海洋防污涂料领域值得注意的新动向

一、防污涂料发展的一般情况船舶、海洋钻井平台、海水冷却管道均需涂防污涂料,用以防止海水中附着生物藤壶等的附着而造成的污损。现在实用的防污涂料都含有毒化合物,防污涂料主要靠防污毒剂(简称防污剂)起防污作用。当防污剂从漆膜中渗出时,在漆膜表面形成有毒环境,阻止海生物附着生长,从而达到防除海生物的目的。现在常用的防     

环境因素对细菌附着的影响

生物污损是船舶及海洋工程面临的主要问题,其中由细菌附着形成的生物膜难以避免,且具有介导无脊椎污损生物幼虫附着的特性,尤为棘手。因此,控制海洋细菌生物膜的形成成为防污研究的重要课题。本文利用海洋细菌Bacillus subtilis和Escherichia coli设计试验,考察环境因素和基底材料对细菌生物膜形成的影响,揭示细菌生物膜的形成规律。研究结果表明:温度、盐度等环境因素对Bacillus subtilis和Escherichia coli附着形成生物膜的影响极显著(方差检验结果即P<0.01),通过控制环境因素可以干扰生物膜的形成。     

微生物粘膜对海洋大型污损生物附着的影响

研究了防污漆表面细菌粘膜的组成,并利用筛选得到的菌株制成人工细菌粘膜,考察了这些人工细菌粘膜对海洋大型污损生物附着的影响。试验结果表明,菌株制成的粘膜一些对大型海洋生物的附着有抑制作用,另一些则有促进作用,还有一些作用不十分明显。     

消息报道

我国仿生防污涂料取得重大进展我国仿生防污涂料研究取得重大进展。船舶在海洋中航行,底部非常容易附着各种各样的污损海生物,会带来极大的危害。为了防止海生物的附着污损,一般采用的方法是在船舶底部涂装海洋防污     

表面微结构在防污涂料中的研究进展

生物污损范围广、危害大。简要介绍了污损生物的附着机理和过程,详细阐述了自然界生物表面微结构防污现象,重点论述了表面微结构的防污机理,在此基础上综述了制备表面微结构防污涂料的研究进展,探讨了表面微结构防污涂料在实际应用中存在的问题,展望了表面微结构防污涂料的应用前景。     

含辣椒素防污涂料在海洋网箱网衣中应用研究

以辣椒素为海洋附着生物防污剂 ,开发出的防污期长、无毒环保且高效防污涂料用于海水养殖网衣材料中 ,经过浅海挂网试验 ,结果证明涂有辣椒素防污涂料的网衣材料具有极佳的防污效果。本文进一步讨论防污涂料的防污效果及影响防污效果的诸多因素     

丙烯酸锌自抛光防污涂料的配套性及防污性能研究

以自制的丙烯酸锌树脂为基料制备自抛光型防污涂料,研究了该自抛光防污漆与配套连接漆的附着特性,同时对该防污涂料的自抛光性能及防污性能进行了研究。结果表明,该防污涂料与配套连接漆的层间附着力大于2 MPa,且以防污漆内聚断裂为主,表明涂层具有较好的配套附着性;防污涂料的自抛光速率稳定,基本保持在65μm/a;经过3年浅海挂板试验后,漆膜表面无任何海洋污损生物附着,防污性能良好。     

防污涂料的现状与未来

防污涂料与船舶的航行经济效果密切相关。国内外船舶涂料界正从各种技术角度研究着新防污涂料。下边就防污涂料的现状与未来作一介绍。 1.海洋生物的污损及其防止方法生物污损可分为藤壶等的动物性污损和藻类等的植物性污损。整个附着污损过程是很复杂的。而防污方法的着眼点,就是选择一个切断其生长的环节。今后,一方面要不断完善过去使用的毒物溶出的方法,另一方面,要研究“不使生物附着的方法”。防污方法的基本原理如下:     

海洋产蛋白酶细菌发酵液防污活性研究

传统的防污剂对海洋环境造成严重污染,随着环保意识的增强以及相关规定的制订,各国竞相开展新型无毒防污剂的研究。本文以海洋产蛋白酶菌株发酵产物为活性物质,研究蛋白酶粗提物对污损生物硅藻(navicula sp.)和贻贝(mytilus edulis)附着行为的影响。结果表明,所研究菌株的发酵液对硅藻(navicula sp.)和贻贝(mytilus edulis)的附着有明显抑制作用。贻贝(mytilus edulis)毒性实验显示,细菌发酵液对贻贝无毒。因此,海洋微生物蛋白酶产生菌粗酶提取物可以作为环保型防污功能添加剂。     

