Synthesis and characterization of novel conducting composites of Fe3O4 nanoparticles and sulfonated polyanilines

Surface charged iron oxide (Fe₃O₄) nanoparticles were used for the synthesis of sulfonated polyaniline (SPAN)‐Fe₃O₄ nanocomposites (SPAN/Fe₃O₄‐NCs). 2,5‐diaminobenzenesulfonic acid (DABSA) and 2‐aminobenzenesulfonic acid (ABSA) were independently polymerized with aniline to form SPAN. The structure of the composites was characterized by means of transmission electron microscopy (TEM), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectra, conductivity and magnetic properties. TEM reveals that Fe₃O₄ nanoparticles are “glued” with SPAN in the composite. TGA indicates that SPAN/Fe₃O₄‐NCs are having better thermal stability. The room temperature conductivity of SPAN/Fe₃O₄‐NCs is higher than that of pristine PANI and SPAN. SPAN/Fe₃O₄‐NCs exhibits magnetic behavior. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4127–4134, 2007     

Anthranilic acid assisted preparation of Fe3O4–poly(aniline‐co‐o‐anthranilic acid) nanoparticles

Magnetic Fe₃O₄–poly(aniline‐co‐o‐anthranilic acid) nanoparticles were prepared by a novel and simple method: anthranilic acid assisted polymerization. The synthetic strategy involved two steps. First, Fe₃O₄ nanoparticles capped by anthranilic acid were obtained by a chemical precipitation method, and then the aniline and oxidant were added to the modified Fe₃O₄ nanoparticles to prepare well‐dispersed Fe₃O₄–poly(aniline‐co‐o‐anthranilic acid) nanoparticles. Fe₃O₄–poly(aniline‐co‐o‐anthranilic acid) nanoparticles exhibited a superparamagnetic behavior (i.e., no hysteresis loop) and high‐saturated magnetization (M_s = 21.5 emu/g). The structure of the composite was characterized by Fourier‐transform infrared spectra, X‐ray powder diffraction patterns, and transmission electron microscopy, which proved that the Fe₃O₄–poly(aniline‐co‐o‐anthranilic acid) nanoparticles were about 20 nm. Moreover, the thermal properties of the composite were evaluated by thermogravimetric analysis, and it showed excellent thermal stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1666–1671, 2006     

Synthesis and characterization of self‐doped poly(aniline‐co‐aminonaphthalene sulfonic acid) nanotubes

Self‐doped poly(aniline‐co‐aminonaphthalene sulfonic acid) (PANI‐ANSA) was synthesized by the copolymerization of 5‐aminonaphthalene‐2‐sulfonic acid (ANSA) and aniline. Scanning electron microscopy and transmission electron microscopy showed that the morphology of PANI‐ANSA synthesized at a high molar ratio of aniline to ANSA was nanotubular, but at a low molar ratio, only a granular morphology formed. A possible formation mechanism for nanotubes was proposed. PANI‐ANSA had better thermal stability than HCl‐doped polyaniline; the highest onset decomposition temperature was as high as 340°C because of ? SO₃H linked with the polymer backbone by a covalent bond. PANI‐ANSA was partially soluble in basic solutions, and its conductivity was between 10^?2 and 10^?4 S/cm, depending on the sulfonation degree. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1297–1301, 2003     

Synthesis and characterization of conducting poly(aniline‐co‐diaminodiphenylsulfone) copolymers

Polyaniline, poly(aniline‐co‐4,4′‐diaminodiphenylsulfone), and poly(4,4′‐diaminodiphenylsulfone) were synthesized by ammonium peroxydisulfate oxidation and characterized by a number of techniques, including infrared spectroscopy, ultraviolet–visible absorption spectroscopy, ¹H‐NMR, thermogravimetric analysis, and differential scanning calorimetry. These copolymers had enhanced solubility in common organic solvents in comparison with polyaniline. The conductivities of the HCl‐doped polymers ranged from 1 S cm^?1 for polyaniline to 10^?8 S cm^?1 for poly(4,4′‐diaminodiphenylsulfone). The copolymer compositions showed that block copolymers of 4,4′‐diaminodiphenylsulfone (r₁ > 1) and aniline (r₂ < 1) formed and that the reactivity of 4,4′‐diaminodiphenylsulfone was greater than that of aniline. The results were explained by the effect of the ? SO₂? group present in the polymer structure. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2337–2347, 2003     

