改性石墨烯/聚苯胺的制备及其环氧涂层的防腐蚀性能

为了改善环氧树脂防腐蚀涂料存在的孔洞缺陷,以改性石墨烯/聚苯胺复合材料作填料来提高环氧涂料的防腐蚀性能。首先采用改进的Hummers法制备了氧化石墨烯(GO),再利用对苯二胺还原GO得到改性石墨烯(PGO),进一步制备出改性石墨烯/聚苯胺(PGO/PANI)复合材料。通过拉曼光谱仪、场发射扫描电镜等研究了PGO/PANI的结构和微观形貌,利用盐雾试验、Tafel曲线和电化学阻抗谱研究了 PGO/PANI的防腐蚀性能。结果表明:PGO/PANI涂层的腐蚀等级由空白环氧涂层的10级提高到5级;PGO与PANI有良好的协同作用,PGO与苯胺单体质量比为0.10时,所制备的PGO/PANI复合涂层的防腐蚀效果较好,腐蚀电压为-194.59mV (vs SCE)、腐蚀电流密度为2.12×10^-9A/cm^2.     

Ce3+掺杂聚苯胺中空微球/环氧涂层防腐蚀研究

聚苯胺作为一种新型的防腐蚀材料,在钢铁防腐蚀领域具有良好的应用前景.通过自组装法在聚(2-丙烯酰胺基-2-甲基丙磺酸)(PAMPS)水溶液中制备了聚苯胺(PANI)中空微球,将稀土Ce~(3+)掺杂到聚苯胺中空微球表面制备了一种新型的Ce~(3+)掺杂修饰的聚苯胺中空微球(PANI-Ce~(3+)).以PANI-Ce~(3+)中空微球为防腐填料添加到环氧树脂(EP)中,制备Ce~(3+)掺杂修饰的聚苯胺中空微球/环氧(PANI-Ce~(3+)/EP)防腐涂层.采用FT-IR、UV-Vis、SEM、XRD等对PANI-Ce~(3+)中空微球进行表征,通过动电位极化法、交流阻抗测试探究PANI-Ce~(3+)/EP涂层的防腐蚀性能.结果表明:PANI-Ce~(3+)/EP涂层具有较高的腐蚀电压(Ecorr=-0.414 V)和较小的腐蚀电流密度(I_(corr)=0.676×10~(-5)μA/cm~2);PANI-Ce~(3+)/EP涂层低频区阻抗模量随浸泡时间呈现先减小后增大的变化趋势,在质量分数3.5%的NaCl水溶液中经过1 680 h腐蚀后,阻抗模量保持在106.6Ω·cm~2;表面有划伤的PANI-Ce~(3+)/EP涂层在质量分数3.5%的Na Cl水溶液进行1 680 h腐蚀实验后,涂层表面不起泡,仅在划痕处有少量铁锈.PANI-Ce~(3+)/EP涂层表现出优异的耐腐蚀性能.     

Synthesis and electrical properties of polymer composites with polyaniline nanoparticles

Nano-sized polyaniline (PANI) particles dispersed in aqueous solution were prepared using both poly(vinyl alcohol) (PVA) and poly(styrene sulfonic acid) (PSSA) as polymeric stabilizers. Size of the spherical PANI particle synthesized using PVA with a HCl dopant (PANI-HCl/PVA) was about 150 nm in diameter, and that with PSSA (PANI-PSSA) was about 50 nm, with a uniform size distribution. Doping level of the PANI-PSSA measured by UV–visible spectrometer was higher than that of PANI-HCl/PVA. The PVA based composite films using both PANI-HCl (PANI-HCl/PVA) and PANI-PSSA (PANI-PSSA/PVA) were prepared by a casting method for different PANI content and their electrical conductivities were measured. A percolation threshold of PANI concentration for conductivity of composite was found only around 10 wt.% of PANI for the PANI-PSSA/PVA, and furthermore, the PANI-PSSA/PVA became more conductive above the threshold point than PANI-HCl/PVA.     

Potassium-selective electrodes with stable and geometrically well-defined internal solid contact based on nanoparticles of polyaniline and plasticized poly(vinyl chloride)

Solid contact potassium-selective electrodes with the internal ion-to-electron transduction layer composed of plasticized poly(vinyl chloride) (PVC) and 2-20% (m/m) of polyaniline (PANI) nanoparticles, with the mean particle size of 8 nm, have been studied in this paper. UV-vis measurements in pH buffer solutions between pH 0 and 12 show that the electrically conducting emeraldine salt (ES) form of PANI has exceptionally good pH stability. Membranes of PANI nanoparticles were mainly in the ES form even at pH 12, in contrast to electrochemically prepared PANI(Cl) films, which are converted completely to the nonconducting form already at pH 6. Long-term UV-vis measurements with the PANI membranes in contact with aqueous buffer solution at pH 7.5 showed no degradation of the ES form. The PANI nanoparticles are homogenously mixed in the PVC-based solid contact (SC) layer. Only the uppermost part of the SC layer is to a minor extent dissolved in the outer potassium-selective PVC membrane. This enabled the preparation of geometrically well-defined inner SC layers, thus improving the reproducibility of the solid contact electrodes and resulting in good mechanical strength between the inner and outer membranes.     

