纳米聚苯胺及聚苯胺/金复合材料的制备与表征

以氯金酸(HAuCl4)为氧化剂,在两种不同无机酸(HCl和H2SO4)的掺杂下,通过调节反应体系中混合溶剂的醇水比例,用一步氧化苯胺聚合法成功制备了不同形貌的纳米聚苯胺及聚苯胺/金复合材料.通过扫描电子显微镜(SEM)、紫外可见吸收光谱(UV-Vis)和红外光谱(FT-IR)对产物的形貌和结构进行了表征.在此基础上,进一步讨论了聚苯胺/金复合材料可能的形成机理.     

K8[Fe(H2O)W11MnO39]/PANI/V2O5三元复合材料的制备、表征及光催化性能研究

本文运用静电自组装法合成了一种新型三元复合材料K₈[Fe(H₂O)W₁₁MnO₃₉]/PANI/V₂O₅,并采用IR、UV、XRD、XPS、SEM、氮气吸附等方法对其进行表征;然后,以龙胆紫为有机污染物进行光催化实验,对此三元复合催化剂的降解性能进行研究。结果表明:K₈[Fe(H₂O)W₁₁MnO₃₉]/PANI/V₂O₅已被成功复合,且仍然保持Keggin结构,稳定性能良好;在pH=2,龙胆紫C初=5 mg·L^-1,此催化剂用量为5 mg的条件下,其脱色率高达93.09%。可见,此复合催化剂具有优异的研究潜力和实用价值。     

TiO~2修饰的介孔分子筛MCM-41的合成、表征及光 催化性研究

首次以三种不同的含钛有机物为氧化钛的前驱体,合成了三种TiO~2呈单层分散状态的TiO~2修饰的介孔分子筛MCM-41,并以XRD,FT-IR,液氮温度下N~2吸附-脱附曲线,固体UV-vis漫反射等表征手段对其结构特征和氧化钛分散状态进行了研究。TiO~2在介孔分子筛MCM-41孔道中分散,MCM-41仍能保持骨架结构,没有晶相TiO~2生成;TiO~2与MCM-41孔道表面的≡Si－OH以化学键连接,生成Si－O－Ti键;TiO~2在MCM-41内孔壁呈均匀单层分散状态;TiO~2粒子的减小使其对紫外光的吸收发生明显的蓝移现象。并以苯酚降解反应为模型检验合成的具有光催化性的TiO~2修饰的MCM-41的光催化活性。     

Inorganic-organic hybrid polyoxometalate: Preparation, characterization and electrochemistry properties

The solid hybrid material (H_3/4pbpy)₄[PMo₁₂O₄₀]·1.25H₂O (1) (pbpy=5-phenyl-2-(4-pyridinyl)pyridine) has been prepared and characterized. A structural feature of compound 1 is that the polyoxometalate anions exhibit a one-dimensional inorganic double chain-like structure via weak interactions of O…O. The organic moiety exhibits regular packing with offset aromatic-aromatic interactions between the pbpys, leading to a compact supramolecular framework structure to accommodate the inorganic chains. Compound 1 was employed to fabricate the three-dimensional bulk-modified carbon paste electrode (1-CPE) to research on its electrochemistry properties. The results indicate that 1 retained Keggin molybdate anion electrocatalytic activities toward the reduction of chlorate, hydrogen peroxide and nitrite.     

Preparation and characterization of polyaniline/MMT conductive composites

Polyaniline/montmorillonite (PAn/MMT) composite material has been prepared through chemical‐oxidative polymerization by using NH₄S₂O₈ as the oxidant, and it was found that both the composites have inorganic and organic material characteristics and many outstanding performance through the copolymerization coupling of MMT and polyaniline. Infrared spectroscopy (FT‐IR), thermogravimetric analysis (TGA), X‐ray diffraction (XRD), and transmission electron microscopy (TEM) are used to characterize the composition and structures of composite materials, as well as test the conductivity of composite materials through a four‐probe technique. The preparation conditions of PAn/MMT conducting composites are optimized. The optimal conditions have been identified for the reaction time, amount of oxidizer, concentration of HCl, and the amount of MMT. Besides, the results show that when the reaction lasts for 8 hr in the ice bath, the amount of MMT is 0.4 g/5 ml An, the mole ratio of oxidant to aniline is 1, and the concentration of hydrochloric acid is 2 M, the composite had the largest conductivity up to 11.5 S/cm. In addition, we also did an elemental analysis of the composite mechanism of PAn/MMT composites. Copyright © 2008 John Wiley & Sons, Ltd.     

