ORCID Profile
0000-0002-0220-2904
Current Organisation
Deakin University
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Publisher: MDPI AG
Date: 21-07-2023
DOI: 10.3390/MOLECULES28145568
Abstract: Corrosion is a significant problem that negatively affects a wide range of structures and buildings, resulting in their premature failure, which causes safety hazards and significant economic loss. For this reason, various approaches have been developed to prevent or minimize the effects of corrosion, including corrosion inhibitors. Recently, biobased inhibitors have gained a certain interest thanks to their unique properties, eco-friendliness, and availability. Among all the green precursors, lignin is of particular interest, being a natural polymer that can be obtained from different sources including agricultural residues. Corrosion inhibitors based on ionic liquids (ILs) also present interesting advantages, such as low volatility and high tunability. If combined, it may be possible to obtain new lignin-based ILs that present interesting corrosion inhibitor properties. In this work, the inhibition properties of new biobased lignin ILs and the influence of anions and cations on the corrosion of mild steel in an aqueous solution of 0.01 M NaCl were investigated by Potentiostatic Electrochemical Impedance Spectroscopy (PEIS) and Cyclic Potentiodynamic Polarization (CPP). Moreover, the surface was characterized using SEM, EDS, and optical profilometry. The IL choline syringate showed promising performance, reducing the corrosion current after 24 h immersion in 0.01 M sodium chloride, from 1.66 µA/cm2 for the control to 0.066 µA/cm2 with 10 mM of the IL present. In addition to its performance as a corrosion inhibitor, both components of this IL also meet or exceed the current additional desired properties of such compounds, being readily available, and well tolerated in organisms and the environment.
Publisher: Informa UK Limited
Date: 26-04-2020
Publisher: Elsevier BV
Date: 09-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D2CP05109E
Abstract: Ionic liquids with cyclopropenium cations containing six large alkyl groups are found to provide excellent lubrication properties when combined with a large dialkylphosphate in steel-on-steel pin-on-disc testing.
Publisher: American Chemical Society (ACS)
Date: 05-02-2021
DOI: 10.26434/CHEMRXIV.13719649
Abstract: a /a High strength steel in marine environments suffers from severe corrosion susceptibility and the presence of bacteria can exacerbate the effect, accelerating degradation via microbiologically influenced corrosion (MIC). Here we propose a novel approach to MIC inhibition by designing a system capable of limiting the effects of both bacteria growth and corrosion. The combination of a newly synthesised compound, cetrimonium 4-hydroxycinnamate, with lanthanum 4-hydroxycinnamate was the only system tested to date that could both inhibit abiotic corrosion in artificial seawater and minimise bacteria consortium densities over an exposure period of 24 hours. The electrochemical data for the La+Cet mixture demonstrated the significant inhibition of both abiotic corrosion to a level similar to La(4OHCin) sub /sub , as well as the ability to reduce bacteria densities of single strains and a consortium. This is unlike the La+CetNal mixture which accelerated abiotic corrosion and the La+IMI which had an insignificant effect on microbial densities (Catubig et al. 2020). A compatible mixture of ionic inhibitors was achieved by using the same cinnamate anion. This mixture of Cet-4OHCin and La(4OHCin) sub /sub demonstrated significant abiotic corrosion inhibition and bacteria density reductions, making it a strong candidate as an MIC inhibitor system for 80HLES. The Cet-4OHCin compound and its mixture with La(4OHCin) sub /sub retained relatively low sensitivity towards skin and intestinal cells, making it a safer and more attractive alternative than other more hazardous corrosion inhibitor materials.
