Application of marine biotechnology in the production of natural biocides for testing on environmentally innocuous antifouling coatings

The widely recognized biofouling phenomenon has many negative consequences for artificial structures that are in contact with seawater in the form of structural defects and additional expenses for maritime companies due to cleaning and prevention processes. After having analyzed the serious environmental problems caused by an indiscriminate use of highly toxic biocides coming from organic derivatives of tin compounds and the uncontrolled emissions of volatile organic compounds (VOC) to the atmosphere, the evolving technology of antifouling paintings (further mandated by current environmental standards) aims to develop environmentally innocuous water-based coverings in which extracts of the very same marine world are used as biocide compounds. Water-based coatings are being developed that use low-toxic elements and natural biocides, where bacteria is isolated from surfaces immersed in the marine environment, creating a promising source of natural antifouling compounds. The result is a new environmentally friendly antifouling coating that is able to mitigate the problem of biofouling without affecting the surrounding medium, and which may be applied on any artificial structure in contact with seawater. An erratum to this article can be found at     

Advances in environmentally benign coatings and adhesives

There is an increased need to develop environmentally benign (no pollution or release of hazardous materials into the air, water or soil from a coating or adhesive either during their manufacture, use and disposal or recycle lifetimes), coatings and adhesives that have equivalent or superior properties to their conventional (non-environmentally benign) counterparts. This paper discusses some of the new concepts or technologies associated with environmentally benign barrier coatings for packaging, abrasion resistant coatings for plastic substrates, new developments in wood finishes, antifouling coatings and new chemistry associated with the design of advanced coating systems. This paper also discusses how Battelle is helping the US Air Force to eliminate hazardous waste associated with structural adhesive technology through the identification of equivalent adhesive systems reducing the number of adhesives used to repair current aircraft and missile equipment. This paper also discusses advances in the area of repulpable/recyclable pressure sensitive adhesives and silicone release coatings used in a variety of commercial applications.     

新型海洋防污涂料用防污剂及树脂的研究进展

防污剂和树脂是决定海洋防污涂料性能的关键成分。本文综述了近年来用于新型海洋防污涂料的天然产物防污剂和人工合成防污剂的研究进展;进一步从防污机理出发,总结了用于新型海洋防污涂料的基体树脂的种类,介绍了无锡自抛光树脂、生物可降解树脂、含杀菌官能团树脂、低表面能树脂和具有微相分离结构的树脂。此外,还展望了新型海洋防污涂料的未来发展方向,即环境友好的同时注重方式友好。     

Bioactive materials for antifouling coatings

Marine fouling is the result of the settling and subsequent growth of marine organisms on surfaces immersed in seawater. The most successful principle in use today for the protection of ship's hulls against this unwanted growth is the release of bioactive materials from antifouling coatings.

Antifouling coatings containing a mixture of cuprous oxide and triorganotin compounds in combination with sophisticated release mechanisms are considered to be today's most efficient systems. However, ever since the first biologically active materials were introduced into antifouling coatings, a search for alternatives has been continuing. Until the mid-1970s this research mainly involved the development of biocides which could simply prolong existing drydocking intervals, i.e. prolong the period in which the ship was fouling free. During the last decade, however, environmental aspects have become a top priority in the development of new biocides for antifouling coatings.     

Urushiol titanium polymer-based composites coatings for anti-corrosion and antifouling in marine spray splash zones

