共聚态聚苯胺的合成及性能

在不同的单体浓度和摩尔分率条件下，合成了聚苯胺-邻氨基苯甲酸、聚苯胺-邻甲氧基苯胺、聚苯胺-邻甲基苯胺和聚苯胺。用红外光谱表征了各聚合物的结构。对其溶解性、电致变色性进行了较详细的研究。结果表明：通过苯胺与带有极性或可溶性基团的苯胺衍生物共聚可有效提高聚苯胺的溶解性和可加工性，溶解性好的共聚态聚苯胺可制得稳定性和电致变色性好的膜。聚苯胺-邻甲氧基苯胺不但具有较高的溶解性而且具有很好的电致变色特性，很容易加工制得电致变色性膜。     

聚(苯胺-邻六氟羟基苯胺)共聚物的合成及其性能表征

采用过硫酸铵作为引发剂,通过化学氧化聚合法制备了一系列可溶性的聚(苯胺-邻六氟羟基苯胺)(PAH)的共聚物。利用傅里叶红外光谱(FTIR)、核磁共振氟谱(19F-NMR)、核磁共振氢谱(1H-NMR)、凝胶渗透色谱(GPC)、紫外光谱(UV)和场发射扫描电子显微镜(FESEM)等对共聚物的化学结构和形貌等进行了表征和分析。结果表明,邻六氟羟基苯胺(HAFIP)成功导入了共聚物主链中,共聚物的数均分子量Mn介于6.51×10~4与9.04×10~4之间。HAFIP的存在抑制了共聚物的醌式结构n→π*跃迁,随着共聚物中邻六氟羟基苯胺(HAFIP)摩尔分数的增大,共聚物形貌逐渐由纳米纤维向纳米颗粒变换。与聚苯胺难于溶解于一般有机溶剂不同的是,当邻六氟羟基苯胺(HAFIP)的摩尔分数超过0.5时,共聚物可以完全溶解于四氢呋喃、乙醇、N-甲基吡咯烷酮、N,N-二甲基甲酰胺等有机溶剂中,表明HAFIP的导入,可以大幅改善聚苯胺的溶解性能,从而扩展聚苯胺的应用范围。     

纳米CdS／聚（苯胺-邻氨基苯甲酸）复合薄膜的制备及表征

以苯胺和邻氨基苯甲酸为单体共聚而成的聚（苯胺-邻氨基苯甲酸）（PAOAA）为基体，制备了纳米CdS／PAOAA复合薄膜。纳米CdS粒子大小均匀，粒径分布窄，较稳定地存在于基体中，且随着硫化时间的延长粒径尺寸有所增加。荧光光谱表明纳米CdS／PAOAA复合薄膜的发光由CdS纳米粒子和PAOAA共同作用产生，在430nm和520nm附近出现了两大发光峰；CdS粒径的增加导致电子-空穴对在CdS内复合增大，表现为纳米CdS的荧光特征峰增强而PAOAA的荧光特征峰减弱。     

界面聚合法合成苯胺与邻甲氧基苯胺的樟脑磺酸掺杂共聚物及其表征

采用界面聚合法在樟脑磺酸存在的状态下合成了聚苯胺、聚邻甲氧基苯胺以及苯胺与邻甲氧基苯胺的共聚物.利用红外光谱,紫外可见吸收光谱,电子扫描微电镜,X-射线粉末衍射,循环伏安,电导率测试等手段对聚合物进行了表征,初步探讨了单体配比对共聚物形貌、结构及性能的影响.结果表明,界面聚合法合成的上述各聚合物均呈现微米级颗粒状分布,颗粒直径大多在100nm以内;共聚后聚合物的结晶性能下降;循环伏安及电导率测试结果表明,随着聚合物主链中邻甲氧基苯胺结构单元的增加,聚合物的电化学活性及电导率呈下降趋势.     

