Amount Of Aniline Research Articles

Synthesis of copolymer of aniline and pyrrole by inverted emulsion polymerization method for supercapacitor

AbstractCopolymer of aniline and pyrrole was synthesized by inverted emulsion polymerization method by oxidizing aniline and pyrrole using benzoyl peroxide in presence of sodium laurylsulphate surfactant and p‐toluenesulphonic acid. Copolymer samples were characterized by infrared, X‐ray diffraction and scanning electron microscopic techniques and compared their properties with the corresponding homopolymers. The optimum reaction conditions for the preparation of copolymer with reasonably good yield (1.72 g) and conductivity (7.3 × 10−2 S/cm) were established. The synthesis procedure was extended to prepare copolymer samples using various protonic acids. Electrochemical characterization such as cyclic voltammetry, charge‐discharge and impedance were carried out on symmetrical supercapacitor cell consists of poly(aniline‐co‐pyrrole)‐p‐toluenesulfonic acid salt, wherein, the copolymer salt was synthesized using equal amount of aniline and pyrrole monomers. The values of specific capacitance, energy and power densities for poly(aniline‐co‐pyrrole)‐p‐toluenesulfonic acid system (PANI‐PPy) were calculated from charge‐discharge studies and are found to be 21 F/g, 5.7 Wh/Kg and 100 W/Kg respectively. Impedance analysis showed specific capacitance value (57 F/g) at 0.01 Hz at 0.22 V. Among the copolymer salts, copolymer prepared with sulfuric acid showed higher capacitance (66 F/g). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Heterogeneous Preparation of Polyaniline-Cellulose Conductive Composites with Cellulose Pretreated by Ultrasonic and its Electrical Properties

A series of conductive composites polyaniline(PANI)-cellulose were heterogeneously synthesized by chemical oxidative polymerization of aniline with native cellulose pretreated by ultrasonic. The morphology and chemical structure of the composites were examined by SEM and FTIR. TGA was used to study their thermal properties. The electrical conductivity was measured at room temperature by the standard four-probe method. For the sake of illuminating the influence of ultrasonic pretreatment on the structure and properties of PANI-cellulose composites, the SEM microphotographs, FTIR spectrum and TG curve of the PANI-cellulose composites prepared with native cellulose without any treatment were also shown in this paper to serve as reference. The PANI content and electrical conductivity of these two composites were also compared. It was found that cellulose surface was severely eroded by ultrasonic wave, and PANI homogeneously dispersed on this eroded cellulose surface in the form of particles. In reverse, the PANI particles loaded on the surface of untreated cellulose with evident aggregation. The homogeneous dispersion of PANI particles would be favor for the improvement of the electrical conductivity of the composites. From the FTIR spectra, it was verified that there was no difference between these two composites. It indicated that ultrasonic force did not lead to the variation of the chemical structure of cellulose. TG curves revealed that the thermal stability of PANI-cellulose composites was obviously enhanced than pure cellulose due to the protection of PANI particles deposited on its surface. Nevertheless, ultrasonic has a negative effect on the thermal stability of the composites, which resulted in the long cellulose molecular chains change into shorter ones, so the decomposition of composite occurred at lower temperature. It was because that ultrasonic pretreatment contributed to the homogeneous dispersion of PANI and more PANI particle depositing on the cellulose surface. Therefore, the PANI-cellulose composites with ultrasonic pretreated cellulose have more PANI content and higher electrical conductivity than the composites with untreated cellulose. Moreover, the difference of these two factors between the two composites became more and more marked with increasing of the amount of aniline. When aniline used was up to 0.5 g, the PANI content in the former was 48.2% more than the latter. This work provided a facile method for the synthesis of PANI-cellulose conductive composites with excellent conductivity.

Chiral polyaniline with flaky, spherical and urchin-like morphologies synthesized in the l-phenylalanine saturated solutions

Chiral polyaniline (PANI), of flaky, spherical and urchin-like morphologies, was synthesized in the saturated l-phenylalanine solution by adjusting the molar ratio of l-phenylalanine to aniline from 0.25 to 40. The concentration of l-phenylalanine solution was constant, which was different from the conventional synthesis. The morphologies of PANI were observed by scanning electron microscopy. The molar ratio of l-phenylalanine to aniline and the amount of aniline were proposed to be crucial to the morphologies. Circular dichroism spectra confirmed that l-phenylalanine endowed predominately one type of chirality to polyaniline by hydrogen bonding. The optical, structural and electrochemical properties of these synthesized PANI were characterized by ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy and cyclic voltammetry, respectively. There were some insulating structures, such as oligomers, in the PANI chains, which were caused by the weak acid circumstance during the polymerization.

