Water-soluble Polyaniline Research Articles

Synthesis and Study of Electro-Optical Properties of Water-Soluble Polyaniline Prepared by Chemical Oxidation

Synthesis and Study of Electro-Optical Properties of Water-Soluble Polyaniline Prepared by Chemical Oxidation

Research progress on preparation methods of water-soluble polyaniline

The application of polyaniline (PANI) in various fields is greatly limited by its poor solubility in water.Many methods which could elevate PANI water-soluble ability were used by researchers to expand its application range. In this paper, the research progress of the commonly used preparation methods of water-soluble PANI in recent years is reviewed. The main preparation methods of water-soluble PANI are categorized into four types including monomer modification, controlling the polymerization process, introducing water-soluble groups or substances, macromolecular reaction. They are composed of aniline derivative method, copolymerization, emulsion polymerization method, dispersion polymerization method, acid doping method, compound method, ATRP method. The principles of various methods to achieve water-solubility of PANI are introduced, the research on each preparation method reported before are introduced and their advantages and disadvantages are summarized.

Red-emitting polyaniline-based nanoparticle probe for pH-sensitive fluorescence imaging.

Fluorescent probes based on semiconducting polymer nanoparticles (NPs) such as polyaniline (PANI) usually require external fluorophore doping to provide fluorescence function. Direct use of PANI-based NPs for bioimaging applications has been limited by PANI's weak blue fluorescence and aggregation-induced quenching in physiological medium. In this report, we developed a facile solid-state synthesis method to produce fluorescent polyaniline nanoparticles (FPNs) that are not only water-soluble but also exhibit high intensity and pH-sensitive red fluorescence. The FPNs showed high photoluminescence quantum yield (PLQY) of 19.3% at physiological pH, which makes FPNs ideal for application as fluorescent nanoprobes in bioimaging. Moreover, we performed an in-depth study of photoluminescence dependence on pH and the phenomena of exciton-polaron quenching at low pH was highlighted. We also found that the ratio of emission intensity at 600nm and 650nm increased from 0.04 to 1.65 as pH was raised from 2.6 to 11.8, which could find its application in ratiometric pH sensing. FPNs exhibited excellent biocompatibility with >85% cell viability for fibroblasts NIH/3T3 and prostate cancer 22RV1 cells even at concentrations as high as 1000μg/mL. In addition, fluorescence microscopy demonstrated concentration-dependent red fluorescence in the cytoplasm owing to the cellular uptake of FPNs in prostate cancer cells.

Water-soluble PANI:PSS designed for spontaneous non-disruptive membrane penetration and direct intracellular photothermal damage on bacteria

The major challenge in the field of antibacterial agents is to overcome the low-permeability of bacteria cell membranes that protects the cells against diverse drugs. In this work, water-soluble polyaniline (PANI)-poly (p-styrenesulfonic acid) (PSS) (PANI:PSS) is found to spontaneously penetrate bacteria cellular membranes in a non-disruptive way, leaving no evidence of membrane poration/disturbance or cell death, thus avoiding side effects caused by cationic ammonia groups in traditional ammonia-containing antibacterial agents. For aqueous synthesis, which is important for biocompatibility, the polymer is synthesized via an enzyme-mimetic route relying on the catalysis of a nanozyme. Owing to its fluorescent properties, the localization of as-prepared PANI:PSS is determined by the confocal microscope, and the results confirm its rapid entry into bacteria. Under 808 nm near-infrared (NIR) irradiation, the internalized PANI:PSS generates local hyperthermia and destroys bacteria highly efficiently from inside the cells due to its excellent photothermal effects. Staphylococcus aureus (S. aureus), Methicillin-resistantStaphylococcus aureus (MRSA) and Escherichia coli (E. coli) could be effectively eliminated as well as the corresponding bacterial biofilms. Results of in vivo antibacterial experiments demonstrate excellent antibacterial activities of the water-soluble PANI:PSS without side effects. Therefore, the prepared water-soluble polymer in this study has great potential in the treatment of various bacterial infections.

