[V10O28]6-柱撑纳米水滑石在AZ31镁合金有机防腐涂层中的应用

研制了一种以钒酸盐阴离子([V10O28]6-)柱撑纳米水滑石防腐颜料替代铬酸盐,用于AZ31镁合金腐蚀防护的有机涂层.研究了水滑石在不同浓度的NaCl溶液里的吸附和离子交换性能,以及钒酸盐缓蚀剂的极化曲线:考察了该水滑石防腐颜料的添加比例对镁合金环氧防腐涂层性能的影响,并通过电化学交流阻抗(EIS)测试技术对各试样进行了性能检测.结果表明,添加了20%(质量分数)水滑石的环氧涂层对镁合金具有较好的防腐作用.     

【V10O28】唯撑纳米水滑石在AZ31镁合金有机防腐涂层中的应用

研制了一种以钒酸盐阴离子（[V10O18]^6-）柱撑纳米水滑石防腐颜料替代铬酸盐,用于AZ31镁合金腐蚀防护的有机涂层。研究了水滑石在不同浓度的NaCl溶液里的吸附和离子交换性能,以及钒酸盐缓蚀剂的极化曲线;考察了该水滑石防腐颜料的添加比例对镁合金环氧防腐涂层性能的影响,并通过电化学交流阻抗（EIS）测试技术对各试样进行了性能检测。结果表明,添加了20％（质量分数）水滑石的环氧涂层对镁合金具有较好的防腐作用。     

植入8-羟基喹啉共存时云母复合改性环氧树脂防腐蚀行为研究

通过吸附方法将8-羟基喹啉植入云母层间,得到8-羟基喹啉缓蚀剂储存器,用红外光谱仪对缓蚀剂纳米储存器进行了结构表征,并将其添加到环氧涂料中得到复合改性涂层,研究了缓蚀剂溶液浓度对复合涂层防腐性能的影响,采用极化曲线与烟雾实验对复合涂层进行了防腐性能测试。实验结果表明,与云母/环氧树脂相比,缓蚀剂的植入可提高环氧涂料防腐能力,当8-羟基喹啉的浓度为26.67 g/L时,复合涂层的防腐效果最好。此时极化电流为5.061E-008Acm-2,耐中性盐雾能力最强。     

环氧／纳米ZnO复合涂层对镁锂合金耐腐蚀性的影响

以聚丙烯酰胺凝胶法制备了纳米ZnO,并对其进行改性,得到了环氧/纳米ZnO复合涂层.采用XRD和SEM对环氧/纳米ZnO复合涂层进行了表征.通过极化曲线和交流阻抗研究了裸基、复合涂层以及经锡酸盐转化处理后涂覆环氧/纳米ZnO的复合涂层的耐蚀性能.结果表明:复合涂层呈明显的两相结构,纳米ZnO分布均匀;复合涂层和锡酸盐转化协同,提高了镁锂合金的耐腐蚀性能.涂层中纳米ZnO质量分数不同,对镁锂合金耐蚀性能有不同的影响,纳米ZnO质量分数为2%时,复合涂层对镁锂合金的保护作用最强.     

LDH型MoO42-缓蚀剂的合成及防腐研究

采用共沉淀法制备了储存缓蚀剂MoO42-的镁铝水滑石(LDH)纳米容器(MoO42—LDH),利用XRD和Raman光谱对样品进行表征。通过缓释实验,讨论了LDH型纳米容器对缓蚀剂的释放能力以及缓蚀剂的缓蚀机理。SEM-EDS、ICP、N2吸附脱附和极化曲线测试结果表明合成的LDH型MoO42-缓蚀剂具有很好的离子交换和吸附Cl-的性能,释放出MoO42-缓蚀剂进入电解液,24h内对镁合金的腐蚀电流保持在9.129A穋m-2,展示了良好的缓蚀防腐性能。添加20%MoO42—LDH颜料的环氧涂层在3.5%NaCl溶液中的EIS测试体现出较好的耐蚀作用。     

尼龙6/水滑石纳米复合材料的制备与表征

利用熔融插层复合法制备了插层型尼龙6／水滑石纳米复合材料。Ⅺ砌分析了水滑石的结构，确认成功制备出了具有典型层状结构的水滑石。利用透射电子显微镜（TEM）观察水滑石在尼龙6基体中的分散，确认制备出了插层型的纳米复合材料。对纳米复合材料的力学性能测试结果表明：加入水滑石之后，材料的屈服强度、定伸强度及拉伸模量都有明显提高，而且冲击强度基本不变。其中2号水滑石与尼龙6复合后拉伸模量与尼龙相比提高了26．8％。DSC和TGA测试结果显示，由于水滑石的存在对纳米复合材料的结晶性能和热稳定性略有影响。     

铝合金微弧氧化表面LDH的制备与性能研究

利用水热合成法在2024铝合金微弧氧化涂层表面原位生长了水滑石(LD H),制备得到硝酸根型微弧氧化水滑石复合膜层(MAO-LDH-NO),再将缓蚀剂VO3-插层到LDH中,得到矾酸根插层的微弧氧化型水滑石复合膜层(MAO-LDH-VO).采用扫描电镜、能谱仪、X射线衍射仪对膜层进行组织结构表征,采用极化曲线及电化学阻...     

