Preparation, characterization and thermal degradation of Polyimide (4-APS/BTDA)/siO2 composite films.

Polyimide/SiO2 composite films were prepared from tetraethoxysilane (TEOS) and poly(amic acid) (PAA) based on aromatic diamine (4-aminophenyl sulfone) (4-APS) and aromatic dianhydride (3,3,4,4-benzophenonetetracarboxylic dianhydride) (BTDA) via a sol-gel process in N-methyl-2-pyrrolidinone (NMP). The prepared polyimide/SiO2 composite films were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The FTIR results confirmed the synthesis of polyimide (4-APS/BTDA) and the formation of SiO2 particles in the polyimide matrix. Meanwhile, the SEM images showed that the SiO2 particles were well dispersed in the polyimide matrix. Thermal stability and kinetic parameters of the degradation processes for the prepared polyimide/SiO2 composite films were investigated using TGA in N2 atmosphere. The activation energy of the solid-state process was calculated using Flynn–Wall–Ozawa’s method without the knowledge of the reaction mechanism. The results indicated that thermal stability and the values of the calculated activation energies increased with the increase of the TEOS loading and the activation energy also varied with the percentage of weight loss for all compositions

Synthesis of Nanocrystalline SnOx (x = 1–2) Thin Film Using a Chemical Bath Deposition Method with Improved Deposition Time, Temperature and pH

Nanocrystalline SnOx (x = 1–2) thin films were prepared on glass substrates by a simple chemical bath deposition method. Triethanolamine was used as complexing agent to decrease time and temperature of deposition and shift the pH of the solution to the noncorrosive region. The films were characterized for composition, surface morphology, structure and optical properties. X-ray diffraction analysis confirms that SnOx thin films consist of a polycrystalline structure with an average grain size of 36 nm. Atomic force microscopy studies show a uniform grain distribution without pinholes. The elemental composition was evaluated by energy dispersive X-ray spectroscopy. The average O/Sn atomic percentage ratio is 1.72. Band gap energy and optical transition were determined from optical absorbance data. The film was found to exhibit direct and indirect transitions in the visible spectrum with band gap values of about 3.9 and 3.7 eV, respectively. The optical transmittance in the visible region is 82%. The SnOx nanocrystals exhibit an ultraviolet emission band centered at 392 nm in the vicinity of the band edge, which is attributed to the well-known exciton transition in SnOx. Photosensitivity was detected in the positive region under illumination with white light

Pencil graphite electrode modified nanosensor for detection and determination of tramadol in blood serum

El tramadol (TD) es un fármaco pseudo-opioide que tiene un efecto de somnolencia. En esta investigación, el electrodo de grafito de lápiz (PGE) fue modificado por nano tubo de carbono (CNT) utilizado para la detección de TD en suero sanguíneo. Para la detección y determinación se utilizó el método de voltametría diferencial de pulso (DPV). Se investigó la influencia de las variables electroquímicas para el tipo de electrodo y el pH de la solución. El sensor fue diseñado para medir TD en el suero sanguíneo. A continuación se investigó el efecto de la interferencia del ácido ascórbico en la medición de TD con este sensor.Bajo condiciones optimizadas, se observó una relación lineal para el pico anódico sobre la raíz cuadrada de la velocidad de exploración. Se observó una respuesta lineal sobre el intervalo de concentración de 5 - 25 M con un coeficiente de correlación (R2) de 0,999 y un límite de detección (LOD) de 0,776 μM.Se observó una distancia de 0,9 V entre el pico de oxidación del ácido ascórbico y el TD en el estudio de interferencia

Simultaneous optimization of nanocrystalline SnO2 thin film deposition using multiple linear regressions

