Homemade Spray Research Articles

Cost-effective nebulizer sprayed ZnO thin films for enhanced ammonia gas sensing – Effect of deposition temperature

ZnO thin films were deposited onto glass substrates using a simple and low-cost homemade nebulizer spray technique by keeping the substrate temperature at 350, 400 and 450 °C. Their ammonia gas sensing property at room temperature under darkness was studied. The results show that the ZnO films deposited at 400 °C substrate temperature exhibit the best response time as well as shortest recovery time. The large number of oxygen vacancies presents in this film and the suitable surface morphology with increased surface to volume ratio may be the reasons for the enhanced gas sensing property of this sample. The photoluminescence, FESEM and XRD results are correlated appropriately with the gas sensing properties of the samples.

Characterization of spray pyrolytically deposited high mobility praseodymium doped CdO thin films

Praseodymium (Pr) doped CdO thin films with high transparency and high mobility were deposited, using a homemade spray pyrolysis setup, on micro-slide glass substrates preheated at 300°C. Polycrystalline nature and Cd-O bond vibration of deposited films were confirmed by X-ray diffraction, micro-Raman and Fourier transform infrared spectroscopy analyses. The oxidation state of Cd2+, O2−, and Pr3+ was confirmed by X-ray photoelectron spectroscopy analysis. The highest average particle size (92nm-FESEM) and high RMS (13.48nm-AFM) values are obtained for 0.50wt% Pr doped CdO thin film. The optical band gap is varied between 2.38eV and 2.52eV, depending on the Pr doping concentration. Photoluminescence spectra revealed that Pr doped CdO thin film exhibits strong green emission at 582nm. High mobility (82cm2/Vs), high charge carrier concentration (2.19×1020cm−3) and high transmittance (83%) were observed for 0.50wt% Pr doped CdO film. A high figure of merit (9.79×10−3Ω−1) was obtained for 0.50wt% Pr doped CdO thin films. The mechanism behind the above results is discussed in detail in this paper.

Optoelectronic properties of SnO2 thin films sprayed at different deposition times

This article presents the elaboration of tin oxide (SnO2) thin films on glass substrates by using a home-made spray pyrolysis system. Effects of film thickness on the structural, optical, and electrical film properties are investigated. The films are characterized by several techniques such as x-ray diffraction (XRD), atomic force microscopy (AFM), ultraviolet-visible (UV–Vis) transmission, and four-probe point measurements, and the results suggest that the prepared films are uniform and well adherent to the substrates. X-ray diffraction (XRD) patterns show that SnO2 film is of polycrystal with cassiterite tetragonal crystal structure and a preferential orientation along the (110) plane. The calculated grain sizes are in a range from 32.93 nm to 56.88 nm. Optical transmittance spectra of the films show that their high transparency average transmittances are greater than 65% in the visible region. The optical gaps of SnO2 thin films are found to be in a range of 3.64 eV–3.94 eV. Figures of merit for SnO2 thin films reveal that their maximum value is about 1.15 × 10−4 Ω−1 at λ = 550 nm. Moreover, the measured electrical resistivity at room temperature is on the order of 10−2 Ω·cm.

Facile synthesis of SnO2 thin film by spray pyrolysis technique, investigation of the structural, optical, electrical properties

In the present contribution a simplistic synthesis of SnO2 thin film on ultrasonically cleaned soda-lime glass is outlined. Precursor solution of strength 0.1 M, 0.2 M and 0.3 M are used for the synthesis using a homemade affordable spray pyrolysis technique. An elaborate structural analysis is carried from the X-Ray diffraction data. The structural analysis is supported by the transmission electron microscopy micrograph and selected area electron diffraction pattern. The crystallite sizes are below 50 nm that makes the films suitable for nano-material application. Formation of texture is observed which indicates the preferred orientation to be the (101) plane. In comparison to techniques like pulsed laser deposition, spray pyrolysis provides better results for certain applications. The morphology of the thin films is investigated using atomic force microscopy. It revealed the control of application dependent roughness of the sample by variation of molarity of the precursor solution. Also the film is uniformly spread throughout the substrate. The optical properties are studied by UV-Visible spectroscopy that further confirms formation of nano-structures. Preliminary electrical investigation of the thin films is done by using a two probe semi-conductor characterization system and is correlated with UV-Visible result. Impedance analysis showed that with higher molarity the impedance remains constant and the barrier height remains fixed for high frequency which predicts that the films can be used for rectifying applications.

