Download or read book Electrodeposition of Organofunctional Silanes for Improved Corrosion Protection of Metals written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been amply demonstrated that thin films of organofunctional silanes deposited by dipping or spraying on metals such as aluminum, can provide protection against various forms of corrosion, including uniform corrosion and pitting. However, the thickness and uniformity of the film are uncontrolled in this process. The work done in this dissertation proposes a new deposition technique for the silane films on the metal surface i.e., by electrodeposition. Electrodeposition results in a highly uniform, non-porous, highly corrosion resistant film on the metal surface. The film formed was characterized mainly using electrochemical, surface and interfacial characterization techniques. Application of x-ray photoelectron spectroscopy (XPS), and time of flight secondary ion mass spectroscopy (TOF-SIMS) to electrodeposited films have provided direct evidence for the presence of O 2 Al(O-Si-O) and OAl(O-Si-O) 2 groups at the silane-aluminum oxide interface. Such bonds have, of course, often been suggested, but they have largely remained elusive over the years.
Download or read book Electrodeposition of Bis silane for the Pretreatment of Aluminum Alloys written by and published by . This book was released on 2006 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: The need for toxic chromate replacements in metal-finishing industries has prompted an intensive search for replacement technologies in recent years. Organofunctional silanes have emerged as an outstanding, environment friendly corrosion protectors of metal substrates for replacing the conventional chromate treatments. It has been recently demonstrated that electrodeposition of silane films on metal surfaces results in improvement of corrosion protection compared to the conventional coating methods like dip coating and spray coating. It has also been proved that uniformity and better control over the thickness of the coating can be achieved by electrodeposition. This thesis dissertation consists of two parts: (1) Identification of a novel silane, which produces comparatively hydrophobic, corrosion resistant film. (2) Development of a new volatile organic content (VOC)-free, water-based silane system. Various combinations of silane mixtures were tested at different voltages, pH's, bath concentrations and exposure times on panels of aluminum alloys. The film formed was characterized mainly using electrochemical, surface and interfacial characterization techniques. Application of time of flight secondary ion mass spectroscopy (TOF-SIMS) to electrodeposited films has provided direct evidence for the presence of O2 Al(O-Si-O)and OAl(O-Si-O)2 groups at the silane-aluminum oxide interface. Also pulsed electrodeposition (alternating positive and negative voltage) of silanes were studied which show better performance, as anodization of the aluminum oxide layer is achieved and the silane film reacts with the metal oxide in a different way.
Download or read book Silanes and Other Coupling Agents written by Kash L. Mittal and published by CRC Press. This book was released on 2004-07-28 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume chronicles the proceedings of the Fourth International Symposium on Silanes and Other Coupling Agents held under the aegis of MST Conferences, LLC in Orlando, FL, June 11-13, 2003. Silanes have been used for about half a century as coupling agents / adhesion promoters to promote adhesion between dissimilar materials in a variety of situations, e.g., coating technology, adhesive bonding, and reinforced composites. However, recently silanes have found other applications, for example, as corrosion inhibitors. Lately there has been tremendous R&D activity in understanding the mechanisms by which silanes work as well as in devising new and improved silanes. This volume contains a total of 16 papers which were properly peer reviewed, revised and edited. The book is divided into two parts: 1. Silane Coupling Agents; and 2. Other Coupling Agents / Adhesion Promoters. Topics covered include: sterically hindered silanes; silane hydrolysis; silane oligomers; adsorption of silanes and their surface characterization; structure of bis-silane water-barrier films; silanes for improving adhesive bonding of aluminim, elastomer-to-metal adhesive bonds, and adhesion in silica-filler tire-tread compounds; electrodeposition of bis-silanes; silanes to provide corrosion resistance and as corrosion fatigue inhibitors; silane and other treatments for musical instrument strings; cyclic azasilanes as coupling agents for nanotechnology; hybrid polymers based on silanes for coating textile fabrics; plasma copolymers as adhesion promoters; organophosphate adsorption; and activation of wood fibres. This volume and its predecessors containing bountiful information should serve as a reference source for the latest R&D activity in the arena of coupling agents. Anyone interested or involved in promoting adhesion between dissimilar materials for any application should find this volume of great use and value.