改性纳米氧化锌对丙烯酸聚氨酯涂层防腐性能的影响

为了改善纳米ZnO在涂料中的分散性,以钛酸酯偶联剂对其进行改性。研究了丙烯酸聚氨酯清漆、含未改性纳米氧化锌的丙烯酸聚氨酯涂层和添加钛酸酯偶联剂改性后的纳米氧化锌的丙烯酸聚氨酯涂层的防腐蚀性能。结果表明,经过钛酸酯偶联剂改性的纳米ZnO其团聚现象明显消失,与涂料表现出良好的相容性,所得的复合涂层的抗渗透能力明显比清漆和含未改性纳米ZnO复合涂层强。改性纳米ZnO显著提高了丙烯酸聚氨酯涂料的防腐性能。     

滑石粉对8-羟基喹啉的吸附储存与缓蚀行为的研究

采用可吸附缓蚀剂的滑石粉为载体,8-羟基喹啉作为缓蚀剂,通过离子交换作用将缓蚀剂离子添加到滑石粉间隙,完成对缓蚀剂的吸附储存。将制作的缓蚀剂储存器添加到环氧树脂中,得到一种新型防腐涂料。采用测厚仪、附着力测试仪,对改性涂层的常规性能进行了测试;用红外光谱仪对改性前后的纳米粒子进行了结构表征;测试了复合改性环氧树脂涂层在3.5%的NaCl溶液中的电化学极化曲线。实验结果表明,添加了8-羟基喹啉的环氧树脂涂料防腐性能得到提高,改性后的涂层较之空白环氧涂层有更好的耐腐蚀性和抗渗透性。     

环氧涂层防腐填料研究进展

综述了环氧涂层防腐填料种类及防腐机理,并对具有片层结构功能填料、孔道结构功能填料、缓蚀剂填料在环氧树脂中的国内外应用进行了详细介绍。最终得出结论,多种机理协同作用成为今后环氧涂层防腐填料的发展方向,尤以负载缓蚀剂为主要方向。     

Synthesis of 3-glycidoxypropyltrimethoxysilane modified hydrotalcite bearing molybdate as corrosion inhibitor for waterborne epoxy coating

Zinc aluminum hydrotalcite intercalated with molybdate (HTM) and modified by 3-glycidoxypropyltrimethoxysilane (HTM-GS) was prepared and incorporated into a waterborne epoxy coating. The synthesized HTM-GS was characterized by FTIR, XRD, SEM, and TEM. The inhibitive action of HTM-GS on carbon steel was evaluated using electrochemical measurement and SEM/EDX analysis. The corrosion protection of the waterborne epoxy coating containing HTM-GS was evaluated and compared to that of the pure waterborne epoxy coating and the waterborne epoxy coating containing HTM by salt spray test and adhesion measurement. It was shown that the molybdate was intercalated in the hydrotalcite structure and the molybdate contents in HTM and HTM-GS were 16.0 and 13.2 wt%, respectively. The polarization curves obtained on the carbon steel electrode showed that HTM and HTM-GS are anodic corrosion inhibitors, and their inhibition efficiencies at concentration of 3 g/l were 92.0 and 94.7%, respectively. Additionally, HTM and HTM-GS at concentration of 0.5 wt% improved corrosion resistance and adhesion of waterborne epoxy coatings. Surface modification by 3-glycidoxypropyltrimethoxysilane ameliorated the dispersion of HTM in epoxy matrix and the effect of HTM on protection properties of waterborne epoxy coating.     

