Camphorsulfonic Acid Research Articles

Chiral helical polyaniline modified electrodes toward efficient enantioselective recognition of tyrosine

Enantiomeric analysis is a crucial aspect of the investigation of the properties of chiral substances, and it plays a pivotal role in the development and application of chiral substances. Therefore, the objective of this study was to develop a highly sensitive and user-friendly tyrosine (Tyr) enantiomer detector based on chiral helical polyaniline (PANI). In this study, the helical PANI was generated in an alcohol-water system and doped with Camphorsulfonic acid (CSA) to enhance its electrochemical properties. The chiral helical PANI was then obtained by eluting the CSA under alkaline conditions. The electrochemical sensors developed using this material enable selective recognition of Tyr enantiomers. The mechanism of enantioselective recognition was also explored from a molecular perspective with the help of modeling software. The chiral recognition ability and properties of the sensor were investigated using DPV, EIS, and CV. The surface characteristics of doped and de-doped chiral sensor were analyzed using FE-SEM, HR-TEM, AFM, CD, XPS, and FT-IR. Finally, an electrochemical analysis method for Tyr enantiomers was established using DPV, offering high sensitivity, superior anti-interference ability, quick analysis speed, and good long-term stability. The constructed chiral electrochemical sensor can be used for the detection of human serum and urine samples, which provides a new idea for the selective recognition of Tyr enantiomers in clinical sample.

Polyaniline/graphitic carbon nitride/reduced graphene oxide ternary nanocomposite film for flexible thermoelectric application

The present study outlines the preparation of a ternary nanocomposite film comprising of polyaniline doped with camphor sulfonic acid (PANI), reduced graphene oxide (rGO), and graphitic carbon nitride (g-C3N4), and delves into its thermoelectric performance. PANI is known to possess high electrical conductivity (σ) and poor thermal conductivity (κ). However, its potential for thermoelectric applications is constrained by the low value of the Seebeck coefficient (S). The incorporation of g-C3N4in PANI has been demonstrated to result in an improvement of the Seebeck coefficient. Furthermore, the addition of rGO to the PANI/g-C3N4sample counteracts the decrease in electrical conductivity. The PANI/g-C3N4/rGO ternary nanocomposite film exhibits an enhanced Seebeck coefficient of ∼2.2 times when compared to the PANI sample. The Seebeck coefficient of the PANI/g-C3N4/rGO nanocomposite is enhanced by the energy filtering effect that occurs at the interfaces between g-C3N4/PANI and PANI/rGO. Theπ-πinteraction between the PANI chains and rGO is responsible for the increased electrical conductivity resulting from the well-ordered polymer chain arrangement on the g-C3N4and rGO surfaces. The ternary nanocomposite sample demonstrated a synergistic improvement in both electrical conductivity and Seebeck coefficient, resulting in a remarkable ∼4.6-fold increment in power factor and an ∼4.3-fold enhancement in the figure of merit (zT), as compared to the pristine PANI film.

RAPID AND AN EFFICIENT ONE-POT THREE-COMPONENT SYNTHESIS OF ISOXAZOLES PROMOTED BY CAS

A straightforward, practical, and economical process for producing isoxazole derivatives is described. It makes use of ethylacetoacetate, hydroxylamine hydrochloride, and substituted aromatic aldehydes with promoted camphor sulfonic acid as a catalyst in a solvent. No toxic organic solvents are used in the current procedure. Shortest reaction time, high product yields, easy work-up process, and non-chromatographic product purification are only a few of this catalysts encouraging reaction response characteristics. The derivatives of desired compounds were analyzed advanced spectroscopic data by 1H NMR, 13CNMR and mass spectrometry was used to verify the products structures. Products were chosen, and their antibacterial activity was examined.