Publisher: American Chemical Society (ACS)
Date: 10-11-2020
Publisher: American Chemical Society (ACS)
Date: 08-01-2021
Publisher: American Chemical Society (ACS)
Date: 05-02-2021
DOI: 10.26434/CHEMRXIV.13719649.V1
Abstract: High strength steel in marine environments suffers from severe corrosion susceptibility and the presence of bacteria can exacerbate the effect, accelerating degradation via microbiologically influenced corrosion (MIC). Here we propose a novel approach to MIC inhibition by designing a system capable of limiting the effects of both bacteria growth and corrosion. The combination of a newly synthesised compound, cetrimonium 4-hydroxycinnamate, with lanthanum 4-hydroxycinnamate was the only system tested to date that could both inhibit abiotic corrosion in artificial seawater and minimise bacteria consortium densities over an exposure period of 24 hours. The electrochemical data for the La+Cet mixture demonstrated the significant inhibition of both abiotic corrosion to a level similar to La(4OHCin) 3 , as well as the ability to reduce bacteria densities of single strains and a consortium. This is unlike the La+CetNal mixture which accelerated abiotic corrosion and the La+IMI which had an insignificant effect on microbial densities (Catubig et al. 2020). A compatible mixture of ionic inhibitors was achieved by using the same cinnamate anion. This mixture of Cet-4OHCin and La(4OHCin) 3 demonstrated significant abiotic corrosion inhibition and bacteria density reductions, making it a strong candidate as an MIC inhibitor system for 80HLES. The Cet-4OHCin compound and its mixture with La(4OHCin) 3 retained relatively low sensitivity towards skin and intestinal cells, making it a safer and more attractive alternative than other more hazardous corrosion inhibitor materials.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0MA00243G
Abstract: Metal-free organic inhibitors that can be incorporated into a polymer coating have great potential, since they can add their intrinsic inhibition effect to the protective layer effect of a polymer coating.
Publisher: Informa UK Limited
Date: 10-2020
Publisher: American Chemical Society (ACS)
Date: 15-12-2016
Abstract: Protic salts have been recently recognized to be an excellent carbon source to obtain highly ordered N-doped carbon without the need of tedious and time-consuming preparation steps that are usually involved in traditional polymer-based precursors. Herein, we report a direct co-pyrolysis of an easily synthesized protic salt (benzimidazolium triflate) with calcium and sodium citrate at 850 °C to obtain N-doped mesoporous carbons from a single calcination procedure. It was found that sodium citrate plays a role in the final carbon porosity and acts as an in situ activator. This results in a large surface area as high as 1738 m
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3LP00017F
Abstract: New poly(ionic liquid) based on poly(diallyl dimethylammonium) and coumarate that can act as a corrosion inhibitor into an acrylic UV-cured formulation.
Publisher: CSIRO Publishing
Date: 15-03-2022
DOI: 10.1071/CH21266
Abstract: High strength steel in marine environments suffers from severe corrosion susceptibility and the presence of bacteria can exacerbate the effect, accelerating degradation via microbiologically influenced corrosion (MIC). Here we propose a novel approach to MIC inhibition by designing a system capable of limiting the effects of both bacterial growth and corrosion. The combination of a newly synthesised compound, cetrimonium 4-hydroxycinnamate (Cet-4OHCin), with lanthanum 4-hydroxycinnamate was the only system tested to date that could both inhibit abiotic corrosion in artificial seawater and minimise bacteria consortium densities over an exposure period of 24 h. This success was proposed to be due to them having the same anion, making them stable when mixed in the solution of the test environment. Furthermore, we confirmed from cytotoxicity testing that Cet-4OHCin demonstrated similarly limited toxicity towards human cells as the commercially available cetrimonium bromide, a known safe additive to cosmetic products. This new system shows promise as a safe and effective multifunctional inhibitor mixture to reduce the effects of MIC.
Publisher: Elsevier BV
Date: 2013
Publisher: Elsevier BV
Date: 05-2014
Publisher: Elsevier BV
Date: 03-2014
Publisher: American Chemical Society (ACS)
Date: 18-09-2019
Abstract: While paint coatings act as important barriers to corrosion, defects can lead to localized, rapid metal loss. The addition of corrosion inhibitors that are capable of leaching from a coating to protect the metal surface at a defect can prevent this type of corrosion. This work investigates the release and corrosion protection capabilities of two rare earth (RE) carboxylate inhibitors from an epoxy coating as an initial step to understanding their leaching behavior and interaction with the coating system. Leaching experiments were performed via inductively coupled plasma mass spectroscopy (ICP-MS) analyses of the solutions in which free-standing coatings loaded with varying concentrations of inhibitor compounds had been immersed. Inhibitor release from the epoxy coating was observed to be dependent on initial inhibitor concentration, inhibitor chemistry, and solution pH conditions. The coating systems with greater initial inhibitor loadings showed higher leaching rates, particularly in acidic environments. Following immersion, the absence of characteristic inhibitor peaks in the FTIR spectra of the coatings also confirmed leaching had taken place. Cross-sectional views of the coatings after exposure to the pH 1 environment presented a chloride infusion zone at the coating/solution interface where the inhibitor had leached out. The RE active inhibition provided by the leached RE carboxylate inhibitors was verified by exposure of a coating defect to a chloride contaminated environment.
