溶胀处理煤对煤结构与煤基聚苯胺导电性影响

首次选用苯胺为溶剂对神府煤(SFC)进行溶胀处理,以研究其对煤结构与煤基聚苯胺导电性的影响,对其结构进行TG/DSC、FTIR和SEM分析,并通过溶胀SFC处理煤为聚合基体,在苯胺和引发剂条件下聚合为煤基聚苯胺,测定了其导电率。结果表明:苯胺溶胀处理破坏了煤中非共价键,降低了煤的交联缔合度,疏松了煤的孔结构,在此条件下的煤基聚苯胺的导电率均小于溶胀处理前原煤为聚合基体的煤基聚苯胺导电率,这与煤大分子网络结构受到一定程度破坏有关,这可为煤基聚苯胺的扩大化生产提供重要参考。     

不同酸搀杂对聚苯胺的结构和形貌的影响

以过硫酸铵为氧化剂,苯胺为单体,不同酸的水溶液为溶剂,采用化学氧化法合成了聚苯胺。利用扫描电镜(SEM)、红外光谱(FTIR)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,不同酸掺杂的环境下,聚合而成的聚苯胺的结构和形貌存在一定的差异。     

手性聚苯胺改性硅藻土复合材料的制备

在樟脑磺酸的手性诱导作用下,在硅藻土表面原位聚合苯胺得到手性聚苯胺改性硅藻土复合材料,利用红外吸收光谱(FTIR)和扫描电子显微镜(SEM)对复合材料的结构进行表征,表明苯胺在硅藻土表面进行了原位聚合,聚合产物呈现纳米棒状态。通过测试复合材料的循环伏安特性曲线(CV)表征材料的电化学性能,对比了在不同手性聚苯胺/硅藻土配比以及不同时间条件下改性材料的性能差异。结果表明:随着苯胺聚合量的增大以及反应时间的增加,复合材料的电化学性能会呈现先增大后减小的趋势。     

银/聚苯胺复合材料的制备及抗菌性能研究

采用一种简单、环保的方法制备银/聚苯胺复合材料。通过苯胺和Ag~+之间的络合,在无溶剂体系中加入氧化剂使苯胺聚合,制备聚苯胺完全包裹银的复合材料。通过扫描电镜、透射电镜、X射线衍射分析仪、傅里叶变换红外光谱仪,X射线光电子能谱分析仪对复合材料进行测试与分析,结果显示银纳米粒子粒径在5~10 nm左右,分散性良好且被聚苯胺完全包裹。银纳米粒子与聚苯胺有着较强的相互作用。抗菌性能测试结果显示银/聚苯胺复合材料对酵母菌的抗菌率达到99.7%。     

煤孔结构对煤/PAN复合材料导电性能的影响

煤基聚苯胺复合导电材料是利用煤的酸性官能团特征、孔结构特征和芳香层片特征 ,以煤为模板 ,用 APS引发苯胺单体 ,在煤中原位聚合而成的 .其中煤的孔结构是影响煤 / PAN导电性能的重要因素 .选择 HNO3 ,H2 O2 氧化及苯胺抽提的方法改变煤的孔结构 ;通过电导率及孔结构分析表明 ,氧化和抽提使煤的孔结构变得发达 ,因而苯胺能更好地进入已溶胀煤的孔结构中 ,提高了煤基聚苯胺的电导率 .     

碳纳米管/聚苯胺复合材料分散性和界面特点

利用原位复合工艺，在碳纳米管与聚苯胺复合过程中进行苯胺的原位聚合获得了碳纳米管／聚苯胺复合材料。利用透射电子显微镜对复合材料中的碳纳米管的分散性、碳纳米管／聚苯胺界面进行了分析、检测。结果表明苯胺能够很好的在碳纳米管上形核长大，并且能够完全包覆和缠绕在碳纳米管上。这种工艺有利于碳纳米管很好的分散在聚苯胺基体中。     

