The Experts below are selected from a list of 21321 Experts worldwide ranked by ideXlab platform
Michael J Walock - One of the best experts on this subject based on the ideXlab platform.
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tribology and wear resistance of the stainless steel the Sol Gel Coating impact on the friction and damage
Tribology International, 2016Co-Authors: Brahim Tlili, A Barkaoui, Michael J WalockAbstract:Abstract The Sol–Gel Coating method is considered to be simple, easy to adopt, requires low processing temperature and leads to high degree of purity oxide Coatings. Moreover, the fabrication of metal oxide thin films by Sol–Gel technic is cost effective, reproducible and applicable to large substrates without any shape restriction. This work focuses on optimizing conditions for depositing alumina Coatings by Sol–Gel method on stainless steel substrates with a low annealing temperature, in order not to degrade the metal substrate. Moreover, to obtain Coatings of several micron thick, the Sol–Gel was adapted by adding ceramic powder or by successive layers deposition which reduces the stresses occurring in the Coatings during the heat treatment. The various as-obtained layers are characterized in terms of morphological features, microstructure, hardness and the tribological behavior and wear resistance. The results showed that the deposited alumina Coating at low temperature crystallized in δ-Al 2 O 3 . Adding to that, the increase of the temperature favors the presence of α-Al 2 O 3 structure. Moreover, the measurements demonstrate that the mechanical properties of Sol–Gel deposited alumina Coatings in terms of hardness, wear resistance are improved in comparison with uncoated stainless steel or the classic nitrited steel.
Thomas J. Webster - One of the best experts on this subject based on the ideXlab platform.
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Enhanced osteoblast adhesion on hydrothermally treated hydroxyapatite/titania/poly(lactide-co-glycolide) Sol-Gel titanium Coatings
Biomaterials, 2005Co-Authors: Michiko Sato, Elliott B. Slamovich, Thomas J. WebsterAbstract:Sol–Gel processing was used to coat titanium substrates with hydroxyapatite (HA), TiO2, and poly(dl-lactic-glycolic acid). Coating surface characteristics were analyzed with XRD, EDS, AFM, SEM, and water contact angle measurements which indicated that the Coatings had a high degree of crystallinity and good resistance to cracking. Coatings were also evaluated by cytocompatibility testing with osteoblast-like cells (or bone-forming cells). The cytocompatibility of the HA composite Coatings prepared in the present in vitro study was compared to that of a traditional plasma-sprayed HA Coating. Results showed that osteoblast-like cell adhesion was promoted on the novel HA Sol–Gel Coating compared to the traditional plasma-sprayed HA Coating. In addition, hydrothermal treatment of the Sol–Gel Coating improved osteoblast-like cell adhesion. Since osteoblast adhesion is a necessary prerequisite for subsequent formation of bone, these results provided evidence that hydrothermally Sol–Gel processed HA may improve bonding of titanium implants to juxtaposed bone and, thus, warrants further investigation.
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enhanced osteoblast adhesion on hydrothermally treated hydroxyapatite titania poly lactide co glycolide Sol Gel titanium Coatings
Biomaterials, 2005Co-Authors: Michiko Sato, Elliott B. Slamovich, Thomas J. WebsterAbstract:Sol–Gel processing was used to coat titanium substrates with hydroxyapatite (HA), TiO2, and poly(dl-lactic-glycolic acid). Coating surface characteristics were analyzed with XRD, EDS, AFM, SEM, and water contact angle measurements which indicated that the Coatings had a high degree of crystallinity and good resistance to cracking. Coatings were also evaluated by cytocompatibility testing with osteoblast-like cells (or bone-forming cells). The cytocompatibility of the HA composite Coatings prepared in the present in vitro study was compared to that of a traditional plasma-sprayed HA Coating. Results showed that osteoblast-like cell adhesion was promoted on the novel HA Sol–Gel Coating compared to the traditional plasma-sprayed HA Coating. In addition, hydrothermal treatment of the Sol–Gel Coating improved osteoblast-like cell adhesion. Since osteoblast adhesion is a necessary prerequisite for subsequent formation of bone, these results provided evidence that hydrothermally Sol–Gel processed HA may improve bonding of titanium implants to juxtaposed bone and, thus, warrants further investigation.
Brahim Tlili - One of the best experts on this subject based on the ideXlab platform.
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tribology and wear resistance of the stainless steel the Sol Gel Coating impact on the friction and damage
Tribology International, 2016Co-Authors: Brahim Tlili, A Barkaoui, Michael J WalockAbstract:Abstract The Sol–Gel Coating method is considered to be simple, easy to adopt, requires low processing temperature and leads to high degree of purity oxide Coatings. Moreover, the fabrication of metal oxide thin films by Sol–Gel technic is cost effective, reproducible and applicable to large substrates without any shape restriction. This work focuses on optimizing conditions for depositing alumina Coatings by Sol–Gel method on stainless steel substrates with a low annealing temperature, in order not to degrade the metal substrate. Moreover, to obtain Coatings of several micron thick, the Sol–Gel was adapted by adding ceramic powder or by successive layers deposition which reduces the stresses occurring in the Coatings during the heat treatment. The various as-obtained layers are characterized in terms of morphological features, microstructure, hardness and the tribological behavior and wear resistance. The results showed that the deposited alumina Coating at low temperature crystallized in δ-Al 2 O 3 . Adding to that, the increase of the temperature favors the presence of α-Al 2 O 3 structure. Moreover, the measurements demonstrate that the mechanical properties of Sol–Gel deposited alumina Coatings in terms of hardness, wear resistance are improved in comparison with uncoated stainless steel or the classic nitrited steel.