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/CH16088
Abstract: An experimental study on copper leaching from Cu1.85S thin films is presented, wherein copper extraction is quantitatively evaluated by changes in film thickness measured by white light interferometric profilometry. Changes in the film morphology and elemental composition, as assessed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, are used to confirm that the loss in film thickness is due to changes in the copper content and that the resultant film species is consistent with the mechanism of copper dissolution. The Cu1.85S thin films were synthesized by chemical bath deposition. The leaching behaviour of copper from the films was investigated in acidic ferric sulfate media at pHs 1, 2, and 3, and pH 1 at redox potentials of ~350–650 mV versus Ag/AgCl in 3 M KCl. The changes in the film thickness and copper sulfur ratio were shown to reflect copper dissolution behaviour from chalcocite. Leaching of the Cu1.85S films demonstrated a greater decrease in film thickness as pH decreased. In addition comparison of the order of reaction as a function of proton concentration in non-oxidative dissolution of Cu1.85S (0.06) and as a function of iron(iii) concentration in ferric oxidation of Cu1.85S (0.40) shows that the proton dissolution reaction is negligible. Leaching of the Cu1.85S films at redox potentials of up to ~476.4 mV versus Ag/AgCl in 3 M KCl produced covellite and demonstrated greater decreases in film thickness with increases in the redox potential. Leaching of the films above ~476.4 mV resulted in the formation of spionkopite and demonstrated a much lesser decrease in film thickness. These results are consistent with Eh-pH diagrams for the Cu–S–H2O system.
Publisher: American Chemical Society (ACS)
Date: 31-12-2013
DOI: 10.1021/LA304394S
Abstract: Transparency sheets, which are normally associated with use on overhead projectors, offer lowered costs and high amenability for optical diagnostics in microplate instrumentation. An alternative microplate design in which circles are scribed on the surface of the transparency to create the boundaries to hold the drop in place is investigated here. The 3D profile of the scribed regions obtained optically showed strong likelihood of affecting three-phase contact line interactions. During dispensation, the contact angle (≈95°) was larger than the drop advancing state (≈80°) due to a period of nonadhesion, where the contact angle later reduced to the drop advancing state followed by increase in the liquid area coverage on the substrate. It was established that 50 μL was needed to fill the well fully, and the maximum volume retainable before breaching was 190 μL. While the tilt angle needed for displacement reduced significantly from 50 to 95 μL, this was markedly better than nonscribed surfaces, where tilt angles always had to be kept to within 30°. It was found that there was greater ability to fill the well with smaller volumes with dispensation at the center. This was attributed to the growing contact line not meeting the scribed edge in parallel if liquid was dispensed closer to it, wherein pinning reduction in some directions permitted liquid travel along the scribed edge to undergo contact angle hysteresis. Fluorescence measurements conducted showed no performance compromise when using scribed transparency microplates over standard microplates.
Publisher: Elsevier BV
Date: 08-2017
Publisher: MDPI AG
Date: 21-01-2013
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/CH16547
Abstract: A series of rare earth 3-(4′-methylbenzoyl)propanoate (mbp–) complexes [RE(mbp)3(H2O)] (RE = rare earth = Y, La, Ce, Nd, Ho, Er) have been prepared by either metathesis reactions between the corresponding rare earth chloride and Na(mbp) or protolysis of rare earth acetates by the free acid. Single-crystal X-ray diffraction studies of [RE(mbp)3(H2O)] (RE = Ce, Nd) and [Ce(mbp)3(dmso)] reveal a 1D carboxylate-bridged polymeric structure in the solid state, featuring 9-coordinate rare earth ions. X-ray powder diffraction patterns of the bulk materials indicates that all of the [RE(mbp)3(H2O)] complexes except RE = La are isomorphous. Hence, there is no structural change from the complex with RE = Ce to that with RE = Er despite the lanthanoid contraction. The 1H NMR spectra of the RE = Ho or Er complexes in (CD3)2SO show large paramagnetic shifts and broadening of the CH2 resonances, indicating the retention of substantial carboxylate coordination in solution.
