Polyaniline Nanoparticles Research Articles

Wearable Multifunctional Hydrogel for Oral Microenvironment Visualized Sensing Coupled with Sonodynamic Bacterial Elimination and Tooth Whitening.

Bacterial-driven dental caries and tooth discoloration are growing concerns as the most common oral health problems. Current diagnostic methods and treatment strategies hardly allow simultaneous early detection and non-invasive treatment of these oral diseases. Herein, a wearable multifunctional double network hydrogel combined with polyaniline and barium titanate (PANI@BTO) nanoparticles is developed for oral microenvironment visualized sensing and sonodynamic therapy. Due to the colorimetric properties of polyaniline, the hydrogel displays a highly sensitive and selective response for visualized sensing of oral acidic microenvironment. Meanwhile, the barium titanate in the hydrogel efficiently generates reactive oxygen species (ROS) under ultrasound irradiation, realizing non-invasive treatment in the oral cavity. Through bacterial elimination experiments and tooth whitening studies, the hydrogel can achieve the dual effect of effectively inhibiting the growth of cariogenic bacteria and degrading tooth surface pigments. Owing to the visualized sensing of the oral acidic microenvironment and efficient sonodynamic therapy function, the proposed hydrogel system offers a solution for the prevention of caries and tooth whitening, which is promising in developing the biomedical system targeting the simultaneous sensing and therapy for oral diseases.

Polyaniline nanoparticles intercalated Ti3C2 MXene reinforced waterborne epoxy nanocomposites for electromagnetic wave absorption and anticorrosion coating applications

Ti3C2 MXene (TM) has great application potential in the field of wave absorption and corrosion resistance due to its unique performance, such as high specific surface area, high electrical conductivity, excellent mechanical and good chemical stability. However, it is difficult to obtain uniformly dispersed TM in the resin matrix due to rapid agglomeration behavior. It is difficult to obtain uniformly dispersed Ti3C2 MXene (TM) in the resin matrix due to rapid agglomeration behavior. Heren, a novel method is presented to improve the corrosion protection and dispersion of TM by polymerizing polyaniline (PANI) nanoparticles between layers. The waterborne epoxy (WEP) coating with PANI-TM had high mechanical properties including impact resistance, adhesion, and flexibility and wear resistance. The PANI-TM-WEP composites can effectively absorb more than 90 % of the electromagnetic waves and demonstrate a decreased glass transition temperature of WEP from 128.0 to 107.6 ℃. Moreover, the |Z|0.01Hz value of the PANI-TM0.5 % was 1.2369 × 106 Ω·cm2, which was one order of magnitude larger than WEP coating. The high-performance anticorrosion of PANI intercalated TM coating is attributed to the synergistic effect of impermeable TM nanosheets and passivation effect of PANI. Therefore, PANI-TM is a potential choice for applications in the fields of anticorrosion and microwave absorption.

Sensitive Electrochemical Sensing Properties for Cyanide Detection Using Polyaniline/Cu-Vanadate Nanobelt-modified Electrode

Background: Cyanide is a toxic anion and may be discarded into the water environment, which is a serious threat to human beings and the environment. Hence, it is essential to explore a facile, sensitive method for cyanide detection. Polyaniline/Cu vanadate nanobelts serve as electrode materials for sensitive cyanide determination. Methods: Polyaniline/Cu vanadate nanobelts were obtained by a simple route using polyaniline, Cu vanadate nanobelts. The polyaniline/Cu vanadate nanobelts were measured via electron microscopy, diffraction, infrared spectrum, and electrochemical methods. Results: Amorphous polyaniline nanoparticles with a particle size of about 100 nm were attached firmly to the surface of Cu vanadate nanobelts. Electrochemical sensing properties for cyanide detection were analyzed using a cyclic voltammetry technique using the nanobelts-modified electrode. The cyclic voltammograms (CV) peaks centered at +0.64 V and +0.54 V were observed using the polyaniline/Cu vanadate nanobelts in 0.1 M KCl solution with 2 mM cyanide. The proposed composite nanobelt-modified electrode possessed the detection range and detection limit of 0.001-2 mM and 0.22 μM, respectively. Conclusion: Polyaniline greatly enhances the electro-catalytic performance of the Cu vanadate nanobelt-modified electrode for cyanide detection.