Template-free synthesize of PANI nanostructures: Modulating structure for enhanced dielectric characteristics and superior electromagnetic wave absorption

To provide electromagnetic protection for intelligent equipment, advanced electromagnetic wave absorption (EWA) materials are highly desired. To reveal the interaction mechanism of structure and electromagnetic waves, polyaniline (PANI) with various structures, including nanosheets, clusters, and nanofibers, is synthesized via a template-free approach. The self-assembly process of PANI can be regulated by camphor sulfonic acid due to the formation and guidance of charge transfer complexes. A comprehensive analysis of structure, chemical constitution, and electromagnetic characteristics is conducted. Clusters with three-dimensional micro-nano structure exhibit superior microwave absorption, achieving a minimum reflection loss of −52.22 dB at 9.84 GHz with a 3.2 mm thickness and an absorption bandwidth of 6.12 GHz at 2.3 mm thickness. The outstanding EWA performance is attributed to the unique architecture, strong dielectric loss capabilities, and effective impedance matching. Moreover, the fabrication process is cost-effective and scalable, making it conducive to practical applicability.

Electrochemical chiral sensor developed using nanofibrous polyaniline chiral Structures: Detection and differentiation of D- and L-tryptophan

In this work, a simple strategy for electrochemical detection and differentiation of D- and L- forms of tryptophan is demonstrated using nanofibrous structures of chiral polyaniline (CP). Basically, CP with desired chirality is prepared using a chiral acid namely, ± camphor sulfonic acid (±CSA) in presence of either a cationic (or) anionic surfactant (CTAB / SDS) through a simple oxidative polymerization process. Structure, morphology and phase purity of the resultant CP materials are characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction studies. Moreover, the chiral properties of these conducting polymers are evaluated using circular dichroism (CD) spectroscopic studies. From these analyses it is found that CP exhibited twisted nanofibrous morphology and possesses the chirality whereas the non-chiral polyaniline (PANI), prepared in the absence of chiral acid, displayed the formation of a simple fibrous structures without any twists or chirality. Interestingly, such CP materials are found to be electrochemically selective for the detection and differentiation of D- and L- forms of tryptophan (Trp). Among the different chiral materials, CP-CT(−) prepared using CTAB displayed a much better sensing characteristics with higher IL/ID ratio, wider concentration range of detection and lower detection limit of 0.98 µM for l-Trp and 1.2 µM for d-Trp respectively. On the other hand, non-chiral PANI does not display any sensing behavior towards the differentiation of amino acid, Trp. Further, chronoamperometric studies reveal the selectivity of this chiral sensor for the detection of Trp among the other potentially interfering analytes. Although the difference in the measured peak current value is smaller, a significant difference of 70 mV peak potential is observed for the differentiation of L- and d-Trp. Moreover, the proposed CP-based sensing platform exhibits excellent stability and reproducibility with statistically negligible error values suggesting the potential use of the developed material towards electrochemical chiral detection and differentiation of amino acid, Trp.

Asymmetric Organocatalytic 1,3-Dipolar Cycloaddition of Azomethine Ylides with β-Substituted Cyclic Enones.

The enantioselective and diastereoselective control of 1,3-dipolar cycloaddition reactions to β-substituted cyclic enones has been developed. The 1,3-dipolar cycloaddition of phthalazinium dicyanomethanides with cyclic dienones affords chiral tetrahydropyrrolo[2,1-a]phthalazine derivatives 3 through vinylogous iminium ion activation by combining a cinchona-based primary amine C3 and a chiral camphorsulfonic acid additive. Conversely, with a weaker 3,5-bis(trifluoromethyl)benzoic acid additive, the 1,3-dipolar cycloaddition of phthalazinium dicyanomethanides with β-substituted cyclic enones leads to chiral hexahydroisoindolo[1,2-a]phthalazin-10(8H)-one derivatives 4 with excellent stereocontrol via endo-dienamine activation.