Seawater is highly corrosive, and the alternating dry and wet environment can cause severe corrosion in metal equipment. Moreover, marine equipment is also seriously affected by marine biofouling. These harsh conditions pose a serious threat to the integrity of marine equipment as well as their associated maritime activities and necessitate the development of effective coatings to minimize damage to the equipment. Urushiol titanium polymer/acrylic resin (UTP/AR) composite materials were developed. Then, marine anti-corrosion and antifouling coatings were prepared from the UTP/AR composite materials using rosin-modified Cu₂O as an antifoulant. The composite coating with a UTP:AR mass ratio of 1:1 (UTP/AR3) showed the best chemical resistance and light aging resistance. UTP/AR3 also exhibited a good corrosion current density (2.009 × 10⁻⁷ A cm⁻²) and corrosion potential (−0.5007 V), further indicating that the UTP/AR composite coatings have excellent anti-corrosive properties. Marine field tests showed that the UTP/AR/Cu₂O composite coatings with rosin-modified Cu₂O contents less than 20% showed stable, long-term antifouling performance after immersion in seawater for 360 day. Briefly, the UTP/AR/Cu₂O composite coatings have broad application prospects in the marine industry for materials in the spray splash zone.     

Recent trends in environmentally friendly water-borne polyurethane coatings: A review

Environmentally friendly waterborne polyurethane (WPU) coatings are used extensively due to their low VOCs emission than solvent based PU coatings. Additionally, WPU coatings have low temperature flexibility, pH stability, water resistance, superior solvent resistance, outstanding weathering resistance and desirable chemical and mechanical properties. This review provides an overview on the recent developments of WPU coatings and their value added applications in the coatings and paint industry. UV-cured WPU coatings provide an important class of green and ecofriendly coatings with outstanding mechanical properties and rapid curing system. Hyper-branched polyurethanes (PUs) show interesting properties, such as high solubility, reactivity and good rheological behavior owing to multiple end groups, compact molecular structure and diminishing chain entanglement. Inherently, WPU coatings have reduced stiffness and mechanical strength that can be increased by the addition of nanoparticles, like Ag, Cu, TiO₂, SiO₂ and many more. Fire retardants, commonly phosphorous, are incorporated in the WPU structure to increase the flame retardancy of WPU coatings.     

Inorganic precursor peroxides for antifouling coatings

Modern antifouling coatings are generally based on cuprous oxide (Cu₂O) and organic biocides as active ingredients. Cu₂O is prone to bioaccumulation, and should therefore be replaced by more environmentally benign compounds when technically possible. However, cuprous oxide does not only provide antifouling properties, it is also a vital ingredient for the antifouling coating to obtain its polishing and leaching mechanism. In this paper, peroxides of strontium, calcium, magnesium, and zinc are tested as pigments in antifouling coatings. The peroxides react with seawater to create hydrogen peroxide and highly seawater-soluble ions of the metal. The goals have been to establish the antifouling potency of an antifouling coating that releases hydrogen peroxide as biocide, and to investigate the potential use of peroxides as water-soluble polishing and leaching pigments. The investigations have shown that it is possible to identify particulates that, when applied as pigments in antifouling coatings, will provide polishing and leaching rates comparable to those of Cu₂O-based coatings. Furthermore, the combination of polishing and hydrogen peroxide leaching by a coating based on zinc peroxide in a suitable binder matrix provides antifouling properties exceeding those of a similar coating based entirely on zinc oxide.     

环境友好涂料用的树脂开发

本文介绍了环境友好低VOC涂料用的树脂最近开发情况。     

Development of environmentally friendly,antifouling coatings based on tethered quaternary ammonium salts in a crosslinked polydimethylsiloxane matrix

The concept of tethering quaternary ammonium salts (QASs) to a crosslinked polysiloxane matrix to produce a hybrid antifouling/fouling-release coating was investigated. A statistical experimental design was used to determine the effect of QAS concentration on biocidal activity toward a marine bacterium, Cellulophaga lytica (C. lytica). In addition to measuring biocidal activity, coating film quality as well as stability upon water immersion were evaluated. The results of the study showed that biocidal activity was strongly dependent on QAS concentration. For addition-curable coatings, the presence of 4 wt% QAS moieties resulted in approximately 50% reduction in C. lytica biofilm retention without any leachate toxicity. Attempts to increase the level of QAS moieties to increase biocidal activity resulted in coating delamination from the substrate and unacceptable film quality upon artificial seawater immersion due to excessive swelling. As a result, a moisture-curable system based on tethered QASs was investigated since moisture curing allows for higher crosslink densities to be achieved which would be expected to minimize swelling upon artificial seawater immersion. The moisture-curable coating developed showed enhanced stability upon artificial seawater immersion, greater than 80% reduction in C. lytica biofilm retention, and greater than 90% reduction in biofilm growth for the marine algae, Navicula incerta. Presented at 2007 FutureCoat! Conference, sponsored by Federation of Societies for Coatings Technology, October 3–5, 2007, in Toronto, Ont., Canada.     