Fibrin Clot Degradation by Polyaniline-Coated AuNP Using Laser Photolysis

Fibrin clots are crucial for hemostasis and the healing of wounds; nevertheless, excessive blood clotting plays an important role in many chronic diseases, including cardiovascular disease. In this study, we demonstrated the effect of the prepared AuNPs@PANI core/shell on the formed fibrin network. The synthesis of nanoparticles combining electrically conducting polymers polyaniline (PANI) and gold nanoparticles (AuNPs) is an appealing field of research currently because of their physical features and prospective applications in biochemistry. AuNPs showed surface plasmonic resonance (SPR) properties in the visible region at 520 nm then, after coating with PANI, there was a dramatic red shift to 610 nm. The morphological conformation was confirmed by characterization at the microscopic (TEM, SEM, EDX). The PANI shell plays a crucial role in this system, first enhances the stability of AuNPs core; also, the surface of the PANI shell has positive charges (zeta potential = +17.8 mV), leading to electrostatic interactions with fibrin clots that have negatively charged surfaces. The synthesized core/shell AuNPs@PANI showed good efficiency for degrading fibrin networks under 1:30 h of irradiation by an external source of laser light, which is a result of AuNPs’ ability to absorb light at 520 nm. The degradation of fibrin was observed using a scanning electron microscope (SEM), which showed a clear change in the shape of the network. The appearance of fibrous endings and gaping indicates the beginning of the degradation and melting of the fibrin network in different sites of the clot. Overall, this method could have a major influence on disease states, for example, deep vein thrombosis, through a localized, catheter-based approach.

Label-free electrochemical aptasensor for the detection of HepG2 hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the most common liver malignancy and is characterized by increasing incidence and high mortality rates. Current methods for the screening and diagnosis of HCC exhibit inherent limitations, highlighting the ever-growing need for the development of new methods for the early diagnosis of HCC. The aim of this work was to develop a novel electrochemical aptasensor for the detection of HepG2 cells, a type of circulating tumor cells that can be used as biomarkers for the early detection of HCC. A carbon screen-printed electrode was functionalized with a composite suspension containing graphene oxide, chitosan, and polyaniline nanoparticles to increase the electrode surface and provide anchoring sites for the HepG2 cell-specific aptamer. The aptamer was immobilized on the surface of the functionalized electrode using multipulse amperometry, an innovative technique that significantly reduces the time required for aptamer immobilization. The innovative platform was successfully employed for the first time for the amplification-free detection of HepG2 cells in a linear range from 10 to 200,000 cells/mL, with a limit of detection of 10 cells/mL. The platform demonstrated high selectivity and stability and was successfully used for the detection of HepG2 cells in spiked human serum samples with excellent recoveries.Graphical abstract

A novel conductive nano-based flame-retardant coating: Preparation and its application for cotton fabric

A novel coating consisting of polyvinyl alcohol (PVA), folic acid (FA), and polyaniline nanoparticles (PANI) was applied to cotton fabric (CF) to enhance its flame retardancy, thermal stability, and electrical properties. The results from different flammability tests indicated a synergistic effect between FA and PANI to enhance the flame retardancy of CF at low weight gain percentages. The rate of burning data displayed that the new coating stopped the flame propagation in CF. The limiting oxygen index (LOI) of CF increased from 18 % to 26.9 % in the sample coated with PVA/FA/PANI. The new coating improved the thermal stability and char residue formation of CF at high temperatures. Moreover, it succeeded in decreasing the smoke density, and the production of toxic gases during treated CF combustion. The tensile strength and colour strength of CF were improved after the addition of PVA/FA/PANI coating. The surface resistance and the AC conductivity of the coated CF were measured. The addition of PVA/FA/PANI to CF increased the AC electrical conductivity due to the growth of conductive paths between the CF and the new coating material.