Development of liquid phase microextraction-based deep eutectic solvent for the extraction and determination of toxic metal ions in herbal medicines

Herein, an eco-friendly, simple, and inexpensive procedure was developed using vortex-assisted combined with deep eutectic solvent-based liquid phase microextraction (VA-LPME-DES) followed by graphite furnace atomic absorption spectrometry. In the present procedure, DES was first synthesized from the combination of l-menthol and (1S)-(+)-camphor-10-sulfonic acid (CSA) in a molar ratio of 5:1, and then it was used as a green and safe extractant instead of common toxic organic solvents. The ability of the presented method was applied for the separation and preconcentration of lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As) in herbal medicines. After optimizing all the parameters of the experiment, the linear ranges were 0.10–200 µg kg−1 with coefficient of determination (r 2) better than 0.985. The limits of detection were in the ranges of 0.03–0.15 µg kg−1. Relative standard deviation values for intra-day and inter-day of the method based on 7 replicate measurements were in the range of 1.8%–3.6% and 3.1%–7.3%, respectively. The relative recoveries of herbal medicines which have been spiked with different concentrations of metal ions were 91.5%–109.8%. The method was successfully used to analyze the heavy and toxic metals in herbal medicine samples.

Dielectric and structural properties of polyaniline-tungsten trioxide nanocomposites: For the packing of nano-electronic devices and EMI shielding

Polymer nanocomposites (PNCs) have showed the significant applications in the fields of packing, energy, safety, defense, sensors, EMI shielding, optoelectronics etc. Tungsten trioxide nanoparticles (NPs) were prepared by propellant chemistry technique using Azadirachta indica extracts as a fuel/surfactant. Conducting polyaniline (PANI) was prepared using aniline monomer and suitable polymerizing agents. Ex-situ nanocomposites were prepared by mixing the different weight percentage of NPs into PANI matrix. For the better dispersion of NPs in to the matrix, solvents like Dodesyl benzene sulphonic acid (DBSA) and Camphor sulphonic acid (CSA) were used. Crystal structure, morphological features and their dielectric response at room temperature were reported. Electromagnetic Shielding (EMI) studies were compared between the PANI-WO3 composites prepared by CSA and DBSA solvents. Composites showed worthy shielding response of 80 dB with CSA and 38 dB with DBSA. Here, the protonation of the solvent and the dispersion of NPs with the polymer matrix matters for the shielding efficiency. Hence, prepared materials are suitable for packing of electronic devices which provides the better EMI shielding and also suppress the heat through effective absorption of EM waves of X-Band.

Camphorsulfonic Acid-Catalyzed Synthesis of a Series of 2-Aryl/heteroaryl/alkyl-1H-anthra[ 1,2-d]imidazole-6,11-dione Derivatives

Abstract: Anthraquinone moiety is very common among naturally occurring bioactive compounds. Many commercially available drug molecules also possess anthraquinone moiety. In recent times, among many other anthraquinone derivatives, specifically, 2- substituted-1H-anthra[1,2-d]imidazole-6,11-diones are gaining extra attention due to their significant anti-cancer, anti-HIV, anti-inflammatory activities, etc. This study aimed to report a simple, straightforward, organocatalyzed method for the efficient synthesis of a series of 2-aryl/heteroaryl/alkyl-1H-anthra[1,2-d]imidazole-6,11-diones from the reactions of 1,2-diaminoanthraquinone and various aldehydes using a catalytic amount of camphorsulfonic acid as an efficient organocatalyst in aqueous ethanol under refluxed conditions. Under the same optimized reaction conditions, along with aryl or heteroaryl aldehydes, aliphatic aldehydes also underwent a smooth reaction and afforded the desired products in excellent yields. All the synthesized compounds were obtained pure in excellent yields by simple filtration and washing subsequently with ethanol. The use of less toxic solvent, low-cost, commercially available metal-free organocatalyst, no column chromatographic separation, good yields, and easy isolation procedure are some of the major advantages of this newly developed protocol.

A Squaramide-Based Organocatalyst as a Novel Versatile Chiral Solvating Agent for Carboxylic Acids.

