active materials, for super capacitor application. By comparison of different results, we conclude that the RGOZnO composite material couples possess the properties of super capacitor.展开更多
The properties of nanoparticles are often different from those of larger grains of the same solid material because of their very large specific surface area. This enables many novel applications, but properties such a...The properties of nanoparticles are often different from those of larger grains of the same solid material because of their very large specific surface area. This enables many novel applications, but properties such as agglomeration can also hinder their potential use. By creating nanostructured particles one can take optimum benefit from the desired properties while minimizing the adverse effects. We aim at developing high-precision routes for scalable production of nanostructured particles. Two gas-phase synthesis routes are explored. The first one - covering nanoparticles with a continuous layer - is carried out using atomic layer deposition in a fluidized bed. Through fluidization, the full surface area of the nanoparticles becomes available. With this process, particles can be coated with an ultra-thin film of constant and well-tunable thickness. For the second route - attaching nanoparticles to larger particles - a novel approach using electrostatic forces is demonstrated. The micron-sized particles are charged with one polarity using tribocharging. Using electrospraying, a spray of charged nanoparticles with opposite polarity is generated. Their charge prevents agglomeration, while it enhances efficient deposition at the surface of the host particle. While the proposed processes offer good potential for scale-up, further work is needed to realize large-scale processes.展开更多
Derived from dry powder coating of metals, electrostatic powder coating for pharmaceuticals is a technology for coating drug solid dosage forms. In this technology, coating powders, containing coating polymers, pigmen...Derived from dry powder coating of metals, electrostatic powder coating for pharmaceuticals is a technology for coating drug solid dosage forms. In this technology, coating powders, containing coating polymers, pigments, and other excipients, are directly sprayed onto the surface of the solid dosage forms through an electrostatic gun without using any organic solvent or water. The deposited coating powders are further cured to form a coating film. Electrostatic powder coating technology has many advantages compared to other pharmaceutical coating methods. It can eliminate the limitations caused by the organic solvent in solvent coating such as environmental issues and health problems. And electrostatic powder coating technology also surpasses aqueous coating due to its shorter processing time and less energy consumption, leading to a lower overall cost. Furthermore, the utilization of electrical attraction can promote the movement of coating powders towards the substrate, leading to an enhanced coating powder adhesion and coating efficiency, which make it more promising compared to other dry coating technologies. The objective of this review is to summarize the coating principles, apparatus, and formulations of different electrostatic powder coating technologies, giving their advantages and limitations and also analyzing the future application in the industry for each technology展开更多
The Al22Si/ZL102 bimetal was designed and prepared by extrusion at near-eutectic temperature.The properties and fracture behaviors of different surface treatments between oxide film and zinc coating were compared betw...The Al22Si/ZL102 bimetal was designed and prepared by extrusion at near-eutectic temperature.The properties and fracture behaviors of different surface treatments between oxide film and zinc coating were compared between the Al22 Si and ZL102 bimetal.The average bonding strength of bimetal with intermittent oxide film interface was about 89.3MPa,which is higher than that of the bimetal fabricated by zinc coating method(about 76.3MPa).During the process of extrusion,the oxidation film was extruded to crush and the metal was extruded through the micro-cracks of the oxidation film,then the two surfaces were joined together.Altogether,the results showed that extrusion at near-eutectic temperature is favorable for achieving a high-quality metallurgical bonded interface.展开更多
文摘This review covers the recent developments in the field of biobased packaging materials. Special emphasis is placed on the barrier properties, which are crucial in terms of food packaging. The state-of-the-art of several biopolymers including pectin, starch, chitosan, xylan, galactoglucomannan, lignin and cellulose nanofibrils is discussed. As in most cases the packaging related properties of single layer biopolymer films are inadequate, the thin film coatings, such as sol-gel and ALD (atomic layer deposition), as well as the multilayer coatings are also briefly touched.