Download or read book Silanes and Other Coupling Agents written by K. L. Mittal and published by . This book was released on 2004 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Peer-reviewed, revised, and edited, the 16 review and research papers explore fundamental and applied aspects of silanes and some new applications in addition their traditional use to promote adhesion between dissimilar materials. Most deal with silane coupling agents, discussing such aspects as the effect of the bridging group on the structure of bis-silane water-barrier films, amino-silane and bis- silane pre-treatments for adhesive bonding of aluminum, and the electrodeposition of organofunctional bis-silanes and their effectiveness in providing corrosion resistance in metals. The others look at other coupling agents and adhesion promoters, among them, cyclic azasilanes as volatile coupling agents for nanotechnology, and organophosphate adsorption on metal oxide surfaces. There is no index. VSP is a subsidiary of Brill. Annotation : 2004 Book News, Inc., Portland, OR (booknews.com).
Download or read book Electro deposition of Resin modified Water based Hydrophobic Silane on Hdg Steel for Corrosion Protection written by Dingchuan Xue and published by . This book was released on 2009 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many past studies by scientists, especially Van Ooij and his research group at the University of Cincinnati, have demonstrated that organo-functional silanes have equivalent and even better corrosion performance than the toxic chromate. Chromate is being replaced because its toxic nature found lately and its usage is also being limited by government. Organo-functional silanes have outstanding corrosion protection performance over conventional chromate in many ways, such as metal pretreatment, passivation as well as paint adhesion. However, there are also disadvantages about organo-functional silanes. Generally, silane solution treatments are mainly executed by immersion or spraying, and this does not provide a uniform film; secondly, most of silane hydrolysis environment contain volatile solvent, especially when excellent hydrophobic silanes are being hydrolyzed, and this can be concerned as the volatile organic compounds (VOCs) release into the environment. In this work, completely water-based cationic epoxy-resin-ester modified hydrophobic BTSE silane solution coated by cathodic electro-deposition was tried on an easily corroded substrate of hot-dipped galvanized steel. In previous research and studies, electro-deposition has been shown to provide more uniform and organized silane films on aluminum than immersion. In the following study, various silane and resin ratios were tested and optimized with different electro-deposition current, curing time, aging time and effect of adding corrosion inhibitor and addition of nano-particle filler of carbon black. The optimized system on HDG has been characterized by electro-chemical, surface and interface tests. Performance tests of SST, EIS, and DCP all agree that the optimized system displayed a much more corrosion protective characteristic by electro-deposition than by immersion. Characterization by FTIR showed a more cross-linked siloxane network by electro-deposition technique than immersion near the metal surface; AFM/SEM/SIMS also further explained why electro-deposition could provide a more corrosion protective and more cross-linked siloxane network than immersion. 3 wt% CB nano-particles addition into the optimal system prepared by electro-deposition further improved the coating anti-corrosive performance and reduced the metal corrosion rate substantially.
Download or read book Corrosion Protection at the Nanoscale written by Susai Rajendran and published by Elsevier. This book was released on 2020-03-10 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion Protection at the Nanoscale explores fundamental concepts on how metals can be protected at the nanoscale by using both nanomaterials-based solutions, including nanoalloys, noninhibitors and nanocoatings. It is an important reference resource for both materials scientists and engineers wanting to find ways to create an efficient corrosion prevention strategy. Nanostructure materials have been widely used in many products, such as print electronics, contact, interconnection, implant, nanosensors and display units to lessen the impact of corrosion. Traditional methods for protection of metals include various techniques, such as coatings, inhibitors, electrochemical methods (anodic and cathodic protections), metallurgical design are covered in this book. Nanomaterials-based protective methods can offer many advantages over their traditional counterparts, such as protection for early-stage, higher corrosion resistance, better corrosion control. This book also outlines these advantages and discusses the challenges of implementing nanomaterials as corrosion protection agents on a wide scale. - Explains the main methods of detection, monitoring, testing, measurement and simulation of corrosion at the nanoscale - Explores how metals can be protected at the nanoscale using nanotechnology and nanomaterials - Discusses the major challenges of detecting and preventing corrosion at the nanoscale