苯胺和环氧丙烷共聚物在BMIHSO4中的电化学聚合和表征

在1-丁基-3-甲基咪唑硫酸氢盐(BMIHSO4)离子液体中，采用循环伏安法合成了苯胺和环氧丙烷共聚物（PAN-PPO），并与聚苯胺（PAN）进行了对比。结果表明：在相同条件下，PAN-PPO的电合成速度远大于 PAN。同时采用红外光谱FTIR和扫描电子显微镜SEM对PAN-PPO进行了表征，FTIR表明苯胺和环氧丙烷在BMIHSO4中发生了共聚，SEM表明PAN-PPO由直径小于80 nm的纳米纤维组成。     

聚苯胺/二氧化钛复合微粒的光催化性能研究

利用原位聚合的方法制备出聚苯胺/二氧化钛复合材料。透射电镜、X射线衍射分析表征表明，聚苯胺修饰后的纳米二氧化钛形貌、晶型和粒径基本没有发生改变；紫外可见漫反射吸收光谱表征表明，PANI/TiO₂纳米复合微粒在可见光区的光吸收能力增强。当苯胺与二氧化钛的摩尔比为1:100，盐酸浓度为2 mol/L，可见光光催化效果最好。经过10次的稳定性循环测试后，降解率能保持在42%，说明复合材料有一定的稳定性。二氧化钛表面的聚苯胺能够吸收可见光的光子产生电子p-p*跃迁，聚苯胺的电子输运性可以有效分离光生电子-空穴对，降低电子-空穴复合的几率，提高了光催化活性。     

等离子体引发聚合制备聚苯胺纳米纤维及其在柔性传感器方面的应用

以等离子体引发聚合的方式在高浓度下得到高产率的聚苯胺(PANI)纳米纤维,并将PANI纳米纤维与聚二甲基硅氧烷(PDMS)混合制备了柔性应变传感器。通过扫描电子显微镜(SEM)、X射线衍射(XRD)、红外光谱(FTIR)、电化学性能测试手段等表征了聚苯胺纳米纤维的结构、组成以及传感器的性能。结果表明,等离子体处理时间的增加,聚苯胺纳米纤维的长径比会逐渐减小,聚苯胺的氧化程度和结晶度会逐渐提高,而产率则呈现出先增后降的趋势;聚苯胺纳米纤维浓度越高,传感器灵敏度越低,稳定性越好。     

DBSA掺杂聚苯胺的制备、表征及其导电性

采用过硫酸铵(APS)为氧化剂在十二烷基苯磺酸(DBSA)微胶束中化学氧化制备纳米棒状聚苯胺;DBSA既起乳化剂也起掺杂剂的作用。制备的掺杂聚苯胺用红外光谱(FTIR)、紫外光谱(UV-vis)、X-射线衍射(XRD)和扫描电镜(SEM)进行了表征;透射电镜(TEM)下首次观察到了聚苯胺的有序排列结构,晶面间距为5.99 Å。考察了掺杂剂/苯胺、氧化剂/苯胺的摩尔比和反应温度、时间等对聚苯胺电导率影响,最高电导率达到了0.72 S/cm。透射电镜怎能看到5.99     

Microstructural and Optoelectronic Studies on Polyaniline: TiO2 Nanocomposites

Thin films of polyaniline (PANi) and PANi: titanium oxide (TiO₂) composites have been synthesized by sol–gel spin coating technique. The TiO₂ powder of particle size 50–60 nm was synthesized by the sol–gel technique and the polyaniline was synthesized by the chemical oxidative polymerization of aniline. The composite films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, UV-vis spectroscopy and the four-probe method. The results were compared with corresponding data on pure polyaniline films. The intensity of diffraction peaks for PANi:TiO₂ composites is lower than that for TiO₂. The characteristic FTIR peaks of pure PANi are observed to shift to a higher wavenumber in PANi:TiO₂ composite, which is attributed to the interaction of TiO₂ particles with PANi molecular chains. The resistivity measurement shows that the molecular chain constitution of polyaniline is the most important carrier in the polyaniline: nano-TiO₂ composite.     