聚邻乙氧基苯胺的导电及溶致变色性研究

研究了一种聚苯胺衍生物聚邻乙氧基苯胺(POEA),以探讨取代基对聚苯胺聚合、掺杂、溶解的影响.通过化学氧化合成及重掺杂手段,制备了盐酸(HCl)、磺基水杨酸(SSA)、樟脑磺酸(CSA)、对甲苯磺酸(PTSA)等掺杂的聚邻乙氧基苯胺.以GPC、紫外、红外、XRD、四探针等测试手段,对不同掺杂态、脱掺杂态POEA进行了对比分析,同时考察了POEA在不同溶剂下的溶致变色行为.研究表明:脱掺杂态POEA数均分子量为62 834,掺杂后电导率达10-5～10-3S/cm,在常用有机溶剂中有良好的溶解性.随不同的氧化、掺杂程度,POEA溶液呈现红-蓝-绿-黄色的渐变历程,其极化子跃迁峰在494～880 nm移动.     

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.     

化学组成对聚苯胺类电流变体电流变效应的影响

制备了聚苯胺、聚甲基苯胺和溴化聚苯胺三种微粒,将其分别分散在氯化石蜡中形成电池变体以考察苯环取代基的性质对聚苯胺电流变效应的影响。结果表明,聚甲基苯胺电流变效应最强、溴化聚苯胺最弱。掺杂程度对聚苯胺和聚甲基苯胺电流变效应影响的研究表明,分别存在一适宜的掺杂程度使其电流变效应较好。少量的聚丙烯酸锂与聚苯胺的复合在不明显减弱其电流变效应的同时可降低其电流密度。     

化学氧化合成N-乙基苯胺与苯胺共聚物的防腐性能

通过开路电位法详细研究了掺杂酸种类、掺杂状态和共聚单体摩尔比等对化学氧化合成的N-乙基苯胺与苯胺(EA/AN)共聚物的防腐性能的影响。结果表明,所有EA/AN共聚物的防腐性能均优于两种单体的均聚物,单体喂入摩尔比EA/AN为20/80的去掺杂态共聚物表现出最优防腐效果。盐酸掺杂共聚物的防腐性能优于其它酸掺杂共聚物的,去掺杂态共聚物又优于掺杂态共聚物。尤其是在强酸性腐蚀介质中,以该共聚物为底漆,环氧树脂为面漆的复合涂层钢板的开路电位在浸泡过程中出现了不降反升现象,涨幅达110 mV左右,较裸露钢板相应正移了约545 mV,较聚苯胺复合涂层涂覆的钢板相应正移了约90 mV,在长达半年的浸泡后,涂层不脱落、不起泡,也无锈点出现。     

生物医用功能材料前驱体壳寡糖接枝聚己内酯的制备与表征

采用邻苯二甲酸酐保护壳寡糖的氨基制备了N-邻苯二甲酰化壳寡糖中间体,又通过引发剂辛酸亚锡引发ε-己内酯开环接枝聚合和脱去保护基的方法制备了新型生物医用功能材料前驱体壳寡糖接枝聚已内酯共聚物,该前驱体可进一步进行活性氨基的化学修饰.采用傅立叶红外光谱(FT-IR)、X射线衍射(XRD)、示差扫描量热仪(DSC)对N-邻苯二甲酰化壳寡糖接枝聚己内酯共聚物的化学结构、结晶性和热性能进行了表征.结果表明随着ε-己内酯与N-邻苯二甲酰化壳寡糖的摩尔比增加,接枝共聚物的DSC曲线出现了聚已内酯侧链的熔融峰,XRD也表明,壳寡糖分子不完善的结晶区被破坏,并在此基础上形成了新的均聚物聚己内酯(PCL)侧链的结晶区.     

共聚法引入甲基对聚苯胺结构及电导率的影响

通过间甲基苯胺与苯胺在右旋樟脑磺酸水性介质中进行化学氧化共聚得到它们各自的均聚物及共聚物,在聚苯胺链段上引入甲基来改变产物的结构与电导率。用FT-IR、UV-Vis、XRD、SEM方法表征聚合物的分子链结构与微观形貌,用四探针法测定聚合物电导率。结果表明,所得聚合物为直径100nm左右的短纤维,聚苯胺分子链上甲基的引入削弱了苯环之间的π-π共轭,使FT-IR、UV-Vis光谱特征峰发生蓝移。在单体总浓度一定的条件下,可通过调节单体比例将聚合物的电导率控制在0.02～6.50S/m的范围内。XRD谱图分析表明,甲基还具有诱导聚苯胺分子链取向的作用,使聚苯胺链聚集态规整性提高。     