A squaramide-based organocatalyst for asymmetric Michael reactions has been tested as a chiral solvating agent (CSA) for 26 carboxylic acids and camphorsulfonic acid, encompassing amino acid derivatives, mandelic acid, as well as some of its analogs, propionic acids like profens (ketoprofen and ibuprofen), butanoic acids and others. In many cases remarkably high enantiodifferentiations at 1H, 13C and 19F nuclei were observed. The interaction likely involves a proton transfer from the acidic substrates to the tertiary amine sites of the organocatalyst, thus allowing for pre-solubilization of the organocatalyst (when a chloroform solution of the substrate is employed) or the simultaneous solubilization of both the catalyst and the substrate. DOSY experiments were employed to evaluate whether the catalyst-substrate ionic adduct was a tight one or not. ROESY experiments were employed to investigate the role of the squaramide unit in the adduct formation. A mechanism of interaction was proposed in accordance with the literature data.

Deoxygenation of sulfoxides using D-camphorsulfonic acid as an efficient reducing agent under metal and additive-free conditions

Deoxygenation of sulfoxides using D-camphorsulfonic acid as an efficient reducing agent under metal and additive-free conditions

Air-Stable and Eco-Friendly Symmetrical Imine with Thiadiazole Moieties in Neutral and Protonated form for Perovskite Photovoltaics.

This paper proposes molecular and supramolecular concepts for potential application in perovskite solar cells. New air-stable symmetrical imine, with thiadiazole moieties PPL2: (5E,6E)-N2,N5-bis(4-(diphenylamino)benzylidene)-1,3,4-thiadiazole-2,5-diamine), as a hole-transporting material was synthesised in a single-step reaction, starting with commercially available and relatively inexpensive reagents, resulting in a reduction in the cost of the final product compared to Spiro-OMeTAD. Moreover, camphorsulfonic acid (CSA) in both enantiomeric forms was used to change the HOMO-LUMO levels and electric properties of the investigated imine-forming complexes. Electric, optical, thermal, and structural studies of the imine and its complexes with CSA were carried out to characterise the new material. Imine and imine/CSA complexes were also characterised in depth by the proton Nuclear Magnetic Resonance 1H NMR method. The position of nitrogen in the thidiazole ring influences the basicity of donor centres, which results in protonation in the imine bond. Simple devices of ITO/imine (with or without CSA(-) or CSA(+))/Ag/ITO architecture were constructed, and a thermographic camera was used to find the defects in the created devices. Electric behaviour was also studied to demonstrate conductivity properties under the forward current. Finally, the electrical properties of imine and its protonated form with CSA were compared with Spiro-OMeTAD. In general, the analysis of thermal images showed a very similar response of the samples to the applied potential in terms of the homogeneity of the formed organic layer. The TGA analysis showed that the investigated imine exhibits good thermal stability in air and argon atmospheres.

Layer‐By‐Layer Chiral Induction of Fluorene‐Based Metal–Organic Framework Films for Circularly Polarized Luminescence Sensing of Enantiomers

AbstractDeveloping films of chiral metal–organic frameworks (MOFs) with high circular polarization luminescence (CPL) is facing a great challenge for chiral sensing applications. Herein, a layer‐by‐layer chiral induction method is first reported to prepare enantiopure MOF films for CPL sensing. By layer‐by‐layer induction with the chiral inductor camphorsulfonic acid, fluorene‐based chiral MOF D/L‐ZnHF‐SO2 film (HF‐SO2 = 3,7‐Dibenzothiophenedicarboxylate, 5,5‐dioxide) with preferential growth orientation and homogeneous surface are prepared, which shows strong chiral feature and CPL with higher asymmetry factor of ±0.073. In addition, by mixed ligand approach, the isostructural fluorene ligand 9‐fluororenone‐2,7‐dicarboxylate is chosen to replace part of HF‐SO2 for preparing a series of chiral MOF films with tunable CPL emission. Furthermore, the prepared chiral MOF films with strong CPL performance are further utilized for enantiomers sensing. The CPL changes consisted with enantioselective adsorption results showed that D/L‐ZnHF‐SO2 film has good discrimination against chiral R/S‐phenylethylamine enantiomers, first reporting chiral MOF‐based candidates for the application in CPL sensing of enantiomers. This work provides a facile and effective approach for preparing chiral MOF films materials with high and tunable CPL performance, and also gives a new way to achieve CPL sensing of chiral enantiomers.

