阳离子表面活性剂作用下制备一维纳米结构聚苯胺

在十六烷基三甲基溴化铵(CTAB)存在下, 以盐酸为质子酸, 过硫酸铵为氧化剂, 制备了平均直径为115 nm、具有分叉结构的聚苯胺纳米纤维和平均直径为75 nm的卷曲聚苯胺纳米线, 两者的结构产率高达90%和100%, 电导率分别为1.6×10-2和9.3×10-2 S/cm. 研究发现, 聚苯胺的一维纳米结构受盐酸浓度和苯胺与CTAB摩尔比的协同影响. 用TEM, SEM和FTIR对产物的形貌和化学结构进行了表征. 利用pH监测反应并结合SEM结果研究了聚苯胺纳米线的形成过程, 结果表明, CTAB阳离子与过硫酸根形成的絮状物的诱导作用是聚苯胺纳米纤维和纳米线形成的关键因素.     

氯化铁氧化掺杂的聚苯胺纳米纤维团簇

没有外加质子酸的条件下,以氯化铁为氧化剂和掺杂剂,在界面体系中由苯胺(An)采用“无模板”的方法成功地制备了电导率为10-2～10-1S/cm的聚苯胺纳米纤维(d=20～30nm).实验证明FeCl3同时起到氧化剂和掺杂剂的双重作用,从而进一步简化了导电聚苯胺纳米纤维的合成条件.与使用过硫酸铵为氧化剂的传统聚合方法相比,FeCl3较小的氧化/还原电位使产物具有较小的直径和较高的结晶性.同时发现聚苯胺的形貌和电导率均与[FeCl3]/[An]的比例有关.FTIR,UV-Vis,XRD结构表征证实所得的聚苯胺纳米纤维为掺杂态.     

界面聚合法合成手性掺杂剂诱导螺旋形聚苯胺纳米纤维

以手性试剂D-樟脑磺酸(D-CSA)和L-樟脑磺酸(L-CSA)为掺杂剂和构象诱导剂,采用界面聚合法合成了螺旋形聚苯胺纳米纤维。通过FESEM、TEM、FTIR和UV-Vis吸收光谱等测试技术对螺旋形聚苯胺纳米纤维结构进行了表征。结果表明,所得聚苯胺纤维具有螺旋形构象,形貌均一,平均直径约为50nm,长度为300～600nm,具有较高的长径比(6:1～12:1)。在水溶液中,聚苯胺纳米纤维以伸展的螺旋形分子链构象存在,调节溶液的pH值,螺旋形聚苯胺纳米纤维表现出可逆的掺杂和脱掺杂性质。循环伏安(CV)测试表明,螺旋形聚苯胺纳米纤维在0.5mol/LHCl溶液中表现出良好的电化学活性。     

以含有阿魏酸和没食子酸的PAM纤维诱导制备聚苯胺纳米棒结构材料

为了研究化感物质的缓释载体材料, 分别以含有阿魏酸和没食子酸的聚丙烯酰胺(PAM)纤维诱导, 采用化学氧化聚合法, 以苯胺为单体, 过硫酸铵为氧化剂, 分别合成了阿魏酸、没食子酸掺杂的聚苯胺(PANI)纳米结构材料. 通过红外光谱(IR)、X射线粉末衍射(XRD)以及电子扫描电镜(SEM)对掺杂态PANI的结构和形态进行了表征. 结果表明, 所制备材料确为阿魏酸、没食子酸掺杂的PANI. SEM研究结果表明, PANI的形态表现为纳米棒状, 直径在200~300 nm范围内. 另外, 对纤维中酸含量以及不同氧化剂和苯胺单体摩尔比对PANI电导率的影响进行了探讨.     

