Laser ablation synthesis and optical properties of copper nanoparticles

Copper nanoparticles (Cu-NPs) were prepared in virgin coconut oil (VCO) using a laser ablation technique. A copper plate immersed in VCO was irradiated by an Nd:YAG laser at wave lengths of 532 nm for 5, 10, 20, and 30 min. By increasing the ablation time from 5 to 30 min, the particle size inside the nanofluid decreased from 11 to 4 nm and the concentration, refractive index, and the volume fraction of copper nanofluid increased. The Cu-NPs were capped with oxygen from hydroxyl groups of the VCO, as verified by Fourier transform infrared spectroscopy. The refractive indices, obtained by analysis of the surface plasmon resonance signals increased from 1.44371 + 0.0034i to 1.44387 + 0.0142i, and special self-phase modulation due to nonlinearity effect was investigated

Surface Plasmon Resonance Characterization of Biodiesel

Surface plasmon resonance (SPR) is a technique to retrieve information on optical properties of biomaterial. Essentially, SPR depends on the optical properties of metal layer and the attached dielectric to the metal layer. It was therefore used in this work as an optical sensing unit in characterizing biodiesel and blend biodiesel for finding the relation of refractive index with concentration of oil in the oil and methanol mixture. This study also includes the novel SPR sensor for detection of corrosion of biodiesel and detection of water in biodiesel and blend biodiesel. To achieve these, two computer programs were written to carry out data acquisition, simulation and analysis of experimental data. These programs are based on matrix methods which were written with matlab software for prism configuration. The fitting process was done by iteratively adjusting the pertinent parameters such as thickness, real and imaginary parts of refractive index, until the lowest sum of the squared error was obtained. By using simulation and experimental data, the effects of sensing layer thickness and variation of wavelength on SPR signals were estimated. Various wavelengths were attempted to induce surface plasmons resonance by using Kretschman scheme. The sensing metal layer was initially sputtered on high index prism in Kretschman configuration. At a fixed sensing layer thickness, the angle of resonance was found to be very sensitive to the characteristics of biodiesel in contact with the sensing gold thin film. Normal grade palm oil biodiesel (NPB) and winter grade palm oil biodiesel (WPB) were initially prepared in tranestrification with NaOH catalyst at 60ºC and 5ºC respectively. The significant difference between NPB and WPB can be found from their dispersion curves. The difference is attributed to the much higher Palmitic acid, 16:0C content in NPB than in WPB. On the other hand, the biodiesel blend was prepared by mixing of Malaysian palm oil biodiesel and Petronas diesel fuel using hand shaking method at room temperature; and the percentage of biodiesel was from 10% to 90% (B10, B20, B30, B40, B50, B60, B70, B80 and B90). A linear relation was discovered between the refractive index and the concentration of palm oil biodiesel . In the case of coconut oil biodiesel it was prepared by mixing the virgin coconut oil and methanol at 63°C. The methyl esters, which contribute in the coconut oil biodiesel, were methyl laurate, methyl myristate and methyl palmitate. The volume ratio (methanol to oil) was found to shift from 9 v/v to 0.12 v/v while the refractive index of the mixture shifted from 1.3426 to 1.4246. Thin Polypyrrole–Chitosan coated on the gold layer was also used to detect 2Zn and2Ni in aqueous solution. The curve of the resonance angle shift against ion concentration fitted well to the Langmuir model

Measurement of copper nanoparticle concentration using surface plasmon resonance

In this work, the concentration of copper nanoparticles in virgin coconut oil were measured using surface plasmon resonance technique, and the gold layer was modified by using Polypyrrole Multi-Walled Carbon Nanotube composite layer. The concentration of nanoparticles and angle of resonance shifted from 0.066 mg/L to 0.71 mg/L and from 64.779° to 64.96°, respectively, and the sensitivity of sensor is about 0.01 mg/L

Surface plasmon resonance determination of methanol concentration during alkaline transestrification

A surface plasmon resonance (SPR) method was applied to determine the methanol concentration during an alkaline transestrification of the mixture of palm oil and methanol. Theoretically, an SPR signal resonance angle relates with the refractive index of the mixture. Experimental data showed a resonance angle by way of refractive index depends on each volume percentage of palm oil, methanol, and methyl ester. The optimized percentages of volume concentration are found to be 12% methanol and 88% palm oil. At the present measurement precision, it resulted in 2% excess unutilized palm oil or methanol in the biodiesel mixture

Application of surface plasmon resonance in biodiesel characterization

Surface plasmon resonance is a versatile technique for characterizing biomaterials. In this work the optical parameter and Lorentz-Lorenz constant for biodiesel were determined. According to the experimental data for biodiesels base on palm oil and coconut oil mixture with methanol the accuracy and sensitivity of SPR for these materials is limited by the measurement resolution of 0.001

Laser Ablation Technique for Synthesis of Metal Nanoparticle in Liquid

Recently, the synthesis and application of metal and ceramic nanoparticle are significant subject in science and engineering. The metal nanoparticles such as silver, gold, and copper nanoparticles have more application in material science, nanomedicine, electronic, photonic, and art. One of the green methods for preparation of metal nanoparticles is laser ablation technique that offers a unique tool for nanofabrication of nanoparticles. In this technique, the high-power laser ablates the metal plate and the nanoparticles are formed in the liquid. The properties of nanoparticles using laser ablation are unique, and they are not reproducible by any other method such as chemical methods. The important parameters to produce the metal nanoparticles are energy, wavelength, repetition rate of laser, ablation time, and absorption of an aqueous solution. Laser ablation is a simple method for fabricating the metal nanoparticles without surfactant or chemical addition. In this chapter, the mechanism of formation of metal nanoparticles in liquid, significant parameters for using the laser ablation technique to prepare the metal nanoparticles, and the preparation of silver, gold and copper nanoparticles will be reviewed

Optical characterization of palm oil biodiesel blend

In this study, Surface Plasmon Resonance (SPR) and minimum deviation methods were used for determining the optical properties of blend biodiesel. The SPR angle of resonance consistently shifted to lower value when the amount of biodiesel added to diesel fuel increased independent of the homogeneity of the sample. On the other hand the consistency of the minimum deviation method was dependent on the homogeneity of the blend biodiesel

Application of surface plasmon resonance sensor in detection of water in palm-oil-based biodiesel and biodiesel blend

In this paper, we present an optical method based on surface plasmon resonance and using the Kretschmann configuration for the detection of water in biodiesel and biodiesel blend. Measurements were carried out at room temperature using a He-Ne laser (632.8 nm, 5 mW) as the monochromatic light source. Two samples, pure palm oil biodiesel (B100) and biodiesel plus diesel fuel (B50) were chosen for angle scan measurements. When the water concentration was changed from 1 to 100 ppm, the resonance angle increased linearly. The real and imaginary parts of the refractive index also increased linearly with the concentration. All data were collected after the sample mixture reached a stable stage. Prior to the data collection, data on the kinetic behavior showed that the resonance angle decreased exponentially with time up to about 50 min or longer before a stable stage can be achieved