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3RA46123H
Publisher: Springer Science and Business Media LLC
Date: 21-09-2010
Publisher: American Chemical Society (ACS)
Date: 22-02-2022
Publisher: American Chemical Society (ACS)
Date: 05-08-2016
Publisher: The Electrochemical Society
Date: 05-2023
Abstract: The increased demand for portable electronic devices and electric vehicles has resulted in an exponential increase in lithium-ion battery (LIB) waste, and becoming in turn an important secondary source for critical metals. Electrowinning is a commonly used method to recover base and precious metals from a solution, which can also be used to recover valuable metals from spent LIBs. This study unveiled the cobalt electrochemical recovery using model Co sources in increasing amounts of ethylene glycol (EG), 67 molar %, 82 molar % and 100 molar %, in a mixture with choline chloride. The electrochemical results show that increasing the amount of EG together with a small concentration of sulfate anions, in conjunction with chloride anions, in the solution mixture favours the reduction of Co 2+ . This improved electrochemistry seems to be related to changes of Co 2+ speciation easing the reduction process. Additionally, the nature of the Co salt has a significant impact on the recovery efficiency, morphology, and purity of the Co electrodeposit. This work will underpin the science to design safe electrolyte mixtures to enhance the electrochemical recovery of Co 2+ in solution from secondary sources.
Publisher: The Electrochemical Society
Date: 2012
DOI: 10.1149/2.015212JES
Publisher: Springer Science and Business Media LLC
Date: 06-06-2020
Publisher: American Chemical Society (ACS)
Date: 14-11-2013
DOI: 10.1021/AM4037614
Abstract: The use of ionic liquids as additives to base oil for the lubrication of steel on aluminum was investigated. The miscibility and wear performance of various phosphonium, imidazolium, and pyrrolidinium ionic liquids in a range of polar and nonpolar base oils was determined. The structure and ion pairing of the ionic liquids was found to be important in determining their miscibility in the base oils. In wear tests, some of the miscible base oil/IL blends reduced the aluminum wear depth when compared to that found with the base oil alone. The nonpolar base oil/IL blends were able to withstand higher wear-test loads than the polar base oil/IL blends. At 10 N, as little as 0.01 mol/kg of IL, or 0.7-0.9 wt %, in the nonpolar base oils was enough to drastically reduce the wear depth on the aluminum. XPS analysis of the wear surfaces suggested that the adsorbing of the IL to the surface, where it can form low-shear layers and also react to form tribofilms, is important in reducing friction and wear. The largest reductions in wear at the highest load tested were found for a mineral oil/P6,6,6,14 (i)(C8)2PO2 blend.
Publisher: Springer Science and Business Media LLC
Date: 13-11-2017
DOI: 10.1038/S41529-017-0016-Z
Abstract: Ionic liquids are unique solvents composed entirely of ions and have recently been considered for applications ranging from synthesis, separations, electrochemical devices, tribology and corrosion. In this perspective, we summarise the literature, and look at the future prospects, surrounding the use of ionic liquids in the engineering of interphases to control charge transport thereby leading to improved performance of high-energy density batteries, including Mg, Li and Na metal as well as corrosion protection of reactive engineering alloys, such as aluminium, magnesium and steel alloys. The ability to create task-specific ionic liquids by controlling the chemistry of either the anion or the cation means that interphases can be engineered for specific substrates and applications. Thus far, fluorine containing anions, such as bis(trifluoromethane) sulfonamide and its analogues, have been favoured for controlling the conductive solid–electrolyte interphase layer on Li and Na, while ionic liquids containing organophosphate anions have been used to form nanometre thick protective interphases on Mg alloys. Recently, ionic liquids based on carboxylate anions have also been shown to provide excellent corrosion inhibition for steel. In the search for cost-effective solutions, a relatively new class of ionic liquids, termed deep eutectic solvents, have also been explored as potential media for controlling surface films on reactive metals. The deep eutectic solvents class of ionic liquid materials offers many possible combinations of chemistry that can be targeted to produce desired properties in this context.
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3NJ02735J
Abstract: A range of rare earth( iii ) 4-hydroxybenzoato (4hob) complexes has been prepared and structurally characterized. The La, Ce and Y complexes are good corrosion inhibitors for mild steel.
Publisher: MDPI AG
Date: 24-06-2022
DOI: 10.3390/MICROORGANISMS10071285
Abstract: Multispecies biofilms represent a pervasive threat to marine-based industry, resulting in USD billions in annual losses through biofouling and microbiologically influenced corrosion (MIC). Biocides, the primary line of defence against marine biofilms, now face efficacy and toxicity challenges as chemical tolerance by microorganisms increases. A lack of fundamental understanding of species and EPS composition in marine biofilms remains a bottleneck for the development of effective, target-specific biocides with lower environmental impact. In the present study, marine biofilms are developed on steel with three bacterial isolates to evaluate the composition of the EPSs (extracellular polymeric substances) and population dynamics. Confocal laser scanning microscopy, scanning electron microscopy, and fluorimetry revealed that extracellular DNA (eDNA) was a critical structural component of the biofilms. Parallel population analysis indicated that all three strains were active members of the biofilm community. However, eDNA composition did not correlate with strain abundance or activity. The results of the EPS composition analysis and population analysis reveal that biofilms in marine conditions can be stable, well-defined communities, with enabling populations that shape the EPSs. Under marine conditions, eDNA is a critical EPS component of the biofilm and represents a promising target for the enhancement of biocide specificity against these populations.
