基于缓蚀剂微/纳米容器的智能自修复涂层研究进展

涂层技术是常用的金属腐蚀防护手段。随着材料的服役环境日益严苛，采用传统的涂覆方法只能起到被动防护的作用，一旦涂层受损则会失效。近年来发展起来的智能自修复防腐涂层可根据环境变化自主修复涂层受损处，增强涂层的防护能力，延长金属基体(钢、镁、铝及其合金)的使用寿命。本文综述了国内外基于负载缓蚀剂的微/纳米容器的自修复涂层在金属腐蚀防护方面取得的最新成果，介绍了不同类型的微/纳米容器的特点及对缓蚀剂的负载与控制释放行为，包括介孔纳米颗粒(二氧化硅、二氧化钛等)、无机粘土(多水高岭石、类水滑石、沸石)等无机纳米容器，聚合物微胶囊、纳米纤维、壳聚糖、环糊精等有机纳米容器，碳纳米管、石墨烯等碳材料，以及多种微/纳米容器的复合应用，并对不同微/纳米容器的优点及缺点进行总结。最后，提出了基于缓蚀剂微/纳米容器自修复防腐涂层研究中存在的问题，并对其未来发展方向进行了展望。     

聚电解质层层组装在甲氨蝶呤负载与缓释方面的应用研究

基于层层组装技术,制备了能够长效释放抗癌药物甲氨蝶呤(MTX)的层层组装膜。分别通过聚天冬氨酸(PASP)和聚烯丙基胺盐酸盐-甲氨蝶呤(PAH-MTX)复合物基于静电作用的层层组装负载,以及先制备空白膜再后扩散负载这两种方法完成了MTX的膜内负载。层层组装负载中,聚电解质浓度增大则MTX负载量增多,当复合物pH=7.5时MTX的负载量较高且可持续释放36h。后扩散负载中,PASP-PAH/PAH空白膜与PASP/PAH及PASP/PAH-PASP空白膜相比,更有利于MTX的后扩散负载。后扩散负载与层层组装负载相比,药物负载量增多,但缓释时间降低。该研究为药物负载及缓释材料的制备提供了参考。     

埃洛石自组装涂层在软质聚氨酯泡沫上的制备及其阻燃抑烟性能

使用层层自组装技术在软质聚氨酯泡沫(PUF)表面制备含埃洛石的层层自组装涂层,使用扫描电子显微镜、能谱分析仪和锥形量热仪等手段对涂层进行表征,研究了涂层对PUF的热稳定性、燃烧性能及烟气释放性能的影响。结果表明：埃洛石基涂层由埃洛石、海藻酸钠和聚乙烯亚胺组成,能均匀地附着在PUF表面;涂层能延缓PUF在高温条件下的热解且使残炭量明显增多;三层埃洛石基涂层PU-3的热释放速率峰值、烟气释放速率峰值以及总烟气释放量比纯PUF(PU-0)分别降低了57.3%、58.9%和80.7%。这表明,埃洛石涂层能提高材料的热稳定和火灾安全性。     

PVDF/FEP/ZnO复合涂层的制备及防垢性能研究

为了解决金属表面的结垢问题,以聚偏氟乙烯（PVDF）和聚全氟乙丙烯（FEP）为原料,通过添加不同含量的纳米ZnO制备了PVDF/FEP/ZnO复合涂层,研究了纳米ZnO添加量对复合涂层疏水性能和防垢性能的影响。通过接触角测量仪、扫描电子显微镜（SEM）和X射线粉末衍射仪（XRD）对涂层进行了表征。结果表明：纳米ZnO的添加量为5.0%（质量分数）时,PVDF/FEP/ZnO复合涂层的表面自由能为8.6 mJ/m²,水接触角为114.8°;PVDF/FEP/ZnO复合涂层在过饱和碳酸钙溶液中结垢336 h后,其表面的碳酸钙结垢量仅为环氧涂层的72%,且文石和球霰石的摩尔分数之和达到了91.4%,表明复合涂层具有优良的防垢性能,在防垢领域具有较好的应用前景。     