无公害渔网防污涂料两例

前言由捕捞所获得的海产品已远不能满足人类的需要,所以从捕捞渔业向养殖渔业发展是当今世界渔业发展的总趋势。网箱养殖所使用的网箱,在海水中要受到海中附着生物的污损。在生物生长旺季,十几天内附着生物就可将网眼堵死,其结果不但因水流受阻而缺氧,而且易使鱼病蔓延,甚至造成鱼类死亡。防除海中附着生物的最好办法是使用渔网防污涂料。最常用的有机锡防污涂料,因其有毒而对环境和鱼类造成污染,正在逐     

The progress on antifouling organic coating: From biocide to biomimetic surface

The advancement in material science and engineering technology has led to the development of antifouling(AF) coatings which are cheaper, durable, less toxic, and safe to the environment. The use of AF coatings containing tributyltin compounds was prohibited at the beginning of 2003, this necessitated the development of environmentally friendly coatings. The fouling release coating(FRC) lacks biocides and has low surface energy, low elastic modulus with smooth surface properties, hence a better release effect to fouling organisms. Several functional coatings have been recently developed based on fouling release(FR) technology to combat the effects of biofouling. Here, we provide a brief overview of innovative technologies and recent developments based on FRCs, including silicone, modified fluorinated polymer,cross-linked coatings, amphiphilic copolymer coating, hydrogel coatings, and biomimetic coatings. We also highlight the key issues and shortcomings of innovative technologies based on FRCs. This may give new insights into the future development of marine AF coatings.     

Functional Enzyme Mimics for Oxidative Halogenation Reactions that Combat Biofilm Formation

Transition‐metal oxide nanoparticles and molecular coordination compounds are highlighted as functional mimics of halogenating enzymes. These enzymes are involved in halometabolite biosynthesis. Their activity is based upon the formation of hypohalous acids from halides and hydrogen peroxide or oxygen, which form bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities in follow‐up reactions. Therefore, enzyme mimics and halogenating enzymes may be valuable tools to combat biofilm formation. Here, halogenating enzyme models are briefly described, enzyme mimics are classified according to their catalytic functions, and current knowledge about the settlement chemistry and adhesion of fouling organisms is summarized. Enzyme mimics with the highest potential are showcased. They may find application in antifouling coatings, indoor and outdoor paints, polymer membranes for water desalination, or in aquacultures, but also on surfaces for food packaging, door handles, hand rails, push buttons, keyboards, and other elements made of plastic where biofilms are present. The use of natural compounds, formed in situ with nontoxic and abundant metal oxide enzyme mimics, represents a novel and efficient “green” strategy to emulate and utilize a natural defense system for preventing bacterial colonization and biofilm growth.     

Antifouling coatings: recent developments in the design of surfaces that prevent fouling by proteins, bacteria, and marine organisms

The major strategies for designing surfaces that prevent fouling due to proteins, bacteria, and marine organisms are reviewed. Biofouling is of great concern in numerous applications ranging from biosensors to biomedical implants and devices, and from food packaging to industrial and marine equipment. The two major approaches to combat surface fouling are based on either preventing biofoulants from attaching or degrading them. One of the key strategies for imparting adhesion resistance involves the functionalization of surfaces with poly(ethylene glycol) (PEG) or oligo(ethylene glycol). Several alternatives to PEG-based coatings have also been designed over the past decade. While protein-resistant coatings may also resist bacterial attachment and subsequent biofilm formation, in order to overcome the fouling-mediated risk of bacterial infection it is highly desirable to design coatings that are bactericidal. Traditional techniques involve the design of coatings that release biocidal agents, including antibiotics, quaternary ammonium salts (QAS), and silver, into the surrounding aqueous environment. However, the emergence of antibiotic- and silver-resistant pathogenic strains has necessitated the development of alternative strategies. Therefore, other techniques based on the use of polycations, enzymes, nanomaterials, and photoactive agents are being investigated. With regard to marine antifouling coatings, restrictions on the use of biocide-releasing coatings have made the generation of nontoxic antifouling surfaces more important. While considerable progress has been made in the design of antifouling coatings, ongoing research in this area should result in the development of even better antifouling materials in the future.     

Water-Triggered Segment Orientation of Long-Lasting Anti-Biofouling Polyurethane Coatings on Biomedical Catheters via Solvent Exchange Strategy

The formation of biofilm and thrombus on medical catheters poses a significant life-threatening concern. Hydrophilic anti-biofouling coatings upon catheter surfaces with complex shapes and narrow lumens are demonstrated to have the potential in reducing complications. However, their effectiveness is constrained by poor mechanical stability and weak substrate adhesion. Herein, a novel zwitterionic polyurethane (SUPU) with strong mechanical stability and long-term anti-biofouling is developed by controlling the ratio of sulfobetaine-diol and ureido-pyrimidinone. Once immersed in water, as-synthesized zwitterionic coating (SUPU3 SE) would undergo a water-driven segment reorientation to obtain much higher durability than its direct drying one, even under various extreme treatments, including acidic solution, abrasion, ultrasonication, flushing, and shearing, in PBS at 37 °C for 14 days. Moreover, SUPU3 SE coating could achieve a 97.1% of exceptional reducing protein fouling, complete prevention of cell adhesion, and long-lasting anti-biofilm performance even after 30 days. Finally, the good anti-thrombogenic formations of SUPU3 SE coating with bacterial treatment are validated in blood circulation through an ex vivo rabbit arteriovenous shunt model. This work provides a facile approach to fabricating stable hydrophilic coating through a simple solvent exchange to reduce thrombosis and infection of biomedical catheters.     