Mathur Gopalakrishnan Sethuraman - One of the best experts on this subject based on the ideXlab platform.
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Surface modification, characterization and corrosion protection of 1,3-diphenylthiourea doped Sol-Gel Coating on aluminium
Progress in Organic Coatings, 2017Co-Authors: Rajendran Babhu Vignesh, J. Balaji, Mathur Gopalakrishnan SethuramanAbstract:Aluminium based materials undergo natural process of deterioration on exposure to corrosive environment. Among the strategies of corrosion control, Sol-Gel Coatings have become popular as they have successfully replaced toxic hexavalent chromate Coatings used hitherto. The adherent ability of Sol-Gel Coatings combined with their ability to prevent the access of electrolyte thereby has made Sol-Gel Coatings a promising and valuable method of corrosion control. In the present work, 3-aminopropyltrimethoxysilane (APTMS) was used as a precursor for silane based Sol-Gel Coatings. In order to improve the active protection of metal, 1,3-diphenylthiourea (DPTU) was introduced into the Sol-Gel system. The nature of the Coatings was studied using FT-IR, SEM and EDX. Thermogravimetric analysis (TGA) showed the thermal stability of the Sol-Gel Coating. The inhibitor doped Sol-Gel Coating increased the hydrophobic nature of the Coating. For comparative studies, Thiourea (TU) was doped over APTMS Sol-Gel matrix and evaluated using electrochemical studies. EIS results of 0.1 M DPTU doped APTMS Sol-Gel coated Al surface showed better anti-corrosion properties than 0.1 M TU doped in 3.5 wt% NaCl medium. DPTU doped APTMS Sol-Gel Coating forms an adherent layer over metallic surface which acts as significant physical barrier against the attack of corrosive ions in neutral medium which may be the reason for the improved corrosion resistance.
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Corrosion protection of copper with 3-glycidoxypropyltrimethoxysilane-based Sol–Gel Coating through 3-amino-5-mercapto-1,2,4-triazole doping
Research on Chemical Intermediates, 2015Co-Authors: J. Balaji, Mathur Gopalakrishnan SethuramanAbstract:In this work, 3-amino-5-mercapto-1,2,4-triazole (AMTa) was incorporated into 3-glycidoxypropyltrimethoxysilane (GPTMS)-based Sol–Gel Coatings, which were self-assembled over a copper surface. The AMTa-doped GPTMS-based Sol–Gel Coatings were characterized by Fourier transform infrared spectroscopy, Scanning Electron Microscopy, and Energy-Dispersive X-ray spectroscopy analyses. The protective ability of these Coatings was evaluated by electrochemical impedance studies and potentiodynamic polarization measurements in 3.5 % NaCl medium. The AMTa-doped Sol–Gel Coating showed enhanced corrosion protection ability compared to the un-doped GPTMS-based Sol–Gel Coating, which may be larGely due to the formation of thiolate bonds between copper and AMTa. The presence of a silane network through the amine group of AMTa could also be a reason for the enhanced protection.
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Enhancement of corrosion protection of 3-glycidoxypropyltrimethoxysilane-based Sol–Gel Coating through methylthiourea doping
Journal of Coatings Technology and Research, 2014Co-Authors: Rajendran Babhu Vignesh, Mathur Gopalakrishnan SethuramanAbstract:Protection of aluminum metal and its alloys from corrosion is a key requirement for many engineering applications. Nowadays, Sol–Gel Coating technology is recognized as the ideal replacement for chromate conversion Coatings. The present work makes use of 3-glycidoxypropyltrimethoxysilane (GPTMS) as a precursor for Sol–Gel Coating. GPTMS was subjected to hydrolysis and subsequent condensation reaction to get a three-dimensional network and methylthiourea (MTU) was incorporated into the Sol–Gel matrix. MTU-doped GPTMS-based Sol–Gel Coatings were applied over aluminum metal by dip Coating method. The resultant Coating was studied by FTIR, XRD and SEM. MTU-doped GPTMS-based Sol–Gel Coatings increased the hydrophobic nature of the Coating and were stable up to a temperature of 450°C. The protective nature of the Coatings was evaluated in a 1% NaCl environment using electrochemical impedance and polarization studies. The study has revealed that doping of MTU enhanced the protection ability of doped GPTMS-based Sol–Gel Coating to a significant extent.