改性纳米氧化锆与水性聚氨酯复合涂层的防腐蚀性能

为了改进纳米氧化锆(ZrO_2)在涂料中的分散性,以丙酮为介质,用3-氨基丙基三甲氧基硅烷(APS)对纳米ZrO_2进行了改性,并在镀锡板表面制备了改性纳米ZrO_2/水性聚氨酯(WPU)复合涂层。通过扫描电镜、原子力显微镜、红外光谱、电化学测试、盐雾腐蚀、附着力测试等技术,研究了WPU与不同含量改性纳米ZrO_2复合涂层的防腐蚀性能。结果表明:改性纳米ZrO_2的含量为0.2%(质量分数)时,在WPU中的团聚现象消失,分散性良好,该复合涂层具有优良的耐蚀性和较大的附着力。     

聚苯胺电活性涂层对碳钢的防腐蚀性能研究

将化学聚合所得的聚苯胺(PANI)粉末分散于羟基丙烯酸树脂中,可制备出粘接力强、有一定导电性的防腐蚀涂料.通过测量不同PANI含量涂层的开路电位、自腐蚀电流及涂层的交流阻抗谱随时间的变化,研究了聚苯胺含量对涂层防蚀性的影响.结果表明,聚苯胺含量过高或过低,涂层的防蚀性均不佳,只有当聚苯胺含量为10%～15%时,涂层的防蚀性最好.基于不同PANI含量的涂层经不同浸泡时间后等效电路的变化,探讨了聚苯胺的防腐蚀机制.     

水性聚苯胺/叔氟丙烯酸酯复合防腐涂层的制备及性能

为研究水性聚苯胺/叔氟丙烯酸酯（PANI/VFAc）复合涂层对Q235钢防腐蚀性能的影响,首先,以叔碳酸乙烯酯（Veova 10）和甲基丙烯酸十二氟庚酯（DFMA）为功能单体合成了VFAc乳液,并将其与PANI乳液混合后涂刷在Q235钢表面,制备了PANI/VFAc复合涂层;然后,采用TEM和FTIR对VFAc的结构进行了表征,采用XPS和接触角（CA）研究了复合涂层的表面性能,采用电化学方法研究了不同改性丙烯酸酯乳液对复合涂层防腐蚀性能的影响。结果表明:PANI/VFAc复合涂层的水接触角为97.56°,湿附着力等级为0,涂层表现出较好的疏水性;其腐蚀电流密度为8.72×10-8 A·cm-2,电化学阻抗达到106 Ω·cm2。所得结论表明PANI/VFAc复合涂层对Q235钢具有良好的防腐蚀性能。      

Zn2+掺杂对电化学合成聚苯胺膜耐蚀性能的影响

为提高聚苯胺（PANI）膜的耐蚀性,在苯胺-硫酸电解液体系中,采用电化学恒电流法在不锈钢表面合成了PANI膜,利用电化学测试技术、SEM和XRD研究了Zn²⁺掺杂对电化学合成PANI膜耐蚀性能的影响。结果表明：Zn²⁺的掺杂使PANI膜微观形貌由不规则片状转变为规则的纤维状形貌;掺杂改性后PANI膜的交流阻抗明显增大,腐蚀电位向正方向移动,腐蚀电流减小;掺杂Zn²⁺的PANI膜经质量分数为10% 的HCl点滴实验测试,腐蚀时间达320 s;经中性盐雾实验48 h后,PANI膜未见锈蚀。     

聚苯胺的制备及其在压载舱涂料中的防腐性能

为满足《船舶专用海水压载舱和散货船双弦侧处所保护涂层性能标准》对压载舱涂层的防腐性能要求,开发新型聚苯胺(PANI)涂层.通过化学氧化法制备聚苯胺,并采用扫描电镜和透射电镜对其进行了形貌观察.将质量分数为5%和10%的聚苯胺添加到呋喃氧茚树脂中制备船舶压载舱防腐涂料,涂覆于Q235碳钢表面.通过附着力测试、极化曲线测试、电化学阻抗谱等表征手段,评价其力学及防腐性能,并初步探讨其防腐机理.结果表明:制备的聚苯胺有纳米纤维网状结构,有利于增加树脂的交联程度,可起到屏蔽作用;添加聚苯胺后,SEM中基体与涂层之间的界面不明显,且涂层缺陷及孔隙变少;5%PANI和10%PANI涂层的附着力分别达12.3和11.8 MPa,涂层的附着力显著提高,符合PSPC的要求;聚苯胺涂层的自腐蚀电流密度下降,自腐蚀电位正移,阻抗弧半径变大,防腐性能有了较大的提高;质量分数5%的聚苯胺涂层试样较10%试样的力学及防腐性能均有所提高,能为Q235碳钢提供更好的保护.     

