新型环保海洋防污材料研究进展

简要论述了海洋防污材料的发展历史及其防污机理,评述了新型环保高性能海洋防污材料的最新研究进展。自有机锡自抛光防污涂料被禁用后,基于聚丙烯酸锌、聚丙烯酸铜和聚丙烯酸硅烷酯的无锡自抛光防污涂料得到了广泛应用。为进一步提升其防污性能和环保性能,接枝防污官能团防污材料、生物降解高分子基防污材料、主链降解型自抛光防污材料、减阻型防污材料以及仿生防污材料成为当今的研究热点。介绍了席夫碱、草甘膦、苯并异噻唑啉酮等几种防污官能团的接枝方法及其防污效果,指出这类方法可提高防污剂的利用率,使防污剂释放更平稳,但实用化还需解决防污剂接枝改性后防污能力下降以及合成工艺复杂等问题。重点介绍了生物降解高分子基防污材料,特别是主链降解-侧链水解型防污材料的结构和合成方法。由于该类可降解/水解树脂具有良好的力学性能和水解可调控性,所制备的防污涂料即使在静态下,防污剂也释放平稳,因此可用于开发新型主链降解型自抛光防污涂料,以提高涂层的静态防污长效性,具有良好的应用前景。还介绍了通过对高分子树脂改性等方法降低涂层水解后的表面粗糙度,该类防污涂层具有良好的减阻性能。最后介绍了仿生防污材料的研究进展。     

天然产物基无铜自抛光防污涂料的制备与性能

随着人们环保意识的增强和环保法规的日益严格,不含重金属防污剂的环境友好防污涂料成为目前研究的热点。文中通过室内的接触角、水解失重和吸水率跟踪测试,研究了3种主链降解型聚丙烯酸锌树脂的表面润湿性能和自抛光性能;并将其与天然产物防污剂(Butenolide)复配制备了天然产物基无铜自抛光防污涂料,通过防污剂释放率测试和浅海浸泡试验对防污剂的释放行为和实海防污能力进行了研究。结果表明：主链降解型聚丙烯酸锌树脂H100Z具有优异的自抛光性能(质量损失可达8.4 mg·cm⁻²)和较低的溶胀程度(吸水率仅为12.3%),可作为Butenolide的载体,实现对其可控、稳定和持续的释放,该防污涂料在南海海域(深圳)和东海海域(厦门)浸泡3个月后均展现出优异的防污效果。     

海洋防污涂层的抗污机制及制备策略研究进展

首先简要陈述了海洋生物/微生物在金属基底表面的生物粘附和代谢物-腐蚀过程,包括条件膜吸附、生物膜形成、藻类和幼虫附着、大型生物寄居4个阶段。其次介绍了海洋防污涂层的2种抗污机制,分别是利用物理法抑制生物污损在材料表面附着和利用化学法释放防污剂或是产生活性氧杀灭微生物,并对比和分析了2种抗污机制的差异及其局限性。进一步将海洋防污涂层的构筑策略分为协同抗污和仿生抗污这两大类,其中协同抗污策略包括利用复配防污剂来提升抗菌广谱性,降低耐药性,或是引入电、热、磁等外场干预来协同强化涂层抗污效果。仿生抗污策略则是师法自然,在材料表面构筑微纳米结构,赋予涂层超浸润、超润滑、动态自抛光等仿生学特性,从而实现涂层的高效抗污。此外,还可以在涂层中引入天然防污剂或合成其衍生物,以降低防污剂对生态环境的毒害作用。最后展望了涂层防污机制的研究方向,并提出了新一代防污涂层的设计思路。     

基于表面微结构复制与润湿性调控的水下仿生防污技术研究进展

海洋生物污损会对人类海洋活动和海洋工业产生诸多不利影响，传统使用有机锡或金属离子杀生剂的防污策略会导致环境污染与生态系统的破坏，大自然生物有机体所展示的天然抗粘附机制为绿色防污材料研发带来新的灵感。受生物表皮物理结构及仿生防污机制启发，本文从生物表皮微结构研究入手，综述了仿生微结构复刻与表面润湿性调控两种水下仿生防生物污损策略的研究进展，并展望其前景。     

绿色海洋防污材料的表面构筑研究进展

海洋生物污损已成为影响船只与装备在海洋环境中服役性能的全球性问题。因此,发展高效、广谱、环境友好的防污材料势在必行。借鉴海洋生物表皮具有的天然防污特性,人们通过对材料的表界面组分、形貌设计,获得了一系列环境友好型防污材料。文中系统归纳和评述了低表面能材料、表面亲水性材料、表面织构化材料和表面植绒材料等依靠表面物化性能调控来获得具有优异防污表现的绿色防污材料的研究进展,最后指出当前绿色防污材料存在的问题及未来的发展方向。     

