Synthesis of core‐shell silver–polyaniline nanocomposites by gamma radiolysis method

Core‐shell silver (Ag)–polyaniline (PAni) nanocomposites have been synthesized by the in‐situ gamma radiation‐induced chemical polymerization method. Aqueous solution of aniline, a free‐radical oxidant, and/or silver metal salt were irradiated by γ‐rays. Reduction of the silver salt in aqueous aniline leads to the formation of silver nanoparticles which in turn catalyze oxidation of aniline to polyaniline. The resultant Ag‐PAni nanocomposites were characterized by using different spectroscopy analyses like X‐ray photoelectron, UV–visible, and infrared spectroscopy. The optical absorption bands revealed that the bands at about 400 nm are due to the presence of nanosilver and the blue‐shifted peak at ～ 555 nm is due to the presence of metallic silver within the PAni matrix. X‐ray diffraction pattern clearly indicates the broad amorphous polymer and the sharp metal peaks. Scanning electron microscopy and transmission electron microscopy of the nanocomposite showed a uniform size distribution with spherical and granular morphology. Thermogravimetric analysis revealed that the composites have a higher degradation temperature than polyaniline alone. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5741–5747, 2007     

不同质子酸掺杂对银/聚苯胺纳米复合材料结构和导电性的影响

利用紫外光作为辅助条件,在反胶束体系中采用一步双原位法合成了硝酸(HNO3)、对甲基苯磺酸(TSA)和5-磺基水杨酸(SSA)掺杂的银/聚苯胺(Ag/PANI)纳米复合材料.通过对复合材料进行红外光谱(FTIR)、紫外光谱(UV-Vis)、扫描电镜(SEM)、X射线衍射(XRD)和导电性能的测试,研究了不同质子酸对Ag/PANI纳米复合材料结构、形貌和导电性能的影响.测试结果表明,3种酸掺杂制备的Ag/PANI纳米复合材料均为聚苯胺包覆银粒子的核-壳结构.不同的质子酸掺杂会对Ag/PANI纳米复合材料的电性能有重要影响.在3种酸掺杂的复合材料中,TSA掺杂的复合材料的电导率最佳,为215.14 S·cm-1.     

Fabrication of poly(aniline‐co‐pyrrole) hollow nanospheres with Triton X‐100 micelles as templates

A one‐step route has been reported for the fabrication of poly(aniline‐co‐pyrrole) (PACP) copolymer hollow nanospheres via the oxidation polymerization of a mixture of aniline and pyrrole in the presence of Triton X‐100. It was found that the variations in polymerization conditions, such as the concentrations of Triton X‐100 and comonomers, and [pyrrole]/[aniline] molar ratios, could change the size and uniformity of copolymer hollow nanospheres. The result of DLS has attested the presence of the spherical Triton X‐100 micelles swelled by the comonomers in reaction system, and such micelles might play template for the formation of hollow nanospheres, followed by developing a possible formation mechanism. The chemical structures and crystallinity of products were characterized by FTIR, UV–visible, ¹H NMR spectra, and XRD patterns, respectively, to prove the copolymer chemical structures of hollow nanospheres. The thermal‐stability and solubility of PACP were improved compared with homopolymers (polyaniline and pyrrole). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3563–3572, 2008     

Preparation and characterization of carbopol‐silver nanocomposites for efficient antimicrobial applications