A nanocrystalline SnO2 thin film was synthesized by a chemical bath method. The parameters affecting the energy band gap and surface morphology of the deposited SnO2 thin film were optimized using a semi-empirical method. Four parameters, including deposition time, pH, bath temperature and tin chloride (SnCl2·2H2O) concentration were optimized by a factorial method. The factorial used a Taguchi OA (TOA) design method to estimate certain interactions and obtain the actual responses. Statistical evidences in analysis of variance including high F-value (4,112.2 and 20.27), very low P-value (<0.012 and 0.0478), non-significant lack of fit, the determination coefficient (R2 equal to 0.978 and 0.977) and the adequate precision (170.96 and 12.57) validated the suggested model. The optima of the suggested model were verified in the laboratory and results were quite close to the predicted values, indicating that the model successfully simulated the optimum conditions of SnO2 thin film synthesis

Novel conductive polypyrrole/zinc oxide/chitosan bionanocomposite: synthesis, characterization, antioxidant, and antibacterial activities

Saeideh Ebrahimiasl,1,2 Azmi Zakaria,3 Anuar Kassim,4 Sri Norleha Basri4 1Department of Nanotechnology, Institute of Advanced Technology, Universiti Putra Malaysia, Serdang, Malaysia; 2Department of Chemistry, Ahar Branch, Islamic Azad University, Ahar, Iran; 3Department of Physics, Universiti Putra Malaysia, Serdang, Malaysia; 4Department of Chemistry, Universiti Putra Malaysia, Serdang, Malaysia Abstract: An antibacterial and conductive bionanocomposite (BNC) film consisting of polypyrrole (Ppy), zinc oxide (ZnO) nanoparticles (NPs), and chitosan (CS) was electrochemically synthesized on indium tin oxide (ITO) glass substrate by electrooxidation of 0.1&nbsp;M pyrrole in aqueous solution containing appropriate amounts of ZnO NPs uniformly dispersed in CS. This method enables the room temperature electrosynthesis of BNC film consisting of ZnO NPs incorporated within the growing Ppy/CS composite. The morphology of Ppy/ZnO/CS BNC was characterized by scanning electron microscopy. ITO&ndash;Ppy/CS and ITO&ndash;Ppy/ZnO/CS bioelectrodes were characterized using the Fourier transform infrared technique, X-ray diffraction, and thermogravimetric analysis. The electrical conductivity of nanocomposites was investigated by a four-probe method. The prepared nanocomposites were analyzed for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl assay. The results demonstrated that the antioxidant activity of nanocomposites increased remarkably by addition of ZnO NPs. The electrical conductivity of films showed a sudden decrease for lower weight ratios of ZnO NPs (5&nbsp;wt%), while it was increased gradually for higher ratios (10, 15, and 20&nbsp;wt%). The nanocomposites were analyzed for antibacterial activity against Gram-positive and Gram-negative bacteria. The results indicated that the synthesized BNC is effective against all of the studied bacteria, and its effectiveness is higher for Pseudomonas aeruginosa. The thermal stability and physical properties of BNC films were increased by an increase in the weight ratio of ZnO NPs, promising novel applications for the electrically conductive polysaccharide-based nanocomposites, particularly those that may exploit the antimicrobial nature of Ppy/ZnO/CS BNCs. Keywords: bionanocomposite, electrodeposition, conductive, antibacterial, antioxidan

Prediction of grain size, thickness and absorbance of nanocrystalline tin oxide thin film by Taguchi robust design

Transparent conductive films of tin oxide were deposited on glass substrates under various deposition conditions. Taguchi analysis was used to model the dependence of the grain size, thickness and absorbance of nanocrystalline tin oxide on the process parameters namely pH value, concentration, time of deposition and bath temperature. The effect of the mentioned process parameters on the grain size, thickness and absorbance of deposited layer during the deposition of nanocrystalline was investigated using X-ray diffraction (XRD) technique, atomic force microscopy (AFM) and UV–Visible spectroscopy. Comparison between the model predictions and the experimental observations predicted a remarkable agreement between them. The predictions of the model and sensitivity analysis showed that among the effective process parameters, deposition time and concentration were the main parameters having significant effect on crystalline size. Bath temperature had the most significant effect on absorbance and deposition time had a dominant effect on thickness

