Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : nanomaterial

An Investigation on The Effect of Carbon Nanoparticles on The Properties of Carbon Brushes

Ahmed A. Alasady; M. I. Mohammad; Suleyman Basturk Basturk

Engineering and Technology Journal, 2022, Volume 40, Issue 12, Pages 1732-1744
DOI: 10.30684/etj.2022.135387.1270

The demand for carbon brushes with specific properties and improvements in production economics in recent years has led to increased interest in metal-graphite composites. Metal matrix composites are considered excellent materials to obtain properties superior to those of the constituent phases and meet the specific requirements of material application. In the present study, we suggested a new composite material by utilizing nanomaterials to improve the properties of metal-graphite composite material usually used as carbon brushes. This has been achieved by adding different percentages of 0.1-0.5wt % of carbon nanotubes, carbon nanospheres, or both to the metal matrix composite. The samples were prepared by powder metallurgy technique. The XRD results gave a sharp line and indicated a high crystalline structure and little amorphous, which improved the conductivity performance of the composite produced within the structure of this work. The density measurement chart results showed an increase in the amounts of the carbon nano additives leading to a decrease in the density of the sample. The investigation of nano additives on hardness showed that increases in the additive led to reduced hardness. On the other hand, the resistivity values have reduced gradually when there is an increase in the amounts of the carbon nano additives, especially on the CNT, which gives better results than CNS, which we obtained the resistivity value =(0.32 Ωcm), Comparing with commercial-grade containing free of nano additives (1.3Ω cm).

The Fundamental of Reduced Graphene Oxide with Nanosilver Composite Films Using the Spin Coating Technique

Hamsa A. Alaloosi; Farah T. M. Noori; Abdulhadi K. Jidran

Engineering and Technology Journal, 2022, Volume 40, Issue 8, Pages 1023-1028
DOI: 10.30684/etj.v40i8.2205

Graphene oxide synthesis by hummers method and reduction by the green chemical method using green tea. Preparation films with reduced graphene oxide (rGO) and Silver Nanoparticles (AgNPs) by a spin coating method. The preparation films and Nanomaterial characteristics with X-Ray diffraction (XRD) GO has a peak at (2θ = 11.22̊ ). While rGO has a wider peak at (2θ = 26.2̊ ). The (rGO +AgNPs) films have five obvious diffraction angles. In Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), flaky sheet (rGO), and spherical (AgNPs) with Nanosize about ~20 nm, the peaks of EDX indicated the presence of Carbon, silver, and oxygen. The energy gap was calculated from the absorbance spectrum and seemed to decrease with increasing AgNPs.

Vision Improvement Using Titanium Dioxide Nanoparticles-Doped PMMA for Contact Lenses

Lina M. Shaker; Ali H. Al-Hamdani; Ahmed A. Al-Amiery

Engineering and Technology Journal, 2020, Volume 38, Issue 5, Pages 681-689
DOI: 10.30684/etj.v38i5A.327

Polymer-based nanocomposites exhibit various optical virtues such as a high refractive index (RI), the dispersion index (Abbe number (νd)) and visible light transmittance (T %) about 95-99%. Titanium dioxide nanoparticles (TiO2 NPs) is suggested as a good candidate to rise the RI and maintain high transparency when it is integrated with Poly(methyl methacrylate) polymer PMMA because TiO2 NPs have a high RI (2.45 and 2.7 for anatase and rutile phase, respectively). The ocular performance was evaluated by modulation transfer function (MTF) and image simulation. The used criteria show that the best visual performance is obtained when TiO2-PMMA-CL of 0.1 wt/volume of TiO2 NPs is used (P < 0.0001) which reduced the generated spherical and chromatic aberrations inside the eye