基金supported by the Mid-Level Researcher National Project of the National Research Foundation(NRF)funded by the Ministry of Science and ICT,Republic of Korea(NRF-2020R1A2C2004192)supported partly by the Competency Development Program for Industry Specialist of the Korea Institute for Advancement of Technology(KIAT)funded by the Ministry of Trade,Industry,and Energy,Republic of Korea(P0002019)。
文摘This work was made to investigate how nucleation and growth behavior of the coating film were affected by surface topographies of Mg–Al–Zn alloy substrate during the initial stage of plasma electrolytic oxidation(PEO).To satisfy this end,a single substrate was prepared by mechanical treatment exhibiting rough and smooth regions with an equal area on the surface.The rough region with prominent hills and grooves induced the breakdown of passive film,which was indicated by an early appearance of plasma discharge on the rough region since nucleation of coating film occurred preferentially around the hills.However,the coating film grown on the grooves was somewhat thicker and more porous than the film grown on the hills and smooth regions.This was due to the fact that the growth of the coating film was found to be localized in the presence of rough region,which was in line with the discharge activities.Herein,the nucleation and growth behavior during the initial stage of PEO will be discussed schematically on the basis of microstructural interpretation.
文摘This paper puts forward the two methods of weightlessness and alkoxyl group content determination to calculate the amount of cross-linking agent after elaborating the curing essence of silicone paint under the action of catalysis , and provides the theoretical basis of fixing the amoount of cross-linking agent accurately and quantitatively. At the same time, the structure of coating film is studied by the use of photoelectronic spectromenter and some other modern technology, and verified in theory. At last, this paper analyses the layer structure and the relationship between it and the coating properties.
基金supported by the National Natural Science Foundation of China (Nos. 10702038 and 10772107)the National Science Foundation of USA (No. CTS-0138057)the Shanghai Leading Academic Discipline Project (No. Y0103)
文摘The onset of instability with respect to the spatio-temporally growing disturbance in a viscosity-stratified two-layer liquid film flow is analyzed. The known results obtained from the temporal theory of instability show that the flow is unstable in the limit of zero Reynolds numbers. The present theory predicts the neutral stability in the same limit. The discrepancy is explained. Based on the mechanical energy equation, a new mechanism of instability is found. The new mechanism is associated with the convective nature of the disturbance that is not Galilei invariant.
文摘A simple method of carbon film coating used in CdZnTe crystal growth was developed. The optimum parameters were selected. Breakdown of carbon film was commonly seen if Cd reservoir was not used in the crystal growth. The carbon film was in good condition when the vapor pressure of Cd was kept around 0.1 MPa during crystal growth.
基金supported by National Natural Science Foundation of China(81202476)Medical Research Foundation of Guangdong Province(B2012079).
文摘Film coating is an important unit operation to produce solid dosage forms,thereby,the monitoring of this process is helpful to find problems in time and improve the quality of coated products.Traditional methods adopted to monitor this process include measurement of coating weight gain,performance of disintegration and dissolution test,etc.However,not only do these methods cause destruction to the samples,but also consume time and energy.There have recently emerged the applications of process analytical technologies(PAT)on film coating,especially some novel spectroscopic and imaging technologies,which have the potential to real-time track the progress in film coating and optimize production efficiency.This article gives an overview on the application of such technologies for film coating,with the goal to provide a reference for the further researches.
文摘A cyanine dye, 2-[7-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1,3,5-heptatrienyl]-1,3,3-trimethyl-3H-indolium iodide (NK-125), is doped in 4-cyano-4'-pentylbiphenyl (5 CB), and the mixture is sandwiched between two pieces of rubbed glass plates. The third-order nonlinear optical properties of the oriented NK-125-SCB layers are measured by the resonant femtosecond degenerate four-wave mixing (DFWM) technique at 760 nm. The third-order nonlinear optical susceptibility of one of the present samples is 5.5×10^-8 esu. The slow DFWM response of the NK-125-SCB layers due to a population grating is accelerated by the increasing laser power because of amplified spontaneous emission (ASE). On the other hand, we do not observe a similar phenomenon for NK-125- polyethylene glycol (PEG-400). Oriented NK-125 molecules in nematic liquid crystals must have very high ASE efficiency. Hence the population grating in a DFWM signal disappears within about 4 ps. It is expected that NK-125-SCB can be used as a material for very fast all-optical switching.
