Polypyrrole Coatings Research Articles

Polypyrrole Coating via Lemieux-von Rudloff Oxidation on Magnetite Nanoparticles for Highly Efficient Removal of Chromium(VI) from Wastewater.

An alternative way for the coating of polypyrrole (PPy) polymer on hydrophobic magnetite (Fe3O4) nanoparticles is reported here to capture toxic chromium ions, Cr (VI), present in water. Iron oxide magnetic nanoparticles (Fe3O4) were synthesized by the conventional coprecipitation technique using FeCl3·6H2O and FeSO4·7H2O iron precursors and subsequently modified with oleic acid (OA). Then OA-Fe3O4 hydrophobic nanoparticles were oxidized using the Lemieux-von Rudloff reaction to transfer OA into hydrophilic azelaic acid (AA) (HOOC(CH2)7COOH-modified magnetic nanoparticles (AA-Fe3O4). Finally, a PPy polymer coating was formed by a seeded polymerization of pyrrole, using AA-Fe3O4 as seeds. The average size of PPy/Fe3O4 nanocomposites is 12.33 nm and is almost spherical in shape. The surface composition is confirmed by FTIR and thermogravimetry analyses. An X-ray diffraction study confirmed the formation of highly crystalline Fe3O4 nanoparticles, and the crystallinity was retained after the surface modification. The adsorption study suggested that the Cr(VI) ion adsorption is highly pH-dependent and the maximum amount of adsorption is obtained at pH 2.0. The adsorption results revealed that the Langmuir model provided the best fit for the isotherm, with a maximum adsorption capacity reaching approximately 173.22 mg g-1 at 323 K. Spontaneous and endothermic adsorption processes were confirmed by evaluating the thermodynamic parameters obtained in this investigation. The kinetics study showed that the interaction between Cr(VI) ions and magnetic nanocomposites was directed by a pseudo-second-order rate process indicating chemisorption. The prepared PPy/Fe3O4 nanocomposites would be promising adsorbents to purify water by eliminating Cr(VI) metal ions from wastewater.

Characteristics and Electrochemical Behavior of AZ31 Mg Alloy Protected with Potentiostatically Deposited Polypyrrole Coatings

Characteristics and Electrochemical Behavior of AZ31 Mg Alloy Protected with Potentiostatically Deposited Polypyrrole Coatings

Anticorrosion and Supercapacitor Applications of Polypyrrole Coated Graphite Nanocomposites

The present investigation reports the successful incorporation of Graphite into the PPy matrix via a chemical in-situ polymerization technique. Obtained composites were thoroughly studied by using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The corrosion inhibition response of the composites on mild steel (MS), treated in acid media was analysed through atomic absorption spectroscopy (AAS), impedance, Tafel diagram (potentiodynamic polarization) and scanning electron microscopy (SEM) techniques. The results have revealed better inhibitory properties of these composites in the premeditated acid media. The Tafel and impedance curves revealed the dependency of polymer compounds on the corrosion protection of MS steel. The surface of MS is examined through the SEM technique (before and after corrosion). The synthesized materials were further studied for supercapacitor applications using electrochemical Cyclic Voltammetry (CV) and Galvanostatic Charging and Discharging studies (GCD) measurements. The supercapacitor and corrosion properties can be further optimized to develop effective PPy/G structures.

Polypyrrole Coated Textiles as Photothermal Material for Interfacial Solar Evaporation

Polypyrrole Coated Textiles as Photothermal Material for Interfacial Solar Evaporation

Research on the Performance of Polypyrrole Coated Conductive Fabrics Prepared from Different Base Materials

Abstract In this paper, polypyrrole coated conductive fabrics were prepared using pyrrole as the monomer, p-toluene sulfonic acid as the doping agent and ammonium persulfate as the oxidant, adopting the simple method of situ polymerization of the liquid phase. Six types of conductive polypyrrole coated fabrics were prepared adopting polyester-cotton blended fabrics, nylon fabrics, wool fabrics, silk fabrics, basalt fabrics and aramid fabric respectively as base materials and using the same process conditions; its electrical conductivity was compared, and the distribution and resistance of the washing fastness of polypyrrole on the surface of those fabrics were studied. Results showed that under the same process conditions, the conductivity of polypyrrole coated terylene fabrics was the best, followed by the polypyrrole coated nylon fabrics and polypyrrole coated wool fabrics. Observed by electron microscope, the distribution of polypyrrole was more homogeneous on different base cloths. After washing, it was concluded that the combination fastness of polypyrrole with polyester-cotton, nylon and wool was better, while the combination fastness of polypyrrole with basalt and aramid was poor.