Highly conductive new aniline copolymers: poly(aniline‐co‐aminoacetophenone)s

Copolymers of aniline and o‐/m‐aminoacetophenone of different compositions were synthesized by oxidative chemical copolymerization. Two different methods were employed, emulsion and inverse emulsion, with different oxidants, ammonium persulphate and benzoyl peroxide, to study the effect of synthesis conditions on the yield, solubility and conductivity of the copolymers. The copolymer compositions were determined using proton NMR spectroscopy. The reactivity ratios determined by the Finemann–Ross method indicate lower reactivity for m‐aminoacetophenone relative to aniline in the emulsion method, while the reverse holds true in the inverse emulsion method. Copolymers formed by the former pathway are random type as determined by the Finemann–Ross method. The copolymers have crystalline/amorphous morphologies and good conductivity. They exhibit enhanced solubility compared with polyaniline. Copyright © 2005 Society of Chemical Industry     

Synthesis and characterization of core‐shell SiO2 nanoparticles/poly(3‐aminophenylboronic acid) composites

SiO₂/Poly(3‐aminophenylboronic acid) (PAPBA) composites were synthesized under different experimental conditions, using ultrasonic irradiation method. Polymerization was carried out in the presence of sodium fluoride and D ‐fructose to anchor 3‐aminophenylboronic acid groups on to SiO₂ surface. The SiO₂/PAPBA nanocomposite prepared by NaF and D ‐fructose in the polymerization medium was found to show different morphology, electrical properties, thermal behavior and structural characterization in comparison to the nanocomposites prepared under other conditions. Ultrasonic irradiation minimizes the aggregation of nanosilica and promotes anchoring of PAPBA units over SiO₂ surface. The morphology of PAPBA/ SiO₂ nanocomposite was investigated by using transmission electron microscopy, UV‐visible spectroscopy; thermogravimetric analysis, Fourier transform infrared spectroscopy, and X‐ray diffraction analysis were used for characterization. Transmission electron microscope of the nanocomposites observation shows that SiO₂/PAPBA composite, prepared with D ‐fructose and NaF under ultrasonication has a core–shell morphology. The thermal and crystalline properties of core‐shell SiO₂/PAPBA nanocomposite was prepared via ultrasonication method is different from the SiO₂/PAPBA nanocomposite prepared via conventional stirring method, in which SiO₂ nanoparticles are submerged in PAPBA. Conductivity of the composite prepared via ultrasonication shows around 0.2 S/cm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2743–2750, 2007     

Synthesis and properties of magnetic sensitive shape memory Fe3O4/poly(ε‐caprolactone)‐polyurethane nanocomposites

Fe₃O₄/poly (ε‐caprolactone)‐polyurethane (PCLU) shape memory nanocomposites were prepared by an in situ polymerization method. The thermal properties, magnetic properties, and shape memory properties of the nanocomposites were investigated systematically. The results showed that the Fe₃O₄ nanoparticles were homogeneously dispersed in the PCLU matrix, which ensured good shape memory properties of nanocomposites in both hot water and an alternating magnetic field (f = 45 kHz, H = 29.7 kA m^?1/36.7 kA m^?1). The nanocomposites started to recover near 40°C, which is slightly higher than body temperature. Thus, they would not change their deformed shape during the implanting process into the human body. Considering potential clinical applications, 45°C was chosen as shape recovery temperature which is slightly higher than 37°C, and the nanocomposites had high shape recovery rate at this temperature. With increasing content of Fe₃O₄ nanoparticles, the shape memory properties of the nanocomposites in an alternating magnetic field increased and the best recovery rate reached 97%, which proves that this kind of nanocomposites might be used as potential magnetic sensitive shape memory materials for biomedical applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013     

Electrochemical synthesis of poly(2‐iodoaniline) and poly(aniline‐co‐2‐iodoaniline) in acetonitrile

Poly(2‐iodoaniline) (PIANI) and poly(aniline‐co‐2‐iodoaniline) [P(An‐co‐2‐IAn)] were synthesized by electrochemical methods in acetonitrile solution containing tetrabutylammonium perchlorate (TBAP) and perchloric acid (HClO₄). The voltametry of the copolymer shows characteristics similar to those of conventional polyaniline (PANI), and it exhibits higher dry electrical conductivity than PIANI and lower than PANI. The observed decrease in the conductivity of the copolymer relative to PANI is attributed to the incorporation of the iodine moieties into the PANI chain. The structure and properties of these conducting films were characterized by FTIR and UV‐Vis spectroscopy and by an electrochemical method (cyclic voltametry). Conductivity values, FTIR and UV‐Vis spectra of the PIANI and copolymer were compared with those of PANI and the relative solubility of the PIANI and the copolymer powders was determined in various organic solvents. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1652–1658, 2003     