基金supported by two research grants(R202007 and R202107)from BNU-HKBU United International College,China.
文摘Sea bass(Lateolabrax maculatus)is one of the important seafood in China.Its shelf-life under refrigerated storage exponentially deteriorate due to the growth of spoilage microorganisms,protein degradation and lipid oxidation.In this study,4 coating materials namely,konjac glucomannan-whey protein isolate(KGM-WPI)film,chitosan-sweet potato starch(CHI-SPS)film,chitosan-bamboo fungus(CHI-BF)film,and chitosan-boehmite alumina(CHI-BAH)have been explored to enhance the shelf life of sea bass during 8 days of refrigerated storage.Overall,CHI-BF was observed to be best in retaining hardness,gumminess and maintaining total volatile basic nitrogen value.Whereas CHI-SPS was found to retain chewiness and maintain lower values for drip loss and peroxide value.CHI-BAH coating was observed to maintain the lower values for pH and EC values of sea bass under refrigerated storage.However,the least increase in total viable count and minimum change in b^(*)value was observed in the case of sea bass coated with KGM-WPI.The current research fi ndings provide a new practical storage method for the entire fresh fish.The fresh fish can be coated with different coating materials and store on the ice at 4℃without packaging during retailing.These film coated whole fresh fish retains its microbial and sensory quality.
基金This project is Supported by National Science Foundation of China (No.59475090)National Science Foundation of USA (No.DDM-93-9669)
文摘Premature failure of coated tool often results from a poor adhesion of coating-substrate and shortens the lifetime of the tool. The results of increasing the adhesion strength of thin film coatings on cutting tool inserts by pretreating the inserts with sandblasting technique to obtain a desirable surface morphology of the inserts are presented. A geometric model representing the ideal surface morphology is established to enhance the nucleation density and adhesion strength of coating-substrate. Thin film coating experiment is conducted on the substrates of four different sample groups. Indentation and wear tests are performed on coated inserts to evaluate the effect of sandblasting on the adhesion strength of the coatings. A theoretical analysis is provided on the formation and growth of atom clusters in terms of the contact angle and the thermodynamic barrier of a substrate to predict thin film nucleation.
文摘In this study,heat-denatured and alcalase-hydrolyzed whey and soy protein films/coatings containing marjoram essential oil(MEO)and thyme extract(TE)were investigated comparatively in terms of physicochemical and functional properties.Heat-denaturated high protein solutions produced self-standing,smooth,transparent and viscoelastic films in the presence of glycerol.Enzymatic hydrolysis provided transparency,elasticity and extensibility to the films of low protein solutions.The addition of MEO and TE triggered hardness and brittleness especially in hydrolyzed high protein films and remarkably changed film color,thickness and viscosity possibly affecting surface adherence of films.Heat denatured films exhibited higher water vapor permeability(WVP)than alcalase-hydrolyzed ones.The lowest hardness was obtained in hydrolyzed low protein films with considerable adhesiveness.Hydrolyzed protein solutions coated to cheese provided better protection against moisture loss and MEO added films caused elevated hardening of cheese.MEO and TE incorporated in film matrices were seemed to suppress mycelial growth and sporulation of Aspergillus niger.This study presented valuable new findings on functional protein films produced by enzymatic hydrolysis as an alternative to heat treatment.