自组装制备铁质文物保护用纳米缓蚀颗粒

长效缓蚀材料对于铁质文物的长期保护有着至关重要的作用.通过层层自组装的方法,在带负电荷的SiO2胶粒表面交替组装上了带正电荷的聚乙烯亚胺(PEI)层,带负电荷的聚苯乙烯磺酸钠(PSS)层,以及带正电荷的缓蚀活性成分苯并三氮唑(BTA)层.利用透射电子显微镜、zeta电位仪、X射线光电子能谱仪(XPS)等对纳米缓蚀颗粒进行了表征.结果表明,随着组装过程的进行,胶体粒子尺寸依次增大,颗粒表面zeta电位出现负正交替变化,表面元素化学环境也随之改变,氮原子的结合能随静电作用的增强向高位移动.缓蚀剂的负载量可通过多层组装方式提高,BTA单层负载量可达到35.4mg/g SiO2.     

装载8-羟基喹啉的纳米SiO_2/环氧涂层的耐腐蚀机理研究

使用纳米SiO_2作为载体、8-羟基喹啉作为客体制备纳米SiO_2/8-羟基喹啉组合物,将其添加到环氧树脂中制备出装载8-羟基喹啉的纳米SiO_2/环氧涂层。对其进行盐雾和电化学阻抗谱实验,研究了装载8-羟基喹啉的纳米SiO_2/环氧涂层的耐腐蚀机理。结果表明,纳米SiO_2/8-羟基喹啉组合物提高了环氧涂层的耐腐蚀性能,添加5%(质量分数)纳米SiO_2/8-羟基喹啉组合物的环氧涂层的耐腐蚀性能较优。8-羟基喹啉从纳米SiO_2孔道中释放并渗透到涂层与钢基材的界面形成含铁的铬合物膜,阻挡了腐蚀介质的渗入,使Q235钢基体的耐腐蚀性能提高。     

LBL技术改善薄膜性能的研究进展

在塑料薄膜上将高分子和各种功能的无机纳米粒子通过层层吸附自组装技术进行组装,制备厚度可控和稳定性好的有机/无机纳米涂层,可大幅度提高薄膜的性能。本文介绍了LBL技术制备纳米涂层对塑料薄膜阻隔性和抗菌性的影响,并对利用LBL技术改善薄膜性能的发展趋势做了展望。     

聚天冬氨酸/壳聚糖季铵盐层层组装膜负载缓释两种正电荷药物的研究

以聚天冬氨酸(PASP)与壳聚糖季铵盐(HTCC)为基元,运用层层组装技术制备了可以释放双药物的层层组装聚合物膜。通过先采用浸泡的形式负载盐酸柔红霉素(DNR)并喷涂阻隔层,再将盐酸万古霉素(VAN)以复合物PASP-VAN的形式与HTCC层层组装的方法,实现了DNR与VAN在膜中的共同负载。探讨了阻隔层的周期数对VAN与DNR释放效果的影响,结果表明,阻隔层可以延缓VAN与DNR的释放速率,VAN与DNR在生理盐水中的释放时间分别持续1680min和2700min,累积释放量分别为2.26mg和0.20mg。     

纳米ZnO-氧化石墨烯及ZnO-氧化石墨烯/水性聚氨酯复合涂层的抗菌性能

循环冷却水系统滋生细菌会导致生物黏泥产生及设备腐蚀,为解决这一问题,由硅烷偶联剂γ-氨丙基三乙氧基硅烷（KH550）改性纳米ZnO,改性纳米ZnO与氧化石墨烯（GO）在二甲基乙酰胺中复合,获得纳米ZnO-GO复合抗菌材料,并利用纳米ZnO-GO改性水性聚氨酯（PU）,得到纳米ZnO-GO/PU复合涂层。对纳米ZnO-GO复合抗菌材料进行表征分析及抗菌性能测试,对纳米ZnO-GO/PU复合涂层进行抗菌性能测试及物理性能分析。结果表明,纳米ZnO成功负载在GO表面,纳米ZnO-GO纯度较高,当GO质量分数为35wt%、纳米ZnO-GO使用量为160 mgL^-1时,其抗菌率可达97.16%;当纳米ZnO-GO质量分数为2.33wt%时,纳米ZnO-GO/PU复合涂层抗菌率可达90.29%,同时拥有4 H的铅笔硬度及93.26%的缓蚀性能。     