Carbopol‐silver nanocomposites, CP‐Ag‐NCs, were prepared by a chemical reducing method by using formaldehyde as a reducing agent (nanocomposite F), and formaldehyde in the presence of an alkaline medium resulting from the addition of Na₂CO₃ (nanocomposite FC), or NaOH (nanocomposite FO) to enhance the rate of reduction of the silver ions. The UV‐visible spectra showed the appearance of bands centered around 275, 286, and 274 nm for the nanocomposites F, FC, and FO, respectively, attributed to small silver nanoparticles (Ag‐NPs) with an average size less than 10 nm. Other bands centered around 405 and 470 nm for the nanocomposites F and FC, respectively, were attributed to large Ag‐NPs with an average size greater than 50 nm. The absence of large Ag‐NPs in the nanocomposites FO makes them as the materials of choice for the preparation of selective ultrasmall Ag‐NPs with an average size less than 3 nm. Furthermore, photoluminescence was observed upon blue excitation of the ultrasmall colloidal Ag‐NPs. Scanning electron microscopy images showed a good dispersion of the metallic Ag‐NPs in the polymer matrix. Moreover, X‐ray diffraction patterns showed peaks corresponding to the face‐centered‐cubic of the Ag‐NPs. The nature of the interaction between carbopol and Ag‐NPs was further studied by attenuated total reflectance‐Fourier transform infrared spectroscopy, and the mechanism of reduction of the silver ions was proposed. The antimicrobial activities of the CP‐Ag‐NCs were examined against Escherichia coli and Candida albicans microorganisms. The results demonstrate that the CP‐Ag‐NCs can provide new applications of these nanocomposites as efficient sensors and antimicrobial materials.     

Nano‐emulsion use for the synthesis of polyaniline nano‐grains or nano‐fibers

We report that nano‐emulsions can be creatively used as a morphology selective synthesis method to prepare not only nano‐grains but also nano‐fibers with high selectivity. Synthesis of the two different morphological materials was demonstrated using polyaniline synthesis as a model case. Polyaniline nano‐grains were synthesized from aniline molecules in nano‐size aqueous droplets as polymerization sites whose droplets were generated by inverse water‐in‐oil nano‐emulsion use, and polyaniline nano‐fibers were synthesized from aniline in aqueous nano‐dimensional channels as polymerization sites whose channels were generated by direct oil‐in‐water nano‐emulsion use containing high population of oil droplets. Using the approaches, we successfully synthesized nano‐fibers of 60 nm diameter with 0.5 µm length and also nano‐grains having diameter of 60–80 nm. The two different polymerization sites of nano‐scale dimension were made by changing the ratio among surfactant, aqueous aniline/HCl solution, and oil, i.e. organic solvent. We found the nano‐fibers synthesized from the channels formed by the direct oil‐in‐water nano‐emulsion have higher bulk electrical conductivity than the nano‐grains which were synthesized from the droplets formed by the inverse water‐in‐oil emulsion. We also found that the emulsion use allows us to use a room temperature synthesis unlike conventional synthesis methods which require to use ice bath temperature. Physical properties of both nano‐fibers and nano‐grains synthesized were characterized by Fourier transform infrared (FTIR), UV–Vis spectra, scanning electron microscopy (SEM), and four probes conductivity measurement. Copyright © 2009 John Wiley & Sons, Ltd.     

Conductive elastomeric nanocomposites based on oxidation of aniline with silver nitrate via inverse emulsion polymerization

The present investigation describes a facile and rapid approach of conductive nanocomposites production and assesses the opportunity of their use as electro‐mechanical sensors. Hybrid materials containing silver and polyaniline nanoparticles reinforcing a thermoplastic elastomeric matrix were studied. The approach developed includes ultrasonically assisted in situ inverse emulsion polymerization of aniline oxidized by a weak oxidant and silver nitrate, and supported with a strong oxidant, ammonia peroxydisulfate. Aniline was doped with dodecylbenzene sulfonic acid in the presence of dissolved styrene–isoprene–styrene thermoplastic elastomer. While conventional polymerization of aniline with silver nitrate takes 2 weeks, by utilization of inverse emulsion polymerization, the reaction time reduces to 5 days. The assistance of a strong oxidant dramatically shortens the reaction time to 30 min. The technique developed results in uniform distribution of polyaniline/silver (PANI/Ag) conductive nanoparticles in the elastomeric matrix. The morphological studies of the films reveal spherically shaped 45 nm Ag particles. The presence of PANI/Ag in the styrene–isoprene–styrene elastomeric matrix enhances the electrical, thermal, and mechanical properties of the nanocomposites. The approach described provides an opportunity of the development of tunable structures and a remarkably distinctive architecture. A rapid electrical resistance response to an applied strain makes the nanocomposites developed useful as sensitive strain sensors. Copyright © 2014 John Wiley & Sons, Ltd.     

