Morphology and Structure Analyses of SnO2 Thin Film Coated on Al2O3 Ultrafine Particles by Gas Phase Reaction in Fluidized Bed

Fluidized chemical vapor deposition (FCVD) technology was developed for coating SnO 2 thin film on ultrafine Al 2O 3 particles.Transmission electron microscopy (TEM) and high resolution electron microscopy (HREM) analyses demonstrated that SnO 2 films with different structures were deposited through controlling the coating temperature, reactant concentration, etc .. Nanocrystalline SnO 2 film was formed at 572.15K by gas phase reaction of SnCl 4 and H 2O.Electron probe microanalyser (EPMA) and energy dispersive spectrometer (EDS) analyses indicated that the distribution of nanocrystalline SnO 2 over inner and outer part of the Al 2O 3 agglomerates was homogeneous.

The Production of Organic-Inorganic Compound Film-Coated Urea and the Characteristics of Its Nutrient Release

The effect of different concentrations of natural macromolecular compound on the characteristics of nutrient release in the membrane materials of organic-inorganic compound film-coated urea was discussed, and the optimal concentrations for better nutrient release was proposed. The characteristics of nutrient release of film-coated urea were evaluated by soil column leaching experiment. Organic-inorganic compound film-coated urea showed good characteristics of nutrient release, which could be well simulated by Logistic curve. The two parameters in this curve, a and r, can be used to present nutrient release of film-coated urea, and followed the order of B 〉 C 〉 A and C 〈 B 〈 A, respectively, indicating that the release was stronger with the increasing concentration of natural macromolecular compound in the membrane, which implied better controllability of nutrient release. The concentration of 5% of natural macromolecular compound showed better characteristic of nutrient release and can be utilized as a membrane material combined with inorganic mineral powders to develop film-coated slow-release fertilizer.

Fabrication of Large-area 3-D Ordered Silvercoated Colloidal Crystals and Macroporous Silver Films Using Polystyrene Templates

The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microspheres were prepared by emulsifier-free emulsion polymerization using methacrylic acid(MAA) as the functional monomer. PS microspheres were self-assembled into close packing colloidal crystals of facecentered cubic arrays to the substrate with vertical deposition method. These colloidal crystals were modified using dopamine(DA) to form poly-dopamine(PDA) during its oxidative polymerization. Through electrostatic interaction, the silver nanoparticles were deposited and adsorbed onto the surfaces of colloidal crystals templates by exposing [Ag(NH_3)_2]^+solution to infrared irradiation. Removal of the polymeric template by etching with methylbenzene solvent resulted in 3D ordered macroporous silver films. The structural and properties of the ordered silver-coated arrays and macroporous silver films were characterized by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD), UV-vis spectroscopy and surface-enhanced Raman spectroscopy(SERS). The results indicate that the prepared silver-coated arrays and macroporous silver films possess the features of ordered multilayer arrangement, uniformity and repeatability as well as an ideal SERS effect.

Potential of RP-UHPLC-DAD-MS for the qualitative and quantitative analysis of sofosbuvir in film coated tablets and profiling degradants

Sofosbuvir is one of the new direct-acting antiviral drugs against hepatitis C virus(HCV) infection. This drug has recently been launched into the market, and generic versions of the medication are expected to be produced by local drug producers in some countries. Therefore, new methods are required to control sofosbuvir in pharmaceuticals. In the present study, a new method based on reversed phase(RP)-ultra-high performance liquid chromatography(UHPLC) coupled to diode array detection(DAD) and mass spectrometry(MS) was developed to facilitate the qualitative and quantitative analysis of sofosbuvir in film coated tablets. A wavelength of 260 nm was selected to perform a cost-effective quantification and the method showed adequate linearity,with an R^2 value of 0.9998, and acceptable values of accuracy(75%–102%) and precision(residual standard deviation < 5%). The detection and quantification limits were 0.07 μg/mL and 0.36 μg/mL, respectively.Furthermore, the use of high-resolution MS enabled us to ensure the specificity, check impurities and better sensitivity. Therefore, this methodology promises to be suitable not only for the routine analysis of sofosbuvir in pharmaceutical dosage forms, but also for potential degradants.

