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Minimizing friction and wear in between mating parts is the main concern in the field of tribological studies. Lubricants with improved tribological properties are continuously explored for minimizing friction and wear. In the present work, an attempt has been made to evaluate the effect of the addition of aluminium oxide (Al2O3) nanoparticles as lubricant additives on the tribological performance of base lubricant oil (SAE10W40) using four-ball tester. Weight in the percentage of Al2O3 nanoparticles was added in base oil and evaluated the effect of additives on wear preventive characteristic and coefficient of friction of base lubricant oil. Integrated Taguchi-Grey relational approach is implemented to obtain the optimum combination of load and % wt. of Al2O3 nanoparticle addition for improving the tribological performance of base lubricant oil. With a load of 250 N and 0.5 wt% of Al2O3 nanoparticles shows an optimum combination for the improved tribological performance of base oil. The wear scar diameter and coefficient of friction found to be reduced by 20.75 % and 22.67 % respectively with the addition of 0.5 wt% of Al2O3 nanoparticles in base lubricant oil. The lubrication performance seems to be improved because of mending effect and ball bearing effect of Al2O3 nanoparticles forming a self-protective film on the friction surface.

As a class of layered materials, two dimensional (2D) materials have attracted great attention all around the world due to their inherent use for next generation nano technology devices. We can see 2D materials including carbon in our daily life and at many places, for instance, graphite, diamond and so on. New study is also being conducted to produce new functional materials by combining 2D material and polymer. Hexagonal boron nitride (h-BN) which is one kind of 2D material is dispersed in Poly methyl methacrylate (PMMA) or poly styrene (PS). The composite material of h-BN coated with polymer shows an improvement in the properties such as the higher thermal conductivity and higher mechanical strength. In this study, the composite material of PMMA, h-BN and gold nanoparticles has been synthesized. Boron nitride nano-structures were prepared by nanosecond laser ablation in acetone and was carried out at room temperature with laser ablation time of 120 min. The PMMA films were made by PMMA granules dissolved in acetone solvent and then mix with h-BN and gold colloid solution. The prepared composite films were characterized by scanning electron microscopy (SEM), and UV-vis spectroscopy. Such type of unique 2D nano-composite materials make their mark for the future exploitation in electronics and nanocomposite-related applications.

Pulsed laser ablation in liquid is a well-known and effective method which can be used to prepare the various nanostructures. However, ablated samples have various problems such as wide size distribution, and effect of solvent to sample during laser ablation in liquid has not been well understood. In response to these problems, in this study, we prepared nanoparticles by irradiating nanosecond laser to samples using different solvents. The experimental results of prepared samples were compared, and we evaluated how the different solvents affect to their morphological and optical properties. The morphology, crystal structures and optical properties of the MoS2 nanoparticle were characterized by Scanning electron microscopy, X-ray diffraction, and UV-Vis absorption spectroscopy. Upon the laser ablation of the samples, the absorbance of UV-Vis spectra increased as approaching the shorter wavelength side. From the SEM images, it confirmed that the particle size became smaller for laser ablated MoS2 sample, which is good agreement with the result of UV-Vis spectra. The XRD spectra shows the appearance of new peak for laser ablated MoS2 in methanol as compared to those samples ablated in ethanol and N-methyl-2-pyrrolidone. It can be said that the crystal structure of the sample has changed after ablation. It suggested that because the particle size became smaller after ablation and the band gap increased. Such MoS2 nanostructure has its own importance for optoelectronics devices.