Browsing by Author "Al-Zubi, Feras"

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Deposition of stainless steel thin films: an electron beam physical vapour deposition approach
    (MDPI, 2019-02-14) Ali, Naser; Teixeira, Joao Amaral; Addali, Abdulmajid; Saeed, Maryam; Al-Zubi, Feras; Sedaghat, Ahmad; Bahzad, Husain
    This study demonstrates an electron beam physical vapour deposition approach as an alternative stainless steel thin films fabrication method with controlled layer thickness and uniform particles distribution capability. The films were fabricated at a range of starting electron beam power percentages of 3–10%, and thickness of 50–150 nm. Surface topography and wettability analysis of the samples were investigated to observe the changes in surface microstructure and the contact angle behaviour of 20 °C to 60 °C deionised waters, of pH 4, pH 7, and pH 9, with the as-prepared surfaces. The results indicated that films fabricated at low controlled deposition rates provided uniform particles distribution and had the closest elemental percentages to stainless steel 316L and that increasing the deposition thickness caused the surface roughness to reduce by 38%. Surface wettability behaviour, in general, showed that the surface hydrophobic nature tends to weaken with the increase in temperature of the three examined fluids.
  • Thumbnail Image
    ItemOpen Access
    The effect of aluminium nanocoating and water pH value on the wettability behavior of an aluminium surface
    (Elsevier, 2018-02-27) Ali, Naser; Teixeira, Joao Amaral; Addali, Abdulmajid; Al-Zubi, Feras; Shaban, Ehab; Behbehani, Ismail
    Experimental investigation was performed to highlight the influence of ionic bounding and surface roughness effects on the surface wettability. Nanocoating technique via e-beam physical vapor deposition process was used to fabricate aluminium (Al) film of 50, 100, and 150 nm on the surface of an Al substrate. Microstructures of the samples before and after deposition were observed using an atomic force microscopy. A goniometer device was later on used to examine the influence of surface topography on deionised water of pH 4, 7 and 9 droplets at a temperature ranging from 10 °C to 60 °C through their contact angles with the substrate surface, for both coated and uncoated samples. It was found that, although the coated layer has reduced the mean surface roughness of the sample from 10.7 nm to 4.23 nm, by filling part of the microstructure gaps with Al nanoparticles, the wettability is believed to be effected by the ionic bounds between the surface and the free anions in the fluid. As the deionised water of pH 4, and 9 gave an increase in the average contact angles with the increase of the coated layer thickness. On the other hand, the deionised water of pH 7 has showed a negative relation with the film thickness, where the contact angle reduced as the thickness of the coated layer was increased. The results from the aforementioned approach had showed that nanocoating can endorse the hydrophobicity (unwitting) nature of the surface when associated with free ions hosted by the liquid.