Facile one‐pot synthesis and characterization of novel nanostructured organic dispersible polyaniline

AbstractNovel polyaniline (PANI) with nanotube, nanosheet, and nanofiber shapes was facilely synthesized by a self‐templating one‐pot process. Anilinium‐dodecylsulfate (DS) complex, obtained by mixing equivalent amounts of aniline and sodium dodecylsulfate (SDS), played a template‐like role in forming PANI nanostructures. It was found that the morphology and electrical conductivity of the PANI nanostructures changed with the amount of SDS and the reaction temperature. Nanotube‐shaped PANI synthesized at the temperature of anilinium‐DS complex formation in presence of SDS (concentration <0.12 M) showed high conductivity (12.9 S/cm). At higher temperature, the morphology changed to shape of a rose flower and electrical conductivity decreased to 3.95 S/cm. This suggested that both temperature and SDS concentration were key parameters for controlling the formation of the anilinium‐DS complex that acted as a template. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1024–1029, 2009

Pathway and Evolutionary Implications of Diphenylamine Biodegradation by Burkholderia sp. Strain JS667

Diphenylamine (DPA) is a common contaminant at munitions-contaminated sites as well as at aniline manufacturing sites. Little is known about the biodegradation of the compound, and bacteria able to use DPA as the growth substrate have not been reported. Burkholderia sp. strain JS667 and Ralstonia sp. strain JS668 were isolated by selective enrichment from DPA-contaminated sediment. The isolates grew aerobically with DPA as the sole carbon, nitrogen, and energy source. During induction of DPA degradation, stoichiometric amounts of aniline accumulated and then disappeared, which suggested that aniline is on the DPA degradation pathway. Genes encoding the enzymes that catalyze the initial steps in DPA degradation were cloned from the genomic DNA of strain JS667. The Escherichia coli clone catalyzed stoichiometric transformation of DPA to aniline and catechol. Transposon mutagenesis, the sequence similarity of putative open reading frames to those of well-characterized dioxygenases, and (18)O(2) experiments support the conclusion that the initial reaction in DPA degradation is catalyzed by a multicomponent ring-hydroxylating dioxygenase. DPA is converted to aniline and catechol via dioxygenation at the 1,2 position of the aromatic ring and spontaneous rearomatization. Aniline and catechol are further biodegraded by the well-established aniline degradation pathway. Genes that encode the complete aniline degradation pathway were found 12 kb downstream of the genes that encode the initial dioxygenase. Expression of the relevant dioxygenases was confirmed by reverse transcription-PCR analysis. Both the sequence similarity and the gene organization suggest that the DPA degradation pathway evolved recently by the recruitment of two gene clusters that encode the DPA dioxygenase and aniline degradation pathway.

Heterogeneous preparation of cellulose–polyaniline conductive composites with cellulose activated by acids and its electrical properties

A series of conductive composites cellulose–polyaniline (PANI) were heterogeneously synthesized by chemical oxidative polymerization of aniline with native cellulose activated by various acids. The chemical structure and morphology of the composites were examined by FT-IR analysis and TEM. TGA was used to study their thermal properties. The composites prepared using the di-basic acids exhibited more favorable conductivity than the composites prepared using the monobasic acids. The content of PANI increased with increasing of activation time, and while the conductivity decreased because of the aggregation of PANI particles at the activation time range from 50 to 120 min. Both the PANI content and the electrical conductivity increased with an increase of the amount of aniline, and reached the maximum values at the 0.5 g aniline, respectively. The acids were able to successfully activate cellulose and lead to the improvement of the accessibility and reactivity of the O–H groups. The composites were highly stable compared to pure cellulose due to the safeguard from PANI slices. This work provided a facile method for the synthesis of cellulose–polyaniline conductive composites with excellent conductivity.

Cp ∗Ir-catalyzed N-alkylation of amines with alcohols. A versatile and atom economical method for the synthesis of amines

A versatile and highly atom economical catalytic system consisting of [Cp ∗IrCl 2] 2/NaHCO 3 (Cp ∗=pentamethylcyclopentadienyl) for the N-alkylation of amines with primary and secondary alcohols as alkylating reagents has been developed. For example, the reaction of equimolar amounts of aniline and benzyl alcohol in the presence of [Cp ∗IrCl 2] 2 (1.0 mol % Ir) and NaHCO 3 (1.0 mol %) in toluene at 110 °C gives N-benzylaniline in 94% yield. The present catalytic system is applicable to the N-alkylation of both primary and secondary amines, and only harmless water is produced as co-product. A wide variety of secondary and tertiary amines can be synthesized with high atom economy under mild and less-toxic conditions. One-pot sequential N-alkylation leading to tertiary amines bearing three different substituents is also described.