基金Supported by National Natural Science Funds of China(11205155)Fundamental Research Funds for the Central Universities(WK2310000041)
文摘TiZrV film is mainly applied in the ultra-high vacuum pipes of storage rings. Thin fihn coatings of palladium, which are added onto the TiZrV film to increase the service life of nonevaporable getters and enhance H2 pumping speed, were deposited on the inner face of stainless steel pipes by dc magnetron sputtering using argon gas as the sputtering gas. The TiZrV-Pd film properties were investigated by atomic force microscope (AFM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and X-Ray Diffraction (XRD). The grain size of TiZrV and Pd films were about 0.42 1.3 nm and 8.5-18.25 nm respectively. It was found that the roughness of TiZrV films is small, about 2 4 nm, but for Pd film it is large, about 17 19 nm. The PP At. % of Pd in TiZrV/Pd films varied from 86.84 to 87.56 according to the XPS test results.
基金the National Science Fund for Distinguished Young Scholars(Grant No.51925504)the National Key R&D Program of China(Grant No.2018YFF01012400)+3 种基金the National Science and Technology Innovation Leading Academic(Ten Thousand Talent Program)the National Defense Science and Technology Bureau Project(Grant No.JSJL2018110A001)the Pre-research of Equipment of the General Armaments Department(Grant No.41422050301)the Graduate Innovation Fund of Jilin University(Grant No.101832020CX103)。
文摘The scaling relationships of elastic-perfectly plastic film/coating materials during sharp indentation have been obtained using dimensional analysis and finite-element modeling. Besides the bulk substrate materials, a wide range of film/coating materials with different ratios in term of the Young’s modulus and yield strength were examined, namely different values of Ef/Esand Yf/Es.Based on these scaling relationships, the substrate effects on indentation response and deformed surface profile of residual imprint are given. Furthermore, the scaling relationship among the work of indentation, reduced elastic modulus and hardness has been found. It is found that the ratio of the indentation hardness to measurement of substrate elastic modulus could be used to characterize the wear resistance of film/coating materials. In addition, a novel method to acquire the intrinsic hardness and elastic modulus of film/coating materials is proposed combined with the well-known 10% critical indentation depth rule, which avoids the error caused by estimating the contact area. This work could be contributed for characterizing the mechanical properties of film/coating materials at micro-and nanoscale.
基金financially supported by the Semnan University Foundation of Iran
文摘A nanostructured ternary coating of Ti/(Ru + Ti + Ce)O2 was prepared by the conventional electrodeposition on the titanium substrate as the cathode with different numbers of coating layers. The main objective of this work was to study nanostructured coatings of ceramic materials. For this purpose, the amount of precursor materials in the electrolyte was a variable parameter. Furthermore, the salt of TiCl4/RuCl3·xH2 O/Ce(NO3)3·6 H2 O with different amounts, hydrogen peroxide, methanol, and distilled water were used as an aqueousunaqueous bath. In addition, the coated samples were put to heat at 300, 450, 650, and 850℃ in an electric furnace for1 h. The crystalline phase of the coating was characterized by X-ray diffraction(XRD). The chemical composition and microstructure of the coating were studied using energydispersive spectroscopy(EDS) and scanning electron microscopy analysis(SEM). Moreover, the electrochemical measurement of Ti/(Ru + Ti + Ce)O2 coatings was carried out. Results show that with the increase in the number of coating layers, the quality of morphology is improved.Then, the best quality of coatings is obtained at six layers on the titanium substrate with electrolyte including TiO2/RuO2/CeO2 with the molar ratio of 70:5:25 after heat treatment at 450 ℃ for 1 h. Besides,with the increase in Ce02 content from 5 wt% to 25 wt% and the number of coating layers, higher thickness of about(20.0±0.1) μm and minimum over potential for chlorine evolution were obtained.