Effect of solution concentration on the structural, optical and electrical properties of SnO2 thin films prepared by spray pyrolysis

The aim of this work is the production of tin oxide thin films with a suitable optoelectronic properties required for application as transparent electrodes. Using a simple and inexpensive homemade spray pyrolysis system of tin chloride (SnCl2) onto glass substrates. The motivation for the use of this technique is its simplicity and effectiveness of preparation. The effect of the molarity (0.05–0.25 mol/l) on structural, optical and electrical film properties was investigated. The results obtained with several characterization techniques such as DRX, AFM, UV–visible transmission and four probe points measurements are well consistent and suggest that the prepared films were uniform and well adherent to the substrates. All the films are polycrystalline in nature with a tetragonal structure having a preferential orientation along the (1 1 0) plane. The obtained SnO2 films, not only have an average transmittance greater than 80% in the visible region, but also have an optical band gap between 3.84 and 4.14 eV depending on the spraying solution concentration. Moreover, the measured electrical conductivity at room temperature was found in the order of 102 (Ω cm)−1.

Alginate Microspheres Containing Temperature Sensitive Liposomes (TSL) for MR-Guided Embolization and Triggered Release of Doxorubicin.

ObjectiveThe objective of this study was to develop and characterize alginate microspheres suitable for embolization with on-demand triggered doxorubicin (DOX) release and whereby the microspheres as well as the drug releasing process can be visualized in vivo using MRI.Methods and FindingsFor this purpose, barium crosslinked alginate microspheres were loaded with temperature sensitive liposomes (TSL/TSL-Ba-ms), which release their payload upon mild hyperthermia. These TSL contained DOX and [Gd(HPDO3A)(H2O)], a T1 MRI contrast agent, for real time visualization of the release. Empty alginate microspheres crosslinked with holmium ions (T2* MRI contrast agent, Ho-ms) were mixed with TSL-Ba-ms to allow microsphere visualization. TSL-Ba-ms and Ho-ms were prepared with a homemade spray device and sized by sieving. Encapsulation of TSL in barium crosslinked microspheres changed the triggered release properties only slightly: 95% of the loaded DOX was released from free TSL vs. 86% release for TSL-Ba-ms within 30 seconds in 50% FBS at 42°C. TSL-Ba-ms (76 ± 41 μm) and Ho-ms (64 ± 29 μm) had a comparable size, which most likely will result in a similar in vivo tissue distribution after an i.v. co-injection and therefore Ho-ms can be used as tracer for the TSL-Ba-ms. MR imaging of a TSL-Ba-ms and Ho-ms mixture (ratio 95:5) before and after hyperthermia allowed in vitro and in vivo visualization of microsphere deposition (T2*-weighted images) as well as temperature-triggered release (T1-weighted images). The [Gd(HPDO3A)(H2O)] release and clusters of microspheres containing holmium ions were visualized in a VX2 tumor model in a rabbit using MRI.ConclusionsIn conclusion, these TSL-Ba-ms and Ho-ms are promising systems for real-time, MR-guided embolization and triggered release of drugs in vivo.

