Abstract: ZnSnO3 thin film was deposited at different deposition time (0.5 h, 2 h, 4 h and 6 h) using sol-gel immersion method and the electrical, optical and structural properties of this film was investigated. This research involved the preparation of nanostructured ZnO thin film by using RF magnetron sputtering, preparation of ZnSnO3 sol-gel solution, metal contact deposition and characterization of humidity sensor. The thin film was characterized using current-voltage (I-V) measurement (Keithley 2400) and field emission scanning electron microscopy (FESEM) (JEOL JSM 6701F) for electrical and structural properties respectively. The sensor was characterized using I-V measurement in a humidity chamber (ESPEC SH-261) and the chamber has been set at room temperature with varied relative humidity (% RH), in the range of 40-90% RH. The film prepared with a deposition time of 2 h shows better sensitivity for humidity sensor. The FESEM investigation shows that crystal size increases with the increasing deposition time.
Abstract: Aluminum nanoislands deposited on silicon substrate were studied by a scanning tunnelling microscopy technique. Measurements completed with spatial resolution up to 1 nm revealed a complex nanoisland structure-rhomboidally ordered near the border of the aluminum-silicon and porous structure in the islands upper parts. Volt-ampere curves demonstrated strong dependency from the film thickness and were interpreted as nanoscale effects. Kelvin probe microscopy was used for simultaneous aluminum-alumina and alumina-air surface scanning.
Abstract: The knowledge of fabrication method plays an important role in the preparation of aligned carbon nanotubes (ACNT) from natural hydrocarbon feedstock. Here ACNT were successfully synthesized by two-stage catalytic chemical vapor deposition method using organic oil (camphor oil) as a precursor. Synthesis was carried out at a fixed growth temperature of 800 °C and in different growth time: 10, 20, 30, 40, 50 and 60 minutes. The optimized condition for the growth of ACNT produced a small amount of by-product amorphous carbon and highly uniform crystal structure. The experimental results demonstrated that formation ACNT is also dependent on the growth time. The nanotubes were characterized by field emission scanning electron microscopy and micro-Raman spectroscopy. Thermal properties were evaluated by thermogravimetric analysis.
Abstract: In this work, we have synthesized carbon nanotubes (CNT) using different bio-hydrocarbon precursors namely palm, olive, coconut, corn and sesame oils. Prior to the synthesis process, thermogravimetric analysis (TGA) characterization was performed on the carbon precursors to facilitate the optimization procedures of CNT and reach maximum yield and higher quality CNT. The CNT arrays were deposited on a silicon substrate by thermal catalytic decomposition of the precursor using 5.33 wt% ferrocene. The synthesis was carried out at 750 °C for 60 min under argon ambient. The samples were characterized using field emission scanning electron microscopy, micro-Raman spectroscopy and TGA analysis. The difference in oil density resulted in different quality and tube diameter of CNT produced. Among all, the CNT synthesized from coconut oil can be considered as the best bio-hydrocarbon precursor for higher quality (ID/IG ~0.62) and good purity (81.95 %) CNT.
Abstract: nanocarbonated hydroxyapatite/Poly (4-vinyl pyridine-co-styrene) composites of varying composition for biomaterial applications have been synthesized. The nanocarbonated hydroxyapatite/Poly (4-vinyl pyridine-co-styrene) composite materials were characterized by XRD, FTIR, 31P NMR, TGA, DTA and FESEM. Carbonated Hydroxyapatite nanorod embedded composite was prepared using Poly (4-vinyl pyridine-co-styrene) as a matrix with different weight percentages (wt %). The results indicated that the size and crystallinity of Carbonated hydroxyapatite nanoparticles decreases with increase in Poly (4-vinyl pyridine-co-styrene) concentration in the composite. SEM confirms the presence of carbonated hydroxyapatite nanorod crystals in Poly (4-vinyl pyridine-co-styrene) matrix. nanoCarbonated hydroxyapatite/ Poly (4-vinyl pyridine-co-styrene) composites were screened for antimicrobial activity and anti inflammatory activity.
Abstract: The effect of nanoclay on the mechanical properties of Isophthalic unsaturated polyester was studied with the help of robust design Concept. Organo modified MMT nanoclay (Nanomer 1.31PS) was used as reinforcement. The weight percentage of nanoclay, impeller blade design, mixing hours and mixing speed were taken as control factors. In Taguchi design of experiments, L9 orthogonal array was employed to investigate the effect of control factors on mechanical properties such as tensile and flexural strength. X-ray diffraction (XRD) and Atomic force microscopy (AFM) results show the intercalation /exfoliation of clays in the polyester matrix.