Structure and stability of thin polyaniline films deposited in situ on silicon and gold during precipitation and dispersion polymerization of aniline hydrochloride

Fresh and one-year-old thin polyaniline films prepared during the in-situ precipitation and dispersion polymerizations of aniline hydrochloride on gold and silicon supports in forms of emeraldine salt and base were characterized by UV-visible, Fourier-transform infrared, and Raman spectroscopies. Raman microscope has been used for the analysis of molecular structure. It has been shown that the films prepared by dispersion polymerization are thinner and more resistant to heating. In all cases, the films prepared on silicon were more stable against aging in air than those prepared on gold, which are, on the other hand, more stable against chemical deprotonation. The role of aniline oligomers adsorbed in the early stages of aniline oxidation on the silicon and gold substrates in the molecular structure and stability of the films has been discussed.     

Synthesis of oriented polyaniline flake arrays

We first report the synthesis of oriented polyaniline (PANI) flake arrays by a self-assembly method with inorganic acid as a dopant. It is found that the morphology and molecular structure depend on aniline concentration. FTIR and XRD results reveal that the oriented PANI flake arrays are in high conductive emeraldine state, which is expected to show excellent electrochemical properties. Cyclic voltammograms of I₂/I^- system measurement shows that the oriented PANI flake arrays present small charge-transfer resistance and high electrocatalytic activity. The oriented PANI flake arrays are expected to be useful in electrical, optical and electrochemical devices.     

Structural determination of a semiconductive tetramer of aniline by IR,UV-visible,ESR, XPS and mass spectroscopy techniques

A tetramer of aniline was obtained by the chemical oxidation of aniline in sulphanilic acid. The analytical techniques of infrared, UV-visible and mass spectroscopy show formation of a relatively short conjugation length oligomer (tetraaniline). The electronic structure elucidated by X-ray photoelectron spectroscopy reveals that the tetraaniline skeleton contains both benzenoid, [-NH-C₆H₄-NH-], and quinoid, [-N=C₆H₄=N-], phenyl rings. In the oxidized state, the tetraaniline backbone containing alternate benzenoid and quinoid phenyl units structurally similar to emeraldine was not evident. Electron spin resonance and electrical conductivity data show localized charge carriers in the backbone. Experimental results predicting the molecular structure of tetraaniline are discussed.     

Synthesis of hollow polyaniline nanoparticles with reactive template

γ-Fe₂O₃ nanoparticles were used as the reactive templates for the fabrication of the hollow polyaniline nanoparticles via the chemical oxidative polymerization of aniline in the presence of hydrochloric acid. The particle size of the doped hollow polyaniline nanoparticles in the emeraldine form was determined by the reactive template. It was found that the reacting temperature played an important role in the formation of the hollow nanoparticles because of the low redox potential of Fe(III) ion. However, the kind of the protonic acids used had no influence on the fabrication of the hollow nanostructure. The formation mechanism of the hollow polyaniline nanoparticles was also proposed.     

Synthesis of polyaniline nanofibrous networks with the aid of an amphiphilic ionic liquid

In this work, polyaniline (PANI) nanofibrous networks were prepared using ionic liquid (IL), 1-hexadecyl-3-methylimidazolium chloride (C16MIMCl), as a template through oxidative polymerization of aniline with ammonium persulfate. The resulting PANI was characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis, and FTIR. It was indicated that the as-prepared PANI was in the emeraldine form and its morphology strongly depended on the molar ratio of aniline/C16MIMCI. A possible mechanism for the formation of PANI nanofibrous networks was that the ordered micro-domains of the IL acted as template to direct the growth of the nanostructures.     