Organic base‐catalyzed sol–gel route to prepare PMMA–silica hybrid materials

AbstractA series of sol–gel‐derived organic–inorganic hybrid materials that comprise organic poly(methyl methacrylate) (PMMA) and inorganic silica (SiO2) was successfully prepared using aniline as an organic base catalyst to catalyze the sol–gel reactions of tetraethylorthosilicate (TEOS). Aniline was adopted not only as a catalyst but also as a dispersing agent during the preparation of the hybrid materials. The as‐prepared hybrid materials were then characterized using transmission electron microscopy, SEM/energy dispersive X‐ray spectroscopy and Fourier transform infrared spectroscopy. The characteristic temperatures (including Td and Tg) of the hybrid materials slightly exceeded those of neat PMMA, as revealed from thermogravimetric analysis and differential scanning calorimetry evaluations. Studies of the protection against corrosion demonstrated that the hybrid coatings all improved the protection performance on cold‐rolled steel coupons relative to that of neat PMMA coatings, according to measurements of electrochemical corrosion parameters. Additionally, incorporating silica particles into the polymer may effectively reduce the gas permeability of the polymer membrane. Reducing the size of silica particles (at the same silica feeding) further improved the gas barrier property. Optical clarity studies indicated that introducing silica particles into the PMMA matrix may slightly reduce the optical clarity of the films/membranes, as determined by UV‐visible transmission spectroscopy. The contact angle of H2O of the hybrid films increased with the amount of aniline. Copyright © 2006 Society of Chemical Industry Society of Chemical Industry

Formation of Acrylanilides, Acrylamides, and Amides Directly from Carboxylic Acids Using Thionyl Chloride in Dimethylacetamide in the Absence of Bases

A general one-pot procedure is described that rapidly converts acrylic acid to anilides upon sequential treatment of the acid in dimethylacetamide (DMAC) with thionyl chloride and stoichiometric amounts of anilines in 88−98% yields, with DMAC offering rate and stability advantages over the use of DMF. The use of DMAC was extended to other organic acids in forming anilides. Benzylamine amides can also be formed using stoichiometric amounts of benzylamine and brought to completion by warming in the absence of additional base. In addition, it was shown that tert-butylamides can be easily formed with the addition of excess tert-butylamine at 20 °C.

Vapor-phase synthesis of 1,2-dihydro-2,2,4-trimethylquinolines from anilines and acetone over group 5–7 metal halide clusters as catalysts

Reaction of aniline with acetone to form 1,2-dihydro-2,2,4-trimethylquinoline ( 1) was studied in a gas-phase reaction over halide clusters as solid acid catalysts. After activation of a niobium halide cluster, [(Nb 6Cl 12)Cl 2(H 2O) 4]·4H 2O ( 2), which has an octahedral metal framework, at an elevated temperature in a hydrogen stream for 1 h, reaction was initiated by introduction of stoichiometric amounts of aniline and acetone at the activation temperature. The catalysis to yield 1 became evident above 200 °C. Both the catalytic activity of 2 and the selectivity for 1 increased with increasing temperature, having a local maximum at 300 °C. The selectivity for 1 was 76% with 34% conversion at 450 °C. Reactions of o-, m-, and p-toluidines with acetone also produced the corresponding quinolines. The chloride clusters of tantalum with the same metal framework and rhenium with a triangular metal framework also catalyzed the condensation. Thus, a halide cluster can be a substitute for liquid acid, particularly at high temperatures.

Synthesis of microsized gold nanoplates by a self-seeding method in ethanol solution

Single-crystalline gold nanoplates with microsized edges have been synthesized by a simple self-seeding method with the assistance of aniline in an ethanol solution. The as-synthesized gold nanoplates showed strong absorption in near infrared region (NIR). Investigation suggests the amount of aniline added to the reaction solution plays a key role in the generation of nanoplates. A possible formation mechanism for these gold nanoplates is also proposed.

Facile synthesis of micrometer-sized gold nanoplates through an aniline-assisted route in ethylene glycol solution

Micrometer-sized edge, polygonal gold plates of several 10 nm thickness, called gold nanoplates, have been synthesized in large quantities through simply introducing aniline to a heated ethylene glycol (EG) solution of hydrogen tetrachloroaurate (HAuCl 4·4H 2O) without any other capping agents or surfactants. Electron diffraction (ED) and X-ray diffraction (XRD) patterns identified the as-prepared gold nanoplates were single crystals bound primarily by {1 1 1} facets. The study of the optical properties showed these large gold nanoplates had strong absorption in near infrared region (NIR). Investigations suggested the amount of aniline added to the reaction solution played a key role in producing gold nanoplates and the size of the gold nanoplates can be tuned by adjusting the stirring speed. The possible formation mechanism of the as-prepared gold nanoplates was also discussed.

