Effect of Processing Technique on the Mechanical Properties of a Functionalized Superhydrophobic Silane

Author(s):  
Akinsanya Damilare Baruwa ◽  
Esther Titilayo Akinlabi ◽  
O. P. Oladijo ◽  
Jyotsna Dutta-Majumdar ◽  
Shree Krishna

Abstract The need to test for the durability and capability of a coating before being subjected to service is highly important for engineering applications. Ultra-low indentation of nano-hardness and nano-scratch are valuable methods of measuring durability and near-surface mechanical properties of thin films. AISI 304 stainless steel was coated with Repellix superhydrophobic coating using chemical vapor deposition (CVD) and atomic layer deposition (ALD) techniques at constant processing parameters. The deposited films were characterized through nanoindentation, nanoscratch, and water contact angle to establish the effect of coating technique on the mechanical properties of the thin films. The results established that the ALD deposition technique has better hardness but less wear resistance when compared to the sample produced using the CVD method. ALD also showed to have a lower contact angle in comparison with a coating deposited by CVD. Overall, it is expected that the substrate coated by CVD would outperform samples produced via ALD as regards to typical applications where good wear and corrosion resistance are required.

2015 ◽  
Vol 19 (4) ◽  
pp. 1353-1356 ◽  
Author(s):  
Jiang-Hui Zhao ◽  
Lan Xu ◽  
Qixia Liu

Poly(vinyl alcohol) nanofibers were prepared by bubble electrospinning. After the ethanol post-treatment, poly(vinyl alcohol) nanofibers showed enhanced hydrophobicity with water contact angle change from 0 to 78.9?, and the break strength of poly(vinyl alcohol) nanofibers was dramatically improved from 8.23 MPa to 17.36 MPa. The facile strategy with improved hydrophobicity and mechanical properties of poly(vinyl alcohol) nanofibers will provide potential benefits for applications of this material, especially in filtration field.


Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 471 ◽  
Author(s):  
Martha Claros ◽  
Milena Setka ◽  
Yecid P. Jimenez ◽  
Stella Vallejos

Non-modified (ZnO) and modified (Fe2O3@ZnO and CuO@ZnO) structured films are deposited via aerosol assisted chemical vapor deposition. The surface modification of ZnO with iron or copper oxides is achieved in a second aerosol assisted chemical vapor deposition step and the characterization of morphology, structure, and surface of these new structured films is discussed. X-ray photoelectron spectrometry and X-ray diffraction corroborate the formation of ZnO, Fe2O3, and CuO and the electron microscopy images show the morphological and crystalline characteristics of these structured films. Static water contact angle measurements for these structured films indicate hydrophobic behavior with the modified structures showing higher contact angles compared to the non-modified films. Overall, results show that the modification of ZnO with iron or copper oxides enhances the hydrophobic behavior of the surface, increasing the contact angle of the water drops at the non-modified ZnO structures from 122° to 135° and 145° for Fe2O3@ZnO and CuO@ZnO, respectively. This is attributed to the different surface properties of the films including the morphology and chemical composition.


2003 ◽  
Vol 778 ◽  
Author(s):  
Z. Xu ◽  
C. Waters ◽  
X. Wang ◽  
N. Sudhir ◽  
S. Yarmolenko ◽  
...  

AbstractComposite thin films of yttria stabilized zirconia (YSZ) and alumina (Al2O3) have been synthesized using liquid fuel combustion chemical vapor deposition (CCVD) and pulsed laser deposition (PLD) in the NSF Center for Advanced Materials and Smart Structures (CAMSS) at North Carolina A&T State University. With the CCVD technique, addition of alumina was realized by adding the designated amount of aluminum-organic in the reagent solution; while with PLD, doping of alumina in YSZ was accomplished by alternative ablations of an YSZ target and an alumina target. Variations in morphology, surface roughness and nano-mechanical properties of the composite thin films of Al2O3/YSZ were characterized. Crystal size of the films processed by CCVD was much larger than that processed by PLD; surface roughness follows the similar tendency. Upon high-temperature annealing, crystals in the PLD processed thin films grew up to 300 nm. The effect of Al2O3 in YSZ thin films on their nano-mechanical properties was dependent on the film deposition techniques in our research. For the films deposited by CCVD, addition of Al2O3 improved the nano hardness and elastic modulus of YSZ thin films, while a decline was observed in the mechanical properties of the films deposited by PLD.


Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 534
Author(s):  
Alessio Aufoujal ◽  
Ulrich Legrand ◽  
Jean-Luc Meunier ◽  
Jason Robert Tavares

Photo-initiated chemical vapor deposition (PICVD) functionalizes carbon nanotube (CNT)-enhanced porous substrates with a highly polar polymeric nanometric film, rendering them super-hydrophilic. Despite its ability to generate fully wettable surfaces at low temperatures and atmospheric pressure, PICVD coatings normally undergo hydrophobic recovery. This is a process by which a percentage of oxygenated functional group diffuse/re-arrange from the top layer of the deposited film towards the bulk of the substrate, taking the induced hydrophilic property of the material with them. Thus, hydrophilicity decreases over time. To address this, a vertical chemical gradient (VCG) can be deposited onto the CNT-substrate. The VCG consists of a first, thicker highly cross-linked layer followed by a second, thinner highly functionalized layer. In this article, we show, through water contact angle and XPS measurements, that the increased cross-linking density of the first layer can reduce the mobility of polar functional groups, forcing them to remain at the topmost layer of the PICVD coating and to suppress hydrophobic recovery. We show that employing a bi-layer VCG suppresses hydrophobic recovery for five days and reduces its effect afterwards (contact angle stabilizes to 42 ± 1° instead of 125 ± 3°).


2010 ◽  
Vol 114 (41) ◽  
pp. 17899-17904 ◽  
Author(s):  
Seol Choi ◽  
Byung Joon Choi ◽  
Taeyong Eom ◽  
Jae Hyuck Jang ◽  
Woongkyu Lee ◽  
...  

RSC Advances ◽  
2017 ◽  
Vol 7 (47) ◽  
pp. 29275-29283 ◽  
Author(s):  
Aoyun Zhuang ◽  
Ruijin Liao ◽  
Sebastian C. Dixon ◽  
Yao Lu ◽  
Sanjayan Sathasivam ◽  
...  

Hierarchical micro/nano-structured transparent superhydrophobic polytetrafluoroethylene films with water contact angle 168°, water sliding angle <1° and visible transmittance >90% were prepared on glass via aerosol-assisted chemical vapor deposition.


2014 ◽  
Vol 32 (2) ◽  
pp. 145-156 ◽  
Author(s):  
J. Judes ◽  
V. Kamaraj

AbstractIn order to overcome limitations in the processing parameters of powder compaction method, a novel processing technique based on sol-gel route has been developed to produce near-net-shaped prototype fine zirconia minispheres with required properties that could potentially be used as grinding media. Impact of magnesia concentration and sintering temperature on the final product has been analyzed in detail. Zirconia minispheres have been characterized to establish a correlation between physical, structural and mechanical properties. Sintering temperature, soaking period, heating rate and viscosity of the sol apparently influence the characteristics of the magnesia stabilized zirconia minispheres. The phase identification, density variation, chemical decomposition, functional group specification, surface area, porosity, shrinkage and microstructural features of the dried and sintered final product have been studied. It has been observed that magnesia content, sintering temperature, density and the grain size of the sintered minispheres have a significant impact on the mechanical properties of the final product.


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