聚苯胺/银复合薄膜的制备及其耐蚀性能

为了研究聚苯胺(PANI)/银复合薄膜对不锈钢的防腐蚀性能,采用循环伏安法在不锈钢表面沉积一层Ag后,再通过对苯胺的电化学聚合制备了PANI膜。利用阳极极化法和交流阻抗法研究了PANI/Ag复合膜的耐蚀性及其影响因素。结果表明:在0.1 mol/L NaC l溶液中,不锈钢覆盖复合膜后的自腐蚀电位比无膜时有所提高,其耐蚀性能得到增强;电化学聚合溶液浓度、扫描速率及扫描上限等因素对复合膜耐蚀性的影响情况为:电解液中苯胺和硫酸浓度过高或过低都会影响膜的致密度,从而影响复合膜的耐蚀性;电化学参数的变化会影响复合膜的聚合速率,使复合膜的抗腐蚀能力不同;当苯胺单体浓度为0.2 mol/L、硫酸浓度为1 mol/L、扫描电位上限为1 V、扫描次数为50次、扫描速率为50 mV/s时,采用循环伏安法聚合苯胺,可形成沉积致密度高、耐蚀性好的复合膜。     

(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。      

Electrochemical study on new polymer composite for zinc corrosion protection

Galvanostatic electrodeposition mode was employed for the synthesis of new polyaniline and polypyrrole-based composite coatings (PANI/PPY) onto pure zinc electrode. Potentiodynamic polarization, open circuit potential measurements and Electrochemical Impedance Spectroscopy (EIS) were employed to assess the ability of these composite coatings to provide an effective barrier to corrosion in chloride environment. Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) observations were employed to characterize the structure and morphology of the modified electrodes. The coatings deposited galvanostatically at lower current density showed the best quality in terms of protection ability towards aggressive medium. It was found that the new PANI/PPY composite coatings had significantly better properties than single polymer coatings regarding the corrosion protection.     

Electrochemical study on new polymer composite for zinc corrosion protection

Galvanostatic electrodeposition mode was employed for the synthesis of new polyaniline and polypyrrole-based composite coatings (PANI/PPY) onto pure zinc electrode. Potentiodynamic polarization, open circuit potential measurements and Electrochemical Impedance Spectroscopy (EIS) were employed to assess the ability of these composite coatings to provide an effective barrier to corrosion in chloride environment. Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM) observations were employed to characterize the structure and morphology of the modified electrodes. The coatings deposited galvanostatically at lower current density showed the best quality in terms of protection ability towards aggressive medium. It was found that the new PANI/PPY composite coatings had significantly better properties than single polymer coatings regarding the corrosion protection.     

One-step electrochemical fabrication of bilayered MgO/polymer coating on magnesium alloy

This research demonstrates a novel one-step electrochemical method to fabricate thick bilayer coatings on magnesium alloy in acid phosphate electrolyte containing aniline monomer and styrene-acrylic emulsion （SAE） with pulsed DC voltage, The morphologies, XRD and FTIR results show that the bilayer coating consists of an inner oxide layer and an outer polyaniline （PANI）/SAE composite layer, It is believed that the bilayered structure achieved results from a hybrid process combining electropoly-merization （EPM） of aniiine, electrophoretic deposition （EPD） of SAE and plasma electrolyte oxidation （PEO） of magnesium alloy substrate. Electrochemical corrosion tests indicate that the bilayer coating can provide superior corrosion protection to the magnesium alloy substrate in 3.5 wt.% NaCl solution.     

Effect of nano Al pigment on the anti corrosive performance of waterborne epoxy coatings

This paper presents the results regarding the effect of nano aluminum powder pigment concentration on the protective properties of waterborne epoxy films in 3.5 wt pct NaCl solution. The anticorrosive performance of the coatings with 0.5, 1, and 3 wt pct pigments and none pigment were investigated using electrochemical impedance spectroscopy （EIS）, scanning electron microscopy （SEM） and Raman spectroscopy techniques. The results show that adding appropriate amount of nano-aluminium powder pigment can enhance the barrier properties of the epoxy coating, which is attributed to the surface effect of nanoparticles and the compatibility of the pigment with the waterborne epoxy coatings.     