Interfacial assembly and electrochemical properties of nafion-modified-graphene/polyaniline hollow spheres

A novel strategy has been developed to prepare hollow structured Nafion-modified-graphene/polyaniline (NGP) composites via interfacial assembly polymerization between an aqueous phase containing oxidant and an organic phase containing aniline monomers and Nafion-modified graphene. Fourier transform infrared (FTIR), Ultraviolet-visible (UV-vis) and X-ray diffraction (XRD) analyses confirmed the generation of polyaniline (PANI) on graphene during the interfacial polymerization. The morphological evolution of the product had been investigated by scanning electron microscopy (SEM) with respect to the reaction time, based on which a conceivable interpretation of the growth mechanism of the sphere architectures with composite component were given. The as-prepared hollow structured composites showed a good rate capability as electrode material for supercapacitor, and the as-designed interfacial assembly preparation strategy for such composites may provide a generic guideline in developing other graphene-base composite hollow spheres with different compositions.     

Characterization and conductivity studies of nanocomposite films with polymer networks containing polyaniline‐alginate/titanium dioxide

Polyaniline nanocomposite films were chemically synthesized in the presence of alginate template by varying the concentration of TiO₂ in the composites. Characterization of the composite samples by FTIR, UV‐Vis spectra (UV), and X‐ray diffraction (XRD) indicates the formation of polyaniline‐alginate/titanium dioxide (PAT) composites. The morphology analysis by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) also supports the formation of the composites. Temperature‐dependent DC conductivity of the polyaniline‐alginate (PA) and PAT composites was studied in the range of 300 ≤ T ≤ 500 K. UV‐Vis and FTIR spectral studies reveal that the alginate is a good template for the chemical interaction between polyaniline and TiO₂, which suggests that the micelles formed by the anilinium‐alginate cations containing TiO₂ are responsible for the transport properties of the PAT composites. POLYM. COMPOS., 31:1754–1761, 2010. © 2010 Society of Plastics Engineers.     

Novel method of fabrication of polyaniline–CdS nanocomposites: Structural,morphological and optoelectronic properties

Polyaniline–CdS nanocomposites have been synthesized by spin coating technique. The nanocrystalline CdS powder of particle size 40–50 nm was synthesized by sol–gel technique and the polyaniline was synthesized by chemical oxidative polymerization of aniline. The composite films were characterized by X-ray diffraction (XRD), field effect scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), UV–Vis spectroscopy and Four probe method. The results were compared with corresponding data on pure polyaniline films. The intensity of diffraction peaks for PANi–CdS composites is lower than that for CdS. The conductivity measurement shows that molecular chain constitution of polyaniline is the most important carrier in polyaniline–CdS nano composite. The optical studies showed that variation in band gap of polyaniline (3.40 eV) to 2.54 eV CdS which is attributed to the interaction of CdS nanoparticles with PANi molecular chains.     

Synthesis and Characterization of Polyaniline:TiO2 Nanocomposites

Thin films of polyaniline (PANi) and PANi:titanium oxide (TiO₂) composites have been synthesized by sol—gel spin coating technique. The TiO₂ powder of particle size 50–60 nm was synthesized by sol–gel technique and the polyaniline was synthesized by chemical oxidative polymerization of aniline. The composite films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) Fourier transform infrared (FTIR) and UV-vis spectroscopy, and the results were compared with polyaniline films. The intensity of the diffraction peaks for PANi:TiO₂ composites is lower than that for TiO₂. The characteristic FTIR peaks of PANi were found to shift to a higher wave number in the PANi:TiO₂ composite. These observed effects have been attributed to the interaction of TiO₂ particles with PANi molecular chains. The room temperature resistivity of polyaniline:nano-TiO₂ composite is 3.43 × 10³ Ω cm and the resistivity of pure nano-TiO₂ particles is 1.60 × 10⁶ Ω cm.     