基金the National Natural Science Foundation of China (Nos. 21573277, 51503221)National Key Research and Development Program (No. 2016YFA0200700)+2 种基金Key Research Program of Frontier Sciences of Chinese Academy of Sciences (No. QYZDB-SSW-SLH031)Natural Sciences Foundation of Jiangsu Province (No. BK20150368),Natural Science Foundation of Inner Mongolia of China (No. 2014JQ02)
文摘Silica is one of the most commonly used materials for dielectric layer in organic thin-film transistors due to its excellent stability, excellent electrical properties, mature preparation process, and good compatibility with organic semiconductors. However, most of conventional preparation methods for silica film are generally performed at high temperature and/or high vacuum. In this paper, we introduce a simple solution spin-coating method to fabricate silica thin film from precursor route, which possesses a low leakage current, high capacitance, and low surface roughness. The silica thin film can be produced in the condition of low temperature and atmospheric environment. To meet various demands, the thickness of film can be adjusted by means of preparation conditions such as the speed of spin-coating and the concentration of solution. The p-type and n-type organic field effect transistors fabricated by using this film as gate electrodes exhibit excellent electrical performance including low voltage and high performance. This method shows great potential for industrialization owing to its characteristic of low consumption and energy saving, time-saving and easy to operate.
基金National Natural Foundation of China(No.5 0 174 0 32
文摘Aluminum borate whiskers (9Al 2O 3·2B 2O 3) can be used to reinforce aluminum alloys to produce light and strong composites. However, the adverse interfacial reactions between the whiskers and the aluminum alloys inhibit their practical uses; therefore, a protective coating is needed on whiskers. In this work, aluminum borate whiskers were coated with chromium coating deposits in a hydrothermal solution containing CrCl 3, Na 2C 4H 4O 6, NaPH 2O 2, and H 3BO 3. The presence of the impurity P in the hydrothermal deposits can be avoided by reducing the amount of NaPH 2O 2 in the coating solution. Thermodynamic analysis was used to discuss the behavior of ions in the coating process. The subsequent heating of the hydrothermal products in air at 800 ℃ yielded smooth Cr 2O 3 films with a thickness of 0.060.07 μm.
基金funded and supported by the Leverhulme Trust Research Project Grant(RPG-2018-344)。
文摘The lifetime of orthopaedic implants can be extended by coating the softer Ti6Al4V alloy with harder biocompatible thin films.In this work,thin films of Ti_((1-x))Au_((x))are grown on Ti_(6)Al_(4)V and glass substrates by magnetron sputtering in the entire x=0-1 range,before their key biomechanical properties are performance tuned by thermal activation.For the first time,we explore the effect of in-situ substrate heating versus ex-situ post-deposition heat-treatment,on development of mechanical and biocompatibility performance in Ti-Au films.A~250% increase in hardness is achieved for Ti-Au films compared to bulk Ti6Al4V and a~40%improvement from 8.8 GPa as-grown to 11.9 and 12.3 GPa with in-situ and ex-situ heat-treatment respectively,is corelated to changes in structural,morphological and chemical properties,providing insights into the origins of super-hardness in the Ti rich regions of these materials.X-ray diffraction reveals that as-grown films are in nanocrystalline states of Ti-Au intermetallic phases and thermal activation leads to emergence of mechanically hard Ti-Au intermetallics,with films prepared by in-situ substrate heating having enhanced crystalline quality.Surface morphology images show clear changes in grain size,shape and surface roughness following thermal activation,while elemental analysis reveals that in-situ substrate heating is better for development of oxide free Ti3Auβ-phases.All tested Ti-Au films are non-cytotoxic against L929 mouse fibroblast cells,while extremely low leached ion concentrations confirm their biocompatibility.With peak hardness performance tuned to>12 GPa and excellent biocompatibility,Ti-Au films have potential as a future coating technology for load bearing medical implants.
