| 1. |
- Andersson Trojer, Markus, 1981, et al.
(författare)
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Imidazole and Triazole Coordination Chemistry for Antifouling Coatings
- 2013
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Ingår i: Journal of Chemistry. - : Hindawi Limited. - 2090-9063 .- 2090-9071. ; 2013
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Tidskriftsartikel (refereegranskat)abstract
- Fouling of marine organisms on the hulls of ships is a severe problem for the shipping industry. Many antifouling agents are based on five-membered nitrogen heterocyclic compounds, in particular imidazoles and triazoles. Moreover, imidazole and triazoles are strong ligands for Cu2+ and Cu+, which are both potent antifouling agents. In this review, we summarize a decade of work within our groups concerning imidazole and triazole coordination chemistry for antifouling applications with a particular focus on the very potent antifouling agent medetomidine. The entry starts by providing a detailed theoretical description of the azole-metal coordination chemistry. Some attention will be given to ways to functionalize polymers with azole ligands. Then, the effect of metal coordination in azole-containing polymers with respect to material properties will be discussed. Our work concerning the controlled release of antifouling agents, in particular medetomidine, using azole coordination chemistry will be reviewed. Finally, an outlook will be given describing the potential for tailoring the azole ligand chemistry in polymers with respect to Cu2+ adsorption and Cu2+ Cu+ reduction for antifouling coatings without added biocides.
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| 2. |
- Movahedi, Alireza, 1983, et al.
(författare)
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Copper-coordinating polymers for marine anti-fouling coatings: A physicochemical and electrochemical study of ternary system of copper, PMMA and poly(TBTA)
- 2016
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Ingår i: Progress in Organic Coatings. - : Elsevier BV. - 0300-9440. ; 97, s. 216-221
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Tidskriftsartikel (refereegranskat)abstract
- Biofouling is a general problem in marine applications. Copper has been used as an anti-biofouling agent in marine coatings for decades; however, its widespread use has resulted in regulatory restrictions due to high copper concentrations in harbors and areas with limited water circulation. Here we present a new approach for anti-fouling coatings using microparticles of poly(tris[(benzyltriazol)methyl]amine) (poly(TBTA)) polymers to absorb and control the interaction between a surface coating and the copper naturally present in seawater with the intention of creating a flux of copper across the water/coating interface. The preparation and characterization of microparticles of poly(TBTA) as well as hybrid PMMA: poly(TBTA) has been described to study the feasibility of tuning the copper-coordination properties of a generic marine coating using these paint-compatible microparticles. The properties of microparticles of poly(TBTA), PMMA and the PMMA: poly(TBTA) hybrid were therefore studied using cyclic voltammetry and NMR spectroscopy. It is demonstrated that the copper ions interact specifically with microparticles containing the coordinating polymer poly(TBTA) and that these microparticles have a high absorption capacity of more than 5 wt% for copper.
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| 3. |
- Movahedi, Alireza, 1983, et al.
(författare)
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Cu(i) stabilizing crosslinked polyethyleneimine
- 2015
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Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 17:28, s. 18327-18337
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Tidskriftsartikel (refereegranskat)abstract
- Polyethyleneimine (PEI) is known for its metal-coordinating properties and in its crosslinked form has applications in different areas ranging from drug delivery to waste water treatment and recovery of trace metals. With the aim to regulate the coordination environment of Cu(i) and Cu(ii) ions in marine coatings, we have prepared a triazole cross-linking agent with 'soft' coordination that can crosslink PEI via indirect reductive amination. We have shown that this triazole crosslinker not only increases the Cu(ii) absorption capacity of the crosslinked PEI in comparison to the traditionally used glutaraldehyde-crosslinked PEI (PEI-GA), but also allows the crosslinked polymer network to stabilize the Cu(i) oxidation state more effectively. The Cu(ii) uptake and Cu(i) stabilization of the polymer have been determined by elemental analysis and UV-vis spectroscopy. It was found that the triazole-crosslinked polymer (PEI-TA) could coordinate up to 12 wt% of Cu(ii) before and 6 wt% Cu(ii) after imine reduction.