Biomimetic dense lamellar scaffold based on a colloidal complex of the polyaniline (PANi) and biopolymers for electroactive and physiomechanical stimulation of the myocardial

A novel biodegradable conductive scaffold containing water-soluble polyaniline (PANi) was manufacture. The conductive dense lamellar scaffolds were obtained by a mixture of collagen, fibroin solution, hyaluronic acid, and water-soluble polyaniline, using plastic compression method. Scaffolds held open and interconnected pores having a pore size ranging from several 100 to 150 μm. PANi-scaffolds had compression modulus and strength of 1.77 ± 0.11 MPa. The isoelectric point of the scaffold was observed by surface zeta potential in pH 7.7. The conductivity of the scaffold was measured as 2.10–6 S.cm−1 for dry PANi-scaffold and 6.10-4 S. cm−1 for hydrated. The PANi-scaffold has physiomechanical, and physico-chemical properties supported the viability and proliferation of cardiomyocytes. Our results highlight the potential of incorporation of PANi as an electroactive moiety for induction of cardiomyocyte proliferation and repair of damaged heart tissue.

Electroactive polyaniline/silica hybrid gels: Controllable sol-gel transition adjusted by chitosan derivatives

In this study, the electroactive hybrid gels with controllable sol-gel process were fabricated based on the water soluble polyaniline complex and water soluble silica precursor. β-cyclodextrin grafted on chitosan (CSCD) acted as a template, a new route for the synthesis of water soluble polyaniline complex (PA@CSCD) was designed by in-situ polymerization. Then, the hybrid silica gels without severe shrinkage were prepared by mixing PA@CSCD complex with water soluble precursor (tetrakis(2-hydroxyethyl)orthosilicates, THEOS). By dynamic rheological measurements, it was found that PA@CSCD complex could trigger and accelerate the sol-gel transition of the silica precursor. The gelation time could be largely shortened with the increase of PA@CSCD complex amount. By SEM observation, the PA@CSCD complex could be well compatible with the silica matrix. Moreover, the hybrid gels showed the good redox electroactivity, which could be successfully applied in a HRP-based biosensor.

Electrochromic Behaviors of Water-Soluble Polyaniline with Covalently Bonded Acetyl Ferrocene

A novel ferrocene-containing hybrid electrochromic material was synthesized via copolymerization of aniline with p-phenylenediamine functionalized acetyl ferrocene in the presence of poly (styrene sulfonate) dopant in an aqueous medium, and neat polyaniline (PANI) was prepared for comparison. The polymerization characteristics and the structure of the copolymer were systematically studied by Fourier-transform infrared, meanwhile, their electrochromic properties and electrochemical behaviors were tested by UV–vis spectra, cyclic voltammetry and electrochemical impedance spectroscopy (EIS). It was found that the strong covalent bond and large conjugated system between PANI and ferrocene enhance the electron transfer rate and electron delocalization in the ferrocene-polyaniline (Fc-PANI) hybrid. In particular, the electrochromic device with Fc-PANI as the active layer shows significant enhancement in optical contrast over the PANI-based device.

Enhancing the electrochromic performances of polyaniline film through incorporating polyaniline nanofibers synthesized by interfacial polymerization approach

