Fabrication of PMMA/PANI/Fe3O4 as a Novel Conducting Hybrid Coating

In this paper, an excellent new hybrid coating including poly(methyl methacrylate) (PMMA), polyaniline (PANI), and magnetite nanoparticles (Fe₃O₄) was obtained. Fe₃O₄ nanoparticles were synthesized using coprecipitation method, and then magnetite nanoparticles have been dispersed into the PANI to increase compatibility with PMMA. Also, PANI/Fe₃O₄ nanocomposites were synthesized through in situ emulsion polymerization, and then PMMA/PANI/Fe₃O₄ hybrid coating was successfully synthesized using batch emulsion polymerization method. Structure, morphology and thermal stability of the samples were characterized using Fourier transform infrared, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and thermal gravimetric analysis (TGA). The synthesized samples were well distributed with an average diameter smaller than 20?nm. Microscopy and X-ray photoelectron spectroscopy results illustrated a great dispersion of magnetite nanoparticles in hybrid matrix. Moreover, the TGA results demonstrated that the PMMA/PANI/Fe₃O₄ hybrid coating nanoparticle is an excellent hybrid coating with high thermal resistance.     

In situ fabrication of polyaniline‐silver nanocomposites using soft template of sodium alginate

Polyaniline (PANI)‐Ag nanocomposites were synthesized by in situ chemical polymerization approach using ammonium persulfate and silver nitrate as oxidant. Characterizations of nanocomposites were done by ultraviolet–visible ( UV–vis), Fourier transform infrared (FTIR), X‐ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy (TEM). UV–vis, XRD and FTIR analysis established the formation of PANI/Ag nanocomposites and face‐centered‐cubic phase of silver. PANInanofibers were of average diameter ～ 30 nm and several micrometers in length. Morphological analysis showed that the spherical‐shaped silver nanoparticles decorate the surface of PANI nanofibers. Silver nanoparticles of average diameter ～ 5–10 nm were observed on the TEM images for the PANI‐Ag nanocomposites. Such type of PANI‐Ag nanocomposites can be used as bistable switches as well as memory devices. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Enhanced NO2 gas sensor device based on supramolecularly assembled polyaniline/silver oxide/graphene oxide composites

Herein, we report a successful synthesis of supramolecularly assembled polyaniline/silver oxide/graphene oxide composite (PANI/Ag₂O/GO) for enhanced NO₂ gas sensing application. The PANI/Ag₂O/GO composite was synthesized by facile stirring followed by an ultrasonication process. The prepared material was characterized by different techniques such as x-ray diffraction, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and Raman-scattering spectroscopy. The detailed analysis revealed that the average crystallite sizes of PANI/Ag₂O and PANI/Ag₂O/GO composites were found to be 37.37 nm and 41.55 nm, respectively. FESEM and TEM analysis showed coral-like rough-surfaced and extensively agglomerated morphology for PANI and ultrathin flexible sheet-like morphology for GO. Ag₂O nanoparticles with diameters 20–30 nm were well incorporated in the GO sheets and PANI matrix in the case of PANI/Ag₂O/GO composites. The synthesized materials were used to make resistive sensor devices that had a high response to NO₂ gas. The fabricated sensors were examined at various temperatures to obtain the optimal sensing temperature. The fabricated NO₂ gas sensor device based on PANI/Ag₂O/GO composite exhibited a highest sensitivity of 5.85 for 25 ppm at an optimized temperature (100 °C) as compared to the pure PANI (2.5) and PANI/Ag₂O composite (3.25). Further, the fabricated sensor device based on PANI/Ag₂O/GO composite was also examined at different NO₂ gas concentrations.     

Synthesis of exfoliated conductive polyaniline–graphite nanocomposites in supercritical CO2

Exfoliated polyaniline–graphite nanocomposites with high electrical conductivity were synthesized. Graphite powders were first expanded with ScCO₂ treatment and then aniline monomers were added to the suspension. The morphology and structure of the synthesized products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV/Vis spectroscopy and XRD analysis. SEM and TEM micrographs revealed that graphite was successfully expanded through ScCO₂ treatment, and the graphite powders are fully exfoliated in the final nanocomposite. FTIR results confirmed formation of polyaniline (PANI), and UV/Vis analysis showed the conductive emeraldine state of the synthesized PANI. Furthermore, it was clearly demonstrated that ScCO₂ medium does not have any effect on chemical structures of the PANI. The electrical conductivities of the PGNs enhanced dramatically with increasing graphite loading up to 40% and subsequently decreased due to the weaker bridged linkage between PANI and graphite layers at high graphite loading.     