Download or read book Development of an Environmentally Benign Anticorrosion Coating for Aluminum Alloy Using Green Pigments and Organofunctional Silanes written by Zhangzhang Yin and published by . This book was released on 2009 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerospace aluminum alloys such as Al alloy 2024-T3 and 7075-T6 are subject to localized corrosion due the existence of intermetallics containing Cu, Mg or Zn. Current protection measurement employs substantial use of chromate and high VOC organics, both of which are identified as environment and health hazards. The approach of this study is to utilize a combination of organofunctional silanes and a compatible inhibitor integrated into high-performance waterborne resins. First, an extensive pigment screening has been done to find replacements for chromates using the testing methodology for fast corrosion inhibition evaluation and pigment. Zinc phosphate and calcium zinc phosphomolybdate were found to have the best overall performance on Al alloys. Some new corrosion inhibitors were synthesized by chemical methods or modified by plasma polymerization for use in the coatings. Low-VOC, chromate-free primers (superprimer) were developed using these pigments with silane and acrylic-epoxy resins. The developed superprimer demonstrated good corrosion inhibition on aluminum substrates. The functions of inhibitor and silane in the coating were investigated. Both silane and inhibitor are critical for the performance of the superprimer. Silane was found to improve the adhesion of the coating to the substrate and also facilitate corrosion prevention. Addition of zinc phosphate to the coating improved the resistance of a scratched area against corrosion. The microstructure of the acrylic-epoxy superprimer coating was studied. SEM/EDAX revealed that the superprimer has a self-assembled stratified double-layer structure which accounts for the strong anti-corrosion performance of the zinc phosphate pigment. Zinc phosphate leaches out from the coating to actively protect the scratched area. The leaching of pigment was confirmed in the ICP-MS analysis and the leaching rate was measured. Coating-metal interface and the scribe of coated panels subjected to corrosion test was studied. ToF-SIMS studies confirmed the presence of silane at the interface and the hydrolysis of the silane. The abundant presence of silane was believed to improve the adhesion and also facilitate the corrosion prevention. The protection mechanism of the acrylic-epoxy superprimer was proposed. The self-assembled double-layer structure of the acrylic-epoxy superprimer consist of a less-penetrable hydrophobic layer (epoxy-dominated) on the top and a hydrophilic layer (acrylic-dominated) accommodating the inhibitors underneath. This unique structure of the acrylic-epoxy accounts for the good protection of the coating. Furthermore, the inhibition mechanism of zinc phosphate was explored and compared to those which have been reported. Based on the protection mechanism of the superprimer, electrodeposition was explored in order to achieve a more organized coating with a better engineered metal/coating interface. The electrodeposited coatings were found to have higher barrier property and anticorrosion performance.
Download or read book Corrosion Protection of Metals by Silane Surface Treatment written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The need for toxic chromate replacements in metal-finishing industries has prompted an intensive search for replacement technologies in recent years. Among the replacements that have been proposed, those that are based upon the use of organofunctional silanes rank very high in terms of performance, broad applicability as well as ease of application. This dissertation presents a four-part work: (1) structural characterization of silane films on metals, (2) mechanism studies of silane-treated metal systems, (3) development of water-based silane systems, and (4) measurements of other properties of silane films. In part 1, silane films, i.e., bis-[triethoxysilylpropyl]tetrasulfide (bis-sulfur silane) and bis-[trimethoxysilylpropyl]amine (bis-amino silane) were deposited on AA 2024-T3 and were characterized mainly using reflection-absorption Fourier-transform infrared spectroscopy (FTIR-RA) and electrochemical impedance spectroscopy (EIS) techniques. The results showed that further hydrolysis and crosslinking occurs in the applied bis-sulfur silane films in the presence of water and moisture. This is because the bis-sulfur silane is difficult to hydrolyze completely in its water/ethanol solution. The remaining ester groups would hydrolyze to silanols when water or moisture presents (e.g., in the processes of curing in the atmosphere and immersion in an aqueous solution). The as-formed silanols would further condense either with themselves or with aluminum hydroxyl groups at the alloy surface, forming siloxanes and aluminum-siloxanes. Three different regions were clearly detected by EIS in the bis-sulfur silane-treated AA 2024-T3 system, and were further observed in the SEM/EDX studies. According to these studies, the three regions are assigned to, from outside to inside, outermost silane film dominated with siloxanes (SiOSi), interfacial layer with both siloxanes and aluminum-siloxanes (AlOSi), and innermost aluminum oxide. In part 2, the mechanistic study of corrosion protection of AA 2024-T3 by bis-sulfur silane film was carried out. In summation, the following two factors play critical roles in the corrosion protection of AA 2024-T3: (1) the formation of a highly crosslinked interfacial layer, and (2) high water resistance of silane films. The former inhibits corrosion in the following two ways: (1) blocking favorable sites for water adsorption by the formation of AlOSi bonds at the interface which effectively reduces the tendency of aqueous corrosion; and (2) bonding tightly to the metal and thus restricting transportation of the existing corrosion products away from their original sites which hinders pit growth. It should be noted that a high density of AlOSi bonds can be obtained employing bis-silanes rather than mono-silanes. A high water