Structural, microstructural, optical and electrical properties of spray deposited rare-earth metal (Sm) ions doped CdO thin films

Rare-earth metal, samarium (Sm) ions, doped cadmium oxide (CdO) thin films were deposited on microscopic glass substrates at 300 °C by a homemade spray pyrolysis experimental setup. The deposited films were characterized for their structural, microstructural, optical and electrical properties. X-ray diffraction analysis confirmed that the deposited films belong to the cubic crystal system. The undoped films show a slight preferential growth along (111) diffraction plane, and the (200) plane emerged as the preferential growth direction when the Sm-doping is higher than 0.75 wt%. Field emission scanning electron microscopy analysis reveals that the average grain size and surface morphology of CdO films are effectively modified by various Sm-doping concentration. The elemental composition of the deposited films was analyzed using energy dispersive spectroscopy. The metal oxide (Cd–O) bond vibrations were observed at 319, 389, 551,779 and 941 cm−1 by micro-Raman studies at room temperature. Oxidation state of Sm3+ was confirmed by X-ray photoelectron spectroscopy analysis. A transmittance (ranging 83–86 %) in the visible and NIR region was observed for the various Sm concentrations. The optical band gap estimated varies between 2.39 and 2.67 eV, depending on the Sm-doping concentration. The negative sign of Hall coefficient confirmed the n-type conductivity and the mobility and carrier concentration are in the 45–78 cm2/V s, and 1.0 × 1020–3.36 × 1020 cm−3 range respectively.

Hydrophilic CdSe thin films by low cost spray pyrolysis technique and annealing effects

Cadmium selenide (CdSe) thin films were deposited on glass substrates at 200°C by homemade chemical spray pyrolysis technique. The as-deposited films were annealed in air atmosphere for 3 hrs, at two different temperatures (350 and 450°C). The as-deposited film has been observed to possess uniform surface with crystalline sphalerite cubic structure and optical band gap of Eg = 2.4 eV. It is worth noting that after annealing, metastable cubic sphalerite phase transforms into stable well crystalline hexagonal wurtzite phase. The optical band gap was found to decrease from 2.4 eV to 1.75 eV. The average surface roughness is 1.5 nm for the as-deposited film which rises to 4.2 nm after annealing the film in air atmosphere. The contact angle was found to vary from 94° ± 1° to 81° ± 1° with annealing temperature. In addition, from Wenzel’s relation it is concluded that CdSe thin film is hydrophilic in nature.

On-Farm Evaluation of Homemade Pepper Extract in the Management of Pests of Cabbage,Brassica oleraceaeL., and French Beans,Phaseolus vulgarisL., in Two Agro-Ecological Zones in Ghana

Cabbage, Brassica oleraceae L., and French beans, Phaseolus vulgaris L., are important vegetables grown in Ghana. However, attack by insect pests affects their quality and marketable yield. On-farm experiment was undertaken during the major rainy season of 2012 at Afari and Kpong, in the moist Semi Deciduous Forest and Coastal Savanna agro-ecological zones of Ghana, respectively, to explore the use of homemade extracts from fruit of hot pepper, Capsicum frutescens L. in the management of insect pests of cabbage and French beans. The treatments included a crude water extract from pepper fruit (20 g/l w/v), the semi-synthetic insecticide emamectin benzoate, ATTACK® (1 ml/l v/v) and tap water as a control. The dominant pests found on cabbage at both locations were the diamondback moth (DBM), Plutella xylostella (L.), the cabbage aphid, Brevicoryne brassicae (L.) and the whitefly, Bemisia tabaci (Gennadius). On French beans, the flower thrips, Megalurothrips sjostedti (Trybom), the whitefly, B. tabaci and a range of leafhoppers, Empoasca spp. were found at both locations. The cowpea aphid, Aphis craccivora (Koch) was present only at Kpong. Among the natural enemies found on cabbage at both locations were the larval parasitoid, Cotesia plutellae (Kurdjumov), the ladybird beetles, Cheilomenes spp., hoverflies and a number of spiders. On French beans, ladybirds and spiders were observed only at Kpong. Generally, the application of pepper and emamectin benzoate were effective in controlling some pests of cabbage and French beans and also conserved the natural enemies. Emamectin benzoate and pepper treated-plots had higher yields of French beans than the control plots at Afari. The potential of homemade pepper spray for pest management on smallholder farms, backyard gardens and in organic vegetable production systems is discussed.

