Papers by Keyword: Gold Nanoparticle

Abstract: The study examines the effects of silver and gold nanoparticles on blood flow in stenosed arteries. The evaluation part of a mathematical model that consisted of linked partial differential equations. These equations have been resolved using the FTCS scheme, along with suitable boundary conditions. The velocity and concentration, temperature, wall shear stress, and volumetric flow rate are all demonstrated with the help of numerical solutions. These are necessary for understanding the impact of different parameters. The present study contributes to the biomedical field by examining the impact of gold and silver nanoparticles on blood flow, which is measured by concentration, wall shear stress, volumetric flow rate, velocity, and temperature, for various values of dimensionless parameters. This understanding is important for the treatment of cardiovascular diseases.Keywords: Stenosis Artery; Gold Nanoparticle; Silver Nanoparticle.

Abstract: The Rhodamine 6G fluorescent dye, It was dissolved at a concentration in ethanol of 6*10-6 M, was investigated an active laser medium in this work, and its optical and spectral properties were investigated. The fluorescent Rhodamine 6G dye, which was dissolved in ethanol at a concentration 6*10-6 M, was investigated an active laser medium in this work, and its optical and spectral properties were investigated. The chemical reduction process was also used to create gold nanoparticles at concentration of 0.01 M. Three concentrations of gold nanoparticles (2.5, 5, and 7.5%) w/v were added to the Rhodamine 6G dye solution in order to examine how they affected the dye's optical and spectral characteristics. Optical and spectral properties Rhodamine 6G dye sample were analyzed both before to following the addition of gold nanoparticles. After adding gold nanoparticle the dye, the results indicated a shift toward lower wavelengths (red shift) and an increase in optical parameters, with the exception of transmittance. Fluorescence intensity, radiative lifetime, quantum yield, stoke shift, and fluoresce cent lifetime were among the spectrum characteristics. The relative fluorescence intensity dropped after the nanoparticles were applied.

Abstract: Aluminium and its alloys are becoming more widely used in engineering due to a growing need for lightweight metals. However, owing to boundary segregation and coarse dendritic grains, typical cast aluminium alloys have low hardness and strength, limiting their use in large-scale and complex-shaped applications. Many studies have shown that reinforcing aluminium alloy with nanoparticles synthesized by various chemical and physical ways improves these shortcomings, but these approaches are both expensive and potentially dangerous. Recycling aluminium scrap is also necessary to save energy and money. Therefore, this research aimed at production of high tensile strength and hardness from scrapped aluminium reinforced with synthetic nano particle and subjected to heat treatment. The elemental composition of aluminium alloy cast from scrap was analyzed using a Light Emission Polyvac Spectrometer, and gold nanoparticles were synthesized from aloe vera leaves. In creating a Metal Matrix Nano Composite, Al alloy was reinforced with gold nanoparticles at various percentages. At 450 °C, the reinforced Metal Matrix Nano Composite was hardened. The composites' hardness, tensile strength, and microstructural analyses were determined. The composites' grain structure demonstrated a uniform distribution of reinforcing phase of Al 6063 Alloy. The microhardness and tensile strength of the composites are influenced by the % weight proportion of AuNps and the heat treatment. After 3 percent and 6 percent weight of AuNps reinforcement were used, the microhardness/tensile strength of the reinforced sample rose by 22.4 Hv/58MPa and 24.7 Hv/80MPa, respectively, but when the composites were hardened, it climbed to 41 Hv/109 MPa and 45.5 Hv/125 MPa. After 3 percent and 6 percent weight of AuNps reinforcement were used, the microhardness/tensile strength of the reinforced sample rose by 22.4 Hv/58MPa and 24.7 Hv/80MPa, respectively, but when the composites were hardened, it climbed to 41 Hv/109 MPa and 45.5 Hv/125 MPa.

Abstract: Abstrac. In the present work, gold nanoparticle (Au NPs) was synthesis by pulsed laser ablation (PLA) by using Q-switched, (Nd: YAG) (E=80mJ) (λ=532,1064nm) and Number of pulses (500)pulse of the gold metal target in deionized water. The optical properties were studied with a UV-vis spectrophotometer which tests the absorbance spectra and comparison of the generated nanoparticles solution. atomic force microscope (AFM) results show that the grain size increase by decreasing wavelength. The optical limiter of the resulting colloidal solution was studied.

Abstract: We attempt to study the effect of gold nanoparticles embedded into the active polymer of regioreguler poly (3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) on the charge kinetic to enhance the performance of bulk-heterojunction solar cell. It has been known that the generation of localized surface plasmon resonance (LSPR) would both increase the photon absorption and improve the efficiency of charge separation. Synthesis of gold nanoparticles stabilized by oleylamine (AuOA) was carried out by reduction method and resulted in the spherical shape of nanoparticles with a diameter size of ~12 nm. The absorbance spectra show the typical of surface plasmon peak of AuOA in solution at ~527 nm. Fabrication of inverted bulk-heterojunction solar cell device was done in the configuration of ITO/ZnO/P3HT:PCBM:AuOA/PEDOT:PSS/Ag. Incorporation of AuOA in polymer solution is clearly detected from the enhanced absorbance peak resulted from UV-Vis measurement and the mix solution of P3HT:PCBM:AuOA is quite stable in the concentration of AuOA less than 10 wt%. In our experiment, fabricated solar cell reveals the enhancement in current density at short circuit condition (J_sc) from 44.57 mA/cm² to 56.14 mA/cm² with the addition of 3.9 wt% AuOA in polymer solution along with the enhancement of power conversion efficiency (PCE) from 4.07% to 6.23% as characterized by J-V measurement. In our case, the voltage at open circuit condition (V_oc) of the device does not show significant improvement.

