Dodecylsulfate-doped Polypyrrole Research Articles

Dodecyl sulfate-doped polypyrrole derivative grains as a light-responsive liquid marble stabilizer

Polypyrrole, poly(N-methyl pyrrole) and poly(N-ethyl pyrrole) grains were synthesized by aqueous chemical oxidative polymerization in the presence of sodium dodecyl sulfate as both a dopant and a hydrophobizing agent. The resulting grain products were characterized in terms of their size, morphology, surface and bulk chemical compositions, hydrophilic–hydrophobic balance, (photo)thermal property, and conductivity. Scanning electron microscopy studies indicated that the grains were aggregates of atypical particles with submicrometer size. Elemental microanalysis and thermogravimetric analysis confirmed the production of dodecyl sulfate-doped polypyrrole, poly(N-methyl pyrrole) and poly(N-ethyl pyrrole) materials, and they showed near-infrared light-to-heat photothermal properties, which was confirmed by thermography. The data obtained through X-ray photoelectron spectroscopy indicated the presence of dodecyl sulfate dopants on the surface of the grains. The dried polypyrrole and poly(N-ethyl pyrrole) grains showed hydrophobic character, and therefore, they can adsorb to the air–water interface and act as a light-responsive liquid marble stabilizer. Locomotion of the liquid marble can be driven by near-infrared laser irradiation-induced Marangoni flow on a planar air–water surface. The release of internal liquid can be achieved by controlled disruption of liquid marbles via external stimulus application. Polypyrrole and poly(N-alkyl pyrrole) grains were synthesized by aqueous chemical oxidative polymerization in the presence of sodium dodecyl sulfate as both a dopant and a hydrophobizing agent. The dried polypyrrole and poly(N-ethyl pyrrole) grains showed hydrophobic character and can act as a light-responsive liquid marble stabilizer. Locomotion of the liquid marble can be driven by near-infrared laser irradiation-induced Marangoni flow on a planar air–water surface. Furthermore, the release of internal liquid can be achieved by controlled disruption of liquid marbles via external stimulus application.

Molecular architecture of highly protective coatings of electrodeposited dodecyl sulfate-doped polypyrrole

The chemical structure and molecular arrangement in polypyrrole coatings electrodeposited in the presence of dodecyl sulfate has been studied using XPS, Raman spectroscopy and linear dichroism in the Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy. The as-deposited polypyrrole has two-dimensional structure with a high proportion of dodecyl sulfate anions. This structure contains one dodecyl sulfate anion for each nitrogen atom involved in the formation of charge carrier or supposedly protonated. This corresponds to drastic changes in the N K NEXAFS spectra observed as complete disappearance of π*-related resonances. The dodecyl sulfate doped polypyrrole shows linear dichroism of the carbon edge NEXAFS spectra, indicating a predominantly flat laying orientation of the pyrrole rings and up-right orientation of the dodecyl sulfate ion tails relative to the substrate plane. Such molecular architecture of the electrodeposited dodecyl sulfate-doped polypyrrole provides its very high anticorrosive properties. The duration of the protection in the 3.5% NaCl solution was 850 h for dodecyl sulfate-doped polypyrrole coating, which is 17 times longer than for traditional polypyrrole coating doped with oxalate ions.

Electrochemical and viscoelastic evolution of dodecyl sulfate-doped polypyrrole films during electrochemical cycling

The correlation between electrochemical and viscoelastic properties of electrodeposited dodecylsulfate-doped polypyrrole (PPy-DS) during electrochemical cycling process was described through combining electrochemical quartz-crystal microbalance (EQCM), ac-electrogravimetric characterizations and electroacoustic measurements. As the PPy-DS electrode evolves during the course of consecutive cycling in aqueous NaCl electrolyte, the film exhibits (i) an obvious ion-selective transition from cations to anions in the charge compensation process; (ii) an inferior electrochemical performance accompanied with increased stiffness (increased storage moduli, Ǵ); and (iii) depleted capability of ionic exchange through film/electrolyte interface. PPy-DS conducting polymer electrodes (CPEs) are of interest in energy storage and the relationship between electrochemical and viscoelastic properties during electrochemical cycling process is essential for promoting the performance of these devices. In this perspective, ac-electrogravimetry combined with electroacoustic measurements can be suggested as an alternative method to synchronously probe the electrochemical and mechanical evolution and has the potential to offer a generalized route to study aging mechanism of CPEs.

Rapid analysis of captopril in human plasma and pharmaceutical preparations by headspace solid phase microextraction based on polypyrrole film coupled to ion mobility spectrometry

A rapid, simple, and sensitive headspace solid phase microextraction coupled to ion mobility spectrometry (HS-SPME-IMS) method is presented for analysis of the highly specific angiotensin-converting enzyme (ACE) inhibitor, captopril (CAP). Positive ion mobility spectra of CAP were acquired with an ion mobility spectrometer equipped with a corona discharge ionization source. Mass-to-mobility correlation equation was used to identify product ions. A dodecylsulfate-doped polypyrrole (PPy-DS) coating was used as a fiber for SPME. The results showed that PPy-DS based SPME fiber was suitable for successfully extracting CAP from human blood plasma and pharmaceutical samples. The HS-SPME-IMS method provided good repeatability (R.S.D.s < 4%) for aqueous and spiked plasma samples. The calibration graphs were linear in the range of 10–300 ng mL −1 ( R 2 > 0.99) and detection limits were 7.5 ng mL −1 for aqueous and 6.3 ng mL −1 for plasma blank samples. Finally, a standard addition calibration method was applied to HS-SPME-IMS technique for the analysis of blood plasma samples and tablets. Purpose method seemed to be suitable for the analysis of CAP in plasma samples as it is not time consuming (state total time from sample preparation to analysis), it required only small quantities of the sample, and no derivatization was required.