The Impact of Al₂O₃ and Multi-Wall Carbon Nanotubes on the Morphology of Roller-Compacted Concrete

Roller-compacted concrete (RCC) is a dry, zero-slump concrete prepared from the same ingredients as conventional cement but with a lower cement percentage. It is frequently compacted in the same way as dirt is. RCC is utilized chiefly to build massive structures such as dams and vast horizontal surfaces like highway foundations. Because of the low cement concentration, it slows the rise of temperature in mass concrete and decreases thermal strains. However, this paper analyzes the possibility of a chemical link forming between functionalized Multi-Wall Carbon Nanotubes and Nano-alpha Alumina in Roller-Compacted Concrete (RCC) structure using spectroscopic analysis. Various characterization methods, including X-ray diffraction patterns, Fourier-transform infrared (FT-IR) spectrometry, and scanning electron microscopy (SEM), were employed to analyze the nanocomposite&#39;s interaction. Based on X-ray diffraction pattern results, Multi-Wall Carbon Nanotubes (MWCNT) peaks show that the powder is amorphous, but it becomes crystalline when combined at high temperatures. The X-Ray diffraction (XRD) profile of the carbon nanotube-doped alumina sample reflects the leading share of Al2O3, with angles and diffraction plates of Al2O3 being the same as &alpha;- Al2O3 orthorhombic crystalline phase owing to the low carbon concentration. Besides, scanning electron microscope analysis revealed that &alpha;-Al2O3 powder samples without MWCNT and containing MWCNT have a shell state that the doped sample tends to be spherical

Novel conductive polypyrrole/zinc oxide/chitosan bionanocomposite: synthesis, characterization, antioxidant, and antibacterial activities

An antibacterial and conductive bionanocomposite (BNC) film consisting of polypyrrole (Ppy), zinc oxide (ZnO) nanoparticles (NPs), and chitosan (CS) was electrochemically synthesized on indium tin oxide (ITO) glass substrate by electrooxidation of 0.1 M pyrrole in aqueous solution containing appropriate amounts of ZnO NPs uniformly dispersed in CS. This method enables the room temperature electrosynthesis of BNC film consisting of ZnO NPs incorporated within the growing Ppy/CS composite. The morphology of Ppy/ZnO/CS BNC was characterized by scanning electron microscopy. ITO–Ppy/CS and ITO–Ppy/ZnO/CS bioelectrodes were characterized using the Fourier transform infrared technique, X-ray diffraction, and thermogravimetric analysis. The electrical conductivity of nanocomposites was investigated by a four-probe method. The prepared nanocomposites were analyzed for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl assay. The results demonstrated that the antioxidant activity of nanocomposites increased remarkably by addition of ZnO NPs. The electrical conductivity of films showed a sudden decrease for lower weight ratios of ZnO NPs (5 wt%), while it was increased gradually for higher ratios (10, 15, and 20 wt%). The nanocomposites were analyzed for antibacterial activity against Gram-positive and Gram-negative bacteria. The results indicated that the synthesized BNC is effective against all of the studied bacteria, and its effectiveness is higher for Pseudomonas aeruginosa. The thermal stability and physical properties of BNC films were increased by an increase in the weight ratio of ZnO NPs, promising novel applications for the electrically conductive polysaccharide-based nanocomposites, particularly those that may exploit the antimicrobial nature of Ppy/ZnO/CS BNCs

A method for depositing tin oxide film.

The present invention relates to a method for depositing tin oxide film on a substrate comprises of providing a substrate; preparing a precursor solution comprises of metal dichloride, hydrogen peroxide and a complexing agent; adjusting the precursor solution at a predetermined pH; maintaining the precursor solution at a predetermined temperature; immersing; and drying the substrate. The tin oxide film is deposited on the substrate by chemical bath deposition at a room temperature