Enzyme‐Catalyzed Synthesis of Conducting Polyaniline Nanocomposites with Pure and Functionalized Carbon Nanotubes

The in situ enzymatic polymerization of aniline onto multi‐walled carbon nanotubes (MWCNT) and carboxylated MWCNT (COOH‐MWCNT) is reported. Nanostructured composites were prepared by this method. Polymerization was catalyzed with the enzyme horseradish peroxidase at room temperature in aqueous medium of pH 4. Hydrogen peroxide was used in low concentration as the oxidant. The nanocomposites were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The TEM studies showed tubular morphology with uniformly distributed MWCNT in the nanocomposites. The SEM and TEM investigations revealed wrapping of the MWCNT with polyaniline (PANI) chains. TGA demonstrated that the PANI component is thermally more stable in PANI/COOH‐MWCNT compared to the PANI/MWCNT composites. The synthesized nanocomposites showed higher conductivity than pure PANI, which may be due to the strong interaction between the PANI chains and the MWCNT.     

Preparation and Characterization of Conductive Polyaniline/Silver Nanocomposite Films and Their Antimicrobial Studies

Silver (Ag) nanoparticles are known to hold an important place in nanotechnology, and studies herein present the preparation and characterization of Ag metallic nanoparticles bearing antibacterial properties. In situ polymerization was used to prepare the conductive polymer polyaniline (PANI) and polyaniline/silver (PANI/Ag) nanocomposites. Increases in electrical conductivities of the nanocomposite films were observed compared to neat PANI, whereby these increases may be a result of the Ag doping effect or its complex formation. Spectroscopic techniques, such as, UV–Vis, FTIR, and photoluminescence were used for the characterizations of PANI and PANI/Ag nanocomposites. UV–Vis and FTIR data showed the quinoid units along the polymer chain being affected, such that strong interactions between Ag nanoparticles and quinoidal sites of PANI were presumed. The PANI/Ag nanocomposites showed higher photoluminescence intensities than neat PANI. TGA analyzes were used to determine weight losses and thermostabilities of PANI and PANI/Ag nanocomposites. Scanning electron microscopy was used for morphological evaluations of the nanoparticles and films, where the micrographs revealed that Ag nanoparticles were well dispersed and isolated in nanocomposite films. The presence and distribution of the Ag nanoparticles in PANI film matrix were analyzed by EDX. Antimicrobial properties of the nanocomposite films obtained were also explored. POLYM. ENG. SCI., 59:E182–E194, 2019. © 2018 Society of Plastics Engineers     

Facile fabrication of superhydrophobic polyaniline structures and their anticorrosive properties

We report a simple approach for the preparation of superhydrophobic polyaniline (PANI) and its application for the corrosion protection coatings. First, PANI was synthesized conventionally by oxidative polymerization with APS. Subsequently, PANI with different wettability was obtained by modification with different surfactants. The surface modification of PANI with three different surfactants (sodium dodecylbenzenesulfonate, polyethylene glycol, and cetyltrimethylammonium bromide) provided excellent surface superhydrophobicity (water contact angle >150°). The structure and morphology of as‐prepared PANI were characterized with Fourier transform infrared, Energy dispersive X‐ray spectroscopy, and Scanning electron microscopy. Corrosion protection performance of PANI with different wettability was evaluated in 3.5% NaCl electrolyte using Tafel polarization curves and electrochemical impedance spectroscopy. The results indicated that various superhydrophobic PANI coatings have better anticorrosion performance as compared to the hydrophilic PANI. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44248.     

Nanomechanical characterization of chemical interaction between gold nanoparticles and chemical functional groups

Core/shell nanostructured carbon materials with carbon nanofiber (CNF) as the core and a nitrogen (N)-doped graphitic layer as the shell were synthesized by pyrolysis of CNF/polyaniline (CNF/PANI) composites prepared by in situ polymerization of aniline on CNFs. High-resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared and Raman analyses indicated that the PANI shell was carbonized at 900°C. Platinum (Pt) nanoparticles were reduced by formic acid with catalyst supports. Compared to the untreated CNF/PANI composites, the carbonized composites were proven to be better supporting materials for the Pt nanocatalysts and showed superior performance as catalyst supports for methanol electrochemical oxidation. The current density of methanol oxidation on the catalyst with the core/shell nanostructured carbon materials is approximately seven times of that on the catalyst with CNF/PANI support. TEM tomography revealed that some Pt nanoparticles were embedded in the PANI shells of the CNF/PANI composites, which might decrease the electrocatalyst activity. TEM-energy dispersive spectroscopy mapping confirmed that the Pt nanoparticles in the inner tube of N-doped hollow CNFs could be accessed by the Nafion ionomer electrolyte, contributing to the catalytic oxidation of methanol.     

