化学氧化聚合制备微/纳米结构聚苯胺研究进展

近年来多种见诸报道的新颖聚苯胺(PANI)微/纳米结构及其制备途径,可大体归为:主要控制了苯胺化学氧化聚合中聚合产物成核、生长过程或对聚合反应施加了影响.主要从聚合产物的生长和团聚、苯胺化学氧化聚合所用氧化剂和掺杂剂三方面归纳了制备微/纳米结构PANI的反应条件及其影响因素.     

超声化学法合成聚苯胺及其表征

采用超声化学法,在没有任何模版的条件下合成了产物纯净、尺寸单一的纳米棒状聚苯胺,采用SEM、XRD、TG和BET等方法对产物进行了表征.研究表明,氧化剂过硫酸铵的用量与产率存在较大关联,氧化剂和苯胺单体的物质的量比1∶1时可以达到最大产率;盐酸浓度对产物形貌有较大影响,只有盐酸浓度达到一定程度才可以得到纳米棒状聚苯胺;超声化学法合成的聚苯胺比表面积要大大高于市售和机械搅拌法合成的聚苯胺,比表面积可达29.5m~2/g.     

聚苯胺/环氧树脂防静电涂料的研制

研究了采用化学氧化聚合法直接合成聚苯胺/环氧树脂防静电涂料的制备工艺。讨论了苯胺与环氧的质量比、氧化剂浓度、反应物酸浓度等反应条件对聚苯胺/环氧树脂防静电涂料性能的影响。结果表明,较佳的工艺条件为:苯胺与环氧树脂的质量比为0.3,盐酸浓度为2mol/L,氧化剂与苯胺的摩尔比为0.5时,制成的聚苯胺/环氧树脂防静电涂料相对较好,各项指标可满足防静电涂料的要求。     

制备条件对聚苯胺结构和形貌影响的研究

以过硫酸铵为氧化剂、苯胺为单体、盐酸的水溶液为溶剂,采用化学氧化法合成了聚苯胺。利用扫描电镜(SEM)、红外光谱(FT-IR)对制备的聚苯胺的结构和形貌进行了表征和分析。结果表明:分析不同的反应浓度、反应温度和不同超声强度对聚苯胺的结构和形貌的影响。     

苯环电子云效应对苯胺聚合反应影响的初步探索

以过硫酸铵(APS)为引发剂,亚硫酸氢钠为反应终止剂,分别以苯胺、2-甲氧基苯胺、对氨基苯磺酸为反应原料,合成了寡聚物。通过一维与二维核磁共振技术分别考察了在中性和酸性反应体系中生成的主要寡聚物化学结构,进而解释了形成这些产物的可能反应机理。通过研究模型化合物的反应规律,有助于深入了解苯胺聚合过程中苯环电子云密度与相应偶联方式之间的联系,对于聚苯胺及纳米结构聚苯胺的合成具有一定的理论指导意义。     

酒石酸掺杂微/纳米结构聚苯胺的制备及表征

以酒石酸为掺杂剂,过硫酸铵为氧化剂,采用"无模板"自组装法合成了掺杂态聚苯胺微/纳米纤维。分析了酒石酸与苯胺的不同摩尔比对产物形貌、分子结构及电性能的影响。结果表明,酒石酸与苯胺摩尔比为1时,生成了长径比较大、有序性较好的聚苯胺微/纳米纤维,该比例下电导率达到9.355×10-2 S/cm。改变反应温度和反应时间,酒石酸在常温下自组装掺杂即可得到较高电导率的聚苯胺产物。傅里叶变换红外光谱、紫外可见光分光光度计、X射线衍射仪的表征结果证明,不同酒石酸与苯胺摩尔比下合成的聚苯胺微/纳米纤维均为掺杂态,且具有一定的导电性。     

聚苯胺纳米矩形管的制备与表征

以樟脑磺酸(CSA)为掺杂剂、过硫酸铵为氧化剂.在水溶液体系中通过苯胺原位聚合制得直径为300～600nm的聚苯胺纳米矩形管,其导电率为0.1～1S/cm.通过扫描电镜(SEM)和透射电镜(TEM)对产物的形貌进行表征.发现n(CSA)/n(ANi)将影响产物的形貌.利用傅立叶红外光谱(FT-IR)和紫外一可见光谱(Uv_vis)对聚苯胺分子结构进行表征,发现产物是质子化掺杂的聚苯胺.通过X射线衍射(XRD)分析发现,聚苯胺纳米矩形管比纤维结构具有更好的分子链排列规整性.     

电致变色材料聚苯胺-邻胺基苯甲酸的合成条件及性能的研究

聚苯胺-邻胺基苯甲酸是一种溶解性能好的电致变色材料.探讨了单体摩尔分数、单体浓度、氧化剂用量、反应时间、反应温度及酸度对聚苯胺-邻胺基苯甲酸性能的影响.得出在苯胺与邻胺基苯甲酸摩尔分数为2∶1时,制得溶解性和电致变色性都很好且产率较高的聚苯胺-邻胺基苯甲酸的较佳反应条件为:盐酸浓度为1.2 mol/L左右,反应时间为4～6h,反应温度为20～25℃,单体浓度为0.4mol/L左右,氧化剂和单体摩尔浓度之比为1∶1.     

