微生物抑制腐蚀机理及生物矿化机理研究进展

微生物既可以加速材料腐蚀,也可以在一定程度上减缓材料腐蚀,这与微生物膜有着密不可分的关系,微生物的抑制腐蚀作用正是微生物膜与腐蚀产物交互作用的结果。一般来说,这种抑制作用不仅仅是通过一类微生物或一种机制实现的。首先分类归纳了微生物膜抑制腐蚀的三种主要机理——微生物的呼吸作用消耗氧气,通过细菌分泌物抑制腐蚀,在材料表面形成保护层,并结合实例进行了分析论述。重点论述了生物矿化抑制腐蚀的机理,包括生物矿化的基础、生物矿化的过程、微生物在生物矿化中所起的作用,特别是EPS对于生物矿化的作用,着重分析了影响矿化产物膜结构与形态的关键影响因素,包括微生物种类、生物膜结构、海水环境等。另外,总结了近年来国内外利用生物矿化提高材料耐腐蚀性能的一些研究,对未来发展趋势做出了展望,并提出了三个亟待解决的问题。     

建筑行业微生物腐蚀与防护研究进展

综述了导致混凝土材料和金属材料微生物腐蚀的研究现状,分别阐述了其微生物腐蚀的机理,包括混凝土生物硫酸腐蚀机制、金属微生物腐蚀的经典腐蚀机制和细胞外电子转移机制。概述了现有的建筑行业混凝土和金属材料微生物腐蚀及混凝土改性、制备保护涂层材料、添加杀菌剂等防护方法的研究进展,为后续建筑材料微生物腐蚀机制和防护技术的深入研究提供参考。     

海洋微生物腐蚀研究进展

海洋环境下,材料在海水中腐蚀过程的主要特征之一是海水的生物活性所引起的微生物腐蚀。海洋工程材料的微生物腐蚀及其随后的生物污损是一个极其严重的经济与环境问题,是影响海洋工程设施安全和性能的关键因素。海洋微生物腐蚀机理、生物污损机理及其相关控制技术是国际海洋腐蚀领域、生物污损领域尚未完全充分认识和解决的重大科学和技术问题。本文对海洋微生物腐蚀研究进展进行了综述。     

高分子涂层在泵维修技术中的应用

本文介绍了苏尔寿泵业上海技术服务中心利用高分子涂层工艺对受磨损、腐蚀的泵做修复和保护;并分析了高分子材料的类型和功能、工艺措施、和应用领域.     

油气管线钢土壤环境硫酸盐还原菌腐蚀研究进展

结合国内外埋地管线钢微生物腐蚀的研究,综述了腐蚀性土壤微生物种类和特点、环境因素对硫酸盐还原菌腐蚀的影响、生物腐蚀研究方法和进展,以及微生物腐蚀防护与监检测技术.最后,对埋地管线钢微生物腐蚀研究进行了展望.埋地管线钢服役环境复杂,受到土壤类型、杂散电流、阴极保护、应力、剥离涂层和微生物等多种因素的影响,而各种因素之间又存在着相互的耦合作用.多因素耦合作用下埋地管线钢微生物腐蚀将成为土壤微生物腐蚀今后的主要研究方向.土壤微生物腐蚀研究涉及土壤学、材料学、腐蚀科学和微生物学等多学科,是一个多学科交叉的研究课题,而化学和电化学分析技术、微生物分析技术以及材料表征技术等的联用也将为土壤微生物腐蚀行为和机制的研究提供更多的研究方法,这也有助于更好地理解微生物/材料之间的相互作用机制.随着对微生物腐蚀研究的深入,人们对硫酸盐还原菌腐蚀机理的认识也更加全面,"生物阴极催化还原"理论从生物能量学和生物电化学角度解释了微生物腐蚀的过程和机理.抗菌涂层开发和耐微生物腐蚀管线钢研发为MIC防治提供了一个新的研究路径.     