Influence of nanocomposite surface coating on biofilm formation in situ

Caries and periodontitis, the most wide-spread oral diseases around the world, are caused by bacterial adherence and biofilm formation onto the natural as well as restored tooth surface. One possible way to prevent the pathogenic consequences of intraoral biofilm formation might be the modification of the tooth surface by application of an anti-adhesive coating that interferes with the bacterial attachment and subsequent bacterial accumulation. The objective of this study was to investigate the effect of an experimental, low surface free energy nano-composite coating material on biofilm formation in situ. For this purpose, an organic/inorganic nano-composite coating (NANOMER, INM, Saarbrücken, Germany) with a surface free energy of 18-20 mJ/m2 was applied to enamel as well as titanium specimens. The nano-composite coated specimens and un-coated controls were attached to removable intraoral splints and carried by volunteers over 24 h in the oral cavity. After intraoral exposure, specimens were processed for transmission electron microscopic analysis. On non-coated enamel and titanium control samples a multi-layer of adherent bacteria was found. In contrast, on nano-composite coated specimens strongly reduced biofilm formation was observed. In most areas of the surface-coated specimens only a 10-20 nm thick electron dense layer of adsorbed salivary proteins with adherent protein agglomerates of 20-80 nm diameter could be detected. In addition, detachment of the adsorbed biofilm from the nano-composite coated surfaces was evident in electron microscopic micrographs. The present investigation provides ultrastructural evidence that it is possible to cover enamel as well as titanium with a nano-composite coating revealing easy-to-clean surface properties that cause reduced biofilm formation and accelerated removal of adherent biofilms under oral conditions.     

Nanofunctionalized Superhydrophobic Antifouling Coatings for Environmental Sensor Applications—Advancing Deployment with Answers from Nature

In this work, a novel preparation for superhydrophobic nanofunctionalized silver and gold, copper‐coated substrates as potential antifouling coatings for environmental monitoring devices are fabricated. The superhydrophobic coating is topographically similar to the design of the Lotus leaf (Nelumbo necifera) and was synthesized by creating an electroless galvanic reaction between copper and the metal salt. In doing so, a nano‐ and micro‐topographical structure was created on the surface of a copper substrate which can be rendered superhydrophobic through the addition of a self‐assembled monolayer (SAM) of CF₃(CF₂)7CH₂CH₂SH. The work investigates whether the hydrophobicity of such materials affects micro‐organism attachment and subsequent biofouling. The materials are deployed in a marine environment in Dublin, Ireland for a 6 week study to determine the overall antifouling capacity. The materials are analyzed for biomass, slime (glycocalyx) production and more specifically protein and carbohydrate adsorption all of which are attributed to the inherent makeup of biofilm and exopolymeric substances (EPS) which are secreted by micro‐organisms during the biofouling process. This work highlights the dominance of combinational antifouling approaches rather than single tactics for such a complex problem and one that plagues multiple research areas. This novel approach in developing a new antifouling material for sensors, and indeed, any aquatic platform has shown excellent results throughout.     

生物膜对金属材料腐蚀性能影响的研究进展(上)

综述了生物膜对金属材料腐蚀的影响,内容包括:1)生物膜的形成;2)生物膜对材料腐蚀的影响;3)生物膜对阴极保护系统的影响;4)海洋极端微生物相关的腐蚀;5)微生物对航空、航天某些系统的影响;6)研究微生物腐蚀所采用的方法等。微生物相关的腐蚀在实际工程中对材料及设备的影响很大,因此,有必要深入开展研究并积极地采取防护措施。     

膜法提取甘露醇过程中膜的微生物污染及其控制

报告了海藻工业膜集成技术提取甘露醇工业化生产过程中膜的微生物污染及其控制的研究结果和长期运行的措施、经验．研究和运行结果表明，膜法提取甘露醇过程，极易发生微生物污染，且发展迅猛，危害严重．影响微生物污染的因素比较复杂，其主要因素是料液水温、含盐浓度、系统设计和运行状况；与常规膜法水处理过程不同，控制发生微生物污染，除了监控进料液SDI指标外，还要求控制进料液内菌群总数小于或等于2000cfv／mL；需重视清洗和杀菌消毒系统设计，确保清洗、杀菌剂能充满一切管阀、部件空间并清洗到每一个部分；选用尽量简短的工艺流程和抗污染膜组件；采用经济、有效、安全的杀菌剂并按规范程序进行消毒，只要严格按上述措施操作就可控制其微生物污染，保障系统稳妥运行．