Abstract: The crafts such as lacquerware have made unique strides through decorating techniques using gold such as “Makie”, the technique to draw picture by scattering powdered gold, and “Chinkin”, the technique to rub gold into the design engraved by carving knives. In conventional techniques, practical knowledge and ability are essential to produce craft products. Therefore, screen printing which consists of simple processes has been developed. However, screen printing requires a masking plate made of silk or nylon to create patterns for transcribing ink into objects. This paper presents the formation of a decorative film by inkjet printing with gold nanoparticles for crafts such as lacquerware. The proposed method consists of on-demand process, which makes design changeable without masking. The aims are threefold: 1) to establish a sintering process of gold nanoparticles for acrylonitrile butadiene styrene (ABS) and phenol resin substrates used for synthetic resin products; 2) to characterize the sintered gold film; 3) to examine applicability to industry. The major results obtained are as follows: the appearance and the reflectance spectra of the gold nanoparticle film vary with heat conditions; the proper heat conditions which prevent thermal damage to substrates are the temperature of 373 K or below for the ABS resin substrate, and 423 K or below for the phenol resin substrate, respectively; the gold nanoparticle film possessed a good surface integrity without any voids when the sintering temperature is higher than 323 K for 1 h. Moreover, the film had such a high adhesion to substrates that no separation occurred after cross-cut test; the proposed method applied a lacquerware product made of ABS resin, yielding the decorative film

Abstract: AuNPs were prepared by using a sacrificial hydrothermal method on Aluminum (Al) /(polymethylsilsesquioxane) PMSSQ / (Silicon) Si substrate. The Al layer was the sacrificial template dissolved in precursor during hydrothermal reaction. The effect of deposition method for Al template on AuNP formation was investigated. Two deposition methods (sputtering and thermal evaporation) of Al template were varied for preparing template. The properties of formed AuNPs were studied using field-emission scanning electron microscopy and X-ray diffractometer. PMSSQ was spin-coated on the produced AuNPs in order to investigate the memory properties, which were then characterized by using a semiconductor characterization system. The sample grown hydrothermally on sputtered Al template exhibited excellent memory properties with the lowest turn “ON” voltage at 2.4 V in I-V characteristics and 34 charges were stored per AuNP in C-V measurement. Therefore, isolate and uniform of AuNPs distribution are crucial for excellent memory properties of devices.

Abstract: In this work, we present the novel robust material, modified natural rubber (NR) composites filled with gold nanoparticles (AuNPs). To investigate its outstanding properties, dielectric, electrical and mechanical properties of NR and modified NR composites filled with gold nanoparticles (AuNPs) were studied. The NR and all composite films were prepared by using solution casting method. The size of the synthetic AuNPs was analyzed by Transmission Electron Microscope (TEM) technique. The dispersion of AuNPs fillers within the NR matrix was investigated by scanning electron microscopy (SEM). Dielectric and electrical properties of NR composites were analyzed as function of filler concentration and frequency in a range of 10⁰-10⁵ Hz, observed with the LCR analyzer. Elastic modulus of all samples was evaluated by a strain gauge set up. It was found that the dielectric constant is inversely related to the frequency. Moreover, the dielectric constant and the electrical conductivity strongly increase in proportional to the AuNPs filler content. In comparison at AuNPs concentration of 0.0010% by weight, it was observed that the dielectric constant of NR composites is eight times larger than the pure NR, while the mechanical properties of the NR composites slightly increase in proportional to the AuNPs. As consequence, the interfacial surface area significantly affects the electrical and mechanical properties of those NR composites.

Abstract: Gold nanoparticles were synthesized using brown seaweed (Sargassum crassifolium) extract and chloroauric acid solution. This is an easy, cheap and environment friendly synthesis method for the formation of gold nanoparticles. The gold nanoparticles with varying amount of seaweed extract was characterized using Ultraviolet-visible spectroscopy. Moreover, Transmission Electron Microscopy characterization was used to observe the shape and size of gold nanoparticles. Experimental results revealed that varying the amount of brown seaweed extract can control the optical absorption spectra of the produced gold nanoparticles. Greater amount of brown seaweed extract will exhibit peak in the lower wavelength while smaller amount of seaweed extract will exhibit peak in the higher wavelength. It is believed that the wavelength of free surface electrons resonance is related to the shift of absorption peak. TEM images revealed a more spherical and smaller particles as the amount of brown seaweed extract was increased. This simple green synthesis method of gold nanoparticles will give a cost effective route in the mass production of gold nanoparticles for biomedical applications.

Abstract: The rapid developments in nanoscience, and its applications on biomedical areas have a large impact on drug delivery, tissue engineering, sensing, and diagnosis. Gold is widely investigated nanomaterial for the last couple of decades, since it has unique surface properties and very low toxicity to biological environment. In this work, we present a novel synthesis of gold nanoparticles (GNPs) exhibiting both visible and near-IR absorbance without agglomeration. The surface of GNPs were analyzed by routine methods and the binding kinetics were investigated by Surface Plasmon Resonance (SPR) Spectroscopy. The unique optical properties of near-IR asorbing GNP colloids hold promise for biological applications.