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

Polyaniline (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     

Synthesis of nanoscale zero‐valent iron modified graphene oxide nanosheets and its application for removing tetracycline antibiotic: Response surface methodology

Nowadays, pharmaceutical antibiotics are known as a serious class of pollutants. Therefore, it is important to develop effective methods for removing these pollutants from aqueous media. Different methods were applied for this purpose, and among these methods, chemical reduction by a cheap and eco‐friendly nanocatalyst is the most efficient and simplest method. In this research, based on graphene oxide supported by zero‐valent iron in mono‐, bi‐, and tri‐metallic systems, various nanocomposites were synthesized and used to degrade tetracycline as a model antibiotic from aqueous media. An investigation was carried out on the synergic effect among graphene oxide and the nano zero‐valent iron‐based tri‐metallic system as well as removal efficiencies. It was found that higher degradation efficiency is yielded by graphene oxide supported by Fe/Cu/Ag tri‐metallic system. The maximum synergic effect occurs at an acidic medium. The Brunauer–Emmett–Teller, Fourier transform spectroscopy, scanning electron microscopy‐energy dispersive X‐ray analysis, transmission electron microscopy, and X‐ray diffraction analysis were used to characterize the synthesized nanocomposites, which has successfully proved the loading of nanoscale Fe/Cu/Ag tri‐metallic on a graphene oxide support. The central composite design was used to model and optimize all involved variables affecting antibiotic removal efficiency. The consequences illustrated the optimum condition regarding the removal of 50 ppm of tetracycline, for the nanocomposites dose of 3.0 mg ml^?1, the contact time of 30 min, and pH of 2, was achieved using the simplex non‐linear optimization method. Moreover, antibiotic adsorption kinetic models were also investigated. Finally, the tetracycline removal from aqueous media at different concentrations, 25, 50, and 75 ppm, was successful by applying the proposed nanocomposite, and the results showed tetracycline removal efficiencies of above 70%.     

Solution route to inorganic nanobelt‐conducting organic polymer core‐shell nanocomposites

A facile and versatile solution‐based approach was developed to prepare semiconductor metal oxide nanobelt‐conducting organic polymer core‐shell nanocomposites. Well‐defined nanobelts of several types of oxide nanobelts were combined with conducting polymer [polypyrrole (PPy) and polyaniline (PANi)] via in situ polymerization in aqueous solution to obtain a new type of inorganic–organic composite nanostructure. Samples were characterized by using X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, electron energy loss spectra, high‐resolution transmission electron microscopy, and ultraviolet–visible techniques. Electron energy loss spectra revealed the existence of C?C and C? N bonds in coating layers to prove the encapsulation of PPy or PANi. The red‐shift of absorption band at high‐energy was observed for PPy‐encapsulated composites via ultraviolet–visible spectroscopy, and significant absorption band shifts were also encountered to PANi‐encapsulated composites, which suggest possibilities of band‐gap tuning of such metal oxide‐conducting polymer composites to be applied especially in solar cell devices. However, the sacrifice of nanobelts‐core led to hollow structures of PPy and PANi, which expands the synthetic strategies to prepare conducting polymer nanotubes. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2892–2900, 2005     

Synthesis of Silver Nanoparticles Using Ionic‐Liquid‐Based Microwave‐Assisted Extraction from Polygonum minus and Photodegradation of Methylene Blue

A green biogenic, nontoxic, high‐yielding synthetic method is introduced for the synthesis of silver nanoparticles (AgNPs) using ionic‐liquid‐based, microwave‐assisted extraction (ILMAE) from Polygonum minus . The aqueous ionic liquid (1‐butyl‐3‐methylimidazolium chloride [BMIM]Cl)‐based plant extract was used as reducing agent to reduce silver ions to AgNPs. The synthesis of AgNPs was confirmed by UV–visible spectrophotometry. Fourier transforms infrared (FTIR) spectra showed that the plant bioactive compounds capped the AgNPs. The particle size and morphology of Ag NPs were characterized by dynamic light scattering (DLS) and field emission scanning electron microscopy (FESEM), respectively. Elemental analysis was carried out by energy‐dispersive X‐ray (EDX) spectroscopy. Photodegradation studies showed that the AgNPs degraded 98% of methylene blue in 12 min.     

