Sharif Digital Repository

Absorptive characteristics of polyaniline synthesized in different solvents were studied. Water and mixture of water with other solvents were implemented for polyaniline synthesis. Synthesized polyanilines in powder shape is used as an adsorbent to remove toxic hexavalent chromium from aqueous solutions. Experiments were conducted in batch mode. Removal mechanism involving polyaniline is the combination of surface adsorption and reduction. The kind of solvent used at synthesizing stage can affect the capacity of produced polyanilines for removal of heavy metals including chromium. Synthesized polyaniline in water had the maximum chromium removal efficiency. The morphology study of... 

In this study, the Polyaniline/Polyvinyl Alcohol (PANi/PVA) composite was examined for arsenite (As(III)) removal from aqueous solution. The effect of several parameters including PVA concetration (0–5 g/L), pH (1–13), adsorbent dosage (0.5–6 g/L), contact time (0–120 min), initial As(III) concentration (0.5–100 mg/L), and As(III) oxidation were evaluated on the adsorption efficiency. The results indicated that PVA has an effective role in increasing adsorptive capacity of PANi, by changing its morphology and extending its active surface sites. The adsorption process was pH dependent and As(III) removal consistently improved by increasing solution pH. Adsorption reached equilibrium within... 

Abstract: The use of thermoelectric fabrics for powering wearable devices is expected to become widespread soon. A thermoelectric fabric was prepared by coating nanocomposite of polyaniline/graphene nanosheets (PANI/GNS) on a fabric. Four samples of the fabric containing different wt% of GNS (0.5, 2.5, 5, and 10) were prepared. To characterize the samples, Fourier transform infrared (FTIR) spectra, attenuated total reflectance-Fourier transform infrared (AT-FTIR) spectra, field-emission scanning electron microscopy (FE-SEM), electrical conductivity and Seebeck coefficient measurements were used. The electrical conductivity increased from 0.0188 to 0.277 S cm−1 (from 0.5 to 10 wt% of the GNS... 

This work, which is a part of our ongoing studies on developing conductive scaffolds for nerve tissue engineering, reports synthesis of highly conductive binary-doped polyaniline nanoparticles and polyaniline/graphene nanocomposites. The samples were synthesized through chemical oxidation of aniline via in situ emulsion polymerization method in presence of hydrochloric acid and sodium dodecyl sulfate. Graphene nanosheets were also prepared via modified Hummer's method followed by chemical reduction using hydrazine monohydrate. Electrical conductivity measurements using a standard four-point probe technique with FTIR and UV-vis studies revealed that conductive binary-doped emeraldine salt... 

In this work, an electrochemical DNA biosensor, based on a dual signal amplified strategy by employing a polyaniline film and gold nanoparticles as a sensor platform and enzyme-linked as a label, for sensitive detection is presented. Firstly, polyaniline film and gold nanoparticles were progressively grown on graphite screen-printed electrode surface via electropolymerization and electrochemical deposition, respectively. The sensor was characterized by scanning electron microscopy (SEM), cyclic voltammetry and impedance measurements. The polyaniline-gold nanocomposite modified electrodes were firstly modified with a mixed monolayer of a 17-mer thiol-tethered DNA probe and a spacer thiol,... 

Peripheral nervous system in contrary to central one has the potential for regeneration, but its regrowth requires proper environmental conditions and supporting growth factors. The aim of this study is to design and fabricate a conductive polyaniline/graphene nanoparticles incorporated gelatin nanofibrous scaffolds suitable for peripheral nervous system regeneration. The scaffolds were fabricated with electrospinning and the fabrication process was designed with Design-Expert software via response surface methodology. The effect of process parameters including applied voltage (kV), syringe pump flow rate (cm3/h), and PAG concentration (wt%), on the scaffold conductivity, nanofibers diameter,... 

Flexible all-solid-state supercapacitors are promising electronic devices have been developed in the past decade. Recent efforts to develop such systems are as to construction of free standing electrodes with high specific capacitance. Among these developments, construction of carbon-based current collectors, with high surface areas and good mechanical properties via a facile and economic way, has been taken a great deal of attention. In this study, porous graphene were used as current collector for placement of the carbon fibers functionalized with polyaniline, to prepare a free-standing supercapacitor electrode through a new and facile method. This method begins through blending of the... 

