Inorganic Fullerene-like Tungsten Disulfide Research Articles

Synthesis of Cr 2O 3-based nanocomposite coatings with incorporation of inorganic fullerene-like nanoparticles

The incorporation of inorganic fullerene-like nanoparticles into coating systems is considered an effective method to provide extra functionality and improve the specific properties of matrix coatings. In the present work, inorganic fullerene-like tungsten disulfide (IF-WS 2) nanoparticles have been incorporated into Cr 2O 3 coatings via a modified aerosol-assisted chemical vapour deposition process (AACVD), for the purpose of reducing friction and improving wear resistance. The deposited nanocomposite coatings are characterized using a combination of X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Ball-on-flat testing has been carried out to evaluate the friction and wear properties of the IF-WS 2/Cr 2O 3 nanocomposite coatings. The microstructure and tribological testing results show that the AACVD process is a promising method for the synthesis of nanocomposite coatings incorporating nanoparticles.

Isothermal crystallization kinetics of isotactic polypropylene with inorganic fullerene-like WS 2 nanoparticles

Nanometric-sized inorganic fullerene-like tungsten disulfide particles (IF-WS 2) were used to produce new isotactic polypropylene (iPP) nanocomposites. A remarkable increase of the crystallization rate of iPP in the nanocomposites was observed by DSC and X-ray diffraction techniques using synchrotron radiation. This fact was related to the high nucleation efficiency of IF-WS 2 nanoparticles on the α-form crystals of iPP. Other parameters such as the Avrami exponent, the equilibrium melting temperature, and the fold surface free energy of crystallization of iPP chains in the nanocomposites were obtained from the calorimetric data in order to determine the effect of the nanoparticles on them. A decrease in the fold surface free energy was calculated with increasing IF-WS 2 content.

Microstructures and tribological properties of PEEK-based nanocomposite coatings incorporating inorganic fullerene-like nanoparticles

The high strength, wear resistance and high operational temperature of polyetheretherketone (PEEK) have attracted increasing interests of this material for tribological applications. The addition of solid lubricant is an effective way to further improve the tribological properties of polymeric materials. In the present work, inorganic fullerene-like tungsten disulfide (IF-WS 2) nanoparticles were incorporated into PEEK coatings with the aim of reducing the coefficient of friction (COF) and improving the wear resistance of the coatings. The microstructures of IF-WS 2/PEEK nanocomposite coatings were characterized using a combination of SEM, XRD and FTIR measurements. The thermal behaviours of the coatings were determined using differential thermal analysis (DTA). Tribological tests had also been carried out to evaluate the friction and wear behaviours of IF-WS 2/PEEK nanocomposite coatings. The results showed that significant improvement can be achieved in the tribological properties of the nanocomposite coatings by incorporating IF-WS 2 nanoparticles.