Synthesis of Polyaniline‐Vanadium Oxide Nanocomposite Nanosheets

Summary: Polyaniline‐vanadium oxide nanocomposite nanosheets with thickness between 10 and 20 nm, and lateral dimensions in the range of hundreds of nanometers to several microns have been synthesized by in situ intercalation polymerization of aniline with layered V₂O₅ under hydrothermal conditions. The product was characterized by field‐emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT‐IR) spectroscopy, and X‐ray diffractometer (XRD). The effects of the concentration of aniline and reaction temperature on the morphologies of polyaniline‐vanadium oxide nanocomposites have also been investigated.

SEM image of tremella‐like polyaniline‐vanadium oxide nanocomposite nanosheets.     

Catalytic reduction of 4‐nitrophenol using silver nanoparticles‐engineered poly(N‐isopropylacrylamide‐co‐acrylamide) hybrid microgels

Nearly monodisperse poly(N ‐isopropylacrylamide‐co ‐acrylamide) [P(NIPAM‐co‐AAm)] microgels were synthesized using precipitation polymerization in aqueous medium. These microgels were used as microreactors to fabricate silver nanoparticles by chemical reduction of silver ions inside the polymer network. The pure and hybrid microgels were characterized using Fourier transform infrared and UV–visible spectroscopies, dynamic light scattering, X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry and transmission electron microscopy. Results revealed that spherical silver nanoparticles having diameter of 10–20 nm were successfully fabricated in the poly(N ‐isopropylacrylamide‐co ‐acrylamide) microgels with hydrodynamic diameter of 250 ± 50 nm. The uniformly loaded silver nanoparticles were found to be stable for long time due to donor–acceptor interaction between amide groups of polymer network and silver nanoparticles. Catalytic activity of the hybrid system was tested by choosing the catalytic reduction of 4‐nitrophenol as a model reaction under various conditions of catalyst dose and concentration of NaBH₄ at room temperature in aqueous medium to explore the catalytic process. The progress of the reaction was monitored using UV–visible spectrophotometry. The pseudo first‐order kinetic model was employed to evaluate the apparent rate constant of the reaction. It was found that the apparent rate constant increased with increasing catalyst dose due to an increase of surface area as a result of an increase in the number of nanoparticles.     

Ternary Ag/Polyaniline/Au nanocomposites: Preparation,characterization and electrochemical properties

Ternary Ag/Polyaniline/Au nanocomposites were synthesized successfully by immobilizing of Au nanoparticles (NPs) on the surface of Ag/Polyaniline (PANI) nanocomposites. Ag/PANI nanocomposites were prepared via in situ chemical polymerization of aniline in the presence of 4-aminothiophenol (4-ATP) capped silver colloidal NPs. Then, uniform gold (Au) NPs were assembled on the surface of resulted Ag/PANI nanocomposites through electrostatic interaction to get Ag/Polyaniline/Au nanocomposites. The nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), ultraviolet visible spectroscopy (UV-Vis), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). Moreover, Ag/PANI/Au nanocomposites were immobilized on the surface of a glassy carbon electrode and showed enhanced electrocatalytic activity for the reduction of H₂O₂ compared with Ag/PANI.     

Soluble,Antibaterial, and Anticorrosion Studies of Sulfonated Polystyrene/Polyaniline/Silver Nanocomposites Prepared with the Sulfonated Polystyrene Template