镀锌钢板表面苯并三氮唑改性硅烷涂层的耐蚀性能

为了提高热镀锌钢板的耐蚀性,研究了苯并三氮唑(BTA)改性双-[γ-(三乙氧基硅)丙基]四硫化物硅烷(BTESPT)溶液处理热镀锌钢板试样的耐蚀性能和组成,并与未经BTA改性的硅烷处理试样以及铬酸盐钝化试样进行比较.结果表明:BTA作为阴极型缓蚀剂改性硅烷涂层,改性涂层主要以Si-O-Si和Si-O-Zn为主,BTA主要以分子形式存在于硅烷涂层中,以[BTA-Zn2]配位化合物存在于涂层/镀锌基体界面处,从而明显提高了改性硅烷涂层的耐蚀性能;改性硅烷涂层主要含Zn,Si,O,S,C和N元素,N含量的变化趋势表明BTA改性硅烷涂层具有自愈合能力.     

One pot graphene-based nanocontainers as effective anticorrosion agents in epoxy-based coatings

A novel nanocontainer using graphene oxide nanoscrolls (GONS) as shell and benzotriazole (BTA) as core is proposed and embedded in epoxy coating for the corrosion protection of carbon steel. BTA/GONS nanocontainer is effectively fabricated by a modified shock-cooling approach. The hybrid material takes the specific shape of graphene oxide sheet spirally wrapped into scroll structure, acting as favorable physical barrier to afford encapsulation performance. A high uptake and storage of BTA in GONS is achieved, showing a loading capacity of 78.40%. The fantastically scrolled structure also provides an effective network to well control the BTA liberation during long-term immersion. The transport of BTA is diverse with pH values. The maximum release capacity of BTA occurs in neutral condition, larger than that in acid or alkaline environment. The liberation for up to 456 h exhibits the steady releasing characteristics of the containers. The corrosion inhibition performance of BTA/GNOS containers was mainly evaluated by electrochemical impedance spectroscopy. In comparison with, the reference epoxy coating, the one modified by BTA/GNOS nanocontainers demonstrate more excellent anticorrosion ability. The successful embedding and homogeneous distribution of BTA-loaded GNOS nanocontainers in epoxy film contributes to the improvement in the corrosion resistance of Q235 carbon steel and the self-healing performance of the coating.     

Encapsulation and release of corrosion inhibitors into titania nanocontainers

Titania nanocontainers were synthesized through a two-step process and then loaded with 8-hydroxyquinoline (8-HQ) and p-toluenesulfonic acid (p-TSA). The size of the containers was 242 +/- 10 nm as determined by Scanning Electron Microscopy (SEM). X-Ray Diffraction Analysis (XRD) showed that the titania nanocontainers consist of anatase and rutile crystalline phases. The presence of 8-HQ and p-TSA in the nanocontainers was confirmed with Fourier Transform Infrared Spectroscopy (FT-IR). The loading of the inhibitors in the nanocontainers was estimated with Thermo Gravimetric Analysis (TGA). The loading amount of 8-HQ is 3.56% w/w and that of p-TSA is 6.13%. Based on the size of the nanocontainers and the assumption that they are not broken, the amount of approximately with 2.83 x 10(6) molecules of 8-HQ and 3.86 x 10(6) molecules of p-TSA per nanocontainer was estimated. Furthermore, release studies of 8-HQ and p-TSA in a corrosive environment were studied by potentiodynamic measurements showing that the inhibitors are released from the nanocontainers, suppressing the corrosion activities. SEM and Dynamic Light Scattering (DLS) measurements confirmed that the nanocontainers are not agglomerated and keep their shape after suspension in 0.5 M NaCI solution for more than 72 hours.     

pH-responsive nanovalves based on hollow mesoporous silica spheres for controlled release of corrosion inhibitor