Nanocomposite particles with core‐shell morphology. I. Preparation and characterization of Fe3O4–poly(butyl acrylate‐styrene) particles via miniemulsion polymerization

Colloidal particles with magnetic properties have become increasingly important both technologically and for fundamental studies. Here, chemical initiator‐free miniemulsion polymerization of styrene and butyl acrylate has been performed for preparation of magnetic nanocomposite particles with the diameter of 81–150 nm in the presence of sodium dodecyl sulfate as surfactant, span 80 as stabilizer, and hexadecane as hydrophobe. The polymerization reaction was initiated and progressed under ultrasonic irradiation, generated by immersed probe into the latex. The key point in achievement of encapsulation of modified Fe₃O₄ nanoparticles was preparation of a stable colloidal dispersion at the end of the reaction. The obtained products in each step were characterized by FTIR spectroscopy. Dynamic light scattering analysis was used to follow particle size diameter of the samples. Morphology of the particles and formation of core‐shell structure were analyzed by SEM and TEM micrographs, respectively. TGA and magnetometry of the polymeric films confirmed the extent of insertion of used magnetite and their corresponding behavior. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Electrochemical preparation of poly(2‐bromoaniline) and poly(aniline‐co‐2‐bromoaniline) in acetonitrile

Electrochemical preparation of poly(2‐bromoaniline) (PBrANI) and poly(aniline‐co‐2‐bromoaniline) [P(An‐co‐2‐BrAn)] was carried out in an acetonitrile solution containing tetrabutylammonium perchlorate (TBAP) and perchloric acid (HClO₄). The cyclic voltammograms during the copolymerization had many features similar to those for the usual polymerization of aniline. The copolymer exhibits a higher dry electrical conductivity value than that of PBrANI and a lower one than that of PANI. The observed decrease in the conductivity of the copolymer relative to PANI is attributed to the incorporation of bromine moieties into the polyaniline chain. The structure and properties of the polymer and copolymer were elucidated using cyclic voltammetry (CV), FTIR, and UV‐vis spectroscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2460–2468, 2003     

Nanocomposite polymer electrolytes containing silica nanoparticles: Comparison between poly(ethylene glycol) and poly(ethylene oxide) dimethyl ether

Nanocomposite polymer electrolytes consisting of low molecular weight poly(ethylene oxide) (PEO), iodine salt MI (M = K⁺, imidazolium⁺), and fumed silica nanoparticles have been prepared and characterized. The effect of terminal group in PEO, i.e., hydroxyl (? OH) and methyl (CH₃) using poly(ethylene glycol) (PEG) and PEO dimethyl ether (PEODME), respectively, was investigated on the interactions, structures, and ionic conductivities of polymer electrolytes. Wide angle X‐ray scattering (WAXS), differential scanning calorimetry (DSC), and complex viscositymeasurements clearly showed that the gelation of PEG electrolytes occurred more effectively than that of PEODME electrolytes. It was attributed to the fact that the hydroxyl groups of PEG participated in the hydrogen‐bonding interaction between silica nanoparticles, and consequently helped to accelerate the gelation reaction, as confirmed by FTIR spectroscopy. Because of its interaction, the ionic conductivities of PEG electrolytes (maximum value ～ 6.9 × 10^?4 S/cm) were lower than that of PEODME electrolytes (2.3 × 10^?3 S/cm). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Synthesis and characterization of poly(ethylene isophthalate‐co‐ethylene terephthalate) copolyesters

Poly(ethylene isophthalate‐co‐ethylene terephthalate) (PEIPET) copolymers of various compositions and molecular weights were synthesized by melt polycondensation and characterized in terms of chemical structure and thermal and rheological properties. At room temperature, all copolymers were amorphous and thermally stable up to about 400°C. The main effect of copolymerization was a monotonic increase of glass transition temperature (T_g) as the content of ethylene terephthalate units increased. The Fox equation accurately describes the T_g–composition data. The presence of ethylene terephthalate units was found to influence rheological behavior in the melt, with the Newtonian viscosity increasing as the content of ethylene terephthalate units increased. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 186–193, 2004     

