Sensing characteristics of a metal film coated long-period fiber grating

To obtain the influence rules of the coating parameters of a long-period fiber grating(LPFG)with respect to temperature,strain and refractive index sensing properties,based on the mode coupling theory,a strict four-layer theorietical model of a metal film coated LPFG is established,and these parameters that affect the spectral characteristics of the metal film coated LPFG are studied.The simulation results show that there is an optimal metal film thickness on the surface of the LPFG that will induce the surface-plasmon resonance(SP R)effect,which results in higher sensitivity to the environmental temperature and refractive index but has little influence on the strain There is theoretical evidence that when the silver thickness is between0.8and1.2nm,the refractive index sensitivity will reach the peak point of42.4026,at which the refractive index sensor sensitivity is increased by4.S%.The theoretical results of coating a long-period fiber grating provide a good theoretical basis and guidance for LPFG design and parameters optimization

Preparation and Characterization of Alumina Membranes on Capillary Supports： Effect of Film-coating on Crack-free Membrane Preparation

Ceramic capillary membrane has received much attention due to its relatively high pack density and favorable mechanical strength.However,it is difficult to prepare capillary membrane on its thin support by a dip-coating method.In this study,alumina microfiltration membranes were prepared on the inner surface of alumina capillary support(outer diameter 4 mm,inner diameter 2.5 mm)by a dip-coating method.Scanning electron microscopy(SEM)observation,gas bubble pressure(GBP)method and membrane permeation test were carried out to evaluate membrane performance.Two major effects in preparation of crack-free membrane,capillary filtration and film-coating,upon the thin support were studied.The as-prepared crack-free membrane presents a narrow pore size distribution,a mean pore size of about 0.6μm and a high pure water flux of 86000 L·m -2 ·h -1 ·MPa.It is proved that the membrane thickness should be sufficiently large to overcome the defects of support surface,but it is only one of the prerequisites for the formation of crack-free membrane.Furthermore,it is demonstrated that the capillary filtration effect is greatly restricted for thin capillary support with the dip-coating method and the film-coating effect plays a crucial role in the formation of crack-free membrane.

Biopolymer Films and Coatings in Packaging Applications--A Review of Recent Developments

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.

Nucleation and growth behavior of coating film on Mg–Al–Zn alloy with different surface topographies via plasma electrolytic oxidation

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.

THE CURING THEORY OF SILlCONE PAINT AND THE STRUCTURE OF COATING FILM

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.

Spatio-temporal instability of two-layer liquid film at small Reynolds numbers

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.

Carbon Film Coating Used in CdZnTe 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.

Study progression in application of process analytical technologies on film coating

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.

红松松仁膜衣提取物体外抗氧化活性研究

本文旨在探明长白山红松松仁膜衣提取物的体外抗氧化活性。分别采用60%乙醇和50%丙酮为提取剂,提取物冻干后,用分光光度法测其总多酚和总黄酮纯度,研究其自由基清除能力和还原铁离子的能力。结果表明,松仁膜衣乙醇提取物总多酚纯度为39.02%,总黄酮纯度为10.19%;丙酮提取物总多酚纯度为44.09%,总黄酮纯度为14.59%。红松松仁膜衣提取物清除ABTS^+·、DPPH·、羟自由基(·OH)的能力和还原铁离子能力都呈现一定的剂量效应关系,且对DPPH·的清除作用和还原铁离子能力强于BHT;丙酮提取物对ABTS^+·和·OH的清除能力显著高于乙醇提取物,表明丙酮提取物的抗氧化能力强于乙醇提取物。同时,在实验范围内,红松松仁膜衣提取物的抗氧化能力与其总多酚、总黄酮的纯度存在正相关性。

Fast Optical Switching Using Oriented Cyanine Dye-Doped Nematic Liquid Crystal

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.

ADHESION STRENGTH OF COATING SUBSTRATE AND SURFACE MORPHOLOGY OF PRETREATMENT

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.

Influence of Ozone Injection on Corrosion Behavior of Steel in Water Ballast Tank

Ozone is the principal active substances and usually employed in ballast water management systems. In the present study, the corrosion protective effect of ozone was conducted by immersion test and electrochemical techniques. It was found that corrosion protective effect was revealed in the range of 2.0 to 2.7 ppm of ozone concentration in seawater. The ratio of the rust area of specimen became 20% in that concentration region. The rusted area is strongly influenced by the ozone concentration and the flow rate determined by FEM （finite element method）. Ozone has a good influence for ballast tanks, i.e., ozone can delay the rust of ballast tanks, provided that the suitable concentration of ozone is selected. In this case, ozone may stop the corrosion at the defects, if a part of the paint in ballast tank is peeled off. However, ozone may also promote the corrosion of steel when the ozone concentration is very high, e.g., 10 ppm. Attention should be paid to the ozone concentration, if we use ozone as an active substance for ballast water management systems.

Formulation Development, in Vitro Evaluation and Stability Study of Aceclofenac Tablet

The objective of the study was to develop film coated tablets of aceclofenac using wet granulation technique. Possible drug-excipient interaction was evaluated by HPLC （high performance liquid chromatography） and FTIR （fourier infrared spectroscopy）. The tablets prepared were assessed for their physicochemical, in vitro dissolution at pH 1.2, 4.5, 6.8 and 7.5 and stability characteristics. Comparison with a commercial aceclofenac product was made in vitro and in vitro studies. There was no interaction between aceclofenac and used excipients. Furthermore, the physicochemical properties of the tablets were satisfactory. The dissolution profile of one of the formulated aceclofenac tablets （D07） was statistically similar （p 〈 0.05） to that of the commercial aceclofenac brand in all the dissolution media. The formulated products ware stable and showed no changes in physical appearance, drug content, or dissolution pattern after storage at 40 ℃/75% RH for 6 months. The results indicate that it is feasible to achieve a stable aceclofenac tablet formulation by using wet granulation technique.

Composite structure of ZnO films coated with reduced graphene oxide: structural,electrical and electrochemical properties

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.

Improving the high frequency response of a loudspeaker using hydrogen-free diamond-like carbon film coating at low temperature

Hydrogen-free diamond-like carbon （DLC） thin films were deposited at low temperature （less than 100~C） by an RF magne- tron sputtering facility. DLC films have the ability to change the sound velocity （E/p） in loudspeakers for applications of hard coating. The hydrogen-free DLC films were coated onto PEI diaphragm substrates. The ID/IG ratio and the surface roughness are 2.09 and less than 0.86 nm （Ra） with a scanning area of 50 um x 50 um, respectively. Frequency response analysis of the DLC films on the diaphragm shows that the high frequency response increases by 0.2 dB-5.1 dB （6 kHz-ll.2 kHz）, -0.4 dB-1.8 dB （11.8 kHz-20 kHz） on average. On the basis of the results of this study, we validated that it was feasible to sputter hydrogen-free DLC films on polymer substrates for mass production. These results also provided useful parameters for future applications of electro-acoustic devices.

Scaling relationships of elastic-perfectly plastic film/coating materials from small scale sharp indentation

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.

Effect of konjac glucomannan and chitosan-based film coatings on the quality of fresh sea bass(Lateolabrax maculatus)under refrigerated condition

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.

Deposition and characterization of TiZrV-Pd thin films by dc magnetron sputtering

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.

Solution-processable precursor route for fabricating ultrathin silica film for high performance and low voltage organic transistors

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.

Thermal activation of Ti_((1-x))Au_((x))thin films with enhanced hardness and biocompatibility

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.