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Sol–Gel Coating with 3-Mercaptopropyltrimethoxysilane as Precursor for Corrosion Protection of Aluminium Metal
Journal of Materials Science & Technology, 2014Co-Authors: Rajendran Babhu Vignesh, Thomas Nesakumar Jebakumar Immanuel Edison, Mathur Gopalakrishnan SethuramanAbstract:Sol–Gel Coatings offer a number of advantages over other methods of protection for metallic materials. In the present work, 3-mercaptopropyltrimethoxysilane (MPTS) was used as the precursor for Sol–Gel Coating on aluminium metal. The Gelation of MPTS Sol–Gel was characterized by Fourier transform infrared spectroscopy (FT-IR) studies. The formed film was found to be stable up to 350 °C as evident from thermogravimetric analysis. X-ray diffraction study and scanning electron microscopy supported the formation of MPTS Coating on aluminium surface while the characterization of the Coating was done by FT-IR studies. The corrosion inhibition potential of the Sol–Gel Coatings on metal in 3.5% (w/v) of NaCl Solution was assessed as a function of different concentrations of MPTS using electrochemical polarization and impedance measurements. The corrosion inhibition efficiency was found to increase with increasing MPTS concentration. The results of the study unravel the use of MPTS as a precursor in the formation of Sol–Gel Coating over aluminium surface so as to protect the metallic surface from corrosion in neutral environment.
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corrosion protection behaviour of Sol Gel derived n n dimethylthiourea doped 3 glycidoxypropyltrimethoxysilane on aluminium
Progress in Organic Coatings, 2014Co-Authors: Rajendran Babhu Vignesh, Mathur Gopalakrishnan SethuramanAbstract:Abstract The present work describes the anticorrosion features of inhibitor doped Sol–Gel Coating on Al metal. Sol–Gel Coatings were prepared by using 3-glycidoxypropyltrimethoxysilane (GPTMS) as parent precursor. In order to improve the corrosion resistance property of Coating, N,N-dimethylthiourea was added into the Sol–Gel matrix. The corrosion inhibitor doped Sol–Gel Coating on metal was characterized by Fourier transform infrared analysis (FTIR) and scanning electron microscope (SEM). Inhibition effect of N,N-dimethylthiourea doped GPTMS Coating on Al substrates in 1% NaCl Solution was investigated using electrochemical impedance (EIS) and polarization studies. EIS results showed that the corrosion resistance of Sol–Gel Coating significantly improved upon addition of N,N-dimethylthiourea. The study had outlined the nuances of doping an organic inhibitor to enhance the protection ability of Sol–Gel Coating on Al metal.
Michiko Sato - One of the best experts on this subject based on the ideXlab platform.
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Enhanced osteoblast adhesion on hydrothermally treated hydroxyapatite/titania/poly(lactide-co-glycolide) Sol-Gel titanium Coatings
Biomaterials, 2005Co-Authors: Michiko Sato, Elliott B. Slamovich, Thomas J. WebsterAbstract:Sol–Gel processing was used to coat titanium substrates with hydroxyapatite (HA), TiO2, and poly(dl-lactic-glycolic acid). Coating surface characteristics were analyzed with XRD, EDS, AFM, SEM, and water contact angle measurements which indicated that the Coatings had a high degree of crystallinity and good resistance to cracking. Coatings were also evaluated by cytocompatibility testing with osteoblast-like cells (or bone-forming cells). The cytocompatibility of the HA composite Coatings prepared in the present in vitro study was compared to that of a traditional plasma-sprayed HA Coating. Results showed that osteoblast-like cell adhesion was promoted on the novel HA Sol–Gel Coating compared to the traditional plasma-sprayed HA Coating. In addition, hydrothermal treatment of the Sol–Gel Coating improved osteoblast-like cell adhesion. Since osteoblast adhesion is a necessary prerequisite for subsequent formation of bone, these results provided evidence that hydrothermally Sol–Gel processed HA may improve bonding of titanium implants to juxtaposed bone and, thus, warrants further investigation.
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enhanced osteoblast adhesion on hydrothermally treated hydroxyapatite titania poly lactide co glycolide Sol Gel titanium Coatings
Biomaterials, 2005Co-Authors: Michiko Sato, Elliott B. Slamovich, Thomas J. WebsterAbstract:Sol–Gel processing was used to coat titanium substrates with hydroxyapatite (HA), TiO2, and poly(dl-lactic-glycolic acid). Coating surface characteristics were analyzed with XRD, EDS, AFM, SEM, and water contact angle measurements which indicated that the Coatings had a high degree of crystallinity and good resistance to cracking. Coatings were also evaluated by cytocompatibility testing with osteoblast-like cells (or bone-forming cells). The cytocompatibility of the HA composite Coatings prepared in the present in vitro study was compared to that of a traditional plasma-sprayed HA Coating. Results showed that osteoblast-like cell adhesion was promoted on the novel HA Sol–Gel Coating compared to the traditional plasma-sprayed HA Coating. In addition, hydrothermal treatment of the Sol–Gel Coating improved osteoblast-like cell adhesion. Since osteoblast adhesion is a necessary prerequisite for subsequent formation of bone, these results provided evidence that hydrothermally Sol–Gel processed HA may improve bonding of titanium implants to juxtaposed bone and, thus, warrants further investigation.