Controlled Synthesis of Metal–Organic-Framework-Derived V2O5 Nanostructures with Polypyrrole Coating for Zinc-Ion Batteries

Here, the vanadium (V) metal–organic-frameworks (MOFs) used as templates are synthesized to obtain nanostructured V2O5, including nanorods, nanowires, nanosheets, and nanoflowers. The formation mechanism for the V-MOF precursors and their derived V2O5 with morphology control is investigated. Engineering oxygen vacancies by manipulating the active sites and electrical conductivity has been demonstrated as a promising method for superior zinc-ion storage in V2O5. Benefiting from the high electronic conductivity and improved structural integrity for the induction of PPy and oxygen defects, the V2O5@PPy-based ZIBs exhibit a high capacity (404.3 mA h g–1 at 0.2 A g–1), enhanced energy conversion efficiency (a superior energy density of 346 W h kg–1 and a power density of 3834.2 W kg–1), and long-term life span (80.7% of the initial capacity remained after 1000 cycles). The assembled quasi-solid-state ZIBs exhibit a stable capacity of 167.9 mA h g–1 after 300 cycles at 3.0 A g–1. This work develops a method to make a promising V2O5 cathode for aqueous ZIBs.

Superior conductive polypyrrole anti‐corrosion coating doped with titanium nitride for 304 stainless steel bipolar plates

AbstractThe conductivity and corrosion performance of metallic bipolar plates were crucial to the development of the proton exchange membrane fuel cell (PEMFC). In this study, polypyrrole (PPy) coatings doped with titanium nitride nanoparticles (TiN NPs) were deposited on 304 stainless steel (304SS) by constant potential polymerization. To improve dispersion and form a negative charge surface, TiN NPs were modified by anionic surfactants such as sodium dodecyl diphenyl ether disulfate (MADS). Through comparing potentiodynamic curves of the composite coatings in the simulated cathodic environment of PEMFC, the PPy‐0.1 TiN (0.1 g/L) coating presented a more positive corrosion potential (Ecorr = 293 mVAg/AgCl) and a lower corrosion current (Icorr = 0.841 μA cm−2). Furthermore, PPy‐0.1 TiN exhibited more stable corrosion resistance during long‐term immersion. Interfacial contact resistance (ICR) testing demonstrated that the addition of TiN NPs improved conductivity compared to a PPy coating. The results indicated that the PPy‐TiN‐coated 304SS could be used as a kind of promising bipolar plate material.

A Disposable Electrochemical Sensor for Lead Ion Detection Based on In Situ Polymerization of Conductive Polypyrrole Coating

Lead, a toxic heavy metal, is considered one of the most serious pollutants in the water environment, posing a grave threat to human health and the global ecosystem. In this work, a simple, fast and sensitive sensor strategy for detecting trace lead ions (Pb2+) in water was proposed. The disposable electrochemical sensor was fabricated with a screen-printed carbon electrode (SPCE), and the working electrode was modified in a single step with in situ polymerized phytic acid functionalized polypyrrole (PA-PPy). Differential pulse anodic stripping voltammetry (DPASV) was employed to realize the efficient detection of Pb2+ in the range of 10–600 nM with a low detection limit of 0.43 nM (S/N = 3). The PA-PPy@SPCE sensor exhibits good stability, repeatability and anti-interference performance, indicating a promising application for real sample detection, and satisfactory recoveries were obtained when detecting Pb2+ in real tap water samples. Furthermore, the rapid sensor strategy with in situ polymerization of phytic acid functionalized polypyrrole composite material enables large-scale Pb2+ sensor preparation.Graphical Abstract

Insight into the corrosion inhibition of the iron anode with electro-deposited polyaniline during the electrocoagulation treatment process of electroplating wastewater

In this study, polyaniline (PANI) and polypyrrole (PPy) coatings were applied to modify iron plate anodes to treat electroplating wastewater by electrocoagulation (EC) treatment.

A Gallic Acid-Doped Polypyrrole Coating with Anticorrosion and Antibacterial Properties on Magnesium Alloy.