resistance makes water penetration difficult in silane films. This is essential for preventing AlOSi bonds from hydrolysis. The results also indicated that hydrophilic bis-amino silane can not provide a good corrosion protection for metals. This is because the bis-amino silane film tends to be positively charged due to the protonation of hydrophilic amino groups. As a result of electrostatic attraction, the transportation of detrimental anions like chloride (Cl- ) ions as well as water is promoted in the film. Without sufficient water resistance of the film, AlOSi bonds at the interface are readily hydrolyzed. Consequently, the interfacial adhesion is lost. Corrosion thus readily proceeds at the alloy surface. Although bis-sulfur silane performs well on Al alloys, it fails on HDG. This is caused by poor film coverage on HDG due to the insufficient wetting of Zn oxide by bis-sulfur silane solution. A mixture at the bis-sulfur/bis-amino ratio of 3/1 enhances the corrosion resistance of both AA 2024-T3 and HDG. A small portion of bis-amino silane makes the mixture solution hydrophilic enough to wet Zn oxide on HDG, which facilitates the formation of a homogenous film on HDG. On the other hand, a large portion of bis-sulfur silane enhances the hydrophobicity of the mixture film, which is the basis for good protective performance of the mixture. In part 3, test results for newly-developed water-based silane systems were reported. The major advantage of these silane systems is that they are highly miscible with water, which makes them more industrially acceptable than alcohol-based silanes. Test results demonstrated that these silanes provide excellent corrosion protection as well as paint adhesion on a variety metals including, Al alloys, Zn-coated steels, carbon steels, and stainless steels. Part 4 reported several other properties of silane films, such as resistivity/conductivity, mechanical properties, and thermal stabilities of silane films.
Download or read book Heat Treating and Surface Engineering written by ASM Heat Treating Society. Conference and Exposition and published by ASM International. This book was released on 2003-01-01 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Materials for Agriculture Food and Environmental Safety written by Ashutosh Tiwari and published by John Wiley & Sons. This book was released on 2014-08-11 with total page 525 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book focuses on the role of advanced materials in the food, water and environmental applications. The monitoring of harmful organisms and toxicants in water, food and beverages is mainly discussed in the respective chapters. The senior contributors write on the following topics: Layered double hydroxides and environment Corrosion resistance of aluminium alloys of silanes New generation material for the removal of arsenic from water Prediction and optimization of heavy clay products quality Enhancement of physical and mechanical properties of fiber Environment friendly acrylates latices Nanoparticles for trace analysis of toxins Recent development on gold nanomaterial as catalyst Nanosized metal oxide based adsorbents for heavy metal removal Phytosynthesized transition metal nanoparticles- novel functional agents for textiles Kinetics and equilibrium modeling Magnetic nanoparticles for heavy metal removal Potential applications of nanoparticles as antipathogens Gas barrier properties of biopolymer based nanocomposites: Application in food packing Application of zero-valent iron nanoparticles for environmental clean up Environmental application of novel TiO2 nanoparticles
Download or read book Electrodeposition of Molybdenum Based Coatings from Aqueous Alkaline Solutions for Enhanced Corrosion Resistance written by Ting Zhou and published by . This book was released on 2018 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zn-Mo coatings are very promising environment friendly anticorrosive coatings as replacement materials for cadmium and chromium (VI) based conversion layers. Electrodeposition has become a favorable technique in fabricating coatings due to its low cost, ease of use, and overall experimental control of coating quality. Very little research so far has been done for the electrodeposition of Zn-Mo coatings under alkaline conditions. In this work, Zn and Zn-Mo coatings were electrochemically deposited on stainless steel from an aqueous alkaline citrate solution. An organic compound, vanillin, was added to the electrolyte as a leveling agent for improving interlayer adherence and corrosion resistance of Zn-Mo coatings. Ni-Mo alloys have been known to possess high tensile strength and excellent corrosion protection of steels, and MoTe2 layers have a potential for the application in anticorrosive coatings due to their hydrophobic properties. In this study, MoTe2-Ni-Mo coatings were deposited on stainless steel using both sputtering and electrodeposition methods. These coatings with high corrosion resistance and other desirable properties are in demand in the oil and gas industry since they can protect and thus extend the lifetime of the underlying materials when exposed to aggressive environments. The Zn-Mo and MoTe2-Ni-Mo coatings were evaluated for chemical composition and corrosion behavior using different types of instrumental and electrochemical techniques. The addition of vanillin to the electrolyte did not change the crystalline structure or composition of the Zn-Mo coating, however, the corrosion resistance of the coating was significantly improved by the leveling effect of vanillin during the electrodeposition. The corrosion resistance of the Ni-Mo coating was also enhanced by applying the hydrophobic MoTe2 monolayer on the top surface.
Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silane Coupling Agents written by Edwin P. Plueddemann and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: * It has been rumored that a bumble bee has such aerodynamic deficiencies that it should be incapable of flight. Fiberglass-reinforced polymer com posites, similarly, have two (apparently) insurmountable obstacles to per formance: 1) Water can hydrolyze any conceivable bond between organic and inorganic phase, and 2) Stresses across the interface during temperature cycling (resulting from a mismatch in thermal expansion coefficients) may exceed the strength of one of the phases. Organofunctional silanes are hybrid organic-inorganic compounds that are used as coupling agents across the organic-inorganic interface to help overcome these two obstacles to composite performance. One of their functions is to use the hydrolytic action of water under equilibrium condi tions to relieve thermally induced stresses across the interface. If equilib rium conditions can be maintained, the two problems act to cancel each other out. Coupling agents are defined primarily as materials that improve the practical adhesive bond of polymer to mineral. This may involve an increase in true adhesion, but it may also involve improved wetting, rheology, and other handling properties. The coupling agent may also modify the inter phase region to strengthen the organic and inorganic boundary layers.
Download or read book Proceedings of the 1st ASM International Surface Engineering and the 13th IFHTSE Congress written by Oludele O. Popoola and published by ASM International(OH). This book was released on 2003 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume contains 101 papers from an October 2002 meeting, detailing advances in case hardening processes, corrosion protection and tribological coatings, laser processes, characterization, modeling, quenching, nano-materials, thermal spray, residual stress, and manufacturing equipmen
Download or read book Passivation of Batch galvanized Steel by Silane Treatment written by Man Xu and published by . This book was released on 2007 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chromate conversion coatings are one of the most efficient intermediate surface treatments for galvanized steel. However, since chromium is toxic, a replacement for chromate conversion coating is needed. Dr. Van Ooij and his research group have developed a series of environmentally friendly silane treatments which showed excellent corrosion protection on various metals. This research is to passivate batch-galvanized steel by silane treatment as potential replacement of chromate treatments. Silane mixture of bis-amino silane and vinyltriacetoxysilane (VTAS) was studied and the optimized ratio was considered to be 4:1 by volume parts. Electrochemical Impedance Spectroscopy (EIS) and Direct Circuit Polarization (DCP) results revealed that this silane film has a hydrophobic nature and outperformed other silane ratios. Two corrosion inhibitors, sodium metavanadate and zinc phosphate, were studied by incorporating them in the optimized silane formulation. Salt spray test and other performance test results indicated that sodium metavanadate can effectively improve the corrosion resistance of the silane film on batch-galvanized steel. Fourier Transform Infrared Spectroscopy (FTIR) results showed a highly crosslinked siloxane network with the incorporation of sodium metavanadate. Mechanism studies such as Time-of-Flight Secondary Ion Mass Spectrometry (TOFSIMS) and scratch cell test showed that sodium metavanadate can crosslink the silane film and is also able to leach-out to defects in the coating.
Download or read book Plating and Surface Finishing written by and published by . This book was released on 2008 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Tradename Dictionary written by Michael Ash and published by John Wiley & Sons. This book was released on 1996-12-17 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: This key reference will serve as the most comprehensive source for identifying and locating products in the international chemical marketplace. It has been written for the chemists, materials sientists, end-product formulators, industrial application specialists and scientists working in associated fields.