Cerium cinnamate as an environmentally benign inhibitor pigment for epoxy coatings on AA 2024-T3

An environmentally friendly inhibitor, cerium cinnamate (CeCin), was studied as an additive to an epoxy coating. The effects of corrosion inhibition on AA 2024-T3 provided by cerium cation and cinnamate anion were investigated by electrochemistry impedance spectra (EIS) and polarization tests. It was found that cerium ion and cinnamate group have synergistic inhibiting effects. The EIS results show that CeCin is an effective inhibitor pigment for improving the corrosion resistance of epoxy coatings on AA2024-T3, as reflected by the much higher coating resistance than that of the blank epoxy coating. The inhibiting effect of CeCin during the onset of corrosion in defects of the epoxy coating was verified using scanning vibrating electrode technique (SVET), which is in agreement with the EIS results.     

A material-centric methodology for developing inherently safer environmentally benign processes

Stringent safety and environmental regulations, and competition have challenged the chemical process industries to bring products to market at low lifecycle costs without compromising on safety and environmental standards. This has led the designers to consider inherent safety and waste minimization principles at the early stages of design. Tools and methods are available for developing inherently safer process and carrying out waste minimization analysis individually without taking into account the close coupling between them. This results in an incomplete and inaccurate analysis. In this paper, we present a systematic methodology for the integrated safety and waste minimization analysis during process design. Safety issues are characterized by unintended effects of materials and waste issues by release of material to the environment. The material-centric view thus brings out the similarities between the source of safety and pollution issues and the strategies necessary for their improvement. It also provides a common framework to identify synergies and tradeoffs among the alternatives generated thus enhancing the decision-making during design process. The integrated methodology is implemented as an intelligent decision support system that can help design inherently safe and environmentally benign chemical processes. The integrated methodology and its implementation are discussed and illustrated on an industrial process involving acrylic acid production process.     

Group contribution-based LCA models to enable screening for environmentally benign novel chemicals in CAMD applications

This study considers the development of suitable models for the estimation of life cycle assessment (LCA) indices of organic chemicals. Unlike state-of-the-art models, the tools developed here correlate LCA indices with the molecular composition according to the well-established group contribution (GC) approach. The LCA indices considered here are global warming potential, cumulative energy demand, and Eco-Indicator 99. The model development uses data from existing LCA databases, where each material is associated with its cradle-to-gate LCA metrics. A variety of regression and nonregression methodologies are recruited to achieve the optimum correlation. GC models can be used to screen for molecules with optimal and/or desirable properties, using appropriate molecular design synthesis algorithms. In this framework, the models developed here are linked to the design algorithm to enable the consideration of LCA features together with other properties, for the design of environmentally benign liquid–liquid extraction solvents.     

Effect of dopant on the corrosion protective performance of environmentally benign nanostructured conducting composite coatings

The present work study reports the comparative corrosion protective performance of nanostructured methyl orange (MO) doped polyaniline (PANI) and camphorsulphonic acid (CSA) doped poly(1-naphthylamine) (PNA) dispersed polyurethane-based composite coatings against mild steel (MS). The influence of the dopant on the passivation of metal was analyzed using two different dopants. The nanostructure of the conducting polymers—MO-PANI and CSA-PNA was confirmed by transmission electron microscopy (TEM). The corrosion protective performance of the coatings against MS was evaluated by the physico-mechanical properties and corrosion rate measurements.     

