Papers by Keyword: Aniline

Abstract: The kinetics of the synthesis of polyaniline in the presence of inorganic fillers was studied. It is shown that the acid-base surface properties of the inorganic filler affect the polymerization time. The introduction of a filler in the reaction mass containing aniline leads to a decrease in the induction period of oxidative polymerization. The decrease in the induction period is due to the fact that aniline is adsorbed on the surface of the filler. This leads to the fact that polyaniline is formed as a thin layer on the surface of the carrier. With a further increase in the content of inorganic filler, the time of the induction period increases. This is due to the fact that the surface of talc has a basic character. The use of mica as an inorganic filler leads to a decrease in the induction period of polymerization in the entire range of the carrier content studied.

Abstract: The aim of these comparative studies consists of synthesis and characterization of membrane assemblies from cellulose acetate (CelAc) and acrylic acid (AA), using as dopant in-situ generated pyrrole–aniline (Py–AN) copolymer intended for use in fuel cells fabrication. The synthesis was conducted through free radical polymerization in a semi-homogeneous system and the casting method was used to form the solid polymer membranes. In selecting the optimal compositional parameters, the influence of the molecular size of the majority matrix component was also observed. These membrane assemblies were studied using FT-IR spectroscopy, UV-Vis spectroscopy, and X-Ray diffraction analysis which highlighted the structure–composition dependence. With the electrochemical impedance spectroscopy the ionic conductivity of the membrane was determined, in order to evaluate the PEM fuel cell performance. In case of thicker membranes, there is an increase in ionic conductivity values over those of lower thickness, which is due to short-order structural order. Also, a superunitary Py:AN is more favorable to conductivity increase than a less than one ratio.

Abstract: In this study, polyaniline on silane-functionalized zinc oxide was fabricated. The zinc oxide particles were functionalized by soaking in silane aniline-ethanol solution. Afterwhich, the polyaniline was polymerized on the grafted silane aniline molecules using oxidative polymerization. The FTIR spectra showed vibrational peaks associated with the silane aniline molecules and grafted polyaniline. The sampled soaked in silane aniline coupling agent showed FTIR peaks associated with grafted silane aniline. The sample soaked for one minute showed FTIR peaks associated with ortho-coupled aniline units that is formed during the start of aniline polymerization. The sample soaked for three minutes showed FTIR peaks that is broader compared to others due to ring vibration in long polymeric chain.

Abstract: Nanostructured anilino-functionalized reduced graphene oxide intercalated with Pt metal nanoparticles was successfully synthesized. Graphene oxide nanosheets were synthesized using a modified Hummers method with simultaneous in-situ functionalization with aniline and ionic Pt reduction and dispersion through sonication. The nanomaterial was characterised with FTIR, UV-visible, SEM, TEM, EDX, XRD and Raman spectroscopy to ascertain surface, chemical, elemental and crystalline properties, composite structures, size, morphology and successful entrapment of metal nanoparticles while the electro-conductivity of the nanomaterial was interrogated using CV. The graphene oxide was successfully functionalized with aniline with new peaks belonging to the N-H and C-N group being present and calculated band gaps of 5.35 eV and 4.39 eV which are attributed to functionalization of graphene oxide. The functionalized graphene oxide was successfully loaded with platinum nanoparticles as TEM revealed that the Pt particles are spread out on the graphene sheets and when magnified a uniform distribution of the nanoparticles can be observed. The material (functionalized graphene oxide loaded with platinum nanoparticles) was used in the design of an asymmetric supercapacitor cell using 6M KOH aqueous electrolyte. On testing by galvanostatic charge/discharge, a high specific capacitance value of 605 F/g with a corresponding energy and power densities of 0.021kWh/Kg and 0.372kW/Kg respectively, were obtained.

Abstract: Classification of simple supramolecular structures (for example molecular complexes), which has been introduced and described by Mulliken [1], is based on types of molecular orbitals of the components. In the paper [2], disadvantages of such classification are shown, which motivate us to return to the re-examination properties of molecular complexes. By this reason, there is a need to research the molecular complexes of one electron acceptor with a wide range of electron donor molecules. This paper have continued work (Part I [3]) on the chloranil complexes by studying the spectral properties complexes of N- and O-unsubstituting anilines and phenols. The present work aimed at analyzing linear relation the energies of charge-transfer bands of molecular complexes are related to ionization potentials of the donor components. All complexes conform to linear relations like involving both adiabatic and vertical ionization potentials of donor components. Mulliken [1] has been proposed to apply the vertical ionization potentials of donor components only. The development of photoelectron spectroscopy has led to the measurement of adiabatic and vertical ionization energies for thousands of molecules, which allow theirs to the present analysis of spectral properties molecular complexes.