ZnO nanoparticles dispersed poly(aniline‐co‐o‐anthranilic acid) composites: Photocatalytic reduction of Cr(VI) and Ni(II)

In this report, poly(aniline‐co‐anthranilic acid)/zinc oxide (poly(ANI‐co‐ANA)/ZnO) nanocomposites were prepared by in‐situ chemical oxidative polymerization. Transmission electron microscopy (TEM), X‐ray diffraction, Fourier transform infrared spectroscopy, and ultraviolet–visible spectroscopy measurements were used to characterize the resulting pure copolymer and nanocomposite. TEM analysis showed that the nanoparticles with a mean diameter of 15–25 nm were dispersed in the copolymer matrix. Thermogravimetric analysis indicated that the nanocomposite had a higher decomposition temperature than the pure copolymer. The conductivity measurements showed the resulting nanocomposite possessed higher conductivity as compared to the pure copolymer. Photocatalytic removal of Cr(VI) and Ni(II) from aqueous solution using as‐synthesized nanocomposite under UV‐light irradiation was studied. The reduction patterns of Cr(VI) and Ni(II) were better fitted to first‐order kinetic model. The nanocomposite was also applied as a photocatalyst for the degradation of methylene blue dye. The result revealed substantial degradation of the dye (∼82%) under UV‐light illumination. POLYM. COMPOS., 35:839–846, 2014. © 2013 Society of Plastics Engineers     

Synthesis of poly(aniline‐co‐o‐toluidine) coatings and their corrosion‐protection performance on low‐carbon steel

Strongly adherent poly(aniline‐co‐o‐toluidine) coatings were synthesized on low‐carbon‐steel substrates by the electrochemical copolymerization of aniline with o‐toluidine with sodium tartrate as the supporting electrolyte. These coatings were characterized with cyclic voltammetry, ultraviolet–visible absorption spectroscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and scanning electron microscopy. The formation of the copolymer with the mixture of monomers in the aqueous sodium tartrate solution was ascertained by a critical comparison of the results obtained from the polymerizations of the individual monomers, aniline and o‐toluidine. The optical absorption spectrum of the copolymer was drastically different from the spectra of the respective homopolymers, polyaniline and poly(o‐toluidine). The extent of the corrosion protection offered by poly(aniline‐co‐o‐toluidine) coatings to low‐carbon steel was investigated in aqueous 3% NaCl solutions by open‐circuit‐potential measurements and a potentiodynamic polarization technique. The results of the potentiodynamic polarization measurements showed that the poly(aniline‐co‐o‐toluidine) coatings provided more effective corrosion protection to low‐carbon steel than the respective homopolymers. The corrosion rate depended on the feed ratio of o‐toluidine used for the synthesis of the copolymer coatings. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:1868–1878, 2007     

Synthesis and characterization of novel biodegradable poly(p‐dioxanone‐co‐ethyl ethylene phosphate)s

Poly(p‐dioxanone‐co‐ethyl ethylene phosphate)s were successfully synthesized by the ring‐opening copolymerization of p‐dioxanone and ethyl ethylene phosphate with triisobutyl aluminum as an initiator; this was confirmed by ¹H‐NMR and infrared spectra. The effects of the reaction conditions, such as the feeding ratio of the monomers and the reaction temperature and time, on the molecular weight of the copolymers were also studied. The in vitro degradation results showed that the introduction of phosphate segments into the backbone chains of the copolymers led to an enhancement of the degradation rate of the copolymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5507–5511, 2006     

Synthesis and characterization of a copolymer: Poly(aniline‐co‐fluoroaniline)

In the present article, we report the chemical synthesis and characterization of poly(aniline‐co‐fluoroaniline) [poly(An‐FAn)]. The copolymerization of aniline and 2‐fluoroaniline was carried out by chemical method in acidic medium. The characterization of poly(aniline‐co‐fluoroaniline) was done using FTIR, UV‐visible spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron micrography (SEM), and a four‐points‐probe conductivity method. X‐ray diffraction (XRD) and SEM characterization reveal crystalline nature of doped copolymer compared to undoped copolymer. The observed decrease in the conductivity of the copolymer relative to polyaniline is attributed to the incorporation of the fluoro moieties into the polyaniline chain. The chemically synthesized copolymer shows good solubility in common organic solvents, and is, therefore, technological useful. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1460–1466, 2001     

Synthesis of CdS nanoparticles dispersed within amphiphilic poly(urethane acrylate‐co‐styrene) films

