scholarly journals Hydrophobic and Corrosion Behavior of Sol-Gel Hybrid Coatings Based on the Combination of TiO2 NPs and Fluorinated Chains for Aluminum Alloys Protection

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1076 ◽  
Author(s):  
Pedro Rivero ◽  
Juan Maeztu ◽  
Calos Berlanga ◽  
Adrian Miguel ◽  
José Palacio ◽  
...  

In this work, layers of a sol-gel hybrid matrix doped with metal oxide nanoparticles (TiO2 NPs) have been deposited on flat samples of AA6061-T6 aluminum alloy using the dip-coating technique, with the aim of obtaining coatings with better anti-corrosive and hydrophobic properties. Two different organic modified silica alkoxides, namely 3-(glycidyloxypropyl)trimethoxysilane (GPTMS) and methyltriethoxysilane (MTEOS), have been used for an adequate entrapment of the metal oxide nanoparticles. In addition, a fluorinated metal-alkoxide precursor has also been added to the hybrid matrix in order to improve the hydrophobic behavior. The experimental results corroborate that the presence of these TiO2 NPs play an important role in the development of the sol-gel hybrid coatings. The water contact angle (WCA) measurements, as well as pencil hardness tests indicate that TiO2 NPs make a considerable increase in the resultant hydrophobicity possible, with better mechanical properties of the coatings. The coating thickness has been measured by cross-section scanning electron microscopy (SEM). In addition, a glow discharge optical emission spectroscopy (GD-OES) analysis has been carried out in order to corroborate the adequate entrapment of the TiO2 NPs into the sol-gel coatings. Finally, potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) have been performed in order to evaluate the corrosion resistance of the coatings. All the results provide insights into the efficacy of the developed sol-gel hybrid coatings for anticorrosive purposes with good mechanical properties.

2020 ◽  
Vol 10 (17) ◽  
pp. 5864
Author(s):  
Lucía Blanco-Covián ◽  
José Ramón Campello-García ◽  
María Carmen Blanco-López ◽  
Manuel Miranda-Martínez

This study explores the potential antibiofouling capacity of coatings based on mixes of poly vinyl alcohol (PVA)-glutaraldehyde (GA) incorporating additions of metal and metal oxide nanoparticles (TiO2, ZnO, CuO, AgNPs and Ag-TiO2NPs). Such a kind of hybrid polymer-nanoparticle mix (PVA/GA/ nanoparticles (NPs)) was uniformly applied by spin coating on the surface of a laboratory raceway and tested in freshwater loaded with green algae communities. The results showed PVA/GA was a convenient carrier for the nanoparticles tested. Image analysis of the coatings showed that Ag-TiO2 nanoparticles exhibited a significant improvement of the antibiofouling effect when compared with that of AgNPs and TiO2-NPs. The effect of the Ag-TiO2 NPs loaded coating about four times better than that of ZnO-NPs. A consistent experimental methodology was developed to test the antibiofouling capacity of the coatings and the hybrid coatings developed have demonstrated promising results as environmentally friendly antibiofouling materials.


Author(s):  
Norhasnidawani Johari ◽  
Noor Azlina Hassan ◽  
Norita Hassan ◽  
Mohd Hanafi Ani

Nanocoatings plays an important role in coating industry. The solution was being prepared through copolymerization of epoxy resin hardener and with the incorporation of metal oxide nanoparticles, Zinc Oxide (ZnO) and Silica (SiO2). ZnO and SiO2 were synthesized using sol-gel. Epoxy hardener acted as host while the metal oxide nanoparticles as guest components. The formulation of nanocoatings with excellent adhesion strength and corrosion protection of carbon steel was studied. The performance of wetting ability with different medium was analysed using contact angle. Water medium showed the addition of 3wt% of hybrid between ZnO and SiO2 was the best nanocoating to form hydrophobic surface and was also the best nanocoating surface to form hydrophilic surface with vacuum oil dropping. In oil dropping, the contact angle was smaller than 90° and the water drop tends to spreads on surface.


Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 94 ◽  
Author(s):  
Laura Corredor ◽  
Maen Husein ◽  
Brij Maini

Recent studies revealed higher polymer flooding performance upon adding metal oxide nanoparticles (NPs) to acrylamide-based polymers during heavy oil recovery. The current study considers the effect of TiO2, Al2O3, in-situ prepared Fe(OH)3 and surface-modified SiO2 NPs on the performance of xanthan gum (XG) solutions to enhance heavy oil recovery. Surface modification of the SiO2 NPs was achieved by chemical grafting with 3-(methacryloyloxy)propyl]trimethoxysilane (MPS) and octyltriethoxysilane (OTES). The nanopolymer sols were characterized by their rheological properties and ζ-potential measurements. The efficiency of the nanopolymer sols in displacing oil was assessed using a linear sand-pack at 25 °C and two salinities (0.3 wt % and 1.0 wt % NaCl). The ζ-potential measurements showed that the NP dispersions in deionized (DI) water are unstable, but their colloidal stability improved in presence of XG. The addition of unmodified and modified SiO2 NPs increased the viscosity of the XG solution at all salinities. However, the high XG adsorption onto the surface of Fe(OH)3, Al2O3, and TiO2 NPs reduced the viscosity of the XG solution. Also, the NPs increased the cumulative oil recovery between 3% and 9%, and between 1% and 5% at 0 wt % and 0.3 wt % NaCl, respectively. At 1.0 wt % NaCl, the NPs reduced oil recovery by XG solution between 5% and 12%, except for Fe(OH)3 and TiO2 NPs. These NPs increased the oil recovery between 2% and 3% by virtue of reduced polymer adsorption caused by the alkalinity of the Fe(OH)3 and TiO2 nanopolymer sols.


2007 ◽  
Vol 1007 ◽  
Author(s):  
Markus Niederberger ◽  
Jelena Buha ◽  
Igor Djerdj

ABSTRACTSol-gel routes to metal oxide nanoparticles in organic solvents under exclusion of water represent a valuable alternative to aqueous methods. In comparison to the complex aqueous chemistry, nonaqueous processes offer the possibility to better understand and to control the reaction pathways on a molecular level, enabling the synthesis of nanomaterials with high crystallinity and well-defined and uniform particle morphologies. The manifold role of the organic species in providing the oxygen for the oxide formation and in controlling the crystal growth and the assembly properties makes it possible to tailor the morphological, structural and compositional characteristics of the final inorganic products.In addition to metal oxides with nearly spherical crystallite sizes in the range of just a few nanometers, also more complex morphologies such as nanowire bundles, nanorods or lamellar organic-inorganic hybrids of varying hierarchical complexity can be achieved in one step and without the use of any surfactants. The spherical nanocrystallites are on the one hand versatile building blocks for the fabrication of fully crystalline and ordered mesoporous materials and on the other hand suitable precursors for the synthesis of metal nitride nanoparticles.This proceeding provides an overview of the various oxidic nanoparticles synthesized via the nonaqueous and surfactant-free sol-gel approach, summarizes the most frequently found formation mechanisms, and offers some insight into the crystallization pathway of nanoparticles. Furthermore, the use of metal oxide nanoparticles as nanobuilding blocks for the preparation of nano- and mesostructures as well as their transformation into metal nitride nanocrystals will be discussed.


2012 ◽  
Vol 1 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Agnieszka Gajewicz ◽  
Tomasz Puzyn ◽  
Bakhtiyor Rasulev ◽  
Danuta Leszczynska ◽  
Jerzy Leszczynski

Author(s):  
Payam Khodaparast ◽  
Zoubeida Ounaies

Nanoparticle modified polymers have promise as hybrid materials that exhibit properties beyond those predicted by mixing law theories. In the case of metal-oxide nanoparticles in a polymer, it is expected that multifunctional properties of the obtained nanocomposite, including dielectric and mechanical, will be dominated by presence of interface rather than predicted by the inherent properties of individual components. This paper will focus on understanding the role of different types of nanoparticles, namely, titania, silica and alumina and a polymer matrix, Polyvinylidene fluoride (PVDF) in affecting the final dielectric and mechanical properties.


2004 ◽  
Vol 847 ◽  
Author(s):  
Guido Kickelbick ◽  
Dieter Holzinger

ABSTRACTTwo general microemulsion-based routes towards surface-functionalized metal oxide nanoparticles serving as macroinitiators in “grafting from” atom transfer radical polymerization (ATRP), are presented. Metal alkoxides modified with several β-diketone derivatives carrying potential ATRP-initiating sites served as precursors for the particle formation leading in an solgel process to in situ-functionalized titanium-, zirconium-, tantalum-, vanadium-, yttrium-, and iron oxide nanoparticles. The obtained systems were compared with metal oxide nanoparticles prepared by using metal salts as precursors which were functionalized in a second step with ATRP-initiator containing silane coupling agents. The obtained particles had diameters between 5 nm and 640 nm and served as multifunctional polymerization initiators in ATRP using styrene and methyl methacrylate as monomers.


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