Tailoring reduced graphene oxide into nanofibrous architectures: fabrication, characterization, and functional insights

Abstract The electrospinning process allows the production of nanofibers from polymer solutions, making them suitable for various applications such as sensors, electronic devices, conductive materials, and advanced composites for high-temperature environments. In this research, polyaniline (PANI) was doped with camphor sulfonic camphor sulfonic acid (HCSA). HCSA dopant is used to modify the electrical and structural properties of polyaniline. To introduce reduced graphene oxide as a nanofiller to enhance the electrical properties of the polymer. Both the HCSA-doped PANI and HCSA-doped PANI with rGO nanofibers were electro-spun separately to create individual nanofibers. Fourier-transform infrared spectroscopy was used to investigate the chemical composition and functional groups present in the nanofibers. Field emission scanning electron microscopy was employed to study the nanofibers’ morphology, structure, and surface characteristics. Thermogravimetric analysis was used to assess the thermal stability of the nanofibers and to approximate the content of rGO. These results indicate that the addition of reduced graphene oxide (rGO) led to improvements in the nanofibers’ electrical conductivity and thermal stability.

Improved thermoelectric properties by copolymerization of conducting with insulating monomers on carbon nanotubes

In the present work, development of carbon nanotube (CNT)/poly(conducting-co-insulating monomer) structures was proposed to improve the thermoelectric (TE) performance in CNT/polyaniline (PANI) composites. To check the validity of this idea, we prepared multiwalled carbon nanotube (MWNT)/poly(aniline-co-acrylonitrile) composites by in-situ inverted emulsion copolymerization, and applied secondary doping with camphorsulfonic acid in m-cresol medium prior to the investigation of TE properties. The samples were characterized by FT-IR, UV–Vis, 1H NMR, DSC, GPC, CHNS elemental analysis, intrinsic viscosity, SEM, XRD, electrical resistance, Seebeck coefficient, thickness, and Hall measurements. We report that nitrile groups were hydrolyzed during the polymerization reactions to provide a polymer structure exhibiting aniline, acrylamide, acrylic acid, and glutarimide groups. Further, the poly(aniline-co-acrylonitrile) that prepared in the present work were random copolymers. Importantly, we found that 30 % MWNT/70 % poly(90ANI-co-10AN) composite exhibited a 63 % higher power factor (PF) of 5.48 μW/mK2 (σ: 225 S/cm, S: 15.6 μV/K) at 35 °C than that of 30 % MWNT/70 % PANI, which exhibited a PF of about 3.37 μW/mK2 (σ: 238 S/cm, S: 11.9 μV/K). This was ascribed to the decrease of carrier concentration together with the increase of carrier mobility in the 30 % MWNT/70 % poly(90ANI-co-10AN) composite as compared to the 30 % MWNT/70 % PANI.

Application of polyaniline/zinc oxide nanocomposites for non-enzymatic cholesterol detection: A preliminary investigation on the effect of dopants on the morphology, thermal stability, electrochemical and sensing behavior of the nanocomposites

ABSTRACT Cholesterol is a major cause for cardiovascular diseases; and therefore, timely detection of cholesterol is of paramount importance to prevent such diseases. Herein, a non-enzymatic sensor for the detection of cholesterol has been fabricated using polyaniline (PANI) and its nanocomposites (NCs) with ZnO nanoparticles (NPs). For this purpose, a series of NCs has been synthesized by varying the loading of the ZnO NPs as 2%, 3%, 5% and 8% with respect to the weight percentage of the aniline monomer. In addition, two different doping agents, namely camphor sulfonic acid (CSA) and hydrochloric acid, have been used to prepare PANI and its NCs. Electrochemical studies have revealed that as the amount of ZnO NPs increased, the capacitive behavior of the composite also increased. Similar trend was observed in case of HCl-doped polyaniline NCs. PANI/ZnO 8% NCs for both HCl and CSA dopant indicated good capacitive behavior for sensing cholesterol. The best electrode was further tested for sensitivity, and was found to exhibit a value of 0.38 mA mM−1 cm−2. The limit of detection of the prepared sensor was found to be 0.30 mM concentration in PBS buffer under the linearity range of 0.75 mM to 1.5 mM (adj. R2 = 0.97).