低温等离子体表面改性高分子材料研究进展

综述了低温等离子体技术的最新进展,指出目前最具开发潜力的低温等离子体有大气压下辉光放电等离子体和介质阻挡放电等离子体。经低温等离子体处理的高分子材料表面发生多种物理和化学变化,例如产生刻蚀、形成致密的交联层以及引入极性基团,使材料的亲水性、粘结性、生物相容性等得到改善,故低温等离子体处理技术广泛用于高分子材料的表面改性,重点介绍了低温等离子体在医用高分子材料、合成纤维材料、薄膜材料中的研究概况和进展。     

微生物腐蚀中生物膜的生成、作用与演变

自然界中,微生物常常附着在材料表面形成生物膜,影响金属表面的电化学过程,从而诱发微生物腐蚀。生物膜与微生物腐蚀的发生密切相关,其结构组成、成膜过程对金属的腐蚀反应类型与速率有着很大的影响。由于微生物活动的复杂性以及缺乏生物膜与金属界面之间交互作用的深刻认识,微生物腐蚀的发生和发展机制尚不清晰。基于此,从生物膜的角度阐述了金属微生物腐蚀的作用机制。介绍了易引起材料腐蚀的常见菌种,如硫酸盐还原菌、硫氧化菌、铁氧化菌、硝酸盐还原菌及其他腐蚀菌,并对它们的腐蚀机理进行了概述。综合论述了生物膜的特征、生成步骤,以及它是如何随时间和外部环境进行动态演变的。着重讨论了影响生物膜生成和发展的因素,包括材料因素以及环境因素,如温度、溶解氧、pH值、Cl~-、Fe~(2+)、水体流速、营养介质、磁场。最后,针对外界影响因素的复杂性,阐述了生物膜研究过程中存在的问题,同时对模拟生物环境过程中合理设计实验方案的重要性进行了展望。     

医用金属材料漫谈

医用材料,又称生物材料,是指能够植入生物体或与生物组织相结合的材料,可用于诊断、治疗生物体内的病症,甚至替换生物机体中的组织、器官以增进其功能。目前用于临床的生物医用材料主要有金属材料、有机材料（主要指有机高分子材料）、无机非金属材料（主要指生物陶瓷、生物玻璃和碳素材料）以及其他复合材料等。与其他材料相比,     

海洋用金属材料的微生物腐蚀研究进展

虽然海洋环境下所使用的金属材料的机械性能和耐蚀性能都较好,但近年来关于海洋工程材料腐蚀失效的报道却越来越多。以海洋环境下金属材料的腐蚀为背景,重点介绍了近年来逐渐引起人们重视的金属材料微生物腐蚀的研究进展。一些经典的腐蚀理论虽然能够解释一些微生物腐蚀现象,但是目前微生物腐蚀逐渐成为很多工业环境下普遍存在的严重问题,这些机理的片面性也就逐渐暴露出来。随着研究的深入,人们对微生物腐蚀机理的认识更加全面、深入。研究者逐步提出了基于生物能量学和生物电化学的微生物腐蚀理论,该理论引入了微生物胞外电子传递过程,解释了微生物为什么和如何腐蚀金属材料,并获得了学术界的普遍认可。为了解决传统抗微生物腐蚀方法的诸多不足,开发新型抗菌材料、研发环保型杀菌剂和杀菌剂增效剂将会为微生物腐蚀防治提供新思路。     

激光表面改性有机高分子材料的研究进展

有机高分子材料具有质轻、易成型、成本低等优点,在汽车、电子等领域有广泛的应用,但有机高分子材料的原始表面多数呈现化学惰性、表面能低,导致其应用受限。激光表面改性技术具有柔性化程度高、区域选择性好、可三维加工等诸多优势。简要综述了激光表面改性有机高分子材料的性能变化、机理和应用的国内外研究进展,表明通过激光改性可以在有机高分子材料表面形成诸如凸起、凹坑、沟槽、多孔和周期性结构等微观形貌,并使表面化学成分发生显著变化,进而影响其表面润湿性、表面能、吸附性、颜色和/或减阻等性能,这主要与有机高分子材料的自身特性、激光改性参数以及改性环境等因素密切相关,而且通过控制激光改性参数,还有可能实现对上述表面性能变化的精密调控。激光表面改性有机高分子材料在理论研究和实际应用中都具有巨大的价值,但目前对于激光表面改性有机高分子材料的理论研究落后于应用研究,还应进一步加强对改性技术和机理的探索与研究。     