The study of optical, dielectric and optoelectronic properties of dodecylbenzene sulfonic acid doped polyaniline

Soluble polyaniline (PANI) doped with dodecylbenzene sulfonic acid (DBSA) was synthesized by chemical oxidation method and was cast on glass using homemade spray, a simple technology used for coating thin film in order to replace other costly complicated techniques. The PANI–DBSA was characterized by FTIR, XRD and UV–vis techniques. The TGA results illustrated that they are three major stages of weight loss of the PANI–DBSA sample. D.C. and A.C. study was performed by pelletizing the sample. D.C. conductivity obtained at room temperature was 3.753×10−3S/cm. The A.C. conductivity and dielectric properties was analyzed in the frequency range 100–1000kHz which indicates that the value of dielectric constant and loss tangent increases with increase in temperature and decreases with increase in frequency and in addition it supports the hopping mechanism. Current density–voltage (J–V) measurements was used to characterize ITO/PANI–DBSA/Al device. The value of various junction parameters such as ideality factor, barrier height and saturation current density was calculated.

Flexible Implantable Microtemperature Sensor Fabricated on Polymer Capillary by Programmable UV Lithography With Multilayer Alignment for Biomedical Applications

In this paper, we present and develop a programmable UV lithography system with multilayer alignment for cylindrical substrates. By using this system various microstructures with different patterns can be fabricated on the capillary surface, and ±1 μm alignment precision can be realized. A home-made spray coating system is also developed for capillary substrates. A flexible implantable microtemperature sensor for hyperthermia application has been designed and fabricated on the polymer capillary with 330 μm diameter. The finite-element transient simulation indicates the sensor can realize ~ 2 ms quick response. Magnetron sputtered platinum film is used as the sensing material considering its good resistance-temperature effect. The test temperature coefficient of resistance of the fabricated flexible microsensors is 0.0035/°C, which is close to the industry standard value of the bulk Pt resistor sensor. The current-voltage curves of the sensor at different temperatures have been tested. The test sensitivity of the temperature sensor is 1.485 Ω/°C. The present flexible implantable microtemperature sensor is promising to be used as an important interventional monitoring device for biomedical applications.

<sub></sub>Structural, Morphological and Optical Characterization of SnO<sub>2</sub>:F Thin Films Prepared by Chemical Spray Pyrolysis

Fluorine doped tin oxide (FTO) films were successfully prepared on glass and quartz substrate at a substrate temperature equal to 450 °C for different fluorine doping (0, 0.05, 0.1, 0.15) by a homemade spray pyrolysis technique. The spray solution prepared from tin tetrachloride pentahydrate (SnCl4 · 5H2O) dissolved in distilled water at (0.1 M) concentration and ammonium fluoride (NH4F) was added into the solution for fluorine doping. X-ray diffraction patterns of the spray-deposited (SnO2: F) films for different fluorine doping show that all the diffractograms contain the characteristic SnO2 orientations. The matching of the observed and standard d-values confirm that the deposited films are of tin oxide with tetragonal structure and the films are polycrystalline with (110) as a preferred growth orientation. The surface morphology of SnO2: F thin film has been examined by atomic force microscopy (AFM). The average transmittance in the visible region (at 550 nm) has been found (40%, 47%, 52%, 59%, 61%) for the fluorine doping (0, 0.05, 0.1, 0.15, 0.2) respectively.

Research on mass transfer of CO2 absorption using ammonia solution in spray tower

Research on mass transfer of carbon capture process plays an important role in the design of absorbing device. The effects of ammonia concentration, L/G, gas flow rate, gas temperature, CO2 partial pressure and other factors on the volumetric overall mass transfer coefficient (KGaV), the gas phase mass transfer coefficient (kG) and the effective mass transfer cross-sectional area (aV) were investigated with ammonia solution as the absorbent in homemade spray tower. Experimental results show that KGaV has upward trend with the increasing ammonia concentration, L/G and gas flow rate, and first increases and then decreases with the rises of CO2 partial pressure and gas temperature; kG increases with the increasing L/G, gas flow rate and CO2 partial pressure; aV increases with the increasing ammonia solution and gas flow rates; CO2 partial pressure has less impact on KGaV, kG and aV. Under the experimental conditions, maximums of KGaV, kG and aV are 0.17kmolm−3h−1kPa−1; 0.0022kmolkPam−2h−1 and 99.25m2m−3 respectively.