Influence of surfactant on conductivity, capacitance and doping of electrodeposited polyaniline films

The electrodeposition of polyaniline films is usually carried out in acid solutions such as hydrochloric acid, perchloric acid or sulfuric acid, and more rarely in organic acids such as camphorsulfonic acid (CSA). In this study, the impact of the presence of a surfactant in the electrolytic solution based on hydrochloric acid or CSA was evaluated by successively using anionic (sodium dodecyl sulfate, SDS), cationic (cetyltrimethylammonium bromide, CTAB), and non-ionic (Tritonx100) surfactants. Whatever the surfactant and the acid used, the electrochemical oxidation of aniline has successfully led to the formation of a thick polyaniline (PANI) film through a quasi-reversible reaction controlled by the diffusion of aniline monomers. The nature of the surfactant was shown to affect physico-chemical properties of the film, in particular its morphological features (morphology, thickness, roughness), electrochemical activity, specific capacitance, and conductivity. For example, PANI films containing SDS had a spongy morphology when PANI films containing Tritonx100 had a more fibrous and compact structure. Glow Discharge Optical Emission Spectroscopy (GDOES) experiments also highlighted differences depending on the acid used since chloride anions, from HCl, were present only on the top surface of the PANI films when camphorsulfonate anions were present everywhere throughout the polymer film, which impacts the doping process and electrochemical activity of the films. Moreover, the specific capacitance of the PANI/CSA films is higher and more sensitive to current density variation than the one of PANI/HCl films. Finally, electrochemical impedance experiments evidenced that the conductivity of PANI films electrodeposited from CSA solutions was much higher than the one of PANI films prepared from HCl solutions, and highly dependent on the nature of the surfactant, the most conductive films being obtained in the presence of SDS and Tritonx100. Therefore, the originality of this work comes from the possibility of modulating the conductivity, capacitance and electroactivity of electrodeposited polyaniline films using surfactants of different polarity, and from the determination of the distribution of ions in the films using the GDOES technique, which is rarely used to characterise organic films.

Solution-mixed PANI-coated Bi2Si2Te6 nanosheet-based composite film for flexible thermoelectric energy harvesting

This paper introduces a novel approach for flexible thermoelectric energy (TE) harvesting via the synthesis and characterization of polyaniline (PANI)-coated Bi2Si2Te6 nanosheet (NS) composite films. The study focuses on enhancing the TE performance of the Bi2Si2Te6 NSs by coating their surfaces with PANI via a solution-mixing method. Specifically, the process involves exfoliation of Bi2Si2Te6 into nanosheets, followed by coating with camphorsulfonic acid (CSA)-doped PANI. An investigation of the TE power factor of the PANI-coated Bi2Si2Te6 NS is then conducted by analyzing the influence of the PANI coating times, and the results are explained in terms of the charge-carrier transport. Thus, the PANI-coated Bi2Si2Te6 NS composite films obtained using two coating cycles are shown to exhibit a maximum power factor of (∼411 μW/m·K2 at 500 K). Further, the flexibility and bending stability of the composites are revealed by an evaluation of their mechanical properties. Moreover, the as-fabricated PANI-coated Bi2Si2Te6 NS composite films exhibit outstanding durability after 1000 bending cycles. The findings contribute to the advancement of flexible inorganic/organic hybrid TE materials and their practical applications.