Copper/Polyaniline Interfaces Confined CO2 Electroreduction for Selective Hydrocarbon Production.

Polyaniline (PANI) provides an attractive organic platform for CO2 electrochemical reduction due to the ability to adsorb CO2 molecules and in providing means to interact with metal nanostructures. In this work, a novel PANI supported copper catalyst has been developed by coupling the interfacial polymerization of PANI and Cu. The hybrid catalyst demonstrates excellent activity towards production of hydrocarbon products including CH4 and C2H4, compared with the use of bare Cu. A Faradaic efficiency of 71.8 % and a current density of 16.9 mA/cm2 were achieved at -0.86 V vs. RHE, in contrast to only 22.2 % and 1.0 mA/cm2 from the counterpart Cu catalysts. The remarkably enhanced catalytic performance of the hybrid PANI/Cu catalyst can be attributed to the synergistic interaction between the PANI underlayer and copper. The PANI favours the adsorption and binding of CO2 molecules via its nitrogen sites to form *CO intermediates, while the Cu/PANI interfaces confine the diffusion or desorption of the *CO intermediates favouring their further hydrogenation or carbon-carbon coupling to form hydrocarbon products. This work provides insights into the formation of hydrocarbon products on PANI-modified Cu catalysts, which may guide the development of conducting polymer-metal catalysts for CO2 electroreduction.

Electromagnetic interference shielding and DFT study of barium hexaferrites nanoparticles coated polyaniline with heterointerface polarization behavior

Barium-hexaferrite-nanoparticles (BHNs) and polyaniline-nanoparticles (PNs) were prepared individually with average particle sizes of 50 nm and 42 nm. The two nanoparticles were then combined to create hybrid nanoparticles (HNs) with a ferritic core and a conductive surface, by chemically coating polyaniline onto the surface of BHNs via in-situ polymerization. The nanoparticle shape, size, structural, and morphological properties were analyzed using SEM, XRD, and PSA. The nanoparticles were dispersed into a PVDF matrix to produce nanocomposite-films (NFs) for testing EMI shielding effectiveness. The NFs exhibited excellent blocking of near infrared radiation and a shielding effectiveness of more than 50 dB in the microwave region when 30 wt% of HNs was used in the PVDF matrix. Density-function-theory (DFT) based on first-principle was used to confirm the interfacial polarization contribution at the heterointerface, revealing different electron occupied states and considerable charge transfer and accumulation at the interface, enhancing the EMI shielding effectiveness.

Functionalization of Carbon Electrode Surface Using Polyaniline and Gold Nanoparticles for Protein Immobilization

This study presents a screen-printed carbon electrode surface functionalization to immobilize proteins. The process involves the deposition of gold nanoparticles on the carbon electrode and subsequent surface modification to immobilize bovine serum albumin–fluorescein isothiocyanate conjugate (BSA-FITC). A combination of conducting polymer and gold nanoparticles was employed to enhance the electrode contact area and current transmission. The electrode surface morphology and properties were evaluated by scanning electron microscopy (SEM) and Raman spectroscopy, showing the porous polyaniline (PANI) film has been formed on the carbon electrode surface with the network of dendritic nanofibers. Gold nanoparticles were evenly distributed on the PANI film to form a nanocomposite material layer on the carbon electrode. The observed size of these gold nanoparticles was significantly smaller than those on the electrode without a PANI film. Additionally, the current transmission of this composite material layer has been verified by cyclic voltammetry (CV). The results show that the amplitude of the redox peak was doubled compared to the bare carbon electrode and gold nanoparticle-only deposited electrode. Moreover, the success of the process was verified by fluorescence and cyclic voltammetry. The fluorescent green color observed under the microscope indicated that BSA-FITC was on the electrode surface. The change of CV signal after each step verified the formation of a new layer on the electrode surface. These results are anticipated to play an important role in developing high-sensitivity immunosensors in the future.