负载型混晶纳米TiO_2/硅藻土复合材料的制备及其光催化性能

选用市售硅藻土作为载体,采用液相沉积法制备了负载型混晶纳米TiO2/硅藻土复合材料;采用扫描电镜、X射线衍射仪及红外光谱仪分析了复合材料的表面形貌和晶体结构;基于甲醛光催化降解实验考察了不同组成的负载型TiO2/硅藻土复合材料的光催化性能.结果表明,TiO2负载量为33.3%(TiO2与硅藻土的质量比为1∶2)的复合材料对甲醛光催化降解具有最佳催化活性.     

Preparation and characterization of perfluorosulfonic resin/titania hybrid transparent films

Preparation and characterization of perfluorosulfonic resin/titania organic-inorganic hybrid films were presented. The transparent hybrid films were prepared by hydrothermal treatment at low temperature of a mixed solution of tetrabutyl titanate and perfluorosulfonic resin with the help of acetylacetone. The characterization was carried out by SEM,XRD,FT-IR,UV-Vis and TGA. The results showed that the perfluorosulfonic resin/titania hybrid transparent films were composed of titania particles dispersed in the perfluorosulfonic resin matrix very well and the titania was of anatase phase. Its diameter de-creased with increasing weight ratio of titania to perfluorosulfonic resin.     

杂多钨酸盐/PANI/TiO_2三元复合催化剂的制备及光催化性能

以过硫酸铵为氧化剂,制备了复合光催化材料α-Si W11Ti/PANI/Ti O2。用UV-Vis、IR、XRD和SEM-EDS等测试手段对其结构及形貌等进行了表征。IR结果表明,复合后聚苯胺的IR振动峰发生红移。N2吸附-脱附显示产物为介孔材料,具有双孔结构,平均孔径约为20.07nm和26.69nm。以刚果红染料废水(15 mg/L)为探针反应,评价了其光催化性能,与一元催化剂Ti O2和二元催化剂/PAIN/Ti O2比较,三元催化剂Si W11Ti/PANI/Ti O2表现出更高的光催化降解性能,经30W紫外灯照射150min后,其降解率为92.44%。     

Controllable synthesis of titania/reduced graphite oxide nanocomposites with various titania phase compositions and their photocatalytic performance

A facile method is presented for preparing TiO2 /reduced graphite oxide(RGO) nanocomposites with phase-controlled TiO2 nanoparticles via redox reaction between the reductive titanium(Ⅲ) precursor and graphite oxide(GO),and a series of TiO2 /RGO composites with various TiO2 phase compositions were obtained.In all the titania/RGO composites,the TiO2 nanoparticles were uniformly distributed on the surface of the RGO.The TiO2 consisted of anatase phase particles in the form of square-plates with edges less than 10 nm and the rutile phase nanorods in diameters less than 10 nm.The performances of the as-prepared TiO2 /RGO composites were investigated on catalytically degrading phenol under visible light irradiation.The TiO2 /RGO composites can effectively degrade phenol under visible light irradiation,and the phase composition of TiO2 in the composites significantly influences the activities of these catalysts.     

多孔雪花状氧化锌分级纳米结构的制备、表征及其光催化性能研究

在H2O和乙二醇(EG)构成的二元体系中,通过Zn AC2与NH4F和H2O的水热反应制备了六角雪花状Zn OHF。Zn OHF在空气中退火,制备出了由单晶Zn O纳米片构建的多孔六角雪花状Zn O。用X射线衍射(XRD),扫描电子显微镜(SEM),透射电子显微镜(TEM)及其热重等多种手段对产物进行结构表征,并提出了可能的化学反应。以甲基橙和酸性大红为例,研究了其光催化性能,结果表明,多孔雪花状Zn O是一种有效的光催化剂。     

Preparation, characterization, and photocatalytic activity of polyaniline/ZnO nanocomposite

Polyaniline (PANI)/zinc oxide (ZnO) nanocomposite was synthesized by in-situ polymerization. X-ray diffraction patterns, UV?Cvisible spectroscopy, SEM, and TEM were used to characterize the composition and structure of the nanocomposite. Nanostructured PANI/ZnO composite was used as photocatalyst in the photodegradation of methylene blue dye molecules in aqueous solution. The photocatalytic activity of PANI/ZnO nanocomposite under UV and visible light irradiation was evaluated and was compared with that of ZnO nanoparticles. ZnO/PANI core?Cshell nanocomposite had greater photocatalytic activity than ZnO nanoparticles and pristine PANI under visible light irradiation. According to these results, application of PANI as a shell on the surface of ZnO nanoparticles causes the enhanced photocatalytic activity of the PANI/ZnO nanocomposite. Also UV?Cvisible spectroscopy studies showed that the absorption peak for PANI/ZnO nanocomposite has a red shift toward visible wavelengths compared with the ZnO nanoparticles and pristine PANI. The effect of different operating conditions on the photocatalytic performance of PANI/ZnO nanocomposite in the photodegradation of methylene blue dye molecules was investigated in a bath experimental setup.     