In this paper, we demonstrate a simple approach to improve the electrochromic performances of polyaniline (PANI) by incorporating PANI nanofibers (PANI-NFs) synthesized by interfacial polymerization into water-soluble PANI:poly(styrene sulfonate) (PANI:PSS). The one-dimensional PANI-NFs endow spin-coated PANI film high electrochemical activities and electrochromic properties. The structures and morphologies of PANI-NFs were characterized by FTIR spectroscopy and SEM observation. The electrochemical behaviors of PANI/PANI-NFs composites were analyzed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrochromic properties of composites were tested using electrochemical working station combining a UV-Vis spectrometer. The results show that the PANI-NFs with even diameter of ~ 30 nm can be synthesized easily using interfacial polymerization method. With the increasing of feeding amount of PANI-NFs, the oxidation peaks of CV curves shift to low potential direction, indicating enhanced electrochemical activities. The electrochromic test confirms that the PANI/PANI-NFs composites films have higher electrochromic contrast of 0.67 as comparison to 0.49 of PANI:PSS film. The PANI/PANI-NFs also exhibit excellent electrochromic stability. After 2000 cycles switching, only less than 4% contrast decay is observed. The enhanced electrochromic properties can be attributed to the small charge-transfer resistance and facile ion diffusion process brought by PANI-NFs. The EIS tests exhibit that with incorporating of highly conductive PANI-NFs, the PANI/PANI-NFs composites possess relatively lower charge-transfer resistance of 76 Ω as comparison to 94 Ω of neat PANI:PSS.

Synthesis of Water-soluble Polyaniline by Using Different Types of Cellulose Derivatives

Pure polyaniline (PAni) is insoluble in water. Water-soluble complexes of PAni with different of cellulose derivatives were successfully synthesized by using chemical oxidation polymerization of aniline in aqueous solution of cellulose derivatives. In this study, cellulose derivatives such as methylcellulose (MC), hydroxypropyl cellulose (HPC), and hydroxypropyl methylcellulose (HPMC) had been used as a steric stabilizer, aniline (Ani) as a monomer with hydrogen chloride (HCl) as an acidic dopant, and ammonium persulfate (APS) as an initiator. The chemical structure of PAni complexes were confirmed by using Fourier Transform Infrared Spectroscopy (FTIR). The interactions of PAni and cellulose derivatives were observable through Ultraviolet-Visible Spectroscopy (UV-Vis) in the wavelength range of 300 nm to 900 nm. The Standard Four-Point Probe Method was used for the conductivity measurements. In the electrical conductivity measurement, PAni in toluene was used as a control. The result showed that water-soluble PAni-cellulose derivatives gave higher conductivity value (9.47 × 10−2 – 1.87 × 10−1 S/cm) than the pristine PAni (1.60 × 10−3 S/cm).

Intra-grain conduction of self-doped polyaniline

The conduction behavior of ultrathin films (about 10 nm thick) composed of self-doped water-soluble polyaniline sulfonate (SPAN) was investigated using nano-gap electrodes under vacuum conditions. The conductance was found to be ohmic even in the high field regime up to 105 V cm−1 over a temperature range of 10–300 K. The temperature dependence of the conductance indicated that SPAN gave the extremely high value of localization length (L) = 300 nm without secondary doping, in comparison with conventional polyaniline. We propose that SPAN forms long-range highly crystalline metallic grains, and we observed intra-grain conduction due to some grains directly bridging the two nano-gap electrodes at low temperature. We conclude that inter-grain conduction becomes dominant as the temperature increases.

NIR probe conjugated polymeric nanoparticles for intelligent drug delivery and imaging

cultured with Se nanoparticles, which was ascribed to increased intracellular OH• generation. Furthermore, the prepared Se nanoparticles were found to able to catalyze green synthesis of water-soluble polyaniline (PANI) as natural peroxidases do. The Se catalyzed PANI can convert near infrared (NIR) light energy to heat, and show remarkable anti-tumor effect for HeLa cells co-cultured with the PANI. Based on our findings, we expect that the red elemental Se nanoparticles can provide future therapeutic potential in tumor theranostics.