STUDIES OF LOW-CONCENTRATION CHROMATE PASSIVE FILM FOR ZINC-BASED ALLOY COATED STEEL WIRES

The corrosion resistance of a low concentration chromate passive film for zinc based alloy coated steel wires was assessed by salt spray and electrochemical corrosion tests. XPS and AES analyses showed that the composition of such chromate passive film was S 5 5, Na 3 4, C 11 8, Ti 7 9, O 41 6, Cr 13 7, Zn 16 0.

Phase Transformation and Optimized Growth of TFA-MOD REBa_2Cu_3O_(7-x) Films for Coated Conductors

Several types of REBa2Cu3O7-x （REBCO, RE=Y, Ho etc.） films are prepared on single crystal substrate LaAIO3 by TFA-MOD method. The phase transformation and optimized growth conditions in the crystallization are studied. Compared with SmBCO and GdBCO, high quality YBCO and HoBCO films are relatively easy to produce. It is revealed that the YBCO grains can form at low temperatures such as 730 ℃ during the initial heating ramp. With a high heating rate of 20 K/min and a low oxygen pressure of 100 ppm, the optimum growth temperature is around 780℃, at which the films show a Jc value of 2.88 MMcm2. Further decrease of the heating rate may produce the highquality YBCO Film with a higher Jc of 3.65 MA/cm2. The temperature dependence of resistances in various magnetic fields up to 9 T shows that the present TFAMOD YBCO and HoBCO films have similar superonducting transition temperature and magnetotransport properties.

Preparation and Properties of Dip-coated CeO_2-TiO_2 Thin Golden Glass Film

The golden and ultraviolet-absorbed CeO2-TiO2 film was prepared on soda-lime glass substrate with the thickness of 2 mm via the sol-gel method. The transmission spectra in range of 200 nm-800 nm were measured, and the crystallization, the abrasion and acid resistance were also investigated. The appropriate sol contents and heat-treatment schedule were determined. The results indicate that the appropriate molar ratio of Ce/Ti was 3：5 to 5：6. The ultraviolet-absorbance ability increased with the increase of the Ce/Ti molar ratio, but when the Ce/Ti molar ratio was higher than 1.5, the homogeneity of the film was deteriorated. With the increase of heat-treatment temperature, the main wavelengths of the color of the coated glasses were equal, but the color＇ s saturation decreased; the transmission peaks were the same, while the intensity of the peaks decreased. The roughness, abrasion and acid resistance of the film were also enhanced at the same time. The appropriate heat- treatment temperature may be 340℃.

Use of buffy coat thick films in detecting malaria parasites in patients with negative conventional thick films

Objective:To determine the frequency of malaria parasite detection from the buffy coal blood films by using capillary tube in falciparum malaria patients with negative conventional thick films.Methods:Thirty six uncomplicated falciparum malaria patients confirmed by conventional thick and thin films were included in the study.The patients were treated with artemisinin combination therapy at Hospital for Tropical Diseases,Bangkok,Thailand for 28 day.Fingerpricks for conventional blood films were conducted every 6 hours until negative parasitemia,then daily fingerpricks for parasite checks were conducted until the patients were discharged from hospital. Blood samples were also concurrently collected in 3 heparinized capillary tubes at the same time of fingerpricks for conventional blood films when the prior parasitemia was negative on thin films and parasitemia was lower than 50 parasites/200 white blood cells by thick film.The first negative conventional thick films were compared with buffy coat thick films for parasite identification. Results:Out of 36 patients with thick films showing negative for asexual forms of parasites, buffy coat films could detect remaining 10 patients(27.8%) with asexual forms of Plasmodium falciparum.Conclusions:The study shows that buffy coat thick films are useful and can detect malarial parasites in 27.8%of patients whose conventional thick films show negative parasitemia.

Interfacial Interaction Between Polyurethane/Poly(Methacrylateco-Styrene) Coating and the Regenerated Cellulose Film

Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film.

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.