CdS nanoparticles were prepared using amphiphilic urethane acrylate nonionomer (UAN) precursor chains having a poly(propylene oxide)‐based hydrophobic segment and a hydrophilic poly(ethylene oxide) segment. Cadmium salts were first dissolved in UAN/styrene solutions, and then the solutions were copolymerized to obtain poly(urethane acrylate‐co‐styrene) films containing dissolved cadmium salts. After reduction with H₂S gas, freestanding films containing CdS nanoparticles were obtained. Transmission electron microscopy images of the films showed that 9.67‐nm CdS nanoparticles were dispersed within the poly(urethane acrylate‐co‐styrene) matrix. The formation of CdS nanoparticles was also confirmed with UV absorption spectra and photoluminescence emission spectra of the films. Transmission electron microscopy and dynamic mechanical analysis measurements confirmed that hydrophilic/hydrophobic microphase separation in UAN/styrene solutions occurred during the dissociation of the cadmium salts, and the microphase‐separated structures were locked in by crosslinking copolymerization. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2357–2363, 2005     

Synthesis and characterization of poly(3,4‐ethylenedioxythiophene)/poly(lactic acid) nanofibres by electrospinning

The poly(3,4‐ethylenedioxythiophene) (PEDOT) family of polymers is a technologically important class of conducting polymers showing high stability, medium band gap, low redox potential and high optical transparency in the electrically conductive state. While PEDOT nanotubes and nanofibres have been synthesized electrochemically, significant opportunity exists for developing a convenient chemical synthetic route for the bulk synthesis of nanostructured PEDOT for potential use in the design of next‐generation nano‐electronic circuits and field emission devices. In this paper, chemical oxidative polymerization was used to synthesize PEDOT nanoparticles. These nanoparticles were co‐electrospun with poly(l ‐lactic acid) from a solution in acetone and N,N‐dimethylformamide. The PEDOT particles were analysed using attenuated total reflectance–Fourier transform infrared spectroscopy and particle size distribution using dynamic light scattering. The synthesized nanofibre mats were studied using differential scanning calorimetry and scanning electron microscopy, and conductivity was measured using a two‐probe conductivity tester. © 2016 Society of Chemical Industry     

Synthesis and characterization of spinning poly(acrylonitrile‐co‐silk fibroin peptide)s

A novel spinning acrylic polymer containing silk protein was synthesized by copolymerization of acrylonitrile (AN) and silk fibroin peptide (SFP) modified by acryloyl chloride (AC) with vinyl groups. From results of the examination to the chemical compositions, we established that the modified SFP is more reactive than AN in the copolymerization. The intrinsic viscosity values of these copolymers showed that the copolymers have good spinnability, which were synthesized under the condition of adding a trace of metal ions into the synthesizing solvent. These copolymers exhibited good thermal property. The fiber based on the poly(acrylonitrile‐co‐silk fibroin peptide) was prepared and characterized by SEM, FTIR measurement of its shell and core flakes, and moisture absorption. The fiber exhibited a smooth surface and could be assumed to have excellent adhesive property between SFP and PAN. Furthermore, these fibers showed a core–shell structure and excellent moisture absorption. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1540–1547, 2004     

Influence of magnetic casting on the permeability and anti-fouling properties of a novel iron oxide/alumina/polysulfone mixed matrix membrane

Novel mixed matrix membranes (MMMs) were fabricated using Fe₃O₄, and Al₂O₃ nanoparticles (NPs) were added to the polysulfone (PSf) and N-methylpyrrolidone (NMP) solution. The nanocomposite membranes were fabricated using the NIPS (non-solvent induced phase separation) method. In order to create preferential permeation pathways for water across the MMMs, membrane formation is accomplished with an external magnetic field. Using magnetic casting cause the targeted placement of NPs in the best location and orientation. The performance of the prepared membranes was examined in terms of pure water flux and fouling parameters. Magnetic casting considerably increased pure water flux and decreased the total resistance of the optimum mixed matrix membrane, which contains 0.2% wt. of Fe₃O₄ NPs to 1175 L/m²h and 13.4 * 10¹¹ (m⁻¹), respectively. This is explained by the ordering of magnetic nanoparticles on the membrane sub-layer cast under the magnetic field of 500 mT, which changed the sub-layer structure. Less rough membrane surface of the mixed matrix membranes offered preferable anti-fouling properties against fouling by BSA proteins. The characterization of fabricated membranes was carried out using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy dispersive X-ray (EDX), and water contact angle measurement methods.