Nanoscaled red elemental se peroxidase mimic designed for tumor cell inhibition and green synthesis of water-soluble polyaniline as photothermal therapy agent

Nanoscaled red elemental se peroxidase mimic designed for tumor cell inhibition and green synthesis of water-soluble polyaniline as photothermal therapy agent

Optical, electrical, and electrochemical properties of graphene based water soluble polyaniline composites

ABSTRACTPolyaniline (PANI) is one of the most common polymers known for its conducting properties. However, poor water solubility limits its applications. In this work, PANI has been functionalized with sulfonic acid groups to produce sulfonated PANI (SPANI) offering excellent solubility in water. To compensate for the decrease of electrical conductivity due to functionalization, SPANI was combined with reduced graphene oxide (RGO) to form SPANI/RGO composites with interesting optical, thermal, and electrical properties. The composites have been characterized using X‐ray diffraction (XRD), field emission scanning electron microscopy, UV–vis absorption spectroscopy, Raman spectroscopy, Fourier‐transform infrared spectroscopy, X‐ray photoelectron spectroscopy, thermogravimetric analysis, cyclic voltammetry, and four probe electrical conductivity measurement. The SPANI/RGO composites show increased thermal stability, reduced optical band gap and improved electrochemical properties compared with the pure polymer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42766.

Hb-induced biocatalyzed synthesis of water-soluble polyaniline nanocomposites with controlled handedness in DBSA–CTAB mixed micelle solutions

A new polymerization system for the synthesis of chiral conducting polyaniline (PANI) with high conductivity catalyzed by hemoglobin (Hb) in dodecylbenzenesulfonic acid (DBSA)–cetyltrimethyl ammonium bromide (CTAB) mixed micelle solutions was developed. For the first time, without any other chiral inducer, PANI with controlled handedness was found to be acquired only in the presence of Hb, indicating that Hb played the role of both the inducer and biocatalyst. The effects of reaction pH, concentrations and ratio of the mixed surfactants on the formation of chiral PANI were explored. Results revealed that the conductivity of chiral PANI was closely associated with the molar ratio of DBSA to CTAB. When the ratio of DBSA to CTAB was 3:1, the highest conductivity of 39.71S/cm was obtained. The chiral PANI was characterized by UV–vis absorption spectroscopy, circular dichroism (CD) spectra, Fourier transform infrared spectra (FTIR), field emitted scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Our results demonstrated that this novel system was specific, simple and green, in which the controlled handedness PANI was obtained with various morphologies and high conductivity.

Water-Soluble Polyaniline–Polyacrylic Acid Composites as Efficient Corrosion Inhibitors for 316SS

Water-soluble polyaniline–poly(acrylic acid) (PANI–PAA) composites with excellent processability and electroactivity were prepared by a one-step in situ polymerization. PAA as a matrix not only improves the solubility of PANI in water but also prevents the formation of macroscopic PANI clusters. The corrosion-inhibition performance of 316 stainless steel (316SS) was evaluated in 0.5 M HCl by electrochemical measurements in the presence of PANI–PAA composites. The results show that PANI–PAA acts as a mixed-type inhibitor, and its inhibition efficiency (IE(R)) increases with inhibitor concentration. The adsorption of the inhibitor on 316SS surface obeys a Langmuir adsorption isotherm. The PANI–PAA composite with an optimized concentration of 200 ppm shows marked increase in IE(R), i.e., 91.68%. The enhanced efficiency is attributed to an insulating interfacial layer formed by the adsorption of PANI–PAA, which obstructs the corrosion reaction at the interface.

A green route to water-soluble polyaniline for photothermal therapy catalyzed by iron phosphates peroxidase mimic

Water-soluble polyaniline showing the photothermal effect was synthesized via a green route using iron phosphates peroxidase mimic as a catalyst.

Fabrication of silver nanoparticles/polyaniline composite thin films using Layer-by-Layer self-assembly technique for ammonia sensing

In this study, the Layer-by-Layer (LbL) deposition technique was used to prepare composite thin films of silver nanoparticles and polyaniline. The multilayer composite thin films were constructed by alternate deposition of anionic and cationic polyelectrolytes. Anionic polyelectrolyte was prepared by chemical reduction of silver ion using water soluble polyaniline as the stabilizing agent to form anionic silver nanoparticles/polyaniline composite solution. The water soluble polyaniline was prepared by interfacial polymerization of aniline monomer in presence of poly(styrene sulfonic acid co maleic acid), (CoPSS). Silver nanoparticles stabilized with anionic water soluble polyaniline were then deposited in thin film with cationic poly(diallyldimethylammonium chloride), (PDADMAC) and characterized for their optical properties. The optical properties of thin films were measured by UV–visible spectroscopy. The surface of the films was measured by atomic force microscopy (AFM). As these films are to be used as sensor for the ammonia detection, the changes in optical properties of the films were evaluated for various ammonia concentration. A strong color shift from orange-red to yellow was visible when exposed to ammonia. These silver nanoparticles/polyaniline composite thin films displayed fast color change and could be used for ammonia sensing in industrial section.