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| 4. |
- Movahedi, Alireza, 1983
(författare)
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Cu(I) stabilizing polymers for marine anti-fouling applications
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The growth of marine organisms on immersed surfaces in seawater is known as biofouling and causes several problems for marine transportation. The need to combat fouling is thus of great importance. Copper has to be used in extreme amounts to act as an efficient biocide. Consequently, several countries have restricted the use of copper based paints due to the adverse effect of high copper concentration on the environment.Both Cu(I) and Cu(II) ions are considered to be toxic for marine foulers, although Cu(I)is generally accepted to be the form of Cu that passes through the biological membranes. At the same time, Cu(I) is unstable in the marine environment and rapidly oxidizes to Cu(II). The stability of Cu(I) ions may however be increased by using Cu(I)-stabilizing coordinating ligands in the coating. The idea behind this project is to have a coating that can absorb the abundant Cu(II) ions in the seawater with the ability to stabilize the Cu(I)oxidation state in the presence of naturally occurring reducing agents with the aim of improving the anti-fouling effect at the coating interface with the seawater.As the first phase of this project, in this thesis, we present several synthetic routes to prepare different variants of polymers based on triazole ligands for further use in marine applications. To do so, we have used robust and high performance chemical reactions such as the Cu-catalyzed alkyne-azide cycloaddition, epoxy ring opening, and reductive amination to modify commercially available polymers in order to increase their affinity to stabilize Cu(I). The synthetic methods employed, the physical and chemical properties of the polymers, as well as their performance upon interaction with Cu ions in solution, is described. The different triazole-containing coordinating polymers which are introduced in this work not only absorb relatively high levels of Cu(II) ions from a Cu(II) solution (5 to 12 wt%), but can also effectively stabilize Cu(I) ions which are produced in the presence of a mild reducing agent such as sodium ascorbate.
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| 5. |
- Movahedi, Alireza, 1983, et al.
(författare)
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One-pot synthesis of TBTA-functionalized coordinating polymers
- 2014
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Ingår i: Reactive and Functional Polymers. - : Elsevier BV. - 1381-5148. ; 82, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- A one-pot method for the functionalization of polyvinylbenzyl chloride with a tris-(benzyltriazolylmethyl)amine (TBTA) ligand via the copper-catalyzed azide–alkyne cycloaddition reaction (CuAAC) is reported, where the ligand is constructed simultaneously with its attachment to the polymer backbone. A hydrophobic TBTA polymer as well as co-polymers containing TBTA ligands were also prepared to demonstrate the possibility of tailoring the properties of the polymers. The polymers were characterized with FT-IR and NMR spectroscopy, elemental analysis, contact angle measurement, differential scanning calorimetry and thermal gravimetric analysis. The metal coordinating properties of films prepared from the polymers was also demonstrated using X-ray photoelectron spectroscopy and their structures inspected by scanning electron microscopy.
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| 6. |
- Nordstierna, Lars, 1976, et al.
(författare)
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New Route for Microcapsule Synthesis
- 2011
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Ingår i: Journal of Dispersion Science and Technology. - : Informa UK Limited. - 1532-2351 .- 0193-2691. ; 32:3, s. 310-311
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Tidskriftsartikel (refereegranskat)abstract
- Studies on the growth of microorganisms on painted surfaces and other coatings has increased during the last decades as many antigrowth agents have gradually been prohibited due to toxicity. Current applications using biocides lose the protection quite rapidly as small molecular size renders a fast diffusional biocide leakage. A promising improvement of antigrowth protection can be achieved by the use of encapsulated biocides in the paint. The candidate method to produce microcapsules has dichloromethane as a key constituent in the synthesis step.[3] Dichloromethane is hazardous and thereby often not allowed to be used at industrial scale. In this article, we show that ethyl acetate has equivalent physiochemical properties as dichloromethane in the production of microcapsules and thus can be used in order to fulfill legislative criteria.
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