高导电聚苯胺/纳米石墨微片复合材料的结构与性能

以天然可膨胀石墨(GN)为原材料,采用酸及快速热处理制备了膨胀石墨(EG),再将膨胀石墨置于超声波中制得了纳米石墨微片(NanoG),最后采用原位聚合法制备了聚苯胺/纳米石墨微片(PANI/NanoG)导电复合物。扫描电镜(SEM)显示纳米石墨微片长径为0.8μm～20μm,厚度为30nm～90nm。聚苯胺均匀覆盖在纳米石墨微片表面;透射电镜(TEM)揭示了纳米石墨微片的片层分散在复合物中并形成了导电网络;电性能测试表明,当纳米石墨微片含量为0.5%(质量分数,下同)时,复合物电导率达到107.3S/cm,其渗滤阈值达到0.1%,纳米石墨微片独特的结构(宽度/厚度的高比值)及在聚苯胺中的分散造就了复合物良好的导电性能。     

Corrosion Resistance of Graphene-Reinforced Waterborne Epoxy Coatings

Graphene(G) was dispersed uniformly in water and used as an inhibitor in waterborne epoxy coatings.The effect of dispersed G on anticorrosion performance of epoxy coatings was evaluated.The composite coatings displayed outstanding barrier properties against H_2O molecule compared to the neat epoxy coating.Open circuit potential(OCP),Tafel and electrochemical impedance spectroscopy(EIS)analysis con-?rmed that the corrosion rate exhibited by composite coatings with 0.5 wt%G was an order of magnitude lower than that of neat epoxy coating.Salt spray test results revealed superior corrosion resistance offered by the composite coating.     

Comparison between poly(methyl methacrylate)-carbon black and polyaniline conductive coatings

This work aims to develop and compare two types of conductive, polymer-based coatings via a dip coating process. The first type of coatings was made by dispersing and incorporating carbon black (CB) nanoparticles in a poly(methyl methacrylate) (PMMA) solution followed by dip coating. The CB content and dipping parameters were varied to explore their effects on the particle dispersion, coating thickness, and conductivity of the coatings. The dispersion of the CB particles in the polymer matrix was examined by scanning electron microscopy (SEM), while the coating thickness and conductivity were measured with a surface profilometer and a four-point probe electrometer, respectively. The good dispersion of carbon nanoparticles in the PMMA matrix was observed in the coatings. The conductivity of the PMMA-CB composite coatings was found to be mainly affected by CB content, particle dispersion as well as coating thickness. On the other hand, polyaniline (PANI) was used to make conductive coatings by dip coating and doping, and the advantages and limitations of the PANI coatings were compared with the PMMA-CB coatings.     

纳米氧化锌改性聚氨酯复合涂层的防腐性能

研究了添加不同颜基比（P／B）ZnO的聚氨酯涂料在3．5％氯化钠溶液中的电化学阻抗谱特征，提出了涂层电极在浸泡阶段对应的不同阻抗模型，结果表明，添加量为P／B=0．3的纳米复合涂层，颜料分布均匀适中，具有最佳电化学及耐盐雾性能．纳米复合涂层的抗介质渗透能力明显优于普通涂层，其原因是纳米材料独特的表面效应使其致密性有所提高，     

Nanocomposite synthesis by absorption of nanoparticles into macroporous hydrogels. Building a chemomechanical actuator driven by electromagnetic radiation

Macroporous hydrogels irreversibly absorb solid nanoparticles from aqueous dispersions. A nanocomposite is made using a macroporous thermosensitive hydrogel (poly(N-isopropylacrylamide-co-(2-acrylamido-2-methyl propane sulfonic acid)) (poly(NIPAm-co-AMPS)) and conductive polymer (polyaniline, PANI) nanoparticles (PANI NPs). Macroporous gels of poly(NIPAm-co-AMPS) were made by a cryogelation technique. NPs of PANI were produced by precipitation polymerization. It is found that PANI NPs are easily absorbed into the macroporous hydrogels while conventional non-porous hydrogels do not incorporate NPs. It is shown that PANI NPs, dispersed in water, absorb NIR laser light or microwave radiation, increasing their temperature. Upon irradiation of the nanocomposite with microwaves or NIR laser light, the PANI NPs heat up and induce the phase transition of the thermosensitive hydrogel matrix and the internal solution is released. Other nano-objects, such as gold nanorods and PANI nanofibers, are also easily incorporated into the macroporous gel. The resulting nanocomposites also suffer a phase transition upon irradiation with electromagnetic waves. The results suggest that, using a thermosensitive matrix and conducting nanoparticles, mechanical/chemical actuators driven at a distance by electromagnetic radiation can be built. The sensitivity of the nanocomposite to electromagnetic radiation can be modulated by the pH, depending on the nature of the incorporated nanoparticles. Additionally, it is possible to make systems which absorb either NIR or microwaves or both.