Antibacterial Properties 2. Pseudomonas PMMA. Other Other authors have reported the formation of biofilm on aluminum, where SEM authors have reported the formation of biofilm on aluminum, where SEM images have shown images have shown bacteria bacteria embedded embedded in in aa layer layer of of extracellular extracellular polymeric polymeric substances substances EPS EPS on on aluminum, aluminum, which which is is similar to what can be observed in Figure 7 [30].
Studies Studies have shown that Pseudomonas aeruginosa adheres less to hydrophobic than hydrophilic surfaces haveshown have shownthatthatPseudomonas Pseudomonas aeruginosa aeruginosa adheres adheres lessless toonto hydrophobic hydrophobic thanthan hydrophilic hydrophilic surfaces surfaces [31]. Figure 7. PMMA coating by in situ polymerization.
AgNPswith AgNPs withsizes sizesbetween between5——10nm nmcan canbebeobserved, observed,andandwith withgood gooddispersion. AgNPs with sizes between 5—10 nm can be observed, and with good dispersion. Figure 8. We evaluated the antibiofilm capability of the PMMA coating with three quantities of aeruginosa.
We evaluated the antibiofilm capability of the PMMA coating aeruginosa. Additionally, we evaluated the bacterial viability of Pseudomonas aeruginosa on aluminum alloy with and without evaluated we evaluated thethe bacterial bacterial viability viabilityofofPseudomonas Pseudomonasaeruginosa aeruginosaon on aluminum aluminum alloy with and and without without coating.
The results showed an inhibition of The coating. Theresults resultsshowed showedanan inhibition inhibition of of The antibacterial property of AgNPs is associated with the release of silver ions. Other works The antibacterial property of AgNPs is associated with the release The antibacterial property of AgNPs is associated with the release of silver ions.
Other of silver ions. Otherworks works have reported that silver ions bind to proteins in the plasma membrane of the bacteria, and alter their have reported have reported that silver silver ions ionsbind bindtotoproteins proteinsinin thethe plasma plasmamembrane membrane of the bacteria, of the and and bacteria, alteralter their permeability. Silver ions also bind to and condense DNA, preventing it from replicating.
Another permeability. DNA, preventing Another it from replicating. Figure Pseudomonas 9. Effect 2. Effectof Effect ofPseudotransesterification of Pseudotransesterificationon Pseudotransesterification onthe on theProtective the ProtectiveCapability Protective Capabilityofof Capability ofCoatings Coatings Coatings InInorder In orderto order toevaluate to evaluatethe evaluate theprotective the protectivecapacity protective capacityof capacity ofthe of thepolymeric the polymericcoatings, polymeric coatings,the coatings, thepotential the potentialcurrent potential current current responses responses of the differently coated aluminum samples were studied in 0.
Figure Figure 10 10shows shows the the exposure to electrolytes for 20 h. Figure 10 shows the results. Figure Figure Anodic Figure Anodicpolarization Anodic polarizationcurves polarization curvesof curves ofaluminum of aluminumalloy aluminum alloysurfaces alloy surfacesdifferently surfaces differentlytreated differently treatedand treated andcoated and coatedby coated by by polymers in 0.
The The corrosion corrosion parameters parameters presented presented in in Table Table 22 were were obtained obtained from from the the Evans Evans diagrams diagrams based based on the polarization curves in Figure Molecules , 23, 10 of 14 The corrosion parameters presented in Table 2 were obtained from the Evans diagrams based on the polarization curves in Figure Table 2.
Open circuit potential, current, and inhibition efficiency of metal surfaces under different treatments obtained from Figure 8. The anodic curves in Figure 10 show that the current density decreases with pseudotransesterification, which could be related to the increased compaction of the coating Figure 4. The decreased current density is an order of magnitude lower than the anodic currents of the bare surface, and two orders of magnitude lower than the surfaces coated with the polymer without anchoring.
The current density of the coating with AgNPs was three orders of magnitude lower than the bare alloy, reaching a high inhibition efficiency of 0. The low current density and high passivation region demonstrate that the film provides an efficient barrier against corrosion agents.
The relationship between the compaction of the polymer coatings and the quality of the anticorrosive protection is well known [33,34]. Corrosion agents can diffuse through pores or cracks and reach the interface.
In these regions, chemical changes can destabilize the polymer locally, and delaminate it. The build-up of stress in these regions can also result in mechanical damage to the polymer. In any case, chemical and mechanical damage results in sites in which aggressive species such as halides or organic acids in aqueous media catalyze the generation of pitting. Materials and Methods 3.
A were obtained from Merck Santiago, Chile. Surface Treatment of the AA Aluminum Alloy The AA aluminum alloy samples were mechanically polished with SiC grinding paper of grits, grits, grits, and grits, and then etched chemically according to the following sequence of steps: i immersed in a 0.