Structural,Morphological, Optical,and Electrical Properties of PANi-ZnO Nanocomposites

Thin films of polyaniline (PANi) and PANi–Zinc oxide (ZnO) nanocomposites have been synthesized by a spin-coating technique. The ZnO powder of particle size 50–60 nm was synthesized by sol–gel technique and the polyaniline was synthesized by chemical oxidative polymerization of aniline. The nanocomposite films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), UV–Vis spectroscopy, and four probe technique, and the results were compared with polyaniline films.     

Synthesis and characterization of novel poly(aniline-co-m-aminoacetophenone) copolymer nanocomposites using dodecylbenzene sulfonic acid as a soft template

A series of dodecylbenzene sulphonic acid (DBSA) doped poly(aniline-co-m-aminoacetophenone) copolymer composites of different compositions were synthesized in micellar solution of DBSA to obtain nanosphere morphology with enhanced processability. The plausible mechanism for the formation of poly(aniline-co-m-aminoacetophenone)-DBSA copolymer composite has been presented. These DBSA doped copolymer composites were characterized by UV–Visible, FTIR spectroscopy and XRD analysis techniques. UV–Vis absorption spectrum of the composites showed 325 and 637 nm which corresponds to the π–π* and n–π* transition. In FTIR spectroscopy a broad band around 2,924 cm^?1 corresponds to C–H vibration of DBSA indicating good agreement with the characteristic bands of DBSA. The sharp band at 1,292 cm^?1 is assigned to C–N stretching mode of vibration of N–Ph–N units. The X-ray diffraction of composites reveals that these composites are amorphous in nature. The number of diffraction peaks decreased with increase in the m-aminoacetophenone content. It indicates that these composites are amorphous in nature. Morphological studies (SEM) reveal that these composites have a spherical morphology with the average size of 100–200 nm. These composites exhibit electrical conductivity value of 0.744 × 10^?3 S/cm and enhanced solubility than polyaniline. Moreover, at the presented work, the DBSA doped copolymer composites were obtained in high yields by keeping an oxidant to co-monomer ratio of 1:1.     

Removal of phenols from the aqueous solutions based on their electrochemical polymerization on the polyaniline electrode

Phenol and 3-nitrophenol in a aqueous solution of NaCl with pH 4.0 can be polymerized on the polyaniline electrode to form polyaniline/polyphenol and polyaniline/poly(3-nitrophenol) composites, respectively, using potential cycling between −0.20 and 1.00 V (vs. SCE). Polyaniline played an important role in lowering passivation of the electrode, which made the consecutive electrochemical polymerization of phenol and 3-nitrophenol become possible. The growth of the polyaniline/polyphenol and polyaniline/poly(3-nitrophenol) films in the electrolytic process was proved by the increasing area of the cyclic voltammograms as the electrolysis proceeded. The SEM images and IR spectra of polyaniline and phenolic polymers demonstrated the formation of the phenolic polymers on the polyaniline electrode. Therefore, the removal of both phenolic compounds is based on the formation of their polymers on the polyaniline film.     

Sisal fibre/polypropylene composites modified with carboxyl terminated hyperbranched polymer

Abstract

In this study, polypropylene (PP)/sisal fibre (SF)/carboxyl terminated hyperbranched polymer (CTHP) composites were prepared by using short SF as the reinforcement, PP as the matrix and CTHP as a compatiliser. The impact fracture surface of PP/SF composites and the interfacial compatibility between PP and SF were analysed. Experimental results showed that the impact strength and flexural strength of PP/SF composites modified with the CTHP (2 wt-% of SF) were 21·5 and 9·7% higher than that of unmodified systems respectively. The SEM photomicrographs of the fracture surfaces have also shown that PP was highly bonded to the SF in the CTHP treated composites; wide angle X-ray diffraction (WAXD) measurement indicated that the CTHP did not change the crystal structure of PP and was still a-type crystal. Moreover, the addition of a small amount of the CTHP was helpful to improve water resistance of SF/LGF/PP composites.