Publisher: Elsevier BV
Date: 07-2012
DOI: 10.1016/J.JCIS.2012.02.071
Abstract: As evaporation does not incur energy introduction, the droplet coffee-stain patterning approach is attractive for biochemical tests conducted in the field or in third world environments. A practical strategy uses chemically functionalized microbeads for the coffee stain deposition process. From an application perspective, it will be necessary to minimize the coffee stain deposition time, as evaporation, depending on the volume of the droplet, can be a slow process. The introduction of a porous media will generate a capillary flow (or wicking) that removes any remnant liquid in the droplet, thus permitting it to be done inexpensively and in the field. Using optical profilometry, we were able to establish that polystyrene microspheres developed more copious and defined single ring coffee depositions than silica of the same size and concentration in a suspension. In analyzing the droplet capillary evacuation process with a porous media, we found the liquid bridge formed during the later stages to rupture and leave behind some liquid material for a second stage evaporation process. This was responsible for a two ring structure that was more visible with silica microspheres. A high degree of hysteresis of the contact angle was found to develop at the contact line in which values below 5° could be achieved. Dynamic observations showed the copious and dense packing of polystyrene particles to be more resistant to ring break up from the evacuation flow. Nevertheless, erosion of the back array portions of the ring was evident notwithstanding either type of microsphere used.
Publisher: MDPI AG
Date: 06-11-2020
Abstract: Chromate free corrosion inhibitors are searched for to mitigate the economic loss caused by mid-steel corrosion. Here, we show metal-free organic inhibitors having free coumarate anions that can be used either as direct corrosion inhibitors or incorporated into a polymer coating obtained by UV-curing. Four different ionic liquid monomers and polymer coatings with hexoxycoumarate anion and different polymerizable counter cations were investigated. Potentiodynamic polarization, electrochemical impedance spectroscopy, and surface analyses have verified their corrosion inhibition performance on a mild steel AS1020 surface. In the case of the coumarate ionic liquid monomers, the most promising inhibitor is the one coupled with the ammonium cation, showing an inhibition efficiency of 99.1% in solution followed by the imidazolium, pyridinium, and anilinium. Next, the ionic liquid monomers were covalently integrated into an acrylic polymer coating by UV-photopolymerization. In this case, the barrier effect of the polymer coating is combined with the corrosion inhibitor effect of the pendant coumarate anion. Here, the best polymer coatings are those containing 20% imidazolium and pyridinium cations, presenting a greater impedance in the EIS (Electrochemical Impedance Spectroscopy) measurements and less evidence of corrosion in the scribe tests. This article shows that the cationic moiety of coumarate based ionic liquids and poly(ionic liquid)s has a significant effect on their excellent corrosion inhibition properties for a mild steel surface exposed to aqueous chloride solutions.
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.JCIS.2021.11.139
Abstract: Molecular interactions between 4-OH-cinnamate and cetrimonium in solution result in improved adsorption of the cinnamate on mild steel, developing a protective mechanism against the diffusion of corrosive chloride to the oxide surface. Fundamental understanding of this mechanism should allow new design routes for the development of eco-friendly corrosion inhibitors. Via classic molecular dynamics, simulations were carried out for cetrimonium and 4-OH-cinnamate in aqueous solutions at different ionic strengths and the results were validated with experimental SAXS data. Self-aggregation of cetrimonium 4-OH-cinnamate on a hydrated hematite surface was then simulated and results were compared with cryo-TEM imaging for the same compound. Finally, the effect of the adsorbed aggregates on chloride diffusion to the oxide surface was modelled. Simulations showed the encapsulation of 4-OH-cinnamate into cetrimonium micelles, consistent with experiments. The newly formed micelles adsorb onto a hydrated iron oxide surface by forming hydrogen bonds between their carboxylate outer-shell groups and the surface hydroxyls. As the adsorbate concentrations increase, there is a morphological transition from spherical to wormlike adsorbed aggregates. The wormlike structure can block chloride ions, demonstrating a synergistic inhibitory mechanism between both cetrimonium and 4-OH-cinnamate. Encapsulation and delivery of active compounds to certain targets, such as carcinogenic tumors, have been well studied in biochemistry research, we demonstrate that the same mechanism can be applied to the design of efficient corrosion inhibitors, optimizing their delivery to the metal surface.