In-situ electropolymerized polyaniline nanoparticles grown on longan shell-derived porous carbon for high-performance supercapacitor electrode

In this study, novel in-situ electropolymerized polyaniline nanoparticles grown on longan shell-derived porous carbon were prepared for high-performance supercapacitor electrode, which exhibited a high specific capacitance of 486F·g−1 at the current density of 0.5 A·g−1 in 1 M H2SO4 electrolyte via a three-electrode test. Further, the asymmetric supercapacitor was constructed with the energy density as high as 47.3 Wh·kg−1 at the power density of 800 W·kg−1 and excellent durability, in which the retention rate of specific capacitance was still as high as 85 % over 10,000 cycles. The excellent electrochemical performance of the as-prepared composite electrode material can be attributed to the large specific surface area of longan shell-derived porous carbon with honeycomb-like morphology up to 1613.2 m2·g−1, as well as the homogeneous electropolymerization of polyaniline nanoparticles grown on porous carbon, resulting in efficient pseudocapacitive charge storage. Noteworthily, natural longan shell as a renewable carbon source can be suitable for the preparation of high-quality and low-cost porous carbon to significantly improve the performance of supercapacitor electrode, which also provides a feasible pathway for high-value utilization of waste biomass resources.

Chromium speciation in water using magnetic polyaniline nanoparticles coupled with microsampling injection-flame atomic absorption spectroscopy.

The chromium speciation procedure was optimized using magnetic polyaniline nanoparticles (Fe3O4@PANI NPs) solid-phase extraction coupled with microsampling injection-flame atomic absorption spectrometry (MIS-FAAS). Chromium speciation was successfully achieved by Fe3O4@PANI NPs at pH 8.0. The recoveries obtained for Cr(III) and Cr(VI) were above 95% and under 5%, respectively. Recoveries of over 95% for Cr(III) from 40.0 mL of the sample were obtained using 25 mg Fe3O4@PANI NPs and 500 μL of 0.2% (w/v) thiourea (TU) solution prepared in 2 mol L-1 HCl as eluent. Total chromium as Cr(III) was extracted quantitatively after reducing the Cr(VI) to Cr(III). The linear range, detection limit, preconcentration factor, and precision of the optimized method for Cr(III) in aqueous solution were 2.5-94.0 μg L-1, 0.335 μg L-1, 80, and 3.07%, respectively. The validation of the method was controlled using SPS-WW2 Batch 114 wastewater and BCR-715 industrial wastewater as standard reference materials (SRMs) for environmental water, and the obtained results were in close agreement with the certified values.

Recovery of Oleuropein from Olive Leaf Extract Using Zinc Oxide Coated by Polyaniline Nanoparticle Mixed Matrix Membranes.

This study explores the integration of zinc oxide coated with polyaniline (ZnO-PANI) nanoparticles into a poly(ether sulfone) (PES) matrix to concurrently enhance permeate flux and oleuropein (OLP) rejection during the filtration of olive leaf extract (OLE). The effect of ZnO-PANI content on porosity, pore size, surface hydrophilicity, and pure water flux (PWF) was studied. The results indicate that an increase in ZnO-PANI content (0-0.2%) leads to a 3-fold increase in mean pore size, permeability (1.29-7.18 L/m2 h bar), porosity (72.2-77.8%), and improved surface hydrophilicity of the prepared membranes. Membrane performance was tested for OLE permeate flux of the OLE and total phenolic compounds (TPC) rejection at various pressures (10-30 bar), the performance of the OLP rejection at 30 bar, and fouling resistance. The 0.2 wt % ZnO-PANI membrane exhibits the highest permeate flux, while the 0.4 wt % ZnO-PANI membrane offers the highest rejection values (90-97% for TPC and 100% for OLP). Bare PES demonstrated the best fouling resistance. Strategic ZnO-PANI incorporation achieves a balance, enhancing both the flux and rejection efficiency. The 0.2 wt % ZnO-PANI membrane emerges as particularly favorable, striking a beneficial equilibrium between permeate flux and OLP rejection. Intriguingly, the use of these membranes for OLE filtration, postpretreatment with ultrafiltration (UF), results in a remarkable 100% rejection of OLP. This discovery underscores the significant and specific separation of OLP from OLE facilitated by a ZnO-PANI-based mixed matrix membrane (MMM). The study contributes valuable insights into the development of advanced membranes with enhanced filtration capabilities for high-added value phenolic compound separation.