基金supported by the National Natural Science Foundation of China(Nos.61464005,51562015)the Natural Science Foundation of Jiangxi Province(Nos.20143ACB21004,20151BAB212008,20171BAB216015)+2 种基金the Jiangxi Province Foreign Cooperation Projects,China(No.20151BDH80031)the Leader Training Object Project of Major Disciplines Academic and Technical of Jiangxi Province(No.20123BCB22002)the Key Technology R&D Program of the Jiangxi Provine of Science and Technology(No.20171BBE50053)
文摘ZnO films coated with reduced graphene oxide(RGO-ZnO) were prepared by a simple chemical approach. The graphene oxide(GO) films transferred onto ZnO films by spin coating were reduced to RGO films by two steps(exposed to hydrazine vapor for 12 h and annealed at 600 °C). The crystal structures, electrical and photoluminescence properties of RGO-ZnO films on quartz substrates were systematically studied. The SEM images illustrated that RGO layers have successfully been coated on the ZnO films very tightly. The PL properties of RGO-ZnO were studied. PL spectra show two sharp peaks at 390 nm and a broad visible emission around 490 nm.The resistivity of RGO-ZnO films was measured by a Hall measurement system, RGO as nanofiller considerably decrease the resistivity of ZnO films. An electrode was fabricated, using RGO-ZnO films deposited on Si substrate as active materials, for super capacitor application. By comparison of different results, we conclude that the RGOZnO composite material couples possess the properties of super capacitor.
文摘The properties of nanoparticles are often different from those of larger grains of the same solid material because of their very large specific surface area. This enables many novel applications, but properties such as agglomeration can also hinder their potential use. By creating nanostructured particles one can take optimum benefit from the desired properties while minimizing the adverse effects. We aim at developing high-precision routes for scalable production of nanostructured particles. Two gas-phase synthesis routes are explored. The first one - covering nanoparticles with a continuous layer - is carried out using atomic layer deposition in a fluidized bed. Through fluidization, the full surface area of the nanoparticles becomes available. With this process, particles can be coated with an ultra-thin film of constant and well-tunable thickness. For the second route - attaching nanoparticles to larger particles - a novel approach using electrostatic forces is demonstrated. The micron-sized particles are charged with one polarity using tribocharging. Using electrospraying, a spray of charged nanoparticles with opposite polarity is generated. Their charge prevents agglomeration, while it enhances efficient deposition at the surface of the host particle. While the proposed processes offer good potential for scale-up, further work is needed to realize large-scale processes.
文摘Derived from dry powder coating of metals, electrostatic powder coating for pharmaceuticals is a technology for coating drug solid dosage forms. In this technology, coating powders, containing coating polymers, pigments, and other excipients, are directly sprayed onto the surface of the solid dosage forms through an electrostatic gun without using any organic solvent or water. The deposited coating powders are further cured to form a coating film. Electrostatic powder coating technology has many advantages compared to other pharmaceutical coating methods. It can eliminate the limitations caused by the organic solvent in solvent coating such as environmental issues and health problems. And electrostatic powder coating technology also surpasses aqueous coating due to its shorter processing time and less energy consumption, leading to a lower overall cost. Furthermore, the utilization of electrical attraction can promote the movement of coating powders towards the substrate, leading to an enhanced coating powder adhesion and coating efficiency, which make it more promising compared to other dry coating technologies. The objective of this review is to summarize the coating principles, apparatus, and formulations of different electrostatic powder coating technologies, giving their advantages and limitations and also analyzing the future application in the industry for each technology
文摘The Al22Si/ZL102 bimetal was designed and prepared by extrusion at near-eutectic temperature.The properties and fracture behaviors of different surface treatments between oxide film and zinc coating were compared between the Al22 Si and ZL102 bimetal.The average bonding strength of bimetal with intermittent oxide film interface was about 89.3MPa,which is higher than that of the bimetal fabricated by zinc coating method(about 76.3MPa).During the process of extrusion,the oxidation film was extruded to crush and the metal was extruded through the micro-cracks of the oxidation film,then the two surfaces were joined together.Altogether,the results showed that extrusion at near-eutectic temperature is favorable for achieving a high-quality metallurgical bonded interface.