Publisher: Springer Science and Business Media LLC
Date: 03-08-2021
DOI: 10.1038/S41598-021-94827-9
Abstract: Chemical biocides remain the most effective mitigation strategy against microbiologically influenced corrosion (MIC), one of the costliest and most pervasive forms of corrosion in industry. However, toxicity and environmental concerns associated with these compounds are encouraging the development of more environmentally friendly MIC inhibitors. In this study, we evaluated the antimicrobial effect of a novel, multi-functional organic corrosion inhibitor (OCI) compound, cetrimonium trans-4-hydroxy-cinnamate (CTA-4OHcinn). Attachment of three bacterial strains, Shewanella chilikensis, Pseudomonas balearica and Klebsiella pneumoniae was evaluated on wet-ground (120 grit finish) and pre-oxidised carbon steel surfaces (AISI 1030), in the presence and absence of the new OCI compound. Our study revealed that all strains preferentially attached to pre-oxidised surfaces as indicated by confocal laser scanning microscopy, scanning electron microscopy and standard colony forming unit (CFU) quantification assays. The inhibitor compound at 10 mM demonstrated 100% reduction in S. chilikensis attachment independent of initial surface condition, while the other two strains were reduced by at least 99.7% of the original viable cell number. Our results demonstrate that CTA-4OHcinn is biocidal active and has promise as a multifunctional, environmentally sound MIC inhibitor for industrial applications.
Publisher: Wiley
Date: 16-03-2022
Abstract: The incorporation of organic corrosion inhibitors into waterborne coatings is optimized in this work. Herein, p‐coumaric acid (4‐hydroxycinnamic acid) is modified by a butyl radical and its effectiveness as an anticorrosive free inhibitor in solution is confirmed by potentiodynamic polarization (PP). The molecule is then successfully incorporated into waterborne polymeric binders by employing different polymerization techniques in dispersed media. Whenever possible, the inhibitor is also blended into the bare latexes to compare the effect of the incorporating method. The anticorrosion performance of the obtained coatings is tested and compared by electrochemical analysis. Promising results are obtained for the coatings produced by semibatch emulsion polymerization even at the low concentration of 1.5 mg of inhibitor g −1 latex. The intact control coating without inhibitor shows an impedance of up to 10 6 Ω and a phase angle of 72° after 1 h of immersion in the corrosive medium, meanwhile the coating with inhibitor shows higher values, 10 6.7 Ω and 80°. Active corrosion inhibition is observed in the coating with inhibitor in which a defect has been done, as the impedances drop to 10 3.9 Ω after 24 h of immersion in the saline solution while in the control scratched coating it drops to 10 3.6 Ω.
Publisher: Springer Science and Business Media LLC
Date: 24-03-2022
DOI: 10.1038/S41529-022-00234-4
Abstract: The formation of multi-species biofilms on marine infrastructure costs the global economy US $ billions annually, resulting in biofouling and microbiologically influenced corrosion. It is well documented that complex biofilms form on almost any submerged surface, yet there are still no truly effective and environmentally friendly treatment or prevention options available. An incomplete fundamental understanding of natural biofilm development remains a key limitation for biofilm control measures. The purpose of this review is to compile the current literature and knowledge gaps surrounding the development of multi-species biofilms in marine conditions on metals.
Publisher: Elsevier BV
Date: 12-2018
Publisher: Elsevier BV
Date: 09-2021
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/CH20197
Abstract: Rare earth (RE) complexes of 3-benzoylpropanoate (bp), [RE(bp)3(H2O)n] (RE=La, n=2 RE=Y, Ce, Pr, Nd, Yb, n=1) and 3-phenylpropanoate (pp), [RE(pp)3] (RE=Y, La, Ce, Nd, Yb), have been prepared by metathesis reactions between the corresponding rare earth chloride and the appropriate sodium carboxylate. Analysis by single-crystal X-ray diffraction finds that both RE bp and pp complexes favour formation of carboxylate-bridged 1-D coordination polymers in the solid state. Here, the former favours heteroleptic 9 or 10-coordinate complexes (splitting between Ce and La) with the carbonyl remaining uncoordinated but participating as a hydrogen bond acceptor with water in the coordination sphere. Lack of bp carbonyl coordination leaves this group available for surface interactions during corrosion inhibition and complex solubilization. The latter pp derivatives form eight-coordinate complexes for Y and Yb and are the first ex les of homoleptic RE pp complexes to be reported.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0CP05295G
Abstract: Recently ionic liquids (ILs) have shown promising tribological properties as additives in base oils however their lack of miscibility is a problem, with very few ILs being compatible with lubricant oil formulation (non-polar base oils).