不同掺杂酸对纤维聚苯胺电化学性能的影响

采用界面聚合法通过不同质子酸掺杂分别制备了平均直径约为50,62,95nm的纤维聚苯胺。通过傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)、透射电镜(TEM)对其化学组成和微观形貌进行了表征,采用循环伏安、恒流充放电和交流阻抗研究了不同质子酸掺杂纤维聚苯胺的超级电容器电容行为,并利用X射线衍射(XRD)、氮气吸脱附及X射线光电子能谱(XPS)等方法对纤维聚苯胺的微观结构进行了深入研究。结果表明:高氯酸(HClO4)掺杂制备的聚苯胺在0.5A/g电流密度下的比容量可以达到397F/g,高于盐酸(HCl,334F/g)和樟脑磺酸(HCSA,383F/g)掺杂聚苯胺的测试结果,纤维的电化学性能主要受其规整度、孔隙率及掺杂度的影响。     

不同质子酸掺杂对银/聚苯胺纳米复合材料结构和导电性的影响

利用紫外光作为辅助条件,在反胶束体系中采用一步双原位法合成了硝酸(HNO3)、对甲基苯磺酸(TSA)和5-磺基水杨酸(SSA)掺杂的银/聚苯胺(Ag/PANI)纳米复合材料.通过对复合材料进行红外光谱(FTIR)、紫外光谱(UV-Vis)、扫描电镜(SEM)、X射线衍射(XRD)和导电性能的测试,研究了不同质子酸对Ag/PANI纳米复合材料结构、形貌和导电性能的影响.测试结果表明,3种酸掺杂制备的Ag/PANI纳米复合材料均为聚苯胺包覆银粒子的核-壳结构.不同的质子酸掺杂会对Ag/PANI纳米复合材料的电性能有重要影响.在3种酸掺杂的复合材料中,TSA掺杂的复合材料的电导率最佳,为215.14 S·cm-1.     

基于碳纸电极电化学快速合成聚苯胺纳米纤维

利用碳纸电极,采用循环伏安法、恒电流法和恒电位法等电化学聚合法快速合成了高氯酸掺杂聚苯胺纳米纤维.利用电子显微镜、红外光谱和四探针测定仪等对聚苯胺的微观形貌结构、掺杂度和电导率进行了研究.用循环伏安法对聚苯胺的电化学特征进行了分析.研究发现,3种方法合成的聚苯胺均为纳米纤维状结构,长度达3μm,直径为50~150 nm.其中,循环伏安法合成的聚苯胺纳米纤维的均一性和电导率均优于其它2种方法,其电导率高达5.97 S/cm.另外,聚苯胺合成速率顺序为恒电流法>循环伏安法>恒电位法,且恒电流法合成的聚苯胺纳米纤维电极材料的放电比容量最大(578 F/g),电容性能最好.     

β-萘磺酸掺杂聚苯胺纳米粒子的固相反应法制备及其表征

利用固相反应法制备了 β 萘磺酸掺杂的聚苯胺纳米粒子 ,并以红外光谱 (FTIR) ,扫描电子显微镜(SEM) ,透射电镜 (TEM) ,X 射线衍射 (XRD)以及粉末微电极等测试方法对其进行了表征 .结果表明 ,固相反应法合成的 β 萘磺酸掺杂聚苯胺粒子直径为 30～ 5 0nm ,聚苯胺分子链排列有序 ,晶化率较好 .粉末微电极的循环伏安测试表明 ,β 萘磺酸掺杂聚苯胺有较好的电化学活性 .     

静电纺丝技术制备Tb（BA）3phen/PANI/PVP光电双功能复合纳米纤维

采用静电纺丝技术将聚苯胺(PANI)和稀土配合物[Tb(BA)3phen]掺杂到高分子材料(PVP)中,制备出一类新型的具有光电双功能的Tb(BA)3phen/PANI/PVP复合纳米纤维.用扫描电子显微镜(SEM)、X射线能量色散谱仪(EDS)、荧光光谱仪及宽频介电松弛谱仪对样品进行了表征.结果表明,复合纳米纤维直径为(331±43)nm.在276 nm紫外光激发下,Tb(BA)3phen/PANI/PVP复合纳米纤维发射出主峰位于491,547和585 nm的绿光,对应Tb3+的5D4→7F6,5D4→7F5和5D4→7F4跃迁.当Tb(BA)3phen∶PANI∶PVP的质量比为15∶10∶100时,复合纳米纤维的荧光发射最强,其电导率随PANI含量的增大而升高,在PANI∶PVP为50%(wt%)时,其电导率在高频(106Hz)下达1.531×10-6S/cm.     