镍基蒙脱土/聚苯胺纳米复合材料的制备与表征

首先通过化学氧化法合成了导电聚苯胺,再将聚苯胺引入镍基蒙脱土层间,合成了镍基蒙脱土/聚苯胺纳米复合材料,并用FTIR、XRD、TEM对其结构进行了表征与分析。结果表明,聚苯胺已进入蒙脱土层间,并使蒙脱土片层间距增大。测定了复合前后材料的电导率并对其进行了合理的解释。     

Preparation and characterization of conducting polyaniline layered magnetic nano composite polymer particles

Considering the application potentials of organic materials possessing both conducting and ferromagnetic functions in various electronic devices, an attempt was made to prepare conducting polyaniline (PANI) layered magnetic nano composite polymer particles. Two routes were used to modify magnetic Fe₃O₄ core particles. In one route, seeded emulsion polymerization of methyl methacrylate (MMA) was carried out in presence of nano‐sized Fe₃O₄ core particles. In another route, cross‐linker ethyleneglycol dimethacrylate (EGDM) was used in addition to MMA. The modified composite particles were named as Fe₃O₄/PMMA and Fe₃O₄/P(MMA‐EGDM), respectively. Finally, seeded chemical oxidative polymerization of aniline was carried out in the presence of Fe₃O₄/PMMA and Fe₃O₄/P(MMA‐EGDM) composite seed particles to obtain Fe₃O₄/PMMA/PANI and Fe₃O₄/P(MMA‐EGDM)/PANI composite polymer particles. The modification of Fe₃O₄ core particles was confirmed by electron micrographs, FTIR, UV–visible spectra, X‐ray photoelectron spectra, X‐ray diffraction pattern and thermogravimetric analyses. A comparative study showed that crosslinking of intermediate shell improved the magnetic susceptibility and electrical conductivity of PANI layered magnetic nano composite particles. Copyright © 2013 John Wiley & Sons, Ltd.     

Preparation,characterization and application of polyaniline/epoxide polysiloxane composite films

Composites of polyaniline(PAn) and epoxide polysiloxane(EPSi) are reported for the first time. EPSi is designed, synthesized and N-grafted onto the PAn backbone through covalent bonds. As-prepared EPSi-g-PAn composites are soluble in organic solvents and the corresponding films can be easily produced via a simple solution-casting procedure. The composite films combine the mechanical characteristics of EPSi and the chemical properties of PAn, enabling the facile introduction of the noble metal particles. The successful fabrication of the composites is confirmed by the investigation of the molecular structure, crystalline structure and microstructure of the materials. The resulting composite films containing noble metal particles are employed as the catalysts for the hydrogenation of phenol to produce cyclohexanone, which exhibit the convenience and recyclability for usage as well as the high catalytic activities, including the conversion ratio of 97%-100% and the selectivity as high as 84%-98%. The present work not only provides a new method to improve the processability of the conducting polymers but also describes a kind of composite materials that may display outstanding preformances in industrial catalysis.     

BiOBr/BiOI复合体的制备及可见光催化性能

以硝酸铋、碘化钾、溴化钠和聚乙二醇-400为主要原料,利用水热法制备出具有较小粒径的BiOBr/BiOI复合体,通过扫描电子显微镜(SEM)、X射线衍射(XRD)、紫外可见漫反射(DRS)等测试手段对样品的形貌、物相组成进行了表征。以罗丹明B为模拟污染物,研究了可见光下所制备样品的光催化性能。结果表明:BiOBr/BiOI复合体的光催化性能高于单一的BiOBr和BiOI,光照80 min后罗丹明B的降解效率可达95.6%。     

Preparation and characterization of polyaniline with high electrical conductivity