<sub></sub>Structural, Morphological and Optical Characterization of SnO<sub>2</sub>:F Thin Films Prepared by Chemical Spray Pyrolysis

Fluorine doped tin oxide (FTO) films were successfully prepared on glass and quartz substrate at a substrate temperature equal to 450 °C for different fluorine doping (0, 0.05, 0.1, 0.15) by a homemade spray pyrolysis technique. The spray solution prepared from tin tetrachloride pentahydrate (SnCl4 · 5H2O) dissolved in distilled water at (0.1 M) concentration and ammonium fluoride (NH4F) was added into the solution for fluorine doping. X-ray diffraction patterns of the spray-deposited (SnO2: F) films for different fluorine doping show that all the diffractograms contain the characteristic SnO2 orientations. The matching of the observed and standard d-values confirm that the deposited films are of tin oxide with tetragonal structure and the films are polycrystalline with (110) as a preferred growth orientation. The surface morphology of SnO2: F thin film has been examined by atomic force microscopy (AFM). The average transmittance in the visible region (at 550 nm) has been found (40%, 47%, 52%, 59%, 61%) for the fluorine doping (0, 0.05, 0.1, 0.15, 0.2) respectively.

Identification and assay of underivatized urinary acylcarnitines by paper spray tandem mass spectrometry

A new analytical approach, using paper spray tandem mass spectrometry, has been developed for assay of carnitine and acylcarnitines in urine. Paper spray (PS) is a very promising technique, especially in clinical investigations, because of its simplicity, low cost, and rapid sample preparation. A home-made paper spray device was used for assay of urinary acylcarnitines (C2-C18). The performance of solvents with different elution efficiency and paper substrates with different porosity grade and structure were tested by use of spiked synthetic urine. Tandem mass spectrometry in multiple reaction monitoring (MRM) mode was optimized to obtain better specificity and sensitivity. Analyte signals were evaluated for stability and reproducibility. Calibration with [(2)H3]propionylcarnitine (C3-d3), [(2)H3]octanoylcarnitine (C8-d3), and [(2)H3] palmitoylcarnitine (C16-d3) as internal standards was used for quantification. Very good linearity was obtained, with correlation coefficients >0.99 for C0-C12 and C16 acylcarnitines and >0.96 for C14 and C18 acylcarnitines. Accuracy and precision (RSD, %) of the proposed procedure were tested at concentrations of 0.8, 8, and 20 mg L(-1) with very satisfactory results: overall mean accuracy was 98.9% and overall mean relative standard deviation 1%. Limits of detection (LOD) between 6 and 208 μg L(-1) for propionylcarnitine and tetradecanoylcarnitine, respectively, can be regarded as very satisfactory. Application of the method to real urine proved that paper spray tandem mass spectrometry is a simple, rapid, and direct tool (no derivatization is required) for assay of carnitine and C2-C12 acylcarnitines in urine.

Study of optical, dielectric and optoelectronic properties of dodecylbenzene sulfonic acid doped polypyrrole

Soluble polypyrrole (PPy) doped with dodecylbenzene sulfonic acid (DBSA) was synthesized by chemical oxidation method and was cast on glass using homemade spray, a simple technology used for coating thin film in order to replace other costly complicated techniques. FTIR, D.C. and A.C. study was performed on pellets of the sample, where FTIR spectrum revealed the presence of all characteristics transmission peaks and D.C. conductivity obtained at room temperature was 8.845×10−3S/cm. The A.C. conductivity and dielectric properties of pellet analyzed in the frequency range 100–1000kHz indicates that the value of dielectric constant and loss tangent increases with increase in temperature and decreases with increase in frequency and in addition it supported the hopping mechanism. Analysis of XRD, UV–visible and diode property for the film obtained using above mentioned novel technology was made, where a band gap of 2.21eV obtained from absorption spectrum confirms its application in the field of solar cell. Current density–voltage (J–V) measurements was used to characterize ITO/PPy-DBSA/Al device. The value of various junction parameters such as ideality factor, barrier height and saturation current density was also calculated.