In this work, multifunctional sulfonated polystyrene/polyaniline/silver (SPS /PANI /Ag) nanocomposites are prepared through using sulfonated polystyrene (SPS ) spheres as templates and utilizing polyvinylpyrrolidone (PVP ) as reducing agent and stabilizing agent. Our method is an environmentally friendly method because no toxic reagents are added during the preparation process. Fourier transform infrared spectrum (FTIR ), field emission scanning electron microscopy (FESEM ), and energy disperse spectroscopy (EDX ) results confirmed the formation of PS spheres, SPS spheres, SPS /PANI nanocomposites, and SPS /PANI /Ag nanocomposites. Powder X‐ray diffraction (XRD ) patterns indicate that the obtained Ag nanoparticles are crystalline. Solubilities measurements show that SPS /PANI /Ag nanocomposites have improved solubilities when compared to pure PANI in common organic solvents and deionized water. Antibacterial studies show that SPS /PANI /Ag nanocomposites can greatly inhibit the growth of Escherichia coli and Staphylococcus aureus . Anticorrosion studies show that the incorporation of SPS /PANI /Ag nanocomposites in waterborne alkyd resin can greatly promote the anticorrosive efficiency of waterborne alkyd resin.     

Preparation and characterization of multi‐walled carbon nanotubes decorated with silver nanoparticles through ultraviolet irradiation reduction

A facile, green and efficient approach was applied to synthesize multi‐walled carbon nanotubes (MWNTs) decorated with silver nanoparticles (MWNT‐Ag) for further potential application. Oxidized MWNTs were decorated with silver nanoparticles (Ag NPs) via a method combining ultraviolet irradiation‐induced reduction and conventional silver mirror reaction without any reducing agent. The obtained product was characterized using various methods. X‐ray diffraction proved that the Ag NPs were synthesized successfully. Moreover, Ag NPs with a diameter of 80 nm, attached onto MWNTs, could be clearly observed in field emission scanning electron microscopy images, which also confirmed Ag NPs. Energy‐dispersive spectroscopy and transmission electron microscopy also indicated the presence of Ag NPs. Furthermore, thermogravimetric analysis was used to measure the content of Ag NPs in MWNT‐Ag, the result indicating that the weight content of Ag NPs was up to 31.88%. UV–visible absorption spectroscopy was adopted to evaluate the dispersion property of MWNT‐Ag. The result illustrated that MWNT‐Ag had a good dispersibility and stability in water. Characterization was also carried out through Fourier transform infrared spectroscopy, Raman spectroscopy and dynamic light scattering analysis.     

Brominated poly(isobutylene‐co‐para‐methylstyrene) (BIMS)‐clay nanocomposites: Synthesis and characterization

In this work, preparation and properties of different nanoclays modified by organic amines (octadecyl amine, a primary amine, and hexadecyltrimethylammonium bromide, a tertiary amine) and brominated polyisobutylene‐co‐paramethylstyrene (BIMS)‐clay nanocomposites are reported. The clays and the rubber nanocomposites have been characterized with the help of Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X‐ray diffraction (XRD). The X‐ray diffraction peaks observed in the range of 3 °–10 ° for the modified clays disappear in the rubber nanocomposites. TEM photographs show predominantly exfoliation of the clays in the range of 12 ± 4 nm in the BIMS. In the FTIR spectra of the nanocomposites, there are common peaks of virgin rubber as well as those of the clays. Excellent improvement in mechanical properties like tensile strength, elongation at break, and modulus is observed on incorporation of the nanoclays in the BIMS. Structure‐property correlation in the above nanocomposites is attempted. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4489–4502, 2004     

Ag‐Enhanced TiO2–x/C Composites with Metal‐Organic Frameworks as Precursors for Photodegradation of Methyl Blue

A series of Ag‐enhanced TiO_2–x/C composites (Ag/TiO_2–x/C composites) with metal‐organic frameworks (MOFs) as precursors were prepared, and their photocatalytic activities were evaluated by the UV‐light driven photodegradation behaviors of methyl blue (MB). The as‐obtained samples were characterized by several techniques such as SEM, XRD, N₂‐adsorption, XPS, UV/Vis spectrophotometry and UV/Vis diffuse‐reflectance spectra. The best photocatalytic performance was achieved in Ag/TiO_2–x/C composite pyrolyzed at 1000 °C (ATC‐P10) due to rapid capture of electrons caused by silver doping, higher density of TiO_2–x lattice oxygen vacancies for better trapping of electrons, and high surface area due to reduction and evaporation of metallic Zn. No obvious deactivation was observed after 10 cycles of UV‐light degradation of MB under the same experimental conditions. This report reveals a new approach to prepare stable and highly efficient UV‐light‐driven photocatalysts for organic pollutants in water.     