Pseudo-doping effect on structural and electrical properties of polyaniline-camphorsulfonic acid

Electroconductive polymers (ECP) are critical for the design of soft electronic and bioelectronic devices. Polyaniline:camphorsulfonic acid (PANI:CSA) is an example of a biocompatible and affordable ECP, whose electroconductivity is highly dependent on chain organization/conformation. PANI:CSA aggregation ordering is overlooked in most works, but it can greatly impact the performance of PANI:CSA-based devices and limit their applicability. A simple and cheap method to avoid random coil aggregation of PANI:CSA is to select solvents with pseudo-doping properties. This work presents a novel alternative solvent system, based on trifluoroethanol (TFE) and hexafluoropropanol (HFP) mixtures, capable of being removed without hampering the structural and electrical properties of PANI:CSA. For the first time, we present a systematic study that compares the performance of solvent systems containing different amounts of TFE and HFP, which, unlike m-cresol, the golden-standard of pseudo-doping, are easy to remove without compromising the ECP’s electroconductivity and biocompatibility. We also evaluate the influence of the processing method, drop-casting vs spin-coating, on the structural and electrical properties of the obtained samples. Samples obtained by spin-coating show a more consistent improvement in electroconductivity (σ(TFE) = 61 S cm−1, σ(TFE:HFP (50:50 vol)) = 70 S cm−1) and more intense near-infrared (NIR) absorption bands. Atomic force microscopy (AFM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) indicate that samples processed with HFP and m-cresol have higher benzenoid content, lower random coil aggregation and more efficient CSA doping. The solvent system comprised of equal parts of TFE and HFP was found to simultaneously enhance the electrical properties and structural ordering of PANI:CSA. We believe our results are critical for the fabrication of PANI-based next generation bioelectronic devices.

Electrochemical synthesis of a novel hybrid nanocomposite based on Co3O4 nanoparticles embedded in PANI- camphor sulfonic Acid matrix for optoelectronic applications

In this study, we report on the preparation and characterization of Co3O4 nanoparticles (NPs) embedded in polyaniline-Camphor Sulfonic Acid (PANI-CSA) polymer matrix via electrochemical polymerization method. Developing conductive organic films with tunable optical properties are crucial for many novel optoelectronic applications. Thus, incorporation of metallic oxide nanoparticles (Co3O4 NPs) into polymer matrix (PANI-CSA) represents an alternative approach to address these desired features. As a result of careful optimization of several growth conditions, PANI-CSA/Co3O4 hybrid nanocomposites with high crystalline and homogeneous structures were successfully synthesized on ITO substrates. The impact of Co3O4 NPs concentrations on the structural and optical properties has been extensively investigated. A variety of structural and optical techniques, including FTIR, UV-VIS spectroscopy, and XRD, were employed to characterize the prepared hybrid nanocomposites. The initial findings and analysis reveal that the integration of Co3O4 NPs into PANI-CSA matrix have a trifunctional role in reducing π-polaron and Urbach energies (EU) whereas increasing π-π* band gaps. A further increase in NPs concentration up to 12 wt % results in continuous increase in the absorbance bands and absorption coefficients, indicating improved optical properties as compared to the control sample (PANI-CSA without NPs). The observed redshifts in absorbance band positions are attributed to narrowing of the optical band gap caused by interactions between PANI-CSA chains and Co3O4 NPs. FTIR spectra confirmed the exact chemical composition of PANI-CSA/Co3O4 nanocomposites, exhibiting broadened and less intense peaks compared to the control sample, indicating their interaction at the molecular levels. Additionally, XRD measurements indicate that no peaks of other phases were detected in all nanocomposites, demonstrating their purity and crystallinity. Finally, A single oscillator model by Wemple-DiDomenico (WDD) coupled with a Sellmeier dispersion relation based on one term has been utilized to model the typical electronic transition excitation energies, dispersion energies, optical conductivities, and many other optical desperation parameters for PANI-CSA and PANI-CSA/Co3O4 at various concentrations. For instance, in response to increased NPs content, linear optical susceptibility, third-order nonlinear optical susceptibility, and nonlinear refractive index decrease. In contrast, the ratio of free carriers to effective mass (N/m) increased from 4.73 × 1039 to 4.91 × 1039 m−3 kg−1 with increasing NPs concentration. Based on the observed results, these hybrid nanocomposites possess improved properties, indicating their potential use as active materials in a variety of novel optoelectronic applications.