Bio-conjugated carbon dots for the bimodal detection of prostate cancer biomarkers via sandwich fluorescence and electrochemical immunoassays.

Bimodal detection facilitates the accurate and reliable detection of cancer biomarkers, which can assist in the early diagnosis of cancer. Herein, S-doped carbon dots (OCDs) with a size of 3 nm and blue emission were synthesized by the hydrothermal treatment of onion extract. The S-doped carbon dots were bioconjugated with an antibody (OCDs@PSAAbHRP) to design a nanoprobe for the detection of prostate specific antigen (PSA), an important serum based prostate cancer biomarker. The detection probe enabled the biomodal assay of PSA via fluorescence immunoassay (FIA) and electrochemical immunoassay (ECIA). In both assays, polyethylenimine stabilized polyaniline nanoparticles (PNPs) were used as the immobilization matrix, which played a major role in widening the linear range of biosensors (0.1 to 100 ng ml-1 for ECIA and 5 to 120 ng ml-1 for FIA). Paper-based and smartphone-integrated fluorescence immuno-array developed using the OCDs@PSAAbHRP detection probe provided cost-effective and rapid detection, while the electrochemical immunoassay provided a high sensitivity (7.8 μA ng-1 ml-1 cm-2) and low detection limit (38 pg ml-1) for PSA detection. The role of OCDs in enhancing the sensor performance was deciphered by carrying out detailed electrochemical studies with HRP enzyme-loaded OCDs. The biosensor was used to detect PSA in human blood serum samples and the results were consistent with conventional techniques. Owing to its analytical properties coupled with simplicity, cost-effectiveness, and portability, the bimodal sensor system has potential for application in clinical analysis.

Facile synthesis of a magnetic molecularly-imprinted polymer adsorbent for solid-phase extraction of diclofenac from water.

Numerous pollutants endanger the safety and purity of water, making water pollution a major worldwide concern. The health of people and aquatic ecosystems are at risk from these contaminants, which include hazardous microbes, industrial waste, and agricultural runoff. Fortunately, there appears to be a viable option to address this problem with adsorptive water treatment techniques. The present study presents a magnetic adsorbent (MMIP) based on molecularly imprinted polyaniline and magnetite nanoparticles for the solid-phase extraction of diclofenac, an anti-inflammatory medication, from industrial wastewater. The adsorbent nanomaterial was characterized using dynamic light scattering, zeta potential measurement, vibrating sample magnetometry, X-ray diffraction, and scanning electron microscopy. The MMIP demonstrated a particle size of 86.3 nm and an adsorption capacity of 139.7 mg g-1 at 600 mg L-1 of diclofenac and after a 200 min incubation period. The highest %removal was attained at pH range of 3-7. The adsorption process follows the pseudo-second order kinetic model. In addition, it was found that the adsorption process is enthalpy-driven and may occur via hydrogen bonding and/or van der Waals interactions.

Addition of silver nanoparticles to the zinc ferrite/polyaniline composition for boosting its visible photocatalytic degradation.