金属表面新型绿色海洋防污功能膜层的研究进展

海洋中金属设备的生物污损会引起许多问题,如设备的额外能量消耗、高额的维护成本以及严重的金属腐蚀破坏,给海洋工程带来很大损失。在金属表面构建防污膜层是解决其海洋生物污损问题的重要途径。概括了海洋防污膜层的发展历程与金属表面环境友好型防污膜层的研究进展,并重点介绍了新型海洋防污功能膜层及其研究方向。目前,金属表面新型海洋防污膜层的开发主要集中于结构防污和功能防污2个方面。在结构防污方面,在金属表面构建仿生微纳结构,并以低表面能物质修饰,形成超疏水表面,能够显著提高其抗海洋生物附着的能力,达到绿色防污的目的;在功能防污方面,在金属表面制备具有可控释放防污抗菌剂能力的功能膜层,可以实现在环境保护前提下的高效抗菌防污,是未来研究的发展方向。层状双金属氢氧化物(LDHs)和金属–有机骨架(MOFs)材料具有合成物选择多样、微观结构独特的特点,自身具备抗菌能力或负载大量防污抗菌剂的能力,并可实现防污抗菌剂的可控释放,有望成为具有理想抗菌功能的新型海洋防污剂负载材料。     

低表面能改性聚丙烯酸酯的合成及防污性能研究

目的制备环境友好型的海洋防污涂料,即低表面能海洋防污涂料。方法以含氟单体甲基丙烯酸十二氟庚酯(FMA)和含硅单体γ-(甲基丙烯酰氧)丙基三甲氧基硅烷(KH570)为改性单体,以甲基丙烯酸缩水甘油酯(GMA)和丙烯酸丁酯(BA)为主要单体,通过自由基共聚合制得氟硅改性的聚丙烯酸酯树脂层,采用傅里叶红外光谱和差示扫描量热法,分别对改性聚丙烯酸酯树脂的化学结构和热性能进行了分析表征。通过对改性聚丙烯酸酯树脂涂层的扫描电子电镜(SEM)分析、接触角测试、表面能计算、附着力测试、耐酸碱测试,防污性能测试等,探讨了FMA和KH570含量对树脂涂层性能的影响。结果当FMA、KH570的含量分别为15%、10%时,树脂涂层的接触角达到112.0°,表面能低至18.425 m J/m~2,附着力达到1级,具有良好的防污性能。结论氟单体和硅单体单独参与共聚改性均具有降低聚丙烯酸酯树脂表面能的作用,而氟单体和硅单体共同改性聚丙烯酸酯对树脂涂层表面能的降低更显著,可作为一种很有潜力的海洋低表面能防污涂料。     

铋系可见光催化海洋防污材料研究进展

生物污损是海洋工程材料在服役过程中面临的重要问题之一,因此开发高效、环保的新型防污材料具有重要意义。铋系半导体材料是近年来广受关注的一类新型光催化剂,因其具有独特的结构和合适的禁带宽度,而表现出了良好的可见光催化性能,在海洋防污领域有巨大的应用前景。本文从铋系可见光催化防污材料和作用机理的角度,阐述了近年来在铋系半导体材料体系方面的研究进展。作为一种新型的防污材料,基于铋系半导体材料的可见光催化防污技术有望在海洋防污领域中提供一种新的策略。     

环保无铜自抛光防污涂料的制备与性能研究

目的得到一种可以媲美传统含铜防污涂料防污效果的涂料配方,且具有对海洋环境友好的特点。方法首先筛选符合无铜涂料技术需求的环保型防污剂,并进行涂料配方研究,得到最优环保无铜防污涂料配方。结果设计开发的2组不同防污剂复配无铜自抛光防污涂料,其实际防污效果可以达到中期效防污涂料的评价标准,在实际防污效果上可以媲美3年期效以Cu2O为主防污剂的传统含铜自抛光防污涂料。2组防污剂复配配方为Econea/Dcoit及Econea/Zn PT,采用上述2种防污剂进行质量比1:1的防污剂复配,具有1+12的实际防污效果,并且在具有较好实际防污效果的同时,具备可以在海水中实现快速降解的优异环境友好性。在无铜涂料配方体系下,中期效防污涂料(3年)中丙烯酸锌树脂的最佳配方含量为40%~50%(湿重)。结论环保无铜防污涂料的各项性能良好,具有广谱、高效的防污效果。     

基于自清洁型海洋智能防污涂层的最新研究进展

从自修复防污涂层、可逆切换粘附表面、自更新动态表面3个方面介绍了自清洁型海洋智能防污涂层技术的研究进展,及其在延长涂层服役寿命和主动防污方面起到的关键作用。自修复涂层通过微胶囊或可逆动态键修复破损的超疏水表面,延长其防污寿命。通过可逆切换粘附表面响应p H、应力或温度变化,进行亲/疏水表面的可逆切换,从而使污染物脱附。自更新动态表面可以根据周围微环境变化产生响应,发生聚合物降解、脱落、杀菌剂控制释放等行为,不仅可以减少污损生物的附着,而且可以使附着污损脱附。综述了自清洁型海洋智能防污涂层的研究成果,介绍了智能涂层在提高海洋防污方面的特点。基于现有研究的不足,对智能涂层的响应机制和应用方面的研究进行了展望。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.