Simultaneous mixed-integer dynamic optimization for environmentally benign electroplating

Hoist scheduling, especially cyclic hoist scheduling (CHS), is used to maximize the manufacturing productivity of electroplating processes. Water-reuse network design (WRND) for the electroplating rinsing system targets the optimal water allocation, such that fresh water consumption and wastewater generation are minimized. Currently, there is still a lack of studies on integrating CHS and WRND technologies for electroplating manufacturing. In this paper, a multi-objective mixed-integer dynamic optimization (MIDO) model has been developed to integrate CHS and WRND technologies for simultaneous consideration of productivity and water use efficiency for environmentally benign electroplating. The orthogonal collocation method on finite elements is employed to convert the MIDO problem into a mixed-integer nonlinear programming (MINLP) problem. The efficacy of the methodology is demonstrated by solving a real electroplating example. It demonstrates that the computational methods of production scheduling, process design, and dynamic optimization can be effectively integrated to create economic and environmental win-win situations for the electroplating industry.     

A review and comparative study of release coatings for optimised abhesion in resin transfer moulding applications

In this study, a number of abhesion-promoting coatings were considered in terms of their physicochemical and release properties. The techniques used to further this study include; field emission gun scanning electron microscopy, atomic force microscopy (AFM), profilometry, X-ray photoelectron spectroscopy, Auger electron spectroscopy, static secondary ion mass spectrometry, Fourier transform infra-red analysis and contact angle analysis for coating physical and chemical characterisation along with pulsed force mode atomic force microscopy (PF-AFM) and other adhesion and mechanical tests to determine surface release properties. These coatings were applied to metal substrates and were based upon silicone, fluoropolymer or metal–PTFE composite chemistry, all being potentially useful as release films for resin transfer moulding applications. The semi-permanent Frekote B15/710 NC mould release coating system, which is based on PDMS, proved extremely effective in terms of release against a cured epoxide applied under pressure. Although fluoroalkylsilane coatings offer a number of technological advantages for release applications, they generally produce very thin coatings which conform to any existing surface topography and adhesion through mechanical interlocking. The commercial PTFE-based coatings were found to provide poor release properties due to the presence of surface microcracks which allowed epoxide penetration when cured under elevated pressure and temperature. Electroless Ni/PTFE composite coatings comprise a hard nickel–phosphorus matrix containing a very fine dispersion of PTFE particles. The matrix proved sufficiently robust for industrial applications and the low friction and surface energy provided by the embedded PTFE combined with macroscopic-scale surface roughness provided efficient mould release.     

低表面能防污涂料的防污特性理论分析

从海洋污损物的粘附机理出发 ,理论上分析了低表面能防污涂料 (主要氟碳树脂防污涂料及有机硅弹性防污涂料 )防污性能的影响因素 ,并综述了低表面能防污涂料的设计思路。     

防污涂料中DDT的快速测定方法

采用裂解气相色谱/质谱联用方法对防污涂料中的DDT进行定性测定,此方法具有样品无需前处理、用量少、对应性强、灵敏度高等特点。     

Transparent antifouling coatings via nanoencapsulation of a biocide

Transparent coatings releasing an antifouling agent (AF) can be used to reduce the marine fouling of optical lenses. A variety of water‐borne coatings based on poly(methyl methacrylate‐co‐butyl acrylate) (PMMA‐co‐PBA) were synthesized using a two‐stage miniemulsion process. During this process, the AF, SeaNine 211, was nanoencapsulated in domains small enough not to scatter light. The release rate of SeaNine 211 was studied for the polymers of different T_g, and found to be sufficient to impart AF properties. However, over time, the coatings were found to develop a whitish aspect (blushing) due to water retrodiffusion. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007