Publisher: Elsevier BV
Date: 10-2016
Publisher: Frontiers Media SA
Date: 21-01-2022
DOI: 10.3389/FBIOE.2022.803559
Abstract: In natural environments, populations of microorganisms rapidly colonise surfaces forming biofilms. These sessile communities comprise a variety of species which contribute to biofouling and microbiologically influenced corrosion (MIC), especially on metals. Species heterogeneity in natural systems confers higher tolerance to adverse conditions such as biocide treatment compared with single species laboratory simulations. Effective chemical treatments to combat recalcitrant biofilms are often dangerous to apply both to operators and the environment, and face international embargoes. Today, there is a drive to exchange current toxic and environmentally hazardous biocides with less harmful compounds. One effective method of achieving this goal is to generate multi-functional compounds capable of tackling corrosion and biofilm formation simultaneously, thus reducing the number of compounds in dosing procedures. In a previous study, a novel corrosion inhibitor demonstrated biocidal effects against three marine isolates during the early stages of biofilm formation. The compound CTA-4OHcinn, holds great promise as a multi-functional inhibitor, however its effect on complex, multi-species biofilms remains unknown. Here we evaluate CTA-4OHcinn biocidal capacity against multi-species biofilms developed from oilfield s les. Mature biofilms were developed and treated with 10 mM CTA-4OHcinn for 4 h. The effects of the compound were assessed using mean probable number (MPN), adenosine triphosphate (ATP) quantification, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Results demonstrate that CTA-4OHcinn significantly reduces the viability of mature biofilms, supporting previous demonstrations on the secondary function of CTA-4OHcinn as a biocide. CLSM results further indicate that CTA-4OHcinn targets the cell membrane resulting in lysis. This finding complements the established corrosion inhibition function of CTA-4OHcinn, indicating the compound is a true multi-functional organic corrosion inhibitor.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1CP21139K
Abstract: We report on the synthesis, characterisation, and physical and tribological properties of halogen-free ionic liquids based on various chelated orthoborate anions with different phosphonium cations, both without halogen atoms in their structure. Important physical properties of the ILs including glass transition temperatures, density, viscosity and ionic conductivity were measured and are reported here. All of these new halogen-free orthoborate ionic liquids (hf-BILs) are hydrophobic and hydrolytically stable liquids at room temperature. As lubricants, these hf-BILs exhibit considerably better antiwear and friction reducing properties under boundary lubrication conditions for steel-aluminium contacts as compared with fully formulated (15W-50 grade) engine oil. Being halogen free these hf-BILs offer a more environmentally benign alternative to ILs being currently developed for lubricant applications.
Publisher: American Chemical Society (ACS)
Date: 21-01-2016
Publisher: Springer Science and Business Media LLC
Date: 08-02-2022
DOI: 10.1007/S11249-022-01567-6
Abstract: The present study investigated the synthesis of novel, oil miscible, multifunctional, silane functionalized imidazoline-based ionic liquids (ILs) with an emphasis towards halogen, sulfur and phosphorous free lubricant additives to replace the conventional additives (ZDDP, MoDTC, etc.), for which there are environmental concerns. These ILs were prepared in different concentrations and proved to be oil miscible for a short time. This stability was improved to over a year using sorbitan trioleate as an emulsifier additive. These additives performed well in reducing friction and wear when investigated on steel-steel contacts at a 5 wt% concentration, with improvements for the TPEIPS BEHP containing blend of up to 39% and 53%, respectively, as compared to the base oil. SEM and EDS analysis shows a phosphorous and oxygen rich tribo-film formation for this combinations. These ILs were further tested to determine their effect on properties such as viscosity, thermal stability, elastomeric and antifoaming compatibility. These new ILs work towards the discovery of environmentally friendly additives for tribological processes.