聚苯胺/醋酸丁酸纤维素导电复合膜制备研究

以机械活化固相法制备的醋酸丁酸纤维素(CAB)为基底,充分溶解后与苯胺均匀混合,以过硫酸铵为氧化剂,盐酸为掺杂剂,采用原位聚合法制得聚苯胺(PANI)/CAB(PANI/CAB)导电复合膜。探讨苯胺加入量、过硫酸铵与苯胺摩尔配合比、盐酸浓度以及反应时间对导电复合膜导电性能的影响,研究结果表明:CAB用量0.5g,苯胺单体加入量1.25g,过硫酸铵与苯胺摩尔配合比为1∶1,盐酸浓度1.5mol/L,反应时间11h条件下,制得的PANI/CAB导电复合膜的导电性最好,电导率达到0.255S/cm。     

新型聚苯胺衍生物——聚邻乙氧基苯胺的合成优化及性能研究

采用化学氧化法,以盐酸为掺杂剂合成一类新型的聚苯胺衍生物——聚邻乙氧基苯胺(POEA)。通过考察反应温度、反应时间、氧化剂用量、掺杂盐酸浓度对POEA溶解性和电性能的影响规律,优化其合成条件:在反应温度15℃,反应时间6h,盐酸摩尔浓度1.00mol/L,过硫酸铵(APS)与邻乙氧基苯胺(OEA)的质量配合比为1∶1条件下,制得的POEA的溶解度为67.52%、电导率达到0.00871S/cm,具有较好的热稳定性和电容性能,在电容电极材料领域应用前景较好。     

The conductive polyaniline/poly(ethylene terephthalate) composite fabrics

Conductive composite fabrics were prepared by chemical polymerization of aniline on poly(ethylene terephthalate) (PET) fabrics in the aqueous hydrochloride acid solutions using potassium dichromate as the oxidant. The effect of the polymerization conditions such as temperature, oxidant, aniline and hydrochloride acid concentrations was investigated on the electrical surface resistance and polyaniline (PAn) content of PAn/PET composite fabrics. The maximum PAn content and the lower electrical resistance of composite fabrics were observed at the HCl concentrations of 0.25 M and 1.5 M, respectively. The electrical surface resistance of the PAn/PET composite fabrics was decreased under vacuum five-fold more than the ones kept under in air. The properties of PAn/PET composite fabrics such as density, diameter and moisture regain were also investigated in comparison with the those of pure PET. The conductive composite fabrics were characterized by surface resistance, FTIR and TGA techniques.     

化学氧化法合成聚苯胺的导电性与产率研究

以过硫酸铵((NH4)2S2O4)为氧化剂,盐酸作为质子酸掺杂,采用化学氧化聚合法合成了导电聚苯胺,研究了氧化剂用量、掺杂质子酸浓度、反应温度和反应时间对聚苯胺导电性及产率的影响,用X射线衍射(XRD)、扫描电子显微镜(SEM)、傅立叶红外变换光谱(FTIR)、紫外-可见光谱(UV-Vis)分析研究了聚苯胺的结构和形貌特征。结果表明,制备导电性好、产率高的掺杂态聚苯胺最佳实验条件为:n((NH4)2S2O4)/n(An)为1︰1,盐酸浓度为1 mol/L,反应温度为5℃,反应时间6 h。在此条件下,制备得到的聚苯胺电导率大于27 S/cm,产率在95%以上,颗粒表现出一定的结晶性。     

软模板法聚苯胺微米管的制备与表征

以同时带有亲水基(-SO3)和疏水基(-C14O14N3)而具有两性分子结构的甲基橙为掺杂剂,利用软模板法制备聚苯胺微米管,通过扫描电镜(SEM)和透射电镜(SEM)对制得的聚苯胺微观形貌进行表征.分别控制盐酸与苯胺的摩尔比为0.5、1.5和2.5,两者摩尔比值为0.5时得到聚苯胺不规则颗粒,两者摩尔比值为1.5和2.5时得到聚苯胺微米管.利用傅里叶红外光谱(FTIR)和紫外-可见光谱(UV-vis)对聚苯胺的分子结构进行表征,结果表明产物是质子化掺杂的聚苯胺,甲基橙阴离子基团(C14O14N3SO3-)已掺杂到聚苯胺分子链中.     