In the present study, a new encapsulation technique for corrosion inhibitor is proposed. The hollow mesoporous silica spheres (HMSs) were synthesized by the co-templates method as nanocontainers for corrosion inhibitor, benzotriazole (BTA) and the supramolecular nanovalves, consisting of cucurbit[6]uril (CB[6]) rings and the functional stalks attached to the surface of HMSs achieved on-demand release. The synthesis process of HMSs and the assembly process of the nanovalves were confirmed by SEM, TEM, N(2) adsorption/desorption, FTIR, TGA and solid-state (13)C CP/MAS NMR. The encapsulation capacity and release characteristics of BTA-loaded, assembled HMSs were investigated. The HMSs assembled with the nanovalves possessed a higher encapsulation capacity for BTA than MCM-41 assembled under the same procedure due to its huge hollow internal structure. The pH-controlled release properties of BTA from the assembled HMSs under different pH environments were monitored by ultraviolet absorption spectra. The release profiles showed that there was almost no leakage of BTA from the assembled HMSs in neutral solution, while in alkaline solution BTA released very quickly, and the release rate increased with increasing pH values. Such a property makes the HMSs assembled with the pH-responsive nanovalves have great potential applications in smart anticorrosion coatings.     

镁锂合金碱性条件下腐蚀的EIS分析

为了研究镁锂合金在碱性条件下的腐蚀行为,测试了镁锂合金在不同pH值0.4 mol/L NaCl溶液中的电化学阻抗谱、pH=9和pH=14条件下不同浓度的NaCl溶液中的电化学阻抗谱及在不同体系的碱性NaCl溶液中腐蚀100 h过程中的电化学阻抗谱,并对电化学阻抗谱进行了拟合、分析.结果表明:溶液的Cl-和pH值显著影响着腐蚀速率,当Cl-浓度相同时,溶液的pH值越大电化学反应电阻越小;当pH相同时Cl-浓度越高电化学反应电阻越小,并且随Cl-浓度的增加pH值对腐蚀速率的影响逐渐减弱;镁锂合金在低Cl-浓度高pH值的条件下腐蚀0~100 h的电化学阻抗谱中随腐蚀时间的增加,高频弧和低频弧均扩张,在低Cl-浓度低pH值及高Cl-浓度任意pH值条件下低频弧变化显著,先扩张后收缩,腐蚀100 h时镁锂合金在Cl-浓度较低的溶液中无论pH值如何,其腐蚀速率远远小于在Cl-浓度较高的溶液中的腐蚀速率.     

镁合金超疏水环氧复合涂层的制备与性能EI北大核心CSCD

传统的超疏水表面的制备过程比较复杂,机械稳定性差,这严重制约了超疏水表面的实际应用。采用“黏合剂+纳米粒子”的方法,在镁合金表面制备一种无氟、持久稳定的超疏水环氧复合涂层。接触角测试结果表明,复合涂层的接触角最高可达160.2°,且在3.5%(质量分数)NaCl溶液中浸泡30天后,接触角仍然高达103°;EIS结果表明,在5个加速老化循环周期后,复合涂层的|Z|_(0.01 Hz)仍高于10^(9)Ω·cm^(2),展现出优异的耐盐雾性能和耐蚀性能;摩擦磨损实验结果显示,在19.6 N的载荷下机械摩擦8 h后,复合涂层的|Z|_(0.01 Hz)高达1.84×10^(9)Ω·cm^(2)。通过“空气垫”的屏障作用,复合涂层能够为镁合金提供高效且持久的腐蚀防护,“黏合剂+纳米粒子”策略为超疏水涂层的制备提供了新的思路。     

Superior anti-corrosion and self-healing bi-functional polymer composite coatings with polydopamine modified mesoporous silica/graphene oxide