Publisher: Elsevier BV
Date: 2000
Publisher: American Chemical Society (ACS)
Date: 17-11-2014
DOI: 10.1021/JZ5021422
Abstract: The remarkable physical properties of ionic liquids (ILs) make them potentially excellent lubricants. One of the challenges for using ILs as lubricants is their high cost. In this article, atomic force microscopy (AFM) nanotribology measurements reveal that a 1 mol % solution of IL dissolved in an oil lubricates the silica surface as effectively as the pure IL. The adsorption isotherm shows that the IL surface excess need only be approximately half of the saturation value to prevent surface contact and effectively lubricate the sliding surfaces. Using ILs in this way makes them viable for large-scale applications.
Publisher: WIT Press
Date: 22-04-2010
DOI: 10.2495/TD100231
Publisher: MDPI AG
Date: 22-06-2016
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2NJ03556A
Abstract: Two series of Rare Earth (RE) 3-thiophencarboxylate (3TPC) complexes have been synthesized by reactions between a RE salt and Na(3TPC). Based on weight loss measurements and potentiodynamic polarization measurements, the compounds show good corrosion inhibitory properties and act mainly as anodic inhibitors.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7FD00189D
Abstract: The important properties and applications of molecular liquid mixtures with ionic liquids and low melting organic salts are discussed.
Publisher: Springer Science and Business Media LLC
Date: 22-06-2021
Publisher: The Electrochemical Society
Date: 17-01-2020
Publisher: Elsevier BV
Date: 07-2018
Publisher: American Chemical Society (ACS)
Date: 19-03-2021
Publisher: Elsevier BV
Date: 09-2014
Publisher: MDPI AG
Date: 13-12-2022
DOI: 10.3390/MOLECULES27248836
Abstract: In this study, two types of Rare Earth (RE) 3-furoate complexes were synthesized by metathesis reactions between RE chlorides or nitrates and preformed sodium 3-furoate. Two different structural motifs were identified as Type 1RE and Type 2RE. The Type 1RE monometallic complexes form 2D polymeric networks with the composition [RE(3fur)3(H2O)2]n (1RE = 1La, 1Ce, 1Pr, 1Nd, 1Gd, 1Dy, 1Ho, 1Y 3furH = 3-furoic acid) while Type 2RE bimetallic complexes form 3D polymeric systems [NaRE(3fur)4]n (2RE = 2Ho, 2Y, 2Er, 2Yb, 2Lu). The stoichiometric mole ratio used (RE: Na(3fur) = 1:3 or 1:4) in the metathesis reaction determines whether 1RE or 2RE (RE = Ho or Y) is formed, but 2RE (RE = Er, Yb, Lu) were obtained regardless of the ratio. The corrosion inhibition behaviour of the compounds has been examined using immersion studies and electrochemical measurements on AS1020 mild steel surfaces by a 0.01 M NaCl medium. Immersion test results revealed that [Y(3fur)3(H2O)2]n has the highest corrosion inhibition capability with 90% resistance after 168 h of immersion. Potentiodynamic polarisation (PP) measurements also indicate the dominant behaviour of the 1Y compound, and the PP curves show that these rare earth carboxylate compounds act predominantly as anodic inhibitors.
Publisher: Elsevier BV
Date: 10-2017
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5CP07061A
Abstract: The efficacy of ionic liquids (ILs) as lubricant additives to a model base oil has been probed at the nanoscale and macroscale as a function of IL concentration using the same materials.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CP40736A
Abstract: Ionic liquids have been shown to be highly effective lubricants for a steel on aluminium system. This work shows that the chemistry of the anion and cation are critical in achieving maximum wear protection. The performance of the ILs containing a diphenylphosphate (DPP) anion all showed low wear, as did some of the tris(pentafluoroethyl)trifluorophosphate (FAP) and bis(trifluoromethanesulfonyl)amide (NTf(2)) anion containing ILs. However, in the case of the FAP and NTf(2) based systems, a cation dependence was observed, with relatively poor wear resistance obtained in the case of an imidazolium FAP and two pyrrolidinium NTf(2) salts, probably due to tribocorrosion caused by the fluorine reaction with the aluminium substrate. The systems exhibiting poor performance generally had a lower viscosity, which also impacts on their tribological properties. Those ILs that exhibited low wear were shown to have formed protective tribofilms on the aluminium alloy surface.
Start Date: Start date not available
End Date: End date not available
Funder: Australian Research Council
View Funded ActivityStart Date: 2018
End Date: 2020
Funder: Australian Research Council
View Funded Activity