Tumor pH‐Responsive Albumin/Polyaniline Assemblies for Amplified Photoacoustic Imaging and Augmented Photothermal Therapy

Tumor‐microenvironment‐responsive theranostics have great potential for precision diagnosis and effective treatment of cancer. Polyaniline (PANI) is the first reported pH‐responsive organic photothermal agent and is widely used as a theranostic agent. However, tumor pH‐responsive PANI‐based theranostic agents are not explored, mainly because the conversion from the emeraldine base (EB) to emeraldine salt (ES) state of PANI requires pH < 4, which is lower than tumor acidic microenvironment. Herein, a tumor pH‐responsive PANI‐based theranostic agent is designed and prepared for amplified photoacoustic imaging guided augmented photothermal therapy (PTT), through intermolecular acid–base reactions between carboxyl groups of bovine serum albumin (BSA) and imine moieties of PANI. The albumin/PANI assemblies (BSA–PANI) can convert from the EB to ES state at pH < 7, accompanied by the absorbance redshift from visible to near‐infrared region. Both in vitro and in vivo results demonstrate that tumor acidic microenvironment can trigger both the photoacoustic imaging (PAI) signal amplification and the PTT efficacy enhancement of BSA–PANI assemblies. This work not only highlights that BSA–PANI assemblies overcome the limitation of low‐pH protonation, but also provides a facile assembly strategy for a tumor pH‐responsive PANI‐based nanoplatform for cancer theranostics.     

Conductive polymer preparation under extreme or non-classical conditions

Polyaniline (PANI) emeraldine salt form and PANI/silver composites have been synthesized by sonochemical and ionizing radiation methods. These composite materials were obtained through sonication and γ irradiation of an aqueous solution of aniline and silver nitrate, in room temperature, respectively. The mechanisms suggested to explain the formation of these products are based on the fact that both methods produce hydroxyl radical ^•OH and hydrogen radical ^•H, where hydroxyl radical ^•OH acts as an oxidizing agent in the polymerization process of aniline monomer; and hydrogen radical ^•H, as a reducing agent for silver ions. Spectroscopic, X-ray, and SEM measures show that PANI and silver nano particles of 40 nm average diameter are produced with ultrasonic methods, whereas silver nano particles of 60 nm average, and fibrillar, highly network morphology for PANI with 60 nm fibrillar diameter average are obtained using γ radiation).     

Effect of iodine solutions on polyaniline films

Polyaniline (PANI) emeraldine-base films have been exposed to iodine solutions. The interaction between the films and the iodine solution was studied using the quartz-crystal microbalance (QCM) technique and the UV-visible absorption spectroscopy. The iodine-treated film of emeraldine base was subjected to dedoping process using 0.1 M ammonia solution. The resulting film was exposed again to the previously used iodine solution. Iodine was found to play multiple roles: the ring-iodination of PANI film, the oxidation of PANI to pernigraniline base, and iodine doping to PANI salt. A sensor based on PANI-coated electrode of QCM was developed to monitor the presence of iodine in solution.     

Flexible, all-organic ammonia sensor based on dodecylbenzene sulfonic acid-doped polyaniline films

A stable chlorobenzene dispersion of conducting polyaniline (PANI) has been obtained by doping emeraldine base with dodecylbenzene sulfonic acid (DBSA) and studied by spectrophotometric measurements in the UV-vis-IR range. The electrical properties of PANI: DBSA films obtained from the above dispersion have been investigated under different temperature and relative humidity conditions. All-organic chemoresistive devices have been developed by spin-coating the PANI: DBSA dispersion on flexible substrates, and then by depositing electrodes on the top, from a carbon nanotube conducting ink. Sensing tests performed under exposition to calibrated amounts of ammonia reveal that these simple and inexpensive sensors are able to detect ammonia at room temperature in a reliable way, with a sensitivity linearly related to concentration in the range between 5 ppm and 70 ppm.     

手性聚苯胺的制备及其电磁学性能研究

采用二次掺杂法制备了具有手征特性的聚苯胺,利用傅立叶红外光谱(FT-IR)、X射线衍射仪(XRD)、圆二色谱仪(CD)和紫外一可见光分光光度计(UV-vis)等分析手段对聚苯胺的结构、性能和手征特性进行了表征.结果表明,通过过硫酸铵作引发剂、盐酸掺杂获得了导电的盐酸掺杂态聚苯胺(PANI-HCI);通过氨水脱掺杂后得到本征态聚苯胺(EB),EB通过手性樟脑磺酸(CSA)诱导,形成了手征性螺旋构型聚苯胺.电磁性能测试表明,与非手性聚苯胺相比,手性聚苯胺具有较优越的吸波性能.