Characterization and thermal degradation studies on polyaniline‐intercalated montmorillonite nanocomposites prepared by a solvent‐free mechanochemical route

AbstractPolyaniline (PANI)‐montmorillonite (MMT) nanocomposites were prepared by direct intercalation of aniline molecules into MMT galleries, followed by in situ polymerization within the nano‐interlamellar spaces under solvent‐free conditions. The basal spacing of aniline‐intercalated MMT increased gradually up to 1.5 nm with increasing amounts of aniline loaded. This result suggests that aniline molecules were adsorbed by MMT clay and that intercalated aniline likely located perpendicular to the silicate sheets. After polymerization, X‐ray diffraction and Fourier transform infrared analyses confirmed the successful synthesis of PANI chains between the MMT nano‐interlayers. The scanning electron microscopy images indicated that the surface morphologies of PANI–MMTs were strongly different depending on the PANI content. The electrical conductivities of PANI nanocomposite particles in pressed pellets ranged in the order of between 10−3 and 10−2 S/cm. UV–vis spectroscopy and doping level measurement were further used to discuss the conductivities of nanocomposites. The thermal stabilities of PANI–MMT nanocomposites were examined by using thermogravimetric‐differential thermal analysis and derivative thermogravimetric analysis, and both analyses consequently demonstrated the improved thermal stabilities of the PANI chains in the nanocomposites as compared to pure PANI. The thermal stabilities of resulting nanocomposites were strongly related to the PANI content, which increased as the PANI content decreased in the nanocomposites. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2705–2714, 2005

The effect of the components of the PdCl2/Fe/I2/Py catalytic system on nitrobenzene carbonylation to ethyl N-phenylcarbamate

AbstractThe PdCl2/Fe/I2/Py catalytic system (Py-pyridine), reported to be highly active in the reaction of nitrobenzene carbonylation to ethyl phenylcarbamate was studied. The present paper describes the role of catalyst components and its effect on the activity and selectivity of the catalyst. The increase in the amount of PdCl2 in the system while retaining a constant level of the other catalyst components, results in the increase of both carbamate and aniline yields. The increase in the amount of iron while retaining the other components constant, initially causes an increase in the carbamate yield; however, at Fe: Pd ratios higher than 36, the carbamate yield remains constant. The change in the amount of iron has no effect on the amount of aniline formed in the system. An increase in the amount of iodine in the system while retaining the other components constant, results in a decrease in carbamate yield and a considerable increase in the aniline yield of the reaction products.

Synthesis and properties of processible copolymer microparticles from chloroanilines and aniline

Two series of functional copolymer microparticles were simply synthesized via an oxidative polymerization of o- and m-chloroanilines (OC and MC) and aniline (AN) in HCl aqueous medium, for a detailed comparison between OC/AN and MC/AN copolymers. The polymerization characteristics, structures, and properties of the copolymers were systematically studied by gel permeation chromatographic, IR and UV-visible spectroscopic, wide-angle X-ray diffractive, and thermogravimetric techniques. The results showed that a small amount of AN can efficiently activate the oxidative polymerization of MC monomer although MC monomer can not homopolymerize oxidatively. A non-linear variation of the polymerization effect, molecular weight, and properties of the copolymers with the comonomer ratio suggests that the OC/AN and MC/AN polymers formed are genuine copolymers rather than a mixture of the corresponding homopolymers. The resultant copolymers show a remarkably enhanced solubility, a colorful solvatochromism and an improved processibility in comparison with polyaniline. The OC/AN copolymers demonstrate a faster polymerization rate, narrower molecular weight distribution, and higher conductivity, but have a lower polymerization yield, molecular weight, thermostability, and air-separation capability than the MC/AN copolymers.

