Solution Spray Rate Research Articles

Hierarchically Structured 3D Nanoporous Vanadium Oxide Transparent Electrodes for Next‐Generation Supercapacitors

AbstractThis article describes the automatic spray pyrolysis deposition (ASPD) process for the synthesis of hierarchically structured 3D nanoporous vanadium oxide (V2O5) transparent material on a fluorine‐doped tin oxide (FTO) substrate. The deposition of material occurs at 673 K using an aqueous solution of NH4VO3, with a constant solution spray rate of 10 mL min−1 and airflow rate of 10 L min−1. Structural analysis confirms the pure orthorhombic structure formation of the V2O5 material, while FE‐SEM images show a well‐organized 3D spongy‐like porous architecture. The excellent conformality of the ASPD enables the deposition of high‐aspect‐ratio 3D structured nanoporous V2O5 electrodes for next‐generation supercapacitor applications. The hierarchical structured 3D nanoporous V2O5 electrode exhibits superior electrochemical performance in a 1M Na2SO3 electrolyte. Within the potential window 0 to ‐1.3 V, the electrode archives the highest specific capacitance (SC) of 453.32 F g−1 and also retains 86% of its capacitance after 5000 cycles. These properties mainly originate from the crystallinity, 3D nanoporous structure, and fast and easy ionic intercalation through the material. Furthermore, a symmetric supercapacitor device using this electrode is fabricated and which yields outstanding electrochemical performance. Overall, the results highlight the potential of 3D nanoporous V2O5 as an outstanding electrode material for next‐generation supercapacitor applications.

Deposition of Cu2ZnSnS4 thin film at different solution flow rates

A thin film of Cu2ZnSnS4, a potential compound semiconductor for the absorber layer in thin film heterojunction solar cells, has been successfully deposited using the spray pyrolysis process. The influence of solution spray rate on deposited film characteristics is investigated. The structural and optical properties of the films have been studied. X-ray diffraction studies revealed the films are polycrystalline in nature with the kesterite structure and the lattice parameters are found to be a = b = 0.542 nm and c = 1.082 nm. Micro Raman spectra confirm the Cu2ZnSnS4 crystal phase. Optical band gap, evaluated from spectral transmittance data, which is close to 1.5 eV. The absorption coefficient of these films is ≥ 104 cm−1. These films are found to be p-type in nature. Finally, work on fabricating a conventional thin film heterojunction solar cell has been undertaken.

Development and verification of a novel design space and improved scale-up procedure for fluid bed granulation using a mechanistic model

A mechanistic model has been developed for scale-up of batch fluid bed (top spray) granulation, leading to a design space which was verified against experimental data at pilot-plant and commercial scales. Current published models fail to give reliable scale-up. The process is very sensitive to operating conditions, and intermittent spray and air flow during filter bag shaking is shown to substantially affect moisture content and the final granule properties. Three parameters (inlet air temperature, flow rate and humidity) are consolidated into a composite parameter Qair which, in combination with solution spray rate msol, gives a two-dimensional design space which is typically trapezoidal. Peak moisture content influences final granule attributes and depends on the ratio Qair/msol. Scale-up and product transfer between different equipment are predicted. The model has been applied to an actual pharmaceutical product, achieving robust product quality at commercial scale, and incorporated into a successful regulatory filing submission.

Optimization of tracer coating parameters and their effects on the mechanical properties and quality of food-grade tracers for grain traceability