Magnesium (Mg) and its alloys exhibit great potential as biomedical implants due to their excellent biological performance and mechanical properties. However, their clinical applications are limited by their rapid corrosion rate in physiological media and the risk of implant-associated infections. Herein, a multifunctional polypyrrole/gallic acid (PPy/GA) coating was deposited on an AZ31 Mg alloy substrate by electrochemical polymerization to enhance simultaneously the corrosion resistance and antibacterial properties of the Mg alloy. Electrochemical and in vitro immersion tests demonstrated that the anticorrosion performance of the Mg alloy was significantly improved with the PPy/GA coating. The thiazolyl blue tetrazolium bromide (MTT) assay and live-dead staining of L929 cells indicated the acceptable cytocompatibility of the PPy/GA coating. In vitro antibacterial tests revealed a remarkable enhancement in the antibacterial activity of the PPy/GA-coated Mg alloy compared with the PPy-coated material and the bare Mg alloy.

Constructing reduced graphene oxide and polypyrrole coatings on glass fiber to enhance its absorbing performance

AbstractIn this work, a new route for improving the absorbing performance of glass fibers (GFs) composites by introducing the reduced graphene oxide (RGO)/polypyrrole (PPy)/RGO coatings through the self‐assembly method and then the in‐situ polymerization method was proposed. The corresponding microstructure and electromagnetic parameters were measured by scanning electron microscopy, X‐ray photoelectron spectroscopy, and vector network analyzer. The result indicated that the RGO/PPy/RGO coatings can adjust the absorbing performance of GFs composites by its synergistic effect, thus exhibiting optimum impedance matching degree and high conduction loss ability. The minimum reflection loss value of the synthesized RGO/PPy/RGO/GFs composite can reach −55.8 dB with the thickness of 4.3 mm, and the effective absorption bandwidths (≤−10 dB) covered the entire X‐band. This work proved that the RGO/PPy/RGO coatings can be used to adjust the radar absorbing performance of GFs composites.

Electrodeposition of polypyrrole coatings doped by benzenesulfonic acid-modified graphene oxide on metallic bipolar plates

Benzenesulfonic acid (BSA)-modified graphene oxide (GO) reinforced polypyrrole (PPY) coatings were electrodeposited on metallic bipolar plates for corrosion protection. The ionization of BSA groups drove the parallel stacking of graphene oxide during the anodic deposition. Meanwhile, the doping effect of BSA groups favored the electro-polymerization of pyrrole and the π-electron delocalization of PPY. The doping level of PPY in the composite coatings increased from 15.6 % to 35.2 % when the concentration of BSA-modified GO (SGO) was increased from 1.5 mg٠mL−1 to 3 mg٠mL−1, while the surface roughness of the coatings decreased from 34.3 nm to 19.3 nm. The corrosion current density under the potentiodynamic polarization test reached 0.18 μA٠cm−2, which was an order of magnitude lower than that of the GO/PPY composite coatings. The interfacial contact resistance of the SGO/PPY coatings was 85 % lower than that of GO/PPY coatings, when the electrical conductivity was increased from 6.72 × 10−3 S٠cm−1 to 13.7 S٠cm−1. The improved performance of composite coatings was attributed to the barrier effect of parallelly stacked graphene sheets, the doping effect of BSA groups grafted on GO, and the two-dimensional template effect of SGO on PPY deposition.

Polypyrrole Coated Multiwalled Carbon Nanotube Hybrids for Corrosion Inhibition

Polypyrrole Coated Multiwalled Carbon Nanotube Hybrids for Corrosion Inhibition

Optimized Anticorrosion of Polypyrrole Coating by Inverted-Electrode Strategy: Experimental and Molecular Dynamics Investigations.

To improve the poor adhesion and the ensuing insufficient anticorrosion efficacy of electropolymerized polypyrrole (PPy) on copper surface, an inverted-electrode strategy was applied after the passivation procedure, for which the compact coating (PPy-I) was deposited on the substrate in a cathodic window. Morphological and physical characterizations revealed that PPy-I exerted satisfactory adhesion strength and suitable thickness and conductivity compared with the analogue prepared via the traditional protocol (PPy-T). Potentiodynamic polarization, electrochemical impedance spectroscopy and frequency modulation were employed to ascertain the propitious protection of PPy-I for copper in artificial seawater (ASW). Due to the dominant electroactivity, the PPy-I-coated sample possessed higher apparent current density and lower charge transfer resistance than its PPy-T-protected counterpart, which maintained the passivation of the substrate. Surface analysis also supported the viability of PPy-I for copper in ASW for a well-protected surface with inferior water wettability. Molecular dynamics simulations evidenced that PPy-I with the higher density retained efficient anticorrosion capacity on copper at elevated temperatures. Therein, the derived time-dependent spatial diffusion trajectories of ions were locally confined with low diffusion coefficients. Highly twisted pore passages and anodic protection behavior arising respectively from the tight coating architecture and electroactivity contributed to the adequate corrosion resistance of PPy-I-coated copper.