Enhancing the photocatalytic activity of ZnFe2O4 with a good energy band gap to degrade industrial waste under sunlight illumination can help to develop green environments. Here, to improve the photocatalytic efficiency of ZnFe2O4 ferrites, they were merged with polyaniline (PAni) and silver (Ag) nanoparticles to synthesize Ag@ZnFe2O4-PAni plasmonic nanostructures. The as-synthesized nanostructures were characterized using a series of advanced characterization techniques to confirm successful formation and investigate photocatalytic improvement origins. It was found that incorporating Ag NPs along with the PAni to ZnFe2O4 increases its absorption power and red-shifts its energy band gap, which increases the electron-hole production rate by exposure to light in ZnFe2O4. Contribution of the surface plasmon resonance effect of Ag NPs and conjugated double bonds of PAni to charge transfer mechanisms in Ag@ZnFe2O4-PAni material increased charge separation during photocatalytic process, boosting the photodegradation performance of ZnFe2O4.

Determination of the relative sensitivity of polyaniline inks and films to deprotonation by ammonia using UV–Vis spectroscopy

The deprotonation behavior of conducting polymers such as polyaniline (PANI) is an important functional parameter in the design of novel printed electronic devices, particularly for sensors and energy storage. PANI can be fabricated into films from precursor liquid-processable ‘ink’ formulations. The effective determination and comparison of the deprotonation behavior of such inks is critical to understanding their subsequent functional performance. While protonation can be measured by titration with protonating and deprotonating agents using UV–vis spectroscopy, comparative analysis has proven challenging due to complexities in the measurement of polymer concentration and consequent lack of comparability. This work introduced a coherent approach to establishing the arbitrary concentration of PANI ink formulations. Dodecylbenzene sulfonic acid (DBSA)-micellar doped PANI nanoparticles suspended in sodium dodecyl sulfate were prepared using various monomer, oxidant, and dopant ratios, titrated with ammonia and analyzed using UV–vis spectroscopy. Isosbestic points unaffected by doping or protonation state were used to establish arbitrary polymer concentration. Similar titrations on films prepared from these formulations were performed using ammonia in the gas phase and were based on calculations of deposited mass. Parameters such as a ‘doping capacity’, and their relative sensitivity to ammonia could be determined, which could in turn be related to the physical and chemical compositions of the resulting inks and films. The developed methodology has the potential to be a simple and convenient means with which to compare and optimize the functional deprotonation behavior of conducting polymer inks and films for device development and production optimization.

Wood shavings combined with polyaniline and carbon nanotube film for flexible high-performance energy storage devices

Wood, as a uniquely ordered porous material, plays an indispensable role in energy storage devices. Here, wood shavings (WS) are utilized as a flexible substrate to form an electrode material with excellent flexibility. A conductive coating material made of spinnable carbon nanotube (CNT) film is applied onto the wood shavings, while polyaniline (PANI) nanoparticles are chemically polymerized in situ and deposited onto the CNT film to create flexible electrodes. CNTs offer optimal pathways for electron transport and establish stable connections among PANI particles. Furthermore, the incorporation of the CNT film causes an augmentation of the conductivity of WS substrate. The PANI/CNT@WS exhibits an outstanding specific capacity of 152.81 F g−1 at 0.2 A g−1. The flexible supercapacitor (FSC) presents a high specific capacitance of 45.89 F g−1 at 0.2 A g−1, and capacity rate is as high as 98.98 % after 1000 charge–discharge cycles. Even when bent to 120°, the capacity remains 62.9 %. Therefore, the composite electrode demonstrates exceptional flexibility and excellent electrochemical performance.

Novel polyethersulfone mixed matrix adsorptive nanofiltration membrane fabricated from embedding zinc oxide coated by polyaniline