Abstract: In this research, kinetics and mechanism of aniline adsorption on different single-walled carbon nanotubes (SWCNT) was investigated, using 2-layer ONIOM (Our own N-layered Integrated molecular Orbital and molecular Mechanics) method at the ONIOM (B3LYP/6-31G (d);UFF) level. Various orientations of aniline relative to the carbon nanotube surface were investigated. To investigate the adsorption of aniline, three models including open-ended (model 1), cap-ended (model 2) and 1-cap-ended (model 3) SWCNT have been modeled. Calculated activation energies of adsorption showed that model 2 has the lowest activation energy of 40.8 kcal.mol^-1. Natural bond orbital and frontier molecular orbital analysis confirmed the charge transfer from the aniline to the SWCNT. Density of states analysis showed that Fermi level is shifted towards the positive values after aniline adsorption which confirmed the effective interactions between the aniline and the SWCNT. According to the quantum theory of atoms in molecules studies, new bonds formed between the SWCNT and aniline which possess a covalence nature. Finally, based on the quantum reactivity indices, new linear correlations between the chemical hardness, charge transfer and activation energy and the inverse relationship of the electrophilic property and chemical electronic potential in the functionalized carbon nanotubes were obtained. Wiberg bond index calculations show that this reaction is carried out through an asynchronous concerted mechanism. Asynchronicity value in the case of model 2 is higher than other models.

Abstract: Aniline is considered as an environment hazard. Aniline-containing wastewater frequently has elevated salinity and high pH, which is generally not degraded by neutrophilic bacteria. The research explored the degradation ability of aniline by the novel isolated bacterial strain under alkaline and hyperhaline conditions. The strain was designated Bacillus sp. AN2 based on 16S rDNA sequence and Biolog Microstation Identification System. This strain had an unusually high salinity tolerance in minimal medium (0-6% NaCl, w/v). The optimal pH for microbial growth and aniline biodegradation was pH 9.0. For the initial concentrations of 200, 500, and 800 mgL^-1, 95%, 74% and 62% of the aniline was degraded, respectively. The results suggest that the strain has potential for aniline degradation under alkaline and elevated salinity environmental conditions.

Abstract: The use of aniline as carbon source has two advantages for the synthesis of carbon materials exhibiting conducting properties: the aromatic ring contributes to the graphitic character and the presence of nitrogen could work as n-dopant, decreasing the band gap of the carbon materials. These conditions contribute to improve their efficiency as electrocatalysts, for example in fuel cells. The objective of this work is to correlate physicochemical characteristics and electrical behavior of carbon samples prepared by nanocasting of aniline in mesoporous silica and its subsequent carbonization under controlled conditions.

Abstract: The saturated vapor pressures of m-xylylenediamine (MXDA) were measured with the static method at the temperatures between 150-180°C, and the Antoine parameters of MXDA were regressed. The Vapor-Liquid Equilibrium (VLE) data of aniline-MXDA system at pressure of 4 kPa were determined. The VLE data were tested by the integral method proposed by Herington and showed to meet thermodynamic consistency. Wilson Equation was used to correlate the experimental data and the model parameters were determined. The calculated data from Wilson Equation agreed well with the experimental data of the above binary system.

Abstract: Aniline is a toxic organic pollutant that is abundantly present in the environment. One of approaches to remove the aniline is by adsorption process. In this study, mesoporous carbon nitride (MCN) was proposed for the first time to be a potential adsorbent for aniline. The adsorption studies were carried out at room temperature on the aniline solution with various initial concentrations for both bulk carbon nitride (BCN) and MCN. Owing to its larger surface area, the MCN showed much higher adsorption capacity towards aniline compared to the BCN. This result indicated that adsorbent with large surface area is very crucial in the adsorption of aniline. Comparison study was also carried out using mesoporous silica, MCM-41, which was reported to act as a good adsorbent for aniline. The adsorption capability of MCN was found to be higher than that of MCM-41. It was suggested that the MCN with larger pore diameter might have more suitable and favourable adsorption sites for aniline compared to MCM-41. This study obviously showed that MCN would be a new potential adsorbent for removal of aniline.