低压近场静电纺丝ZnO/PVDF复合微米纤维阵列的制备及压力传感性

利用低压近场静电纺丝技术制备了ZnO/PVDF(聚二偏氟乙烯)微米纤维平行阵列, 通过光学显微镜、扫描电子显微镜(SEM)和X射线能量色散光谱(EDS)对ZnO/PVDF微米纤维进行了表征. 该复合纤维的平均直径约为40 μm. EDS分析测试证明ZnO纳米颗粒已经掺杂进入了平行微米纤维中. 压电性能和电学性能测试结果表明, ZnO/PVDF微米纤维阵列的压电性能增强. 研究结果表明, 近场电纺丝ZnO/PVDF复合微米纤维阵列在压电型压力传感器和纳米发电机领域具有潜在的应用价值.     

Ceforanide: a new and efficient corrosion inhibitor for mild steel in HCl solution

The corrosion inhibition properties of ceforanide for mild steel in HCl solution were analyzed by electrochemical impedance spectroscopy, potentiodynamic polarization, and gravimetric methods. The increase in inhibitor concentration and immersion time showed a positive effect on inhibition efficiency. The experimental data showed a frequency distribution and therefore a modeling element with frequency dispersion behavior and a constant phase element have been used. In aqueous acid solution, mild steel reacts by evolution of hydrogen. Visual observations showed that the hydrogen evolution decreased (i.e., corrosion inhibition effect increased) with increasing concentration of ceforanide. Potentiodynamic polarization study revealed that ceforanide acted as a mixed type of inhibitor. The results obtained from different methods are in good agreement. The adsorption behavior of ceforanide is experimentally investigated by contact angle measurement on metal surface. The contact angle of metal surface to the acid solution increased with inhibitor concentration; thereby confirming the increased hydrophobic nature of metal surface to the acid solution having inhibitors.     

二硫代酰胺类化合物在盐酸中对碳钢的缓蚀性能(英文)

采用失重实验,动电位极化,交流阻抗,量子化学计算和拉曼光谱等方法研究了N,N′-二异丙氧基丙基二硫代二丙酰胺(DPDA)在1 mol.L-1盐酸溶液中对碳钢的缓蚀性能.失重实验结果表明,DPDA在盐酸溶液中能够有效地抑制碳钢的腐蚀,当缓蚀剂DPDA的浓度为1×10-3 mol.L-1时,其缓蚀效率达到90.2%.极化曲线表明DPDA为混合型缓蚀剂,单一的容抗弧变化表明碳钢电极表面的腐蚀过程主要由电荷转移步骤控制.由失重实验,动电位极化和电化学交流阻抗方法得到的DPDA缓蚀效率具有较好的相关性,均表现为缓蚀效率随着DPDA浓度的增大而增加.另外,DPDA在碳钢表面的吸附符合Langmuir吸附等温式.吸附过程的吉布斯自由能(ΔG0a0d0s)为-38.65 kJ.mol-1,这说明DPDA分子在碳钢表面形成共价键而发生了自发的化学吸附.拉曼光谱表明DPDA分子有效地吸附在碳钢表面,量子化学计算结果证明DPDA分子在碳钢表面的化学吸附活性中心集中在S原子上.     