In the present paper, polyaniline (PANI) was polymerized by ammonium persulphate using a chemically oxidative process under mild tempertures ranging from ?5–20°C. Electrical conductivity of as synthesized PANI got enhanced gradually owing to the increase in molecular weight and crystallinity with decrease in synthesis temperature. Extraction with tetrahydrofuran (THF) was employed as the purification method of emeraldine base (EB) to enhance the electrical conductivity of PANI effectively attributed to the removal of the low molecular weight fractions and defective molecular chains. Methanesulfonic acid (MSA) was used to dope EB due to its strong acidity and small molecular size, and the amount of dopant versus EB was also optimized. Using a novel “synergistic doping” process with m‐cresol, electrical conductivity of PANI is further enhanced owing to more regular molecular chains which resulted in better interchain charge carriers' conduction. The emeraldine salts obtained finally have high electrical conductivity reaching up to 32.5 S cm^?1, which is much higher than that of the conventionally synthesized sample reported previously. Copyright © 2008 John Wiley & Sons, Ltd.     

Preparation of a nanowire-structured polyaniline composite and gas sensitivity studies

To obtain organic nanowire sensors with high sensitivity and rapid response times, based on the inducement effect of surfactants during in situ polymerization, nanostructured polyaniline composites are obtained by using a chemical oxidation method by adding a small amount of surfactant. A casting method is employed on interdigitated carbon electrodes. The gas sensitivity to a series of chemical vapors is examined at room temperature. The results indicate that polyaniline with regular nanowire structure is obtained when succinic acid is added. The gas sensitivity and response rates of a film with nanowire structure are much better than those of conventional polyaniline films produced by means of organic solution spin coating methods. The film described in this work shows good selectivity to trimethylamine and other related gases and, the reaction being reversible with the use of high-purity nitrogen.     

Preparation of highly conductive, self-assembled gold/polyaniline nanocables and polyaniline nanotubes

One-dimensional gold/polyaniline (Au/PANI-CSA) coaxial nanocables with an average diameter of 50-60 nm and lengths of more than 1 mum were successfully synthesized by reacting aniline monomer with chlorauric acid (HAuCl(4)) through a self-assembly process in the presence of D-camphor-10-sulfonic acid (CSA), which acts as both a dopant and surfactant. It was found that the formation probability and the size of the Au/PANI-CSA nanocables depends on the molar ratio of aniline to HAuCl(4) and the concentration of CSA, respectively. A synergistic growth mechanism was proposed to interpret the formation of the Au/PANI-CSA nanocables. The directly measured conductivity of a single gold/polyaniline nanocable was found to be high (approximately 77.2 S cm(-1)). Hollow PANI-CSA nanotubes, with an average diameter of 50-60 nm, were also obtained successfully by dissolving the Au nanowire core of the Au/PANI-CSA nanocables.     

Preparation and characterization of RuO2/polyaniline composite electrodes

RuO₂–polyaniline (PANI) composites have been prepared by a novel method resulting in a composite material at the electrode surface. The method is based on the utilization of the chemical oxidation of aniline by the RuO₂ attached to the gold substrate in acid media. Electrochemical quartz crystal nanobalance combined with cyclic voltammetric and chronoamperometric measurements was used to study the oxidative deposition process as well as the exchange of ions and solvent molecules during cycling. The chemical reaction between RuO₂ and aniline results in a surface mass increase at the open circuit, and it also manifests itself in the substantial decrease of the open-circuit potential after addition of aniline into the supporting electrolyte. The potential range, the nature of the electrolyte, and the pH have been varied. The results of the piezoelectric nanogravimetric studies obtained for the redox transformation of RuO₂ and the composites are elucidated by the transport of ions and water molecules. It has been shown that the behavior of RuO₂ as well as of the composites strongly depends on the spontaneous and potential-dependent solvent sorption, the nature of the electrolyte, and the potential range. It has been found that the value of the specific capacitance was substantially increased by the polyaniline present without any significant deterioration of stability of the capacitor.     

Preparation of ZnO/GO composite material with highly photocatalytic performance via an improved two-step method

ZnO/graphene oxide(ZnO/GO) composite material,in which ZnO nanoparticles were densely coated on the GO nanosheets,was successfully prepared by an improved two-step method and characterized by IR, XRD,TEM,and UV-vis techniques.The improved photocatalytic property of the ZnO/GO composite material,evaluated by the photocatalytic degradation of methyl orange(MO) under UV irradiation,is ascribed to the intimate contact between ZnO and GO,the enhanced adsorption of MO,the quick electron transfer from excited ZnO particles to GO sheets and the activation of MO molecules viaπ-πinteraction between MO and GO.