Novel mixed matrix polymeric membranes were prepared by incorporating self-produced zinc oxide coated by polyaniline (ZnO-PANI) nanoparticles into polyethersulfone (PES) matrix using phase inversion method. Nanoparticles were synthesized, characterized and incorporated in PES matrix with loadings from 0.05 to 0.6 wt%. ZnO-PANI demonstrated effectiveness as a low-cost adsorbent, especially at a loading of 0.2 wt%. ZnO-PANI was used for adsorbing total phenolic compounds (TPC) from olive leaf extract (OLE) at different initial adsorbate concentration (49.92–466.59 mg/L) and pH (2−6). ZnO-PANI proved to be an effective and low-cost adsorbent to remove TPC from OLE. Langmuir model described the adsorption of TPC better than Freundlich model. Effect of incorporated nanoparticles on membranes morphology and hydrophilic properties studied using contact angle measurement, water content, membrane pore size and porosity, SEM, FTIR and pure water flux. Prepared membranes showed a significant increment in porosity, pore size and hydrophilicity by addition of ZnO-PANI in the casting solution up to 0.2 wt%. This led to a considerable improvement in permeability, which decreased with higher additive concentration. During OLE filtration tests (10–30 bar) using bare PES and 0.2 wt% ZnO-PANI/PES membranes, 0.2 wt% ZnO-PANI/PES showed the highest permeate flux and good TPC rejection (83–87%). Bare PES exhibited impressive TPC value rejections (85–92%) and better fouling resistance. Using 0.2 wt% ZnO-PANI achieved a balanced permeate flux and TPC rejection. The research emphasizes the practical applicability of these membranes in various industries due to their enhanced efficacy in removing phenolic compounds from natural extracts, offering a balanced approach between permeate flux and TPC rejection.

Electrorheological Effect of Suspensions of Polyaniline Nanoparticles with Different Morphologies.

Polyaniline (PANI) nanospheres, nanofibers, and nanoplates were prepared using the oxidative polymerization method. Scanning electron microscopy (SEM) was used to observe the three morphologies of PANI, and their structure was tested using infrared spectroscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. The influence of particle morphology on the electrorheological (ER) effect was studied through rheological experiments and molecular dynamics (MD) simulation. The experimental and simulation results indicate that without applying an electric field, the nanofibers easily form a three-dimensional network structure in the suspension, resulting in yield stress. The three-dimensional network structure of the nanoplate suspension becomes weaker and the PANI nanosphere suspension lacks the ability to form a three-dimensional network structure. After applying an electric field, under the same condition, the yield stress and electric field-induced shear stress increment of PANI nanofibers are the highest, followed by nanoplates, and those of PANI nanospheres are the lowest. This indicates that the ER effect increases with the increase in particle morphology anisotropy. Through three-dimensional visual simulation analysis, it can be concluded that the enhanced ER effect associated with increased particle anisotropy can be attributed to improved stability in the ER chain structure.

Optical and Color Investigation of the Effect of Laser Radiation on Polyaniline/Polyvinyl Pyrrolidone/Zinc Sulfide Nanocomposite Films

A nanocomposite (NC) of polyaniline (Pani), polyvinyl pyrrolidone (PVP) and zinc sulfide (ZnS) nanoparticles (NP) was prepared using chemical coprecipitation and ex-situ casting procedures. ZnS NP were synthesized using the chemical coprecipitation technique in atmospheric air. The x-ray diffraction (XRD) scans indicated that the synthesized ZnS had a nanonature and fit the cubic zinc blended structure. We used an infrared pulsed laser to irradiate the Pani/PVP/ZnS NC samples with fluences ranging from 3 to18 J/cm2. The induced changes in the NC were investigated using the UV spectroscopy and International Commission on Illumination (CIE) color difference methodology. When the laser fluence increased up to 18 J/cm2 both the direct and indirect optical bandgaps (Eg) decreased. Additionally, we used the optical dielectric loss (ε”) to detect the type of microelectronic transition for the NC samples. The Eg of the exposed NC samples and the pristine samples exhibited indirect allowed transitions. The laser effects on the absorbance, extinction coefficient, transmission, refractive index, dielectric parameters and optical conductivity of the NC were studied. Lastly, the color differences between the pristine and exposed samples were determined. The pristine Pani/PVP/ZnS showed a significant color difference with the laser irradiated samples. The changes of the studied optical parameters with the laser fluence indicated that the laser radiation represents a convenient tool that would allow the application of Pani/PVP/ZnS NC in optoelectronic devices.