Photocatalytic oxidation of aniline using Ag +-loaded TiO 2 suspensions

The photocatalytic decomposition of aniline has been investigated using Ag +-loaded TiO 2 suspensions as a sensitizer. The amounts of aniline, Ag + and TiO 2 have been optimized by following the rates of decomposition of aniline and formation of product(s). The initial consumption of aniline follows pseudo-first-order kinetics. The loading of 0.2 wt.% of Ag + almost doubled this rate compared to that of the unmodified particles. The increased activity of these particles has been attributed to the modified surface properties of TiO 2 due to the presence of Ag/Ag + on its surface, which may act as a trap for electrons and, thereby, inhibit the e −–h + recombination. Azobenzene has been found to be one of the main products of its oxidation. Its formation has been explained by the direct participation of holes in the oxidation process. Under the used experimental conditions, aniline could be completely decomposed in about 10 h. The addition of Na 2CO 3 to Ag +-loaded TiO 2 suspensions enhances the photodecomposition of aniline significantly. Mechanisms of these processes are discussed.

Organic/inorganic hybrid materials formed from TiO2 nanoparticles and polyaniline

This paper describes the synthesis and characterization of organic/inorganic hybrid materials formed from TiO2 nanoparticles and polyaniline (PANI). The preparation method is based on a sol-gel technique using titanium tetra-isopropoxide as oxide precursor, and two synthetic routes to the hybrids formation were employed, based on the addition of aniline after or before the sol formation. Different amounts of aniline were used to verify this effect on the characteristics of the formed materials. Samples were characterized by electronic spectroscopy, Raman spectroscopy, Fourier transformed infrared spectroscopy, thermal analysis, X-ray diffractometry and cyclic voltammetry. Results show that the different experimental routes are successful to produce hybrids formed by oxides nanoparticles and polyaniline in its conducting form, the emeraldine salt. There are no strong differences between the samples obtained by the two synthetic routes employed, except by the amount of polymer in the final material.

Hydrogenation of nitrobenzene with supported platinum catalysts in supercritical carbon dioxide: effects of pressure, solvent, and metal particle size

Hydrogenation of nitrobenzene (NB) has been investigated with Pt/C catalysts in supercritical carbon dioxide (scCO 2) and ethanol. The selectivity of aniline (AN) in scCO 2 is ⩾80%, which is twice as high as that in ethanol, in which comparable amounts of AN and azobenzene (AB) are produced. In scCO 2, the overall conversion of NB increases with CO 2 pressure, has a maximum at around 10 MPa, and then decreases at 14 MPa. The product selectivity in scCO 2 does not change much with the size of Pt particles while, in ethanol, the selectivity to AN and AB changes slightly with the particle size. The overall hydrogenation of NB is not structure sensitive in scCO 2, while it is structure sensitive in ethanol in which turnover frequency tends to decrease with an increase in the degree of Pt dispersion.

Preparation and Characterization of Novel Hybrid Materials Formed from (Ti,Sn)O2 Nanoparticles and Polyaniline

This paper describes the synthesis and characterization of new organic/inorganic hybrid materials formed from the mixed oxide (Ti,Sn)O2 nanoparticles and polyaniline (PANI). The preparation method is based on a sol−gel technique using titanium tetra-isopropoxide and tin tetrachloride as oxide precursors, and two synthetic routes to the hybrids formation were employed, based on the addition of aniline after or before the sol formation. Different amounts of aniline were used to verify this effect on the characteristics of the formed materials. Samples were characterized by thermal analysis, X-ray diffractometry, Raman, UV−vis, and FT-IR spectroscopy, transmission electron microscopy, cyclic voltammetry, and conductivity measurements. Results show that the different experimental routes are successful in producing hybrids formed by oxide nanoparticles or nanotubes and polyaniline in its conducting form, the emeraldine salt. There is little difference between the samples obtained by the two synthetic routes employed, except by the amount of polymer in the final material. The hybrids that contain approximately 10% weight of polyaniline are formed as a core/shell mixed oxide/polyaniline material.

Kinetics and mechanisms of the gas‐phase elimination of N‐phenylglycine and its ethyl ester

AbstractThe elimination kinetics of the title compounds were determined over the temperature range 290.4–420.3°C and pressure range 14.5–44.0 Torr. The reactions, carried out in seasoned vessels and in the presence of the free radical inhibitor toluene, are homogeneous, unimolecular and follow a first‐order rate law. The rate coefficient is expressed by the following Arrhenius equation: for N‐phenylglycine ethyl ester, log [I1 (s−1)]=(12.13±0.38)− (193.6±4.9) kJ mol−1 (2.303 RT)−1; and for N‐phenylglycine, log [k1 (s−1)]=(12.95±0.52)−(177.4±5.8) kJ mol−1 (2.303 RT)−1. Both substrates yield mainly N‐methylaniline and a small amount of aniline. N‐Phenylglycine as a neutral amino acid decomposes 130 times faster than its ethyl ester at 380°C. The mechanisms of these elimination reactions are presented and discussed. Copyright © 2003 John Wiley & Sons, Ltd.