Neutral inhibitor molecules entrapped into polypyrrole network for corrosion protection

For the performance of smart self-healing coatings, several factors are of critical importance: the type of inhibitors that can be released, the kind of trigger signal, the rate of trigger signal spreading and the transport capability in the coating for providing sufficiently fast sufficient amounts of active agents to the defect. In recent works, it was shown that intrinsically conducting polymer (ICP) applied between the metal and the top coating cannot only significantly enhance the signal spreading, but also the transport of active agents towards the defect. Hence, in combination nano-containers with ICP layers can play a crucial role in designing intelligent self-healing coatings. However, an interesting question is whether such ICP layers could also play a direct role in storing active agents and their smart release. Here, the idea is presented of entrapping inhibitor directly inside the ICP matrix. For this polypyrrole (PPy) coatings were electrodeposited in the presence of additions of β-Cyclodextrine, benzotriazole or 8-Hydroxyquinoline in the deposition electrolyte containing pyrrole and 3-nitrosalicylate (as counter-anion). The structure, composition, and morphology of these PPy coatings were evaluated by FTIR, Raman, XPS and SEM and the entrapment of the molecules was confirmed by triggered release and detection by UV–vis. The self-healing performance was investigated by monitoring both the corrosion potential in an electrolyte filled defect and the delamination behavior by SKP. An excellent performance in terms of an extraordinarily significant passivation effect is observed, which is proposed to be a consequence of a synergy between the inhibitors and re-oxidation of the PPy. Most notably, the delaminated interface is fully restored.

Characteristics and Electrochemical Behavior of Az31 Mg Alloy Protected with Potentiostatically Deposited Polypyrrole Coatings

Characteristics and Electrochemical Behavior of Az31 Mg Alloy Protected with Potentiostatically Deposited Polypyrrole Coatings

Corrosion protection properties of polypyrrole coatings formed onto 316 L SS from a solution containing molybdate and salicylate

The electrosynthesis of PPy films onto 316L stainless steel from nearly neutral and alkaline solutions containing molybdate and salicylate is reported. The corrosion behaviour of the coatings constituted by hollow rectangular microtubes was monitored in Ringer solution using open circuit potential measurements, polarization techniques and electrochemical impedance spectroscopy. The polymer formed in a solution of pH 8 was the most efficient in terms of corrosion protection. The coating significantly reduced the pitting corrosion of the substrate. The results were interpreted taking into consideration the polymer electroactivity, the galvanic interaction polypyrrole/substrate and the nature of dopants. Silver species were effectively immobilized onto the hollow rectangular-sectioned microtubes of PPy. The modified coatings demonstrated that they have a good bactericidal activity against Escherichia coli and they were also able to protect the substrate against corrosion in Ringer solution.

Synthesis and Characterization of Heparin-Doped Polypyrrole Coatings Using an Electrochemical Quartz Crystal Microbalance (EQCM)

Synthesis and Characterization of Heparin-Doped Polypyrrole Coatings Using an Electrochemical Quartz Crystal Microbalance (EQCM)

High Performance Organic Coatings of Polypyrrole Embedded with Manganese Iron Oxide Nanoparticles for Corrosion Protection of Conductive Copper Surface

High Performance Organic Coatings of Polypyrrole Embedded with Manganese Iron Oxide Nanoparticles for Corrosion Protection of Conductive Copper Surface

Preparation and performances of modified Ti4O7 doped polypyrrole coating for metallic bipolar plates

In view of the high chemical stability and good electrical conductivity of Ti4O7 particles, it is proposed in this work to develop Ti4O7 doped polypyrrole coatings on 316 L metallic bipolar plates by electrodeposition technique. Thereby, the conductive Ti4O7 particles are prepared and hydroxylated. Then the modified Ti4O7 particles are chemically bonded with sulfur-containing doped acid, and combined with polypyrrole chain through electrostatic interaction. The composite coating can keep high chemical stability in simulated cathodic proton exchange membrane fuel cells environment at 25 and 70 °C. Meanwhile, the electrical conductivity and hydrophobicity are also significantly enhanced.