Spray Pyrolysis Deposition of Nanostructured Tin Oxide Thin Films

Nanostructured SnO2 thin films were grown by the chemical spray pyrolysis (CSP) method. Homemade spray pyrolysis technique is employed to prepare thin films. SnO2 is wide bandgap semiconductor material whose film is deposited on glass substrate using aqueous solution of SnCl4·5H2O as a precursor. XRD (X-ray diffraction), UV (ultraviolet visible spectroscopy), FESEM (field emission scanning electron microscopy), and EDS (energy dispersive spectroscopy) analysis are done for structural, optical, surface morphological, and compositional analysis. XRD analysis shows polycrystalline nature of samples with pure phase formation. Crystallite size calculated from diffraction peaks is 29.92 nm showing nanostructured thin films. FESEM analysis shows that SnO2 thin film contains voids with nanoparticles. EDS analysis confirms the composition of deposited thin film on glass substrate. UV-visible absorption spectra show that the bandgap of SnO2 thin film is 3.54 eV. Bandgap of SnO2 thin film can be tuned that it can be used in optical devices.

Preparation and Physical Properties of ITO Thin Films by Spray Pyrolysis Method

Indium tin oxide (ITO) films were deposited on glass substrates by using the homemade spray pyrolysis system. Orthogonal test was designed to examine the optimal conditions for preparation of the ITO films. The results showed that the ITO thin films can be prepared by the homemade spray pyrolysis device successfully. The device is simple in structure and easy to use. The substrate temperature is the main factor on the photoelectric properties of the ITO films. The optimal conditions for preparing the ITO thin films were as following: the substrate temperature is 300oC, the carrier gas flow of the air was 1.5 L•min-1, the annealing temperature was 500oC, the proportion of the indium and tin was 10:1, the distance between substrate and nozzle was 8 cm, and the deposition time was 3.5 min. The average optical transmittance in the visible range and sheet resistance of the ITO film were 93% and 2786Ω/□, respectively.

Effect of heat treatment on electrical properties of fluorine doped tin dioxide films prepared by ultrasonic spray pyrolysis technique

Fluorine doped tin dioxide (FTO) films were prepared on glass substrates by a homemade ultrasonic spray pyrolysis system and the electrical properties were improved by annealing in air. The as-deposited film was prepared from SnCl4 solution. This spray solution prepared from tin tetrachloride pentahydrate (SnCl4 5H2O) dissolved in deionized water at 0.3M concentration and NH4F was added into the solution for fluorine doping. The NH4F/SnCl4 ratio was varied as 0, 5, 10, 20 and 40%mol, respectively. All of films were prepared at the same period of time, 15minutes, and substrate temperatures of 300oC. The lowest resistivity of prepared films was found about 8.40x10-1Ω cm at the optimum NH4F/SnCl4 ratio of 10%mol. The heat treatment parameters were annealed temperature and time. The annealed temperature was varying as 200, 250, 300 and 350 oC and annealed times were set at three different values as 15, 30 and 45min. for each annealed temperature. After heat treatment process, the transmittance in the near infrared range was decreased due to the decreasing of resistivity.

Fabrication of a MEMS Temperature Sensor on the Capillary Surface for Hyperthermia Intervention Monitoring

A micro temperature sensor has been designed and fabricated on a capillary by surface micromachining. Considering cylindrical capillary surface used as the substrate, a new and home-made spray coating system has been developed and the effect of heater and process parameters on the photoresist film is also evaluated. The capillary with coated photoresist has been successfully patterned using our previous cylindrical projection lithography equipment. Platinum as a stable noble metal was selected to form the key sensing element. Magnetron sputtering and lift-off processes were used to fabricate the temperature sensor on the capillary with 300 μm outside diameter. Finally, the fabricated temperature sensor was characterized by scanning electron microscope. The fabricated micro temperature sensor can be widely used as an important intervention monitoring device in several biomedical applications, especially in the hyperthermia.