Cerium nitrate loaded polyaniline (PANI) nanofibers were synthesized in this work via a chemical route. PANI nanofibers act as a host structure for the corrosion inhibitor, forming a Ce(III)-PANI complex. This complex is pH sensitive, and a change of pH can cause breaking of the complex and releasing of Ce(III). The Ce(III) loaded PANI nanofibers were embedded into epoxy ester coating and the self-healing corrosion protection ability was investigated by Scanning Vibrating Electrode Technique (SVET) and Electrochemical Impedance Spectroscopy (EIS). The results showed that by embedding of Ce(III) loaded PANI nanofibers into the coatings a superior corrosion protection and self-healing... 

In this research, different coating methods of polyaniline (PANI) on the anode electrodes and their performance in microbial fuel cells (MFCs) were investigated. The performance of systems in a discontinuous state was studied using the high energy content dairy industry wastewater. The phase enrichment assessment was conducted under open circuit potential (OCP) and the performance of MFCs coated with PANI through three methods was evaluated via chemical oxygen demand (COD), polarization, power density, energy coulombic efficiency (ECE), coulombic efficiency (CE), and potential efficiency (PE) values. The results showed the maximum value for the power density of 28Wm-3, CE of 17%, and COD of... 

A polymeric material, polyaniline, was employed as a new sorbent for solid-phase extraction (SPE) of some environmental pollutants from water samples. Chlorophenols were extracted from aqueous samples by SPE using 120 mg polyaniline and determined by gas chromatography with electron-capture detection. The acetate esters of these phenols were formed by the direct addition of acetic anhydride to the organic extractant in the presence of K2CO3. Different conditions were applied to obtain higher retaining capacity and breakthrough volumes. The results compared with those obtained by other groups. The RSD for a river water sample spiked at sub-ppb level was lower than 10% (n = 3) and detection... 

In this study, a new type of magnetite nanocomposite with a core-shell structure was synthesized using Fe3O4 nanoparticles as a core and polyaniline (PANI) as a shell. For this propose, the surface of Fe3O4 was chemically modified with hexamethylenediisocyanate (HMDI) to improve its compatibility and interphase interaction with the polymeric matrix. Thereafter, the PANI was reacted with modified Fe3O4 to anchor them to PANI by covalent bands which acted as a shell. In the second step, the poly (maleic acid-co-acrylic acid) (P(MAc-co-AA)) as polymeric dopant for the PANI was synthesized. Finally, the PANI anchored to Fe3O4 was immersed in an aqueous solution of poly (maleic... 

Polyaniline nanofiltration membranes were synthesized to examine a potential candidate for application of solvent recovery from lube oil. An integrally skinned polyaniline membrane was cast on a woven polyester fabric and then was chemically crosslinked with glutaraldehyde in order to further increase the membranes resistant in a methyl ethyl ketone and toluene mixture. Subsequently, membrane performance was tested under different operational conditions. The operation pressure was fixed at 35 bar and was held constant for all of the tests. The membrane demonstrated a permeate flux of 10 l/(m2 h) and oil rejection of 69%. Abbreviations: PANi: Polyaniline; PI: polyimide; MEK: methyl ethyl... 

Polyaniline nanofiltration membranes were synthesized to examine a potential candidate for application of solvent recovery from lube oil. An integrally skinned polyaniline membrane was cast on a woven polyester fabric and then was chemically crosslinked with glutaraldehyde in order to further increase the membranes resistant in a methyl ethyl ketone and toluene mixture. Subsequently, membrane performance was tested under different operational conditions. The operation pressure was fixed at 35 bar and was held constant for all of the tests. The membrane demonstrated a permeate flux of 10 l/(m 2  h) and oil rejection of 69%. Abbreviations: PANi: Polyaniline; PI: polyimide; MEK: methyl ethyl... 

In this study, polyaniline nanoparticles (PANI NPs) in emeraldine base (EB) form were prepared by a modified method and characterized by FTIR and UV–vis spectroscopies. The average size of the nanoparticles was 140 nm measured by DLS method. The nanoparticles were embedded into polylactic acid (PLA) nanofibers prepared by electrospinning method. It was found that inclusion of PANI NPs in PLA resulted in reduced diameter of the fibers during the electrospinning process. Also, the surface of nanofibers appeared smooth in FE-SEM images without formation of beads. Improvement in mechanical and electrical properties of PLA/PANI nanofibers over the neat PLA nanofibers implied a good dispersion of...