ZnS nanoparticles incorporated in polyaniline composite: Preparation and optical characterization

Hybrid polyaniline based composites incorporating zinc sulfide nanoparticles have been synthesized by using chemical oxidation technique. Morphological and optical properties of the nanocomposite were characterized by scanning electron microscopy, Fourier transform infrared and UV–Vis spectroscopy measurement. The results were compared with pure polyaniline. The characteristic FTIR peaks of polyaniline were found to shift to lower wave-number in nanocomposite. The band gap of nanocomposites increases and the refractive index of the nanocomposites decreases with increasing content of ZnS nanoparticles. These results showed the interaction between ZnS nanoparticles and polyaniline.     

Fabrication of graphene‐silver/polyurethane nanofibrous scaffolds for cardiac tissue engineering

The graphene‐based nanocomposites are considered as great candidates for enhancing electrical and mechanical properties of nonconductive scaffolds in cardiac tissue engineering. In this study, reduced graphene oxide‐silver (rGO‐Ag) nanocomposites (1 and 2 wt%) were synthesized and incorporated into polyurethane (PU) nanofibers via electrospinning technique. Next, the human cardiac progenitor cells (hCPCs) were seed on these scaffolds for in vitro studies. The rGO‐Ag nanocomposites were studied by X‐ray diffraction (XRD), Raman spectroscopy, and transmission electron microscope (TEM). After incorporation of rGO‐Ag into PU nanofibers, the related characterizations were carried out including scanning electron microscope (SEM), TEM, water contact angle, and mechanical properties. Furthermore, PU and PU/nanocomposites scaffolds were used for in vitro studies, wherein hCPCs showed good cytocompatibility via 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay and considerable attachment on the scaffold using SEM studies. Real‐time polymerase chain reaction (PCR) and immunostaining studies confirmed the upregulation of cardiac specific genes including GATA‐4, T‐box 18 (TBX 18), cardiac troponin T (cTnT), and alpha‐myosin heavy chain (α‐MHC) in the PU/rGO‐Ag scaffolds in comparison with neat PU ones. Therefore, these nanofibrous rGO‐Ag–reinforced PU scaffolds can be considered as suitable candidates in cardiac tissue engineering.     

Green synthesis of polymer nanofibers and their composites as flame‐retardant materials for polymer nanocomposites

Polyaniline nanofibers and their composites with carbon nanotubes were developed as an effective flame‐retardant material using a facile green method. Polyaniline nanofibers were used as a smart flame‐retardant for acrylonitrile–butadiene–styrene polymer. The polyaniline nanofibers were dispersed in polymer matrix forming well‐dispersed polymer nanocomposites. Effect of polyaniline nanofiber mass ratio on the polymer nanocomposite properties was studied. Polyaniline nanofiber composites with carbon nanotubes were also dispersed in polymer matrix. The thermal stability and flammability properties of the polymer nanocomposites were investigated. The rate of burning of polymer nanocomposites achieved 82.5% reduction (7.32 mm/min) compared with virgin polymer (42.5 mm/min). The reduction in peak heat release rate and total heat release of the polymer nanocomposites containing nanofibers achieved 74 and 34%, respectively. Interestingly, the average mass loss rate was significantly reduced by 58% and the emission of carbon monoxide and carbon dioxide gases were suppressed by 20 and 47%, respectively. The effect of polyaniline nanofibers composites on the flammability of polymer nanocomposites was also studied. Polyaniline nanofibers and their composites were characterized using Fourier transform infrared spectroscopy and transmission and scanning electron microscopy. The dispersion of polyaniline nanofibers in polymer nanocomposites was characterized using transmission electron microscopy. The different polymer nanocomposites were characterized using thermogravimetric analysis, UL94 flame chamber, and cone calorimeter tests. Copyright © 2016 John Wiley & Sons, Ltd.