All of the solutions were prepared with deionized water. The MMA monomer, the catalyst PTSA, and hydroquinone were added to the distillation system in the presence of the aluminum alloy, which was previously hydroxylated, in the same manner as in the surface treatment of the above-described AA aluminum alloy.
The excess MMA was distilled off under reduced pressure. Specimens were then washed with methanol. Polymerization of Methyl Methacrylate on Aluminum Alloy The aluminum alloy was coated by mass radical polymerization using the MMA monomer to form a poly methyl methacrylate film on the alloy surface Scheme 1. MMA polymerization was carried out in a Schlenk reactor, loading the previously modified aluminum alloy sample Section 2. In parallel, MMA was polymerized in the absence of the aluminum alloy sample in the same conditions as indicated above.
Surface Analysis XPS. The energy resolution that was used was 0. The 1s elemental peak was from carbon eV. The data was processed with CasaXPS, version 2. The morphologies of the uncoated and coated aluminum alloy surfaces were investigated by scanning electron microscopy SEM using a Philips XL30 Philips, Amsterdam, Netherlands at an acceleration voltage of 5 kV. Cross-sections of the coated samples were cut by ultramicrotomy to characterize the surface-coating interface.
The samples were rinsed twice with 0. Aluminum alloy AA electrode plates were carefully prepared, leaving a 1-cm2 area exposed to the electrolyte. The polarization curves were obtained in 0. Conclusions Pseudotransesterification is a feasible metallic surface pretreatment to form covalent bonds with polymer coatings. XPS spectra reveal that the polymer on the transesterified specimen grows differently from that grown on the surface without pseudotransesterification. Thus, pseudotransesterification promotes polymerization reactions on alloys, resulting in coarser surface coatings.
While the PMMA coating allowed the adhesion of Pseudomonas aeruginosa, the presence of AgNPs prevented biofilms from generating and bacteria from adhering. As well, the decrease in the anodic currents of the coatings, as compared to the bare AA, demonstrated the corrosion protection capacity of the coatings.
Finally, the protective and antibiofilm features of this coating demonstrate that it is suitable for use in a variety of applications. Author Contributions: L. All authors read and approved the final manuscript. Conflicts of Interest: The authors declare no conflict of interest. References 1. Baldan, A. Adhesively-bonded joints and repairs in metallic alloys, polymers and composite materials: Adhesives, adhesion theories and surface pretreatment.
Hollaway, L. Progress in the technique of upgrading metallic structures with advanced polymer composites. Islam, M. Influence of metal surface preparation on its surface profile, contact angle, surface energy and adhesion with glass fibre prepreg. Forsgren, A. Corrosion Control through Organic Coatings, 2nd ed. Qi, J. Trivalent chromium conversion coating formation on aluminium. Svoboda, J. In Advances in Manufacturing, 1st ed. Molecules , 23, 13 of 14 7. This in tum has led to the emergence of the new field of surface engineering the design of a composite system coating plus substrate that produces a.
Handbook of Modern Coating Technologies: Fabrication Methods and Functional Properties reviews different fabrication methods and functional properties of modern coating technologies. The topics in this volume consist of nanocoatings by sol—gel processes for functionalization of polymer surfaces and textiles and mechanical fabrication methods of nanostructured surfaces such surface mechanical. Advances in Surface Treatments provides information on technologies, applications, and effects of surface treatment processes on different materials.
The book is divided into six. Despite advances in alternative materials, metals are still the biomaterial of choice for a number of clinical applications such as dental, orthopedic and cardiac implants. However, there are a number of intrinsic problems associated with implanting metal in the biological environment, such as wear, corrosion, biocompatibility and toxicity, which must. Chapman,Joseph Chapman Anderson, published by Unknown which was released on So change is only physical and can be reversed to its original form by using thinner.
Chemical changes occur in the coating and dry film is different from its liquid state. Epoxy, alkyds, etc. Surface preparation is the most important part of a coating system. The surface preparation of the coating system is what a foundation is to a building. Proper application of the protective coating is an important criterion in giving the paint system. Four main application procedures:. I am a Mechanical Engineer turned into a Piping Engineer. I am very much passionate about blogging and always tried to do unique things.
This website is my first venture into the world of blogging with the aim of connecting with other piping engineers around the world. Would love to have some more details on tank inside coating spec, application techniques and surface preparation for hydrocarbon and water rich environments.
Your email address will not be published. Save my name and email in this browser for the next time I comment. The mechanism involves atomic hydrogen which diffuses into a metal Thermal relief valves are also known as thermal safety valves, temperature relief valves, or thermal expansion relief valves.
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