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Crystals of hydroxyapatite (HAp) were grown on silk fibers using simulated body fluid (SBF) at a temperature of 37 °C. Two different conditions of silk thread were investigated for efficiency of inducing HAp: i) with sericin protein and ii) without sericin protein. Effect of simulated body fluid (SBF) concentrations at 1.0 × SBF and 1.5 × SBF and sericin protein on HAp growth was discussed. The results showed that HAp was successfully crystallized on silk from both 1.0 × SBF and 1.5 × SBF concentrations. The crystal size obtained from the 1.5 × SBF concentration was larger than that of the 1.0 × SBF concentration. However, it was found that the 1.5 × SBF offered less number of the crystals per unit area than that of the 1.0 × SBF. The physical and chemical compositions of HAp were characterized by XRD, SEM and optical microscopy. This study may be very useful for many applications, especially in biomedical and material science.

Electrical conductivity of bulk graphite was investigated as a function of its volume density and temperature. The bulk graphite was prepared from pressing natural graphite powders obtained from two different conditions: i) without any treatment and ii) with 24 hr of ultrasonic treatment. Powders from each condition were consolidated using an isobaric press of different pressures, including 5, 10, 20, 30, 40 and 50 MPa. Ultrasonic treatment helped to exfoliate graphene from its parent graphite which enhanced the electrical conductivity of the compressed bulk graphite. Scanning electron microscopy (SEM) and UV-Vis spectroscopy confirmed that multilayer graphenes and nanographite were obtained after the sonication. Raman spectroscopy was also used to investigate the graphitic characteristics of sonicated graphite. The bulk graphite of 50 MPa consolidation from the sonicated powders offered the highest electrical conductivity which was due to its highest density as well as a combination of multilayer graphene. Effect of temperature on the electrical conductivity was discussed. The conductivity increases when increasing the temperature.

Alumina nanoparticles were synthesized from a bulk aluminium using laser ablation from Nd:YAG laser with a wavelength of 1064 nm in deionized water. Physical and chemical properties of the nanoparticles were investigated as a function of the laser pulse energies, including 1, 3 and 5 J. 3 J of laser energy offered plenty of spherical nanoparticles with a uniform size distribution of less than 100 nm. UV-visible spectroscopy was used to evaluate the optical property of the obtained suspension, representing a strong peak at 213 nm. XRD analysis showed that plenty of the nanoparticles are κ-Al2O3, which would be very useful for many applications.