Hollow nitrogen-containing core/shell fibrous carbon nanomaterials as support to platinum nanocatalysts and their TEM tomography study

Core/shell nanostructured carbon materials with carbon nanofiber (CNF) as the core and a nitrogen (N)-doped graphitic layer as the shell were synthesized by pyrolysis of CNF/polyaniline (CNF/PANI) composites prepared by in situ polymerization of aniline on CNFs. High-resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared and Raman analyses indicated that the PANI shell was carbonized at 900°C. Platinum (Pt) nanoparticles were reduced by formic acid with catalyst supports. Compared to the untreated CNF/PANI composites, the carbonized composites were proven to be better supporting materials for the Pt nanocatalysts and showed superior performance as catalyst supports for methanol electrochemical oxidation. The current density of methanol oxidation on the catalyst with the core/shell nanostructured carbon materials is approximately seven times of that on the catalyst with CNF/PANI support. TEM tomography revealed that some Pt nanoparticles were embedded in the PANI shells of the CNF/PANI composites, which might decrease the electrocatalyst activity. TEM-energy dispersive spectroscopy mapping confirmed that the Pt nanoparticles in the inner tube of N-doped hollow CNFs could be accessed by the Nafion ionomer electrolyte, contributing to the catalytic oxidation of methanol.     

Synthesis of polyaniline/montmorillonite nanocomposites with an enhanced anticorrosive performance

Polyaniline/montmorillonite (PANI/Mt) nanocomposites (1–7% (w/w) Mt based on the aniline content) were synthesized by in situ chemical oxidative polymerization with a 73.4–75.8% monomer conversion level. Fourier-transform infrared and scanning electron microscopy analyses confirmed the presence of Mt incorporation into PANI, whilst X-ray diffraction analysis revealed the exfoliated structure and that PANI was intercalated between the Mt layers. Thermogravimetric analysis revealed that the thermal properties of PANI and PANI/Mt composites were enhanced with increasing Mt levels.     

Microemulsion route to fabrication of silver and platinum‐polymer nanocomposites

Polymethylmethacrylate (PMMA)‐platinum and PMMA‐silver nanocomposites have been produced using polymerization of W/O microemulsions. MMA monomer was used as the oil or continues phase of the microemulsion system and polymerized following formation of Pt and Ag nanoparticles in the fluid medium. The UV‐vis absorption spectra have been used to trace the growth process of the nanoparticles in the microemulsion system. Scanning electron microscopy and transmission electron microscopy (TEM) have been used to determine the morphology and particle size of the Pt and Ag particles in the synthesized nanocomposites. Image analyses of TEM micrographs confirm that the Pt and Ag particles in the synthesized nanocomposites have a narrow size distribution. Meanwhile, Fourier‐transform infrared spectroscopy was used to verify polymer‐nanoparticles interaction in nanocomposite bulk. POLYM. COMPOS., 35:2023–2028, 2014. © 2014 Society of Plastics Engineers     

In situ doping of PANI nanocomposites by gold nanoparticles for high‐performance electrochemical energy storage

Polyaniline (PANI) in situ doped with gold nanoparticles (Au/PANI) is synthesized by oxidative polymerization as electrode material for supercapacitor. The morphologies and structure of the obtained products are characterized by transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy; and electrochemical behaviors were measured by electrochemical workstation. The results show that the nanocomposites of Au/PANI are fabricated with gold nanoparticles (nano‐Au) dispersed well in PANI bulk; and specific capacitance (SC) and rate ability of Au/PANI are improved compared to the pristine PANI due to the introduction of nano‐Au. With nano‐Au content increasing, SC first increase and then decrease and the maximum SC of Au/PANI nanocomposite is up to 462 F g^?1 with the nano‐Au content of 1.64 wt %. Finally, both asymmetric and symmetric supercapacitor devices are assembled, exhibiting high energy densities of 8.95 and 4.17 Wh kg^?1, respectively. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45309.     