Towards all-polymer field-effect transistors with solution processable materials

We have fabricated polymer field-effect transistors (FET) from solution processable polymers. Starting with an inorganic structure using only an organic semiconductor (regio-regular poly(3-hexylthiophene)), the transistor performance was studied as the inorganic materials were replaced with polymeric alternatives one at a time. We see a gradual increase in subthreshold swing and off-currents and an increased threshold voltage when substituting the inorganic materials with polymer materials. The small reduction in transistor performance when going from inorganic substrate and insulator to polymeric materials indicates that it is possible to make flexible polymer devices from solution processed materials suitable for roll-to-roll processing. The all-polymer FET was realized using two different conducting polymers, polyaniline for the source and drain electrodes and poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), PEDOT:PSS, for the gate electrode.     

高分子连接技术的研究应用

简述高分子材料通用连接技术,着重讨论焊接技术,并阐述焊接技术为人们接受的蛇行模型.介绍焊接技术在微米及纳米技术中的一些应用.     

Effect of cross-linking of polymer precursors on electrochemical properties of resultant carbons

Urea–formaldehyde resin and polymethacrylate, as two typical polymers for heterochain and carbon chain polymers, respectively, were synthesized and pyrolyzed to prepare carbonaceous materials for the anode of lithium ion batteries. The effect of cross-linking structure of both polymeric precursors on the physical and electrochemical properties of as-prepared carbons was investigated by thermal analysis, X-ray diffraction and cyclic charge/discharge method and compared with each other. It was found that, even though two typical types of polymers were used, the two types of resultant carbons showed the same trend with the change of cross-linking density of polymers in the size of graphene layers and in the lithium accommodation capacity. The same positive influence of the cross-link structure of both representative polymers on the ability of lithium insertion in resultant carbons was confirmed.     

New developments on the use of polymeric materials in sheet metal forming

Advanced polymers offer at the present time concrete possibilities in reducing the product development time and production of prototypes and small series of sheet metal parts. However, the applicability of such materials requires different approaches in comparison to conventional materials for sheet metal forming dies. This paper presents investigation results dealing with tribological and tool design aspects for the use of polymeric materials in sheet metal forming. Friction and wear of sheets with different surface topologies have been investigated. A new test method for measuring polymer/sheet wear is presented. A coupled simulation model for the production of a test geometry aimed specifically at the investigation of die deformations and loads is presented. The behaviour of two polymeric materials by forming the test geometry has been simulated and the maximal loads and deformations during the process have been quantified. Simulation results have been subsequently validated in experimental testing.     

Glass transition temperature measured at high frequencies by piezoelectric excitation

As the temperature of a polymer melt or rubber is lowered, a point known as the glass transition temperature, T_g, is reached where polymeric materials undergo a marked change in properties associated with the virtual cessation of local molecular motion. In fact, as the thermal energy reduces, the distance between macromolecules, and consequently the specific volume of the sample, diminishes. However, this change is not abrupt, that is, the glass transition is not a rigorous phase transition from the thermodynamical point of view. Effectively, it depends not only on the polymeric structure but also on the heating rate, the measuring method, etc. Since there is a copious literature referring to traditional methods employed to measure T_g, this work will only present them as a frame to compare them with the experimental procedure we used. The determination of T_g is based on the change of the real component of the dynamic modulus with temperature. This modulus is measured at high frequencies on exciting the sample with a piezoelectric crystal attached to it. Glass transition temperatures of several glassy polymers are determined. These results are compared with values measured through other methods. Finally, the advantages of our procedure are discussed.     