Headspace-solid-phase microextraction using a dodecylsulfate-doped polypyrrole film coupled to ion mobility spectrometry for analysis methyl tert-butyl ether in water and gasoline

A simple and sensitive method for the determination of methyl tert-butyl ether (MTBE) in water using headspace-solid-phase microextraction (HS-SPME) at sub-ng mL −1 concentrations is described. The analysis was carried out using a cooled SPME fiber coated with a film of dodecylsulfate-doped polypyrrole coupled to ion mobility spectrometry equipped with corona discharge ionization. The headspace-solid-phase microextraction experimental procedures to extract MTBE in water samples were optimized with a dodecylsulfate-doped polypyrrole coated fiber at a 30 min extraction time, extraction temperature of 40 °C, sodium chloride concentration of 2.5 mol L −1 and desorption temperature of 140 °C. Two linear calibration curves respectively in the ranges of 2–17 ng mL −1 and 10–70 ng mL −1 with detection limits of 0.7 ng mL −1 and 4.9 ng mL −1 were obtained. Relative standard deviations for three replicates in water samples were <10%. The capability of dodecylsulfate-doped polypyrrole to extract MTBE has been compared with the results obtained based on the literature data for commercial fiber. The results shows that dodecylsulfate-doped polypyrrole, as a solid-phase microextraction fiber coating, is suitable for successful extraction of MTBE having detection limits comparable to what obtained with commercial fibers. Finally, the proposed method was applied to the analysis of MTBE in three ground water samples and regular unleaded gasoline from petrol station in Tehran central district, Iran.

Headspace solid-phase microextraction using a dodecylsulfate-doped polypyrrole film coupled to ion mobility spectrometry for the simultaneous determination of atrazine and ametryn in soil and water samples

A simple and rapid headspace solid-phase microextraction (HS-SPME) based method is presented for the simultaneous determination of atrazine and ametryn in soil and water samples by ion mobility spectrometry (IMS). A dodecylsulfate-doped polypyrrole (PPy-DS), synthesized by electrochemical method, was applied as a laboratory-made fiber for SPME. The HS-SPME system was designed with a cooling device on the upper part of the sample vial and a circulating water bath for adjusting the sample temperature. The extraction properties of the fiber to spiked soil and water samples with atrazine and ametryn were examined, using a HS-SPME device and thermal desorption in injection port of IMS. Parameters affecting the extraction efficiency such as the volume of water added to the soil, pH effect, extraction time, extraction temperature, salt effect, desorption time, and desorption temperature were investigated. The HS-SPME–IMS method with PPy-DS fiber, provided good repeatability (RSDs < 10 %), simplicity, good sensitivity and short analysis times for spiked soil (200 ng g −1) and water samples (100 and 200 ng mL −1). The calibration graphs were linear in the range of 200–4000 ng g −1 and 50–2800 ng mL −1 for soil and water respectively ( R 2 > 0.99). Detection limits for atrazine and ametryn were 37 ng g −1 (soil) and 23 ng g −1 (soil) and 15 ng mL −1 (water) and 10 ng mL −1 (water), respectively. To evaluate the accuracy of the proposed method, atrazine and ametryn in the three kinds of soils and two well water samples were determined. Finally, comparing the HS-SPME results for extraction and determination of selected triazines using PPy-DS fiber with the other methods in literature shows that the proposed method has comparable detection limits and RSDs and good linear ranges.

Rapid screening of methamphetamines in human serum by headspace solid-phase microextraction using a dodecylsulfate-doped polypyrrole film coupled to ion mobility spectrometry

A simple, rapid and highly sensitive method for simultaneous analysis of methamphetamine (MA) and 3,4-methylenedioxy methamphetamine (MDMA) in human serum was developed using the solid-phase microextraction (SPME) combined with ion mobility spectrometry (IMS). A dodecylsulfate-doped polypyrrole (PPy-DS) was applied as a new fiber for SPME. Electrochemically polymerized PPy is formed on the surface of a platinum wire and will contain charge-compensating anion (dodecylsulfate) incorporated during synthesis using cyclic voltammetry (CV) technique. The extraction properties of the fiber to MA and MDMA were examined, using a headspace-SPME (HS-SPME) device and thermal desorption in injection port of IMS. The results show that PPy-DS as a SPME fiber coating is suitable for the successful extraction of these compounds. This method is suitable for the identification and determination of MAs, is not time-consuming, requires small quantities of sample and does not require any derivatization. Parameters like pH, extraction time, ionic strength, and temperature of the sample were studied and optimized to obtain the best extraction results. The HS-SPME–IMS method provided good repeatability (RSDs < 7.8 %) for spiked serum samples. The calibration graphs were linear in the range of 20–4000 ng ml −1 ( R 2 > 0.99) and detection limits for MDMA and MA were 5 and 8 ng ml −1, respectively. HS-SPME–IMS of non-spiked serum sample provided a spectrum without any peak from the matrix, supporting an effective sample clean-up. Finally, the proposed method was applied for analysis one of