In this article,graphene oxide (GO) and benzotriazole-loaded mesoporous silica nanoparticles (BTA/MSNs)are combined on micro scale through the in situ polymerization of polydopamine (PDA),preparing a self-healing bi-functional GO (fGO) used as nano-fillers for anti-corrosion enhancement of waterborne epoxy(WEP) coatings.Scanning electronic microscopy (SEM) images show that the BTA/MSNs are uniformly distributed on the surface of high aspect ratio GO nanosheets to endow GO nanocontainer characteristics.UV-vis profiles demonstrate that fGO has pH-controlled release function.Modulus at lowest frequency is generally used for comparing the corrosion resistance of organic coatings.Modulus at lowest frequency(1.42 × 107 Ω cm2) after 30 days immersion in 3.5 wt.％ NaCl solution revealed 2 orders of magnitude higher that of blank WEP (1.17 × 105 Ω cm2).With artificial cracks on its coatings,fGO/WEP had no obvious rust compared with blank WEP after 240 h of immersion.We anticipate that self-healing and physical barrier bi-functional nanocontainers improve the traditional anticorrosion coating efficiency with better,longer-lasting performance for shipping,oil drilling or bridge maintenance.     

(H4N)2S对电合成CoO/聚苯胺复合膜腐蚀性能的影响

在CoSO₄-C₆H₇N-H₂SO₄混合液中,采用恒电位法合成了CoO/聚苯胺（PANI）复合膜,研究了添加剂（H₄N）₂S对CoO/PANI复合膜的影响。通过电化学测试技术、SEM、XRD和加速腐蚀试验等方法对CoO/PANI复合膜的微观形貌及耐腐蚀性能进行分析。结果表明,合成的CoO/PANI复合膜中,CoO以晶体形式存在,（H₄N）₂S的加入改变了CoO/PANI复合膜膜层的微观形貌,由不致密不规则的片状结构转变为均匀致密规则的片状一体结构,（H₄N）₂S加入量过大导致（H₄N）₂S-CoO/PANI复合膜表面出现少量孔洞;未添加（H₄N）₂S的CoO/PANI复合膜自腐蚀电流密度为7.079×10-6 A/cm2,自腐蚀电位为-0.545 V,添加0.3 g/L的（H₄N）₂S后,（H₄N）₂S-CoO/PANI复合膜自腐蚀电流密度达到7.943×10-7 A/cm2,自腐蚀电位达到-0.314 V,极化电阻为6 426.8 Ωcm2,经过10% HCl点滴腐蚀时间达478 s,中性盐雾实验56 h未见锈蚀,（H₄N）₂S显著提高了CoO/PANI复合膜的耐腐蚀性能。      

SiC纳米颗粒对TC4钛合金微弧氧化涂层组织结构及耐蚀性能的影响

在基础电解液中加入SiC纳米颗粒,利用微弧氧化技术在TC4钛合金表面制备微弧氧化陶瓷涂层,研究纳米颗粒的添加对微弧氧化涂层组织结构及耐蚀性能的影响。结果表明:550,600V及650V条件下,基础电解液中SiC的加入,使TC4微弧氧化涂层的厚度由9.2,12.8μm和12.4μm分别增大到12.0,14.9μm和20.0μm。随着电压的升高,微弧氧化涂层的表面粗糙度逐渐增大,分别为2.65, 3.34μm和3.61μm。SiC的加入有效抑制微弧氧化涂层表面裂纹的产生,增加涂层厚度从而降低涂层的阳极电流密度,提高微弧氧化涂层的耐蚀性能。微弧氧化涂层增加了TC4的开路电位及自腐蚀电位。     

Effect of plasma electrolytic oxidation treatment on the corrosion and stress corrosion cracking behaviour of AM50 magnesium alloy

The effect of a silicate-based plasma anodization treatment on the corrosion and stress corrosion cracking behaviour of a cast AM50 magnesium alloy was studied. Electrochemical tests revealed the beneficial effect of the plasma electrolytic oxidation (PEO) in improving the corrosion resistance of the alloy. Although the coating had provided an improved resistance to stress corrosion cracking in this test environment at a nominal strain rate of 10⁻⁶ s⁻¹, it could not completely eliminate the SCC susceptibility of the alloy. Cracking of the coating under conditions of straining was found to be the reason for SCC of PEO-coated alloy.