反向微乳液法合成导电聚苯胺纳米粒子

以ＴｒｉｔｏｎＸ－１００为乳化剂、正己醇为助乳化剂,得到以苯胺盐酸盐为水相、正己烷为分散介质的反向（Ｗ／Ｏ）微乳液。进一步以过硫酸铵为氧化剂,合成了导电离子分材料聚苯胺的钠米粒子,对合成反应条件和产物的性能进行了初步的研究。     

导电聚苯胺/二氧化锰复合材料原位化学合成制备及表征

通过合理选择二氧化锰加入苯胺/过硫酸铵/酸水反应体系的时间,制备了各种含量的聚苯胺/二氧化锰复合材料(PANI/MnO₂)。用FTIR、UV-VIS、XRD和SEM对原位制备的PANI/MnO₂进行了表征。XRD证明了原位合成的复合材料中聚苯胺组分为无定型,MnO₂的晶型在反应前后未发生变化。SEM证明了反应中形成的聚苯胺倾向于在MnO₂颗粒表面沉积,得到一种包裹型的PANI/MnO₂复合材料。用苯胺的盐酸溶液在静止状态下处理复合材料,可得到一种树状珊瑚形貌的聚苯胺,这种形貌的聚苯胺不同于酸水体系中常见的颗粒状聚苯胺。     

Electrochemical synthesis and characterization of chloride doped polyaniline

Chloride doped polyaniline conducting polymer films have been prepared in a protic acid medium (HCl) by potentiodynamic method in an electrochemical cell and studied by cyclic voltammetry and FTIR techniques. The FTIR spectra confirmed Cl^- ion doping in the polymers. The polymerization rate was found to increase with increasing concentration of aniline monomer. But the films obtained at high monomer concentration were rough having a nonuniform flaky polyaniline distribution. Results showed that the polymerization rate did not increase beyond a critical HCl concentration. Cyclic voltammetry suggested that, the oxidation-reduction current increased with an increase in scan rate and that the undoped polyaniline films were not hygroscopic whereas chloride doped polyaniline films were found to be highly hygroscopic.     

Polyaniline as a Gas-Sensor Material

Polyaniline (PANI) was synthesized by oxidative polymerization of aniline using ammonium persulfate in an acid medium. The polyaniline salt was converted to base form by treatment with ammonium hydroxide. The polyaniline base was dissolved in N-methyl pyrrolidone (NMP) for film casting. The cast film was doped with HCl for obtaining higher conductivity. Both doped and undoped PANI films were characterized by UV-visible, FTIR, and XRD analyses. The electrical conductivity of the PANI film was studied by a four-point probe method at room temperature. Finally, ammonia gas-sensing characteristics of the prepared polyaniline film were studied by measuring the change in electrical conductivity on exposure to ammonia gas at different concentrations. The influence of concentration of acid during polymerization of aniline and dopant concentration on the gas sensing characteristics of PANI film are reported in this paper.     

Polyaniline Nanofiber Based Surface Acoustic Wave Gas Sensors—Effect of Nanofiber Diameter on H2 Response

A template-free rapidly mixed reaction was employed to synthesize polyaniline nanofibers using chemical oxidative polymerization of aniline. Hydrochloric acid (HCl) and camphor sulfonic acid (CSA) were used in the synthesis to obtain 30- and 50-nm average diameter polyaniline nanofibers. The nanofibers were deposited onto layered ZnO/64deg YX LiNbO₃ surface-acoustic-wave transducers. The sensors were tested toward hydrogen (H₂) gas while operating at room temperature. The dopant for the polyaniline nanofiber synthesis was found to have a significant effect on the device sensitivity. The sensor response was found to be larger for the 50-nm diameter CSA-doped nanofiber based sensors, while the response and recovery times were faster for the 30-nm diameter HCl-doped nanofibers     

Synthesis of high-performance one-dimensional polyaniline nanostructures using dodecylbenzene sulfonic acid as soft template

High-performance one-dimensional polyaniline (PANI) nanostructures, i.e. nanotubes and nanofibers were synthesized in the presence of dodecylbenzene sulfonic acid (DBSA) and hydrochloric acid (HCl) aqueous solution, with ammonium peroxydisulfate (APS) as oxidant. And the resulting PANI nanotubes possessed the diameters of 350-650 nm and length up to tens of micrometers and PANI nanofibers with diameters of 120-160 nm, respectively. Especially, the PANI nanotubes had a very uniform structure (nearly 100% in nanotubes) and the reaction yield was about 110% (compared to the quantity of aniline in the reaction). The formation mechanism of 1D PANI nanostructures was also proposed. The guide effect of the initial “soft-template” formed by aniline and DBSA was greatly controlled by its content and chemical structures.     

Synthesis and characterization of wormhole-like mesostructured polyaniline

Wormhole-like mesostructured polyaniline (PANi) has been synthesized by using sodium dodecyl benzene sulfonate (SDBS) as a structure directing agent and iron trichloride (FeCl₃ · 6H₂O) or ammonium persulfatee (APS, (NH₄)₂S₂O₈) as an oxidant in an acidic solution. The formation mechanism and structure of polyaniline was studied by powder X-ray diffraction, transmission electron microscopy and FT-IR spectroscopy. It was indicated that aniline (AN)/SDBS would form lamellar structure in an acidic solution, then after introducing oxidant, the wormhole like mesostructures would be formed. The reaction conditions, such as oxidant, oxidant/AN molar ratio, HCl/AN molar ratio, and the reaction temperature had influence on the formation of mesostructures.