Synthesis and electrochemical properties of a new class of boron-containing n-type conjugated polymers

Several electron-deficient polymers containing the 9,10-diboroanthracene unit have been synthesized and characterized. Electrochemical study shows that they have high electron affinities. Photoluminescence of rr-P3HT is quenched in the presence of one of the polymers in the solid state, demonstrating the potential utility of this class of polymer as powerful n-type materials in organic photovoltaic devices.     

温敏智能纺织材料的研究进展

温敏纺织材料是指对环境温度刺激具有响应性的一种智能材料,通过物理或化学方法将其与纺织品结合,赋予传统织物新颖的功能和高经济附加值。近年来,温敏纺织品的发展迅速,在调温调湿、抗浸储水、香精缓释、生物医用等领域具有良好的应用前景,其工业化发展的方向是稳定性好、灵敏度高、可穿着性能良好、成本低。介绍了温敏高分子的基本原理,包括常见温敏高分子种类、相转变过程和最低』临界溶解温度（LCST）的调节方法。另外,详细介绍了温敏纺织品的最新发展方向,温敏高分子与纺织品结合的接枝与交联新技术以及温敏高分子在不同纤维和织物上的功能性应用方法。最后提出了温敏纺织品发展中存在的问题和解决思路。     

Metallization of Various Polymers by Cold Spray

Previous results have shown that metallic coatings can be successfully cold sprayed onto polymeric substrates. This paper studies the cold sprayability of various metal powders on different polymeric substrates. Five different substrates were used, including carbon fiber reinforced polymer (CFRP), acrylonitrile butadiene styrene (ABS), polyether ether ketone (PEEK), polyethylenimine (PEI); mild steel was also used as a benchmark substrate. The CFRP used in this work has a thermosetting matrix, and the ABS, PEEK and PEI are all thermoplastic polymers, with different glass transition temperatures as well as a number of distinct mechanical properties. Three metal powders, tin, copper and iron, were cold sprayed with both a low-pressure system and a high-pressure system at various conditions. In general, cold spray on the thermoplastic polymers rendered more positive results than the thermosetting polymers, due to the local thermal softening mechanism in the thermoplastics. Thick copper coatings were successfully deposited on PEEK and PEI. Based on the results, a method is proposed to determine the feasibility and deposition window of cold spraying specific metal powder/polymeric substrate combinations.     

~(27)Al MAS-NMR study of inorganic polymer formation at ambient temperature

Inorganic polymers are a novel class of materials formed by the polymerization of silicon, aluminium and oxygen species to form an amorphous three-dimensional framework structure. The basis of this process is the alkaline solutions to induce a certain amount of Si and Al atoms to dissolve from a feedstock such as aluminosilicate. A study of 27Al MAS-NMR was carried out in an attempt to understand the reaction mechanism of the inorganic polymerization at ambient temperature. Scanning electron microscopy (SEM) and X-ray diffractometry (XRD) were also employed to establish the composition and microstructure of the inorganic polymerization. Specimens were prepared with different Al/Si mole ratios from the starting materials. The higher the Al content, the more sufficient the Al atoms that can combine with SiO4, and the longer the reaction time, the more the bonded Si—O—Al—O polymer structure, and then the higher the Al content, the fewer the octahedral Al with a uniform Si—O—Al—O structure in four directions, because four Al atoms are combined with SiO4, resulting in a uniform Si—O—Al—O structure in four directions. The results show that they have an amorphous microstructure.     

材料表面可控修饰新技术

聚合物"刷"是端接枝超薄聚合物层的形象描述,在材料表面形成聚合物"刷"是控制材料表面性质的一种有效手段.因其在材料表面结构分子设计中具有突出的优越性,近年引起了材料表面改性专家的广泛关注.介绍了表面引发可控/"活性"聚合制备可控聚合物"刷"技术,并展示了其在材料表面可控修饰中的应用.