Adsorption and Corrosion Inhibition Behavior of Schiff Base-Based Cationic Gemini Surfactant on Mild Steel in Formic Acid

The adsorption and corrosion inhibition behavior of synthesized Schiff base-based cationic gemini surfactant bis[p-(N,N,N-tetradecyldimethylammonium bromide)benzylidene]thiourea (14-S-14) on mild steel in 20% formic acid in the temperature range of 30°C to 60°C was evaluated using weight loss measurements, solvent analysis of iron ions and potentiodynamic polarization measurements. The synthesized inhibitor was characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and thin layer chromatography (TLC). The surface morphology of the corroded mild steel specimen was evaluated using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDAX), and atomic force microscopy (AFM). Thermodynamic/kinetic parameters were calculated to elaborate the adsorption and corrosion inhibition mechanism of the inhibitor. The inhibition efficiency of the compound was found to vary with inhibitor concentration, immersion time, and temperature. The adsorption of the compound on the steel surface was found to obey Langmuir adsorption isotherm.      

The effect of 2-aminoquinoline-6-carboxylic acid on the corrosion behavior of mild steel in hydrochloric acid

The inhibitive effect of 2-aminoquinoline-6-carboxylic acid (AQC) against mild steel corrosion in 1?M HCl solutions was investigated using conventional weight loss, potentiodynamic polarization, linear polarization and electrochemical impedance spectroscopy methods. The weight loss results showed that AQC is an excellent corrosion inhibitor since its efficiency increased with the concentration to attain 91.8?% at 500?mg?l^?1. Electrochemical polarization measurements revealed that AQC acted as a mixed-type inhibitor and the results of electrochemical impedance spectroscopy have shown that the change in the impedance parameters, charge transfer resistance and double layer capacitance, with the change in concentration of the inhibitor is due to the adsorption of the molecule leading to the formation of a protective layer on the surface of mild steel. The adsorption was assumed to occur on the steel surface through the active centers of the molecule. The inhibition action of AQC was discussed in view of Langmuir adsorption isotherm. Density functional theory calculations of quantum parameters were used to explain efficiency in relation with molecular structure.     

Kopsia Singapurensis提取物对酸性介质中低碳钢的缓蚀效应(英文)

The influence of the alkaloid extract of Kopsia singapurensis on the corrosion behavior of mild steel (MS) in 1 mol·L-1 HCl and 1 mol·L-1 H2SO4 was studied using electrochemical techniques, viz., potentiodynamic polarization and AC impedance. The experimental results clearly show that the plant extract effectively inhibits corrosion in both acid media and the inhibition efficiency obtained from the electrochemical techniques is in good agreement. Furthermore, the polarization technique indicates that the extract acts as an anodic type inhibitor in HCl and as a mixed type in H2SO4. Scanning electron microscopy (SEM) was carried out to examine the surface morphological changes of metal specimens in both the inhibited and uninhibited solutions. SEM images show the formation of an adsorbed layer over the metal surface by the inhibitor molecule. The presence of alkaloidal constituents in the plant extract was confirmed by Fourier transform infrared (FTIR) spectroscopy and chemical analysis.     

Corrosion protection of carbon steel in acidic media by expired bupropion drug; experimental and theoretical study

The effects of expired bupropion on the corrosion protection of carbon steel in hydrochloric acid (1.0 M) and sulfuric acid (0.5 M) solutions were examined by Fourier transform infrared (FTIR) spectroscopy, Tafel polarization and electrochemical impedance spectroscopy (EIS). Bupropion concentrations in both acid solutions were raised, which improved corrosion prevention. Bupropion was a mixed inhibitor because it retarded the anodic and cathodic processes, as indicated by polarization data. The inhibition efficiency decreased with the increasing temperature from 25 to 55 °C. In the presence of bupropion, the activation energies of corrosion in both acid solutions increased. The thermodynamic quantities were deduced from the influence of temperature on the corrosion process of carbon steel in both acid media. Bupropion adsorption on carbon steel followed the Langmuir adsorption isotherm. The polarization data yielded outcomes consistent with the results arising from impedance measurements. FTIR spectroscopy showed the active sites of bupropion molecule during adsorption on the alloy surface. The theoretical study and molecular dynamics simulation of bupropion was done by a density functional theory (DFT) approach to realize the effects of molecular structure on the inhibitive action of bupropion.     