A Bilayer High-Temperature Dielectric Film with Superior Breakdown Strength and Energy Storage Density

The further electrification of various fields in production and daily life makes it a topic worthy of exploration to improve the performance of capacitors for a long time,including thin-film capacitors.The discharge energy density of thin-film capacitors that serves as one of the important types directly depends on electric field strength and the dielectric constant of the insulation material.However,it has long been a great challenge to improve the breakdown strength and dielectric constant simultaneously.Considering that boron nitride nanosheets(BNNS)possess superior insulation and thermal conductivity owing to wide band gap and 2-dimensional structure,a bilayer polymer film is prepared via coating BNNS by solution casting on surface of polyethylene terephthalate(PET)films.By revealing the bandgap and insulating behavior with UV absorption spectrum,leakage current,and finite element calculation,it is manifested that nanocoating contributes to enhance the bandgap of polymer films,thereby suppressing the charge injection by redirecting their transport from electrodes.Worthy to note that an ultrahigh breakdown field strength(~736 MV m^(−1)),an excellent discharge energy density(~8.77 J cm^(−3))and a prominent charge-discharge efficiency(~96.51%)are achieved concurrently,which is ascribed to the contribution of BNNS ultrathin layer.In addition,the modified PET films also have superior comprehensive performance at high temperatures(~120°C).The materials and methods here selected are easily accessible and facile,which are suitable for large-scale roll-to-roll process production,and are of certain significance to explore the methods about film modification suitable for commercial promotion.

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.

Preparation and optical properties of Nb-NbN multilayer films as solar selective absorptive coatings

Based on the cermet double layer structure, Nb-NbN multi-layer films for solar selective coatings were deposited by direct current reactive magnetron sputtering. The Nb/Nb-NbN/Al2O3 trilayered structure was deposited on a stainless steel (SS) substrate by using a single niobium target. The expected components were adjusted by changing the gas flowing ratios of Ar: N2. The Al2O3 antireflective layer on the top of the film was produced by r. f. magnetron sputtering using Al2O3 ceramic target. A solar absorptivity of 0.94 and a normal emissivity of 0.16 at room temperature have been achieved for the coating. Thermal vacuum aging to the samples was carried out at 350 and 500 ℃ for 1 h. The results show a good thermal stability. Microstructure and its dependence on temperature of the Nb, NbN and Nb-NbN single layers were investigated, respectively.

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.

Preparation of CuInSe_2 thin films by paste coating

Precursor pastes were obtained by milling Cu-In alloys and Se powders. CulnSe2 thin films were successfully prepared by precursor layers, which were coated using these pastes, and were annealed in a H2 atmosphere. The pastes were tested by laser particle diameter analyzer, simultaneous thermogravimetric and differential thermal analysis instruments （TG-DTA）, and X-ray diffractometry （XRD）. Selenized films were characterized by XRD, scanning electron microscopy （SEM）, and energy dispersive spectroscopy （EDS）. The results indicate that chalcopyrite CuInSe2 is formed at 180℃ and the crystallinity of this phase is improved as the temperature rises. All the CuInSe2 thin films, which were annealed at various temperatures, exhibit the preferred orientation along the （112） plane. The compression of precursor layers before selenization step is one of the most essential factors for the preparation of perfect CuInSe2 thin films.

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.

Thin film dynamics in coating problems using Onsager principle

A new variational method is proposed to investigate the dynamics of the thin film in a coating flow where a liquid is delivered through a fixed slot gap onto a moving substrate. A simplified ODE system has also been derived for the evolution of the thin film whose thickness hf is asymptotically constant behind the coating front. We calculate the phase diagram as well as the film profiles and approximate the film thickness theoretically, and agreement with the well-known scaling law as Ca2/3 is found.

Effect of substrate curvature on thickness distribution of polydimethylsiloxane thin film in spin coating process

The polymer spin coating is critical in flexible electronic manufaction and micro-electro-mechanical system（MEMS）devices due to its simple operation, and uniformly coated layers. Some researchers focus on the effects of spin coating parameters such as wafer rotating speed, the viscosity of the coating liquid and solvent evaporation on final film thickness.In this work, the influence of substrate curvature on film thickness distribution is considered. A new parameter which represents the edge bead effect ratio（re） is proposed to investigate the influence factor of edge bead effect. Several operation parameters including the curvature of the substrate and the wafer-spin speed are taken into account to study the effects on the film thickness uniformity and edge-bead ratio. The morphologies and film thickness values of the spin-coated PDMS films under various substrate curvatures and coating speeds are measured with laser confocal microscopy. According to the results, both the convex and concave substrate will help to reduce the edge-bead effect significantly and thin film with better surface morphology can be obtained at high spin speed. Additionally, the relationship between the edge-bead ratio and the thin film thickness is like parabolic curve instead of linear dependence. This work may contribute to the mass production of flexible electronic devices.

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.