Preparation of Polyaniline/Au0 Nanocomposites Modified Electrode and Application for Hydrazine Detection

AbstractThe PANI/Au0 nanocomposite films were successfully prepared on glassy carbon electrode (GCE) using a simple alternate adsorption of water soluble polyaniline (PANI) and ${{\rm AuCl}{{- \hfill \atop 4\hfill}}}$. The growth of the films was monitored by UVVis spectroscopy and cyclic voltammetry. ${{\rm AuCl}{{- \hfill \atop 4\hfill}}}$ was in‐situ reduced in the film due to the redox interaction between PANI and ${{\rm AuCl}{{- \hfill \atop 4\hfill}}}$, without extra reductant. The ultrafine Au nanoparticles with the size of 2–4 nm were observed by transmission electron spectroscopy. The existence of zero‐valence Au nanocrystals (Au0) was confirmed by X‐ray photoelectron spectroscopy, X‐ray Diffraction and FTIR. PANI in the nano‐structured PANI/Au0 composite films displayed a good redox activity in neutral pH solution. The as‐obtained PANI/Au0/GCE presents an excellent electrocatalytic activity to hydrazine oxidation, and the mechanism of hydrazine oxidation was studied. The calibration curve on (PANI/Au0)5/GCE was obtained in the concentration range of 0.01–6 mM with the detection limit of 1 µM (S/N>3). The modified electrode has a great potential for hydrazine sensor application due to its ease of fabrication, good reproducibility and high stability.

Water soluble polyaniline/polysaccharide composite: Polymerization, carbonization to yield carbon micro-bubbles

We report synthesis of water soluble polyaniline composite using polysaccharide, alginic acid, by oxidative chemical polymerization. Spectroscopy measurements for the composites with infrared (IR), UV–vis spectroscopy, electron spin resonance (ESR), and scanning electron microscopy (SEM) were carried out. We confirmed water solubility of the composite and carbonization allowed the composite to form carbon micro-bubble structures.

Water soluble polyaniline coated electrode: A simple and nimble electrochemical approach for ascorbic acid detection

We report the design, synthesis, electrochemical stability and electrocatalytic applications of a new kind of water soluble polyaniline (PANI) composite. These water soluble PANI composites are extremely important in electrochemical sensor, semiconducting devices, light-emitting diodes, ultra-thin and flexible display devices, photoconductive sensors, and new fluorescent bio-probes. In the present work, we have prepared water soluble PANI using our designed and synthesized perylene disulphonic acid (PRSA) dopant. This PRSA dopant is a new and superior doping acid for synthesis of water soluble PANI. The PRSA/PANI composite prepared with it exhibits good electrochemical stability and superior electrocatalytic activity. It can sense ascorbic acid, a very important biomolecule, in neutral pH up to mM concentration level at the low electrochemical oxidation potential. Additionally, the modified electrode prepared from aqueous medium of PANI on ITO glass, is reusable and requires only a water rinsing and drying cycle in between measurements. PRSA/PANI composites also show a good semiconducting behavior and follow 1D-VRH (variable range hopping) electron transportation mechanism. The importance and novelty of this method are (i) synthesis of water soluble PANI by ‘in-situ’ polymerization method, which overcome the major and common problem of PANI processability in water; (ii) high performance electrocatalytic activity and reusability of PANI coated electrode. It also overcomes the electrochemical drawback of PANI synthesis, i.e. low yield, cost effective, limited processabilty etc.