Ag-doped ZnO Reinforced Polymeric Ag:ZnO/PMMA Nanocomposites as Electron Transporting Layer for OLED Application

Nanostructured Ag-doped ZnO nanoparticles, and its polymeric nanocomposites (Ag:ZnO/PMMA) were synthesized in the laboratory via free radical polymerization process. The formation of PMMA matrix, its nanocomposites and relative changes in nano structured properties were examined by Fourier transform infrared spectroscopic (FTIR) analysis. Nanohexagonal structure was formed in the PMMA polymeric pattern with the incorporation of Ag:ZnO nano fillers, as examined by surface morphology images. Optical absorption spectra associated with the blue region of visible range and the optimized concentration showed reduced band gap ~2.55 eV which led to increase the p-type conductivity. Increased rate of electron–hole radiative recombination and an enhanced current density ~85.70% were examined. This revealed a significantly improved conductivity of the Ag:ZnO/PMMA nanocomposites. The nano fillers Ag:ZnO have fairly improved the optical absorption, conduction and an enhanced current density of nanocomposites which can be used as electron transport layer in the OLED device fabrication.     

Effects of surfactants on the characteristics and biosensing properties of polyaniline

To investigate the effects of surfactants on the properties of polyaniline (PANI), a series of PANIs was synthesized in the presence of surfactants by chemical polymerization of aniline in an acidic medium, using (NH₄)₂S₂O₈ as oxidant. Three types of surfactant were used: (i) non‐ionic poly(ethylene oxide) (20) sorbitan monolaurate (Tween 20) and poly(ethylene oxide) (20) sorbitan monopalmitate (Tween 40); (ii) cationic (1‐tetradecyl)trimethylammonium bromide; and (iii) anionic sodium 1‐dodecanesulfonate and sodium 1‐pentanesulfonate. The structural, morphological and thermal properties of the various samples were characterized using Fourier transform infrared and UV‐visible spectroscopy, scanning electron microscopy and thermogravimetric analysis. Calorimetry was used to compare enthalpy changes during polymerization. The electrochemical and glucose biosensor properties of the PANIs were investigated using cyclic voltammetry and amperometric measurements. PANI‐Tween 20 and PANI‐Tween 40 were found to be good for immobilization of glucose oxidase enzymes and potential candidates for use in glucose biosensing. Copyright © 2010 Society of Chemical Industry     

Preparation of polyaniline/phosphorylated poly(vinyl alcohol) nanoparticles and their aqueous redispersion stability

A novel approach for the preparation of the colloidal conducting polyaniline (PANI) nanoparticles was developed. The polyaniline/partially phosphorylated poly(vinyl alcohol)(PANI/P‐PVA) nanoparticles were prepared by the chemical oxidative dispersion polymerization of aniline monomer in 1.0 M HCl aqueous media with the partially phosphorylated poly(vinyl alcohol) (P‐PVA) as the stabilizer and codopant. The PANI/P‐PVA nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), electrical conductivity measurement, and redispersion stability testing. All the results were compared with the properties of the conventional polyaniline in the emeraldine salt form (PANI ES). It was found that the P‐PVA/aniline feeding ratio obviously affected the morphology, redispersion stability and electrical conductivity of the PANI/P‐PVA nanoparticles. When the P‐PVA/aniline feeding ratio ranged from 50 to 60 wt %, the PANI/P‐PVA nanoparticles showed spherical shape with good uniformity, significant redispersion stability in aqueous media, and good electrical conductivity up to 7 S/cm. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

Preparation of a graphene nanosheet/polyaniline composite with high specific capacitance

A graphene nanosheet (GNS)/polyaniline (PANI) composite was synthesized using in situ polymerization. The morphology and microstructure of samples were examined by scanning electron microscopy (SEM), transition electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. Electrochemical properties were characterized by cyclic voltammetry (CV) and galvanostatic charge/discharge. GNS as a support material could provide more active sites for nucleation of PANI as well as excellent electron transfer path. The GNS was homogeneously coated on both surfaces with PANI nanoparticles (∼2 nm), and a high specific capacitance of 1046 F g⁻¹ (based on GNS/PANI composite) was obtained at a scan rate of 1 mV s⁻¹ compared to 115 F g⁻¹ for pure PANI. In addition, the energy density of GNS/PANI composite could reach 39 W h kg⁻¹ at a power density of 70 kW kg⁻¹.     

