No abstract

The reinforcement of different polymers by natural fibers has recently been the center of attention among many research groups around the globe. The major factors that affect the mechanical performance for the composites are the surface treatment for the reinforcing material as well as the variation in the fiber diameters. In this study, coir fibers with different grain sizes varied between 250 and 950 μm were chemically treated by alkali solution and employed as a reinforcing agent for epoxy. The morphology and the mechanical performance represented by impact and flexural strength for the neat polymer and the resulted composites were investigated. The weight fraction was 10.0 wt %, and the approach employed for preparing the samples was hand layup technique. The obtained results confirmed a mechanical improvement for the composites compared to the neat polymer. Flexural strength was considerably improved (~ 94%) for the composite with higher grain size of 950 μm. On the other hand, the impact strength was also significant as it was improved by 92% for the composite of lower grain size of 250 μm. The scanning electron microscopy (SEM) results were correlated with the mechanical performance of the polymer and its composites.

No abstract

The doping process with materials related to carbon has become a newly emerged approach for achieving an improvement in different physical properties for the obtained doped films. Thin films of CuPc: C60 with doping ratio of (100:1) were spin-coated onto pre-cleaned glass substrates at room temperature. The prepared films were annealed at different temperatures of (373, 423 and 473) K. The structural studies, using a specific diffractometry of annealed and as deposited samples showed a polymorphism structure and dominated by CuPc with preferential orientation of the plane (100) of (2θ = 7) except at temperature of 423K which indicated a small peak around (2θ = 31) for C60. AFM remarks showed the existence of a compact packing film with a smooth surface. The FTIR spectra emphasized the bonding between CuPc and C60. UV-Vis Absorption spectroscopy confirmed that the CuPc was dominating the optical properties with a small shift in Q band towards higher wavelengths.