Anti-corrosive properties of Poly(aniline-co-2,3-xylidine)/ZnO nanocomposite coating on low-carbon steel

A copolymer nanocomposite Poly(aniline-co-2,3-xylidine)/ZnO [Poly(AN-co-XY)/ZnO], pure copolymer and its homopolymers namely, Poly(aniline-co-2,3-xylidine) [Poly(AN-co-XY)], Polyaniline (PANi) and Poly (2,3-xylidine) were synthesized by chemical oxidative polymerization using ammonium persulfate as an oxidant in hydrochloric acid medium. The synthesized compounds were characterized by FTIR, XRD, SEM, and TEM techniques. Saturated solutions of the synthesized compounds were made in N-methyl-2-pyrrolidone and casted on low-carbon steel specimens using 10% epoxy resin as a binder. The anticorrosion behavior of polymeric coatings was studied in 3.5 wt% NaCl solution at a temperature of 30 °C by electrochemical techniques, which include: open-circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy. Protective properties of nanocomposite coating were also evaluated at different immersion times for an extended period of 60 days. Anticorrosion properties of nanocomposite coating were compared with parent copolymer and individual homoplymers. SEM photomicrographs of the coated surface showed that Poly(AN-co-XY)/ZnO nanocomposite coating is crack free, uniform, and compact, whereas, copolymer and homopolymer coatings have surface defects. The performance of the polymer coatings followed the order: Poly(AN-co-XY)/ZnO > Poly(AN-co-XY) > PANi > Poly(2,3-xylidine). The presence of ZnO nanoparticles in copolymer resulted in significant improvement in corrosion resistance and provided better barrier properties.     

Epoxy/polyaniline–ZnO nanorods hybrid nanocomposite coatings: Synthesis,characterization and corrosion protection performance of conducting paints

The objective of this research is the production of an epoxy coating blended with organic–inorganic hybrid nanocomposite as a corrosion inhibiting pigment applied over carbon steel grade ST37. A series of conducting polyaniline (PANI)–ZnO nanocomposites materials has been successfully prepared by an in situ chemical oxidative method of aniline monomers in the presence of ZnO nanorods with camphorsulfonic acid (CSA) and ammonium peroxydisulfate (APS) as surfactant and initiator, respectively. The synthesized polymers were characterized by X-ray diffraction pattern (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA) and electrical conductivity techniques. Synthesized nanocomposites were solved in tetraethylenpentamine (TEPA), and then prepared solution was mixed with epoxy and then was applied as a protective coating on carbon steel plates. The anti-corrosion behavior of the epoxy binder blended with PANI–ZnO nanocomposites were studied in 3.5% NaCl solution at a temperature of 25 °C by electrochemical techniques including electrochemical impedance spectroscopy (EIS) and chronopotentiometry at open circuit potential (OCP). It was observed that the epoxy coating containing conducting PANI–ZnO nanocomposites exhibited higher corrosion resistance and provided better barrier properties in the paint film in comparison with pure epoxy and epoxy/PANI coatings. In the case of conducting coatings, the OCP was shifted to the noble region due to presence of PANI pigments. Additionally, the possibility of formation of a passive film in the presence of PANI was reinforced at the substrate–coating interface. SEM studies taken from surface of the coatings showed that epoxy/PANI–ZnO hybrid nanocomposite coating systems (EPZ) are crack free, uniform and compact. Furthermore, it was found that the presence of ZnO nanorods beside PANI can significantly improve the barrier and corrosion protection performance of the epoxy coating due to the flaky shaped structure of the PANI–ZnO nanocomposites.     

Hierarchical polymer nanocomposite coating material for 316L SS implants: Surface and electrochemical aspects of PPy/f-CNTs coatings

Biocompatible nanocomposite coatings can be synthesized to offer improved surface properties for biomaterials and biomedical implants. Nanocomposite coatings containing polypyrrole (PPy) matrix reinforced with functionalized multi-wall carbon nanotubes (f-CNTs) were deposited on 316L SS substrates using electrochemical route. FT-IR, XRD, SEM, and TEM were employed to characterize the nanocomposite microstructure. High resolution imaging showed relatively uniform dispersion of the CNTs in the nanocomposite with a typical tubular structure. Micro-indentation tests revealed improvement in the hardness of the PPy/CNTs coatings. Measurement of the contact angle indicated enhanced surface wettability of the nanocomposite coatings. The corrosion behavior of 316L SS samples coated with PPy/CNTs was studied in SBF medium. The corrosion potential and the breakdown potential of coated 316L SS substrates shifted to more noble values as compared to uncoated 316L SS samples. The results suggest that incorporating CNTs as reinforcements in PPy coatings can provide enhanced properties in terms of surface hardness, biocompatibility, and corrosion resistance.     