Synthesis,characterization, and properties of new conducting polyaniline/copper sulfide nanocomposites

This article reports the facile synthesis of copper sulfide (CuS)/polyaniline (PANI) nanocomposites by in situ polymerization. The composites were characterized by scanning electron microscopy (SEM), UV–visible and Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). SEM analysis showed that the metal sulfide nanoparticles were uniformly dispersed in the polymer matrix. The characteristic peaks in FTIR and UV–vis spectra of PANI were found to be shifted to higher wave numbers in PANI/CuS composite, which is attributed to the interaction of CuS nanoparticles with PANI chain. XRD pattern revealed the structurally ordered arrangement of polymer composite and this regularity increases with increase in concentration of nanoparticles. Glass transition temperature of the nanocomposite increased with increase in the concentration of nanoparticles and it indicated the ordered arrangement of the polymer composite than PANI. TGA studies indicated excellent thermal stability of polymer nanocomposite. The electrical properties of nanocomposites were studied from direct current and alternating current resistivity measurement. Conductivity, dielectric constant, and dissipation factor of the nanocomposite were significantly increased with the increase in CuS content in the nanocomposite. The enhancement of these properties suggests that the proposed PANI/CuS nanocomposites can be used as multifunctional materials for nanoelectronic devices. POLYM. ENG. SCI., 54:438–445, 2014. © 2013 Society of Plastics Engineers     

Preparation of cadmium sulfide/poly(methyl methacrylate) composites by precipitation with compressed CO2

Cadmium sulfide (CdS) nanoparticles and poly(methyl methacrylate) (PMMA) were first synthesized in methyl methacrylate (MMA)/sodium bis(2‐ethylhexyl) sulfosuccinate (AOT) microemulsion, in which MMA acts as the solvent and monomer. Then compressed CO₂ was used as an antisolvent to precipitate the CdS and PMMA simultaneously. Using this method, a CdS/PMMA composite was successfully prepared. The CdS nanoparticles dispersed in the polymer matrices were characterized by transmission electron microscopy. The higher pressure is favorable to producing CdS nanoparticles of smaller size. The phase structure of the obtained composite was characterized by X‐ray diffraction, which reveals that cubic CdS particles were formed. The FTIR spectra of the composite showed that there is no chemical bonding or strong interaction between CdS and PMMA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1643–1648, 2004     

三种表面活性剂对Fe3O4纳米颗粒的形貌影响

选用十六烷基三甲基溴化铵(CTAB)、聚乙烯吡咯烷酮(PVP)、十二烷基磺酸钠(SDS)3种表面活性剂,研究了这3类不同表面活性剂和不同添加量对Fe3O4纳米颗粒的形貌调控作用,利用透射电镜(TEM)对样品进行表征分析,并给出了机理解释。结果表明:1)3种不同的表面活性剂的加入都获得球形或近球形的纳米颗粒。根据TEM及沉积时间的综合分析,3种活性剂的平均粒径比较:SDS相似文献   

Electrospun silk fibroin/PAN double-layer nanofibrous membranes containing polyaniline/TiO<Subscript>2</Subscript> nanoparticles for anionic dye removal

In the present study, novel silk fibroin (SF)/polyacrylonitrile (PAN) double-layer nanofilters defined by a variable composition of polyaniline (PANI)/TiO₂ nanoparticles were prepared using an electrospinning technique, and their application for dye removal was investigated. Scanning electron microscopy (SEM) showed that fibrous mats characterized by nanoscale diameters (70–120 nm) and random ultrafine fiber orientations without beads were successfully obtained. Tensile test results revealed that the strength and Young’s modulus were markedly enhanced in the hybrid double-layer SF-PAN membranes relative to single-layer polymers. In addition, the incorporation of PANI/TiO₂ nanoparticles within the hybrid samples resulted in a notable increase in strength and modulus. The adsorption-assisted nanofiltration performance of the membranes in removing anionic reactive black (HFGR) dye from aqueous solution was investigated using a dead-end stirred cell filtration device. The effect of several variables, including PANI/TiO₂ nanoparticle content, pH and dye concentration, were evaluated. Hybrid nanofilters containing 7.5 wt% PANI/TiO₂ nanoparticles demonstrated excellent dye removal efficiency of up to ~92% in acidic solution.