Inhibition effect of environmentally benign Karanj (Pongamia pinnata) seed extract on corrosion of mild steel in hydrochloric acid solution

The inhibition of the corrosion of mild steel in hydrochloric acid solution by the seed extract of Karanj (Pongamia pinnata) has been studied using weight loss, electrochemical impedance spectroscopy, potentiodynamic polarization, and linear polarization techniques. Inhibition was found to increase with increasing concentration of the extract. The effect of temperature, immersion time, and acid concentration on the corrosion behavior of mild steel in 1 M HCl with addition of extract was also studied. The adsorption of the extract on the mild steel surface obeyed the Langmuir adsorption isotherm. Values of inhibition efficiency calculated from weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy are in good agreement. Polarization curves showed that Karanj (P. pinnata) seed extract behaves as a mixed-type inhibitor in hydrochloric acid. The activation energy as well as other thermodynamic parameters for the inhibition process was calculated. The adsorbed film on mild steel surface containing Karanj (P. pinnata) seed extract inhibitor was also measured by Fourier transform infrared spectroscopy. The results obtained showed that the seed extract of Karanj (P. pinnata) could serve as an effective inhibitor of the corrosion of mild steel in hydrochloric acid media.     

Inhibition of mild steel corrosion in HCl solution using chitosan

The efficiency of chitosan (a naturally occurring polymer) as a corrosion inhibitor for mild steel in 0.1 M HCl was investigated by gravimetric, potentiodynamic polarization, electrochemical impedance spectroscopy measurements, scanning electron microscopy, and UV–visible analysis. The polymer was found to inhibit corrosion even at a very low concentration. Inhibition efficiency increases with a rise in temperature up to 96 % at 60 °C and then drops to 93 % at 70 °C, while it slightly increases with an increase in chitosan concentration. Polarization curves indicate that chitosan functions as a mixed inhibitor, affecting both cathodic and anodic partial reactions. Impedance results indicate that chitosan was adsorbed on the metal/solution interface. Adsorption of chitosan at the mild steel surface is found to be in agreement with Langmuir adsorption isotherm model. Chemical adsorption is the proposed mechanism for corrosion inhibition considering the trend of protection efficiency with temperature. Calculated kinetic and thermodynamic parameters corroborate the proposed mechanism.     

Surface morphological and impedance spectroscopic studies on the interaction of polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP) with mild steel in acid solutions

The inhibition of mild steel corrosion in aerated acid mixture of 0.5 N H₂SO₄ and 0.5 N HCl solution was investigated using potentiodynamic polarization studies, linear polarization studies, electrochemical impedance spectroscopy, adsorption, and surface morphological studies. The effect of inhibitor concentration on corrosion rate, degree of surface coverage, adsorption kinetics, and surface morphology is investigated. The inhibition efficiency increased markedly with increase in additive concentration. The presence of PEG and PVP decreases the double-layer capacitance and increases the charge-transfer resistance. The inhibitor molecules first adsorb on the metal surface following a Langmuir adsorption isotherm. Both PEG and PVP offer good inhibition properties for mild steel and act as mixed-type inhibitors. Surface analysis by scanning electron microscopy (SEM) and atomic force microscopy (AFM) shows that PVP offers better protection than PEG.     

An Electrochemical Study on the Corrosion Inhibition of Stainless Steel by Polyaniline Film

Polyaniline(PANI)film was electrosynthesized on 304 stainless steel by cyclic voltammetry using aqueous oxalic acid as supporting electrolyte.The potential sweep rates were changed to achieve the PANI film with different thickness and structures.Protective properties of the PANI film for corrosion of stainless steel in 3% NaC1 aqueous solution were investigated by monitoring potentiodynamic polarization curves and electrochemical impedance spectroscopy(EIS).The results showed that the PANI film which was formed with lower sweep rate led to more positive shift of corrosion potential and greater charge transfer resistance,reflecting higher inhibition for corrosion of the stainless steel.