Studying the effects of micro and nano sized ZnO particles on the corrosion resistance and deterioration behavior of an epoxy-polyamide coating on hot-dip galvanized steel

The effects of micro and nano sized ZnO particles on the corrosion resistance and hydrolytic degradation of an epoxy coating were studied. Different analytical techniques including scanning electron microscope (SEM), electrochemical impedance spectroscopy (EIS), dynamic thermal mechanical analysis (DMTA) and nano-indentation were utilized to evaluate the hydrolytic degradation as well as the corrosion resistance of the coatings in exposure to 3.5 wt% NaCl solution. It was found that the epoxy coating resistance against corrosive electrolyte was significantly improved using nano and micro sized ZnO particles. The corrosion resistance of the nanocomposite was considerably greater than the one reinforced with the micro-ZnO particles. Moreover, the resistance of the coating reinforced with the nano sized particles against hydrolytic degradation in exposure to the corrosive electrolyte was considerably greater than the one reinforced with the micro sized particles. Decrease in both nano hardness and cross-linking density of the epoxy coating reinforced with nanoparticles after exposure to the corrosive electrolyte were considerably lower than the blank sample and the sample reinforced with the micro sized ZnO particles. Using nano sized particles the coating adhesion loss decreased.     

Characterization of hybrid sol–gel coatings doped with hydrotalcite-like compounds to improve corrosion resistance of AA2024-T3 alloys

The inhibition effect of hydrotalcite addition to hybrid sol–gel coatings applied on AA2024-T3 alloy was evaluated. Hydrotalcite belongs to the anionic clay family with wide applications, most of them based on its anion exchange capacity due to its double layered structure. In this work hydrotalcite (HT) powder was prepared by the classical co-precipitation method using magnesium and aluminum nitrates as precursors. Different weight percentages (1, 5 and 10%, w/w) of hydrotalcite with Mg/Al ratio of 2.5 were added to hybrid sols prepared by copolymerization of 3-Glycydoxypropyltrimethoxysilane (GPTMS) and tetra-n-propoxyzirconium (TPOZ). The sol–gel coatings were deposited by dip-coating method on AA2024-T3 substrate. Scanning electron microscopy (SEM) and mechanical profilometry measurements revealed the heterogeneous particle sizes and the distribution of the agglomerates. Hydrotalcite additions significantly increased the bond strength between metal and coating, according to pull-off test results.The corrosion performance was evaluated by the salt spray fog chamber test and by Electrochemical Impedance Spectroscopy (EIS). The results showed a marked improvement of the corrosion resistance on the aluminum alloy when HT was added to the hybrid sol–gel coating. This positive effect was more evident at higher weight percentages of hydrotalcite.     

Effect of Ti amount on wear and corrosion properties of Ti-doped Al2O3 nanocomposite ceramic coated CP titanium implant material

Al₂O₃ and Ti-doped Al₂O₃ nanocomposite ceramic coatings were prepared by using a sol-gel dip-coating process. Corrosion and wear resistance of Al₂O₃ ceramic coatings in relation to Ti amount were carried out using pin-on-disk tribotester, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Surface characterizations before and after the corrosion and wear tests were investigated by the scanning electron microscope (SEM) and X-ray diffraction (XRD) and hardness analysis. The results of corrosion and wear tests exhibited that the corrosion and wear resistance of nanocomposite ceramic coatings became better than uncoated samples. Also, corrosion and wear resistance of nanocomposite ceramic coatings improved with Ti doping content increased.     

Conducting polymer based hybrid nano-composites for enhanced corrosion protective coatings

Hybrid composite coatings containing zinc oxide (ZnO) and polyaniline (PANI) as nano-additives dispersions were prepared with poly(vinyl acetate) (PVAc) as the major matrix. The steel plates dip-coated with these formulations were tested for corrosion protection by immersion in saline water over long periods. The Tafel plots for the determination of open circuit potential (OCP) and corrosion current (I_corr) were recorded. The coatings containing both ZnO and PANI showed improved corrosion resistance as compared to the single component coating. The I_corr values of PVAc–ZnO–PANI are found to be two-order magnitude lower than that of PVAc and PVAc–ZnO coatings. The results are explained on the basis of enhancement in barrier properties due to nano-particulate additives in PVAc–ZnO–PANI film together with the redox behaviour of PANI and protective oxide layer formation near the substrate.     

Effect of hydrotalcite on the physical properties and drug‐release behavior of nanocomposite hydrogels based on poly[acrylic acid‐co‐poly(ethylene glycol) methyl ether acrylate] gels

A series of nanocomposite hydrogels used for bioadhesive were prepared from acrylic acid, poly(ethylene glycol) methyl ether acrylate, and intercalated hydrotalcite (HT) by photopolymerization. The microstructures of the intercalated HT and sample gels were identified by X‐ray diffraction (XRD). The results showed that the swelling ratio for these nanocomposite hydrogels increased with an increase in HT, but the gel strength and adhesive force for these gels decreased with an increase in HT. The XRD results indicated that the exfoliation of intercalated HT was achieved in the xerogels and swollen gels. Finally, the drug‐release behaviors for these gels were also examined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 692–699, 2004