The purpose of this study was to optimize the coating process of food-grade tracers to manufacture tracers with good physical, mechanical and practical properties and an excellent appearance. The effects of the coating weight gain (1.00%-5.00%), coating solution spray rate (1.50-7.50 g/min) and tablet bed temperature (30°C-40°C) on the coating appearance quality, moisture absorption rate, friction coefficient, peak shear force, breaking rate, barcode recognition rate, transport wear rate and transport recognition rate were analysed using a Box–Behnken design (BBD) of response surface methodology (RSM). The experimental data were fitted to quadratic polynomial models by multiple regression analysis. The mathematical models of the barcode recognition rate, transport wear rate and transport recognition rate exhibited no statistically significant difference in these data. The optimum coating parameters were as follows: a 5.00% coating weight gain, spray rate of 5.47 g/min and tablet bed temperature of 35.42°C. Under the optimized conditions, the tracers had a good appearance (coating appearance quality), moisture resistance (moisture absorption rate), and frictional (friction coefficient), compression (peak shear force), and impact characteristics (breaking rate). Keywords: grain traceability, food-grade tracer, coating process, optimization, Box–Behnken design DOI: 10.25165/j.ijabe.20191202.4180 Citation: Liang K, Zhang L L, Chen X H, Shen M X. Optimization of tracer coating parameters and their effects on the mechanical properties and quality of food-grade tracers for grain traceability. Int J Agric & Biol Eng, 2019; 12(2): 201–209.

Structural, morphological, optical, and electrical properties of In2O3 nanostructured thin films

Indium oxide (In2O3) nanostructured thin films are prepared by ultrasonic spray technique on glass substrates at 350°C. Solution flow rate influence on the structural, morphological, optical and electrical properties of these samples is then studied. A number of techniques, as well as X-ray diffraction (XRD), SEM, and UV–vis are used to characterize the physical properties of these films. X-ray diffraction analysis indicates the spherical indium oxide nanoparticles (20nm to 67nm) were in single-crystalline phase with body-centered cubic structure, and the preferred growth orientation change with the change of Solution Spray Rate. The films exhibit high optical transparency >80% in the visible region. The higher value of the optical band gap was 3.93eV due to the quantum confinement effect. The film grown at 55ml/h showed low resistivity (8.510−3Ωcm).

Formulation Development, Process Optimization, and In Vitro Characterization of Spray-Dried Lansoprazole Enteric Microparticles.

This research focuses on the development of enteric microparticles of lansoprazole in a single step by employing the spray drying technique and studies the effects of variegated formulation/process variables on entrapment efficiency and in vitro gastric resistance. Preliminary trials were undertaken to optimize the type of Eudragit and its various levels. Further trials included the incorporation of plasticizer triethyl citrate and combinations of other polymers with Eudragit S 100. Finally, various process parameters were varied to investigate their effects on microparticle properties. The results revealed Eudragit S 100 as the paramount polymer giving the highest gastric resistance in comparison to Eudragit L 100-55 and L 100 due to its higher pH threshold and its polymeric backbone. Incorporation of plasticizer not only influenced entrapment efficiency, but diminished gastric resistance severely. On the contrary, polymeric combinations reduced entrapment efficiency for both sodium alginate and glyceryl behenate, but significantly influenced gastric resistance for only sodium alginate and not for glyceryl behenate. The optimized process parameters were comprised of an inlet temperature of 150°C, atomizing air pressure of 2 kg/cm2, feed solution concentration of 6% w/w, feed solution spray rate of 3 ml/min, and aspirator volume of 90%. The SEM analysis revealed smooth and spherical shape morphologies. The DSC and PXRD study divulged the amorphous nature of the drug. Regarding stability, the product was found to be stable under 3 months of accelerated and long-term stability conditions as per ICH Q1A(R2) guidelines. Thus, the technique offers a simple means to generate polymeric enteric microparticles that are ready to formulate and can be directly filled into hard gelatin capsules.

Influence of Spray Rate on Structural and Optical Properties of Sprayed ZnO Films

In this report, the ZnO nanostructure films have been deposited by ultrasonic spray pyrolysis technique (USP) on fluorine doped tinoxide~(FTO) substrate using zinc acetate and aqueous 2-propanol as reactants. The effects of solution spray rate on structural, morphological and optical properties of ZnO nanostructure films were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and UV-Vis measurements. ZnO films were crystallized in the hexagonal wurtzite phase and preferential orientation changed with changing of spray rate. Grain size and roughness of films depended on spray rate. Increasing spray rate made the films grown with bigger grain size and higher roughness. Band gap energy was determined from the UV-Vis. Its value was found to be of 3.25 eV and was almost independent on the spray rate.

Optimization of Deposition Parameters on the Physical Properties of TiO2 Thin Films by Spray Pyrolysis Technique

Titanium dioxide (TiO2) thin films have been deposited on microscopic glass substrate by spray p yrolysis technique. The effect of deposition parameters such as substrate temperature, molarity (precursor concentration) and solution spray rate on the structural, surface morphological and optical properties of the films ha ve been studied. The prepared films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) with EDS and UV-Vis spectroscopy. The XRD patterns indicated that the films have amorphous and polycrystalline structure and the size of the crystallite s have been changed from 9 to 48 nm. The optical band gap of the TiO2 films is determined to be about 3.40 to 3.65 eV to the change of deposition co nditions.

Study of structural, electrical and optical properties of vanadium oxide condensed films deposited by spray pyrolysis technique

Vanadium oxides condensed films are prepared on glass substrates, using spray pyrolysis (SP) technique. The effects of substrate temperature, vanadium concentration in initial solution and the solution spray rate on the nano-structural, electrical, and optical properties of deposited films were investigated. Characterizations of the samples were performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectroscopy methods. The type and concentration of the charge carriers were determined and measured by Hall effect experiment. XRD patterns showed that the prepared films had polycrystalline structure, mostly tetragonal β-V2O5 and V4O9 phases with the preferred orientation along (200) direction. The Hall effect experiment revealed that all samples were n-type, except the ones deposited at substrate temperatures T sub = 300 °C and T sub = 450 °C, vanadium concentration 0.1 mol/L and solution spray rate 10 mL/min. The charge carrier concentrations obtained were in the range 1016–1018 cm−3. The lowest sheet resistance (R s) was obtained for the samples prepared at T sub = 450 °C, vanadium concentration 0.05 mol/L and solution spray rate 10 mL/min. It was also found that the optical transparency of the samples changed from 20% to 75% and the optical band gap of the samples was from 2.22 eV to 2.58 eV, depending on the deposition conditions.

Intermittent spray pyrolytic growth of nanocrystalline and highly oriented transparent conducting ZnO thin films: Effect of solution spray rate

Abstract Uniformly distributed jet of fine droplets was created with control of spray rate ( S f ) to deposit nanocrystalline ZnO thin films by spray pyrolysis technique. X-ray diffraction analysis indicated the polycrystalline film growth with most preferred orientation along c -axis [0 0 2] direction for S f ⩽ 4.5 ml/min, above which films favored [1 0 1] direction. FE-SEM and AFM analysis revealed the uniform vertical growth of ZnO nano-rods for S f = 2.5 ml/min and the film exhibited highest transmittance (95%) with lowest dark resistivity (∼10 −2 Ω-cm). The deposition rate increased due to rise in S f . Alteration of crystallinity, grain size and film thickness with variation in S f lead to variation of band-gap energy from 3.198 eV to 3.302 eV. ZnO film deposited at optimal S f = 2.5 ml/min exhibited maximum electrical conductivity σ = 78.8 Ω −1 -cm −1 , minimum sheet resistance R s = 2.04 × 10 2 Ω/□ and highest figure of merit Φ TC = 2.93 × 10 −3 Ω −1 .

CHARACTERIZATION AND ELECTROCHROMIC PROPERTIES OF VANADIUM OXIDE THIN FILMS PREPARED VIA SPRAY PYROLYSIS

Vanadium oxide thin films were grown on glass substrates using spray pyrolysis technique. The effects of substrate temperature, vanadium concentration in the initial solution and the solution spray rate on the nanostructural and the electrochromic properties of deposited films are investigated. Characterization and the electrochromic measurements were carried out using X-ray diffraction, scanning electron microscopy and cyclic voltammogram. XRD patterns showed that the prepared films have polycrystalline structure and are mostly mixed phases of orthorhombic α- V 2 O 5 along with minor β- V 2 O 5 and V 4 O 9 tetragonal structures. The preferred orientation of the deposited films was found to be along [101] plane. The cyclic voltammogram results obtained for different samples showed that only the films with 0.2 M solution concentration, 5 ml/min solution spray rate and 450°C substrate temperature exhibit two-step electrochromic properties. The results show a correlation between cycle voltammogram, morphology and resistance of the films.

Effect of Solution Spray Rate on the Properties of Chemically Sprayed ZnO:In Thin Films

ZnO:In thin films were grown from 100 mL of spray solution on glass substrates by chemical spray at Ts = 400°C using solution spray rates of 0.5–6.7 mL/min. Zinc acetate and indium(III)chloride were used as Zn and In sources, respectively, with [In]/[Zn] = 3 at.%. Independent of solution spray rate, the crystallites in ZnO:In films grow preferentially in the (101) plane parallel to the substrate. The solution spray rate influences the surface morphology, grain size, film thickness, and electrical and optical properties. According to SEM and AFM studies, sharp‐edged pyramidal grains and canvas‐resembling surfaces are characteristic of films grown at spray rates of 0.5 and 3.3 mL/min, respectively. To obtain films with comparable film thickness and grain size, more spray solution should be used at low spray rates. The electrical resistivity of sprayed ZnO:In films is controlled by the solution spray rate. The carrier concentration increases from 2 · 1019 cm−3 to 1 · 1020 cm−3 when spray rate is increased from 0.5 mL/min to 3.3 mL/min independent of the film thickness; the carrier mobilities are always lower in slowly grown films. Sprayed ZnO:In films transmit 75–80% of the visible light while the increase in solution spray rate from 0.5 mL/min to 3.3 mL/min decreases the transmittance in the NIR region and increases the band gap in accordance with the increase in carrier concentration. Lower carrier concentration in slowly sprayed films is likely due to the indium oxidation.

Investigation on Side-Spray Fluidized Bed Granulation with Swirling Airflow

Top-spray fluidized bed granulation with axial fluidization airflow from the bottom of the granulator is well-established in the pharmaceutical industry. The application of swirling airflow for fluidized bed granulation was more recently introduced. This study examined the effects of various process parameters on the granules produced by side-spray fluidized bed with swirling airflow using the central composite and Box-Behnken design of experiment. Influence of the amount of binder solution, spray rate, and distance between spray nozzle and powder bed were initially studied to establish operationally viable values for these parameters. This was followed by an in-depth investigation on the effects of inlet airflow rate, atomizing air pressure and distance between spray nozzle and powder bed on granule properties. It was found that the amount of binder solution had a positive correlation with granule size and percentage of lumps but a negative correlation with size distribution and Hausner ratio of the granules. Binder solution spray rate was also found to affect the granules size. High drug content uniformity was observed in all the batches of granules produced. Both inlet airflow rate and atomizing air pressure were found to correlate negatively with granule size and percentage of lumps but correlate positively with the size distribution of the granule produced. Percentage of fines was found to be significantly affected by inlet airflow rate. Distance between spray nozzle and powder bed generally affected the percentage of lumps.

Manufacturing of solid dispersions of poorly water soluble drugs by spray drying: Formulation and process considerations

Spray drying is an efficient technology for solid dispersion manufacturing since it allows extreme rapid solvent evaporation leading to fast transformation of an API-carrier solution to solid API-carrier particles. Solvent evaporation kinetics certainly contribute to formation of amorphous solid dispersions, but also other factors like the interplay between the API, carrier and solvent, the solution state of the API, formulation parameters (e.g. feed concentration or solvent type) and process parameters (e.g. drying gas flow rate or solution spray rate) will influence the final physical structure of the obtained solid dispersion particles. This review presents an overview of the interplay between manufacturing process, formulation parameters, physical structure, and performance of the solid dispersions with respect to stability and drug release characteristics.

Cu1−xInxSe2 thin films: Deposition by spray pyrolysis and characteristics

Deposition of copper indium selenide (Cu1−xInxSe2 (0⩽x⩽1)) thin films onto the spectroscopic grade amorphous glass substrates was carried out by a chemical spray deposition technique. The deposition parameters, viz. temperature (400°C), time (8min), solution spray rate (5ml/min), nozzle to substrate distance (30cm), air pressure (1.2kg/m2), etc. were optimized so as to obtain good quality samples. The chemical composition and structure of these as-deposited films were determined by the EDS and XRD analyses techniques. The films are nonstoichiometric. Copper and indium contents in the films vary in proportion with the x and 1−x values. Selenium content in the films (for low In-concentration) was less than that of the expected (50%) whereas it exceeds 50% for higher In-concentration in the films. The crystal structure of these films as-revealed by an X-ray diffraction technique showed that the deposits are composites of the CuSe2, CuInSe2, and In2Se3 phases. The observed data have fair match with the JCPD data. The optical studies conducted in the range of wavelengths between 300nm and 1300nm showed absorption coefficient of the order of 104–105cm−1 and the transitions to be of the direct type. The energy band gap decreased continuously from 2.10eV to 1.15eV as x was varied from 0 to 1. The surface morphology revealed a web of needle like long and tapered at one end, randomly oriented crystallites. Some globule like overgrowth has also been observed. The electrical conductivity studies showed that the films are semiconducting in nature and conductivity is found to be increased with increasing In-content up to x=0.4 and decreased thereafter. A highest electrical conductivity of 1.1×10−4 (Ωcm) has been observed for the films with x=0.4. The activation energies of an electrical conduction were then determined for these samples. Thermo power measurements showed same trend of variations analogous to the electrical conductivity and the samples exhibit n as well as p-type conduction.

Experimental Study of Fluidized Bed Co-Granulation of Two Active Pharmaceutical Ingredients: An Industrial Scale-Up Perspective

This article presents our efforts toward the development and scale-up of a fluidized bed process for co-granulation of two highly water-soluble active pharmaceutical ingredients (APIs) with a polymeric binder. The granulations were produced at three scales using Glatt GPCG3 (small), GPCG15 (pilot), and GPCG120 (commercial) fluid bed columns. The effects of binder concentration, atomization air pressure, and inlet air temperature were first investigated at the small scale. Based on the process knowledge generated at the small scale, various granulations were produced at the pilot scale to determine the effects of solution spray rate. We have demonstrated that, for a given binder solution, the droplet size distribution can be maintained similar by adjusting the atomization pressure when different spray rates were used upon scale-up. Superficial air velocity and moisture level in the powder bed appear to be the other key response parameters, which are, in turn, governed by various process and design parameters as well as formulation properties. This article demonstrates that the process and product quality remains invariant when the aforementioned key response variables are maintained during scale-up through some simple scale-up rules.

Structure, composition and optical properties of ZnS thin films prepared by spray pyrolysis

Abstract Thin films of zinc sulfide (ZnS) are prepared by spray pyrolysis using mixed aqueous solutions of ZnCl2 and thiourea. The structure, surface morphology, chemical composition and optical properties of these films are investigated as a function of substrate temperatures Ts, deposition times td and solution spray rate s. These parameters are optimized in order to obtain films with a good crystalline quality and high transmittance. It is found that the films prepared at substrate temperature of 500°C, deposition time of 35 min (about 1 μm thick) and solution spray rate of 5 ml min−1 have good adherence to the glass substrates and exhibit a mixture of hexagonal (α) and cubic (β) phases, with a preferential orientation along the (1 1 1 )β direction. The X-ray photoelectron spectroscopy (XPS) and electron probe microanalysis (EPMA) show that the optimized films contained very little oxygen and is nearly stoichiometric. These films also show an optical transmittance more than 70% in the visible range.

Effect of Aqueous Film Coating Conditions on Water Removal Efficiency and Physical Properties of Coated Tablet Cores Containing Superdisintegrants

AbstractFew studies have examined the effect of aqueous film coating process conditions on the physical integrity of the final coated product. Characterization of the aqueous film coating process was previously carried out by selecting water removal efficiency as the response variable to detect and monitor moisture accumulation in the tablet bed [1]. In this study, regression techniques were utilized to obtain the relationship between some physical characteristics of aqueous film coated tablet cores that contained superdisintegrant and several process parameters such as inlet air temperature, spray rate, and pan speed. Tablet response variables measured included residual moisture content, tensile strength and percent porosity. Predicted values of these properties were plotted as a function of the inlet air temperature and the coating solution spray rate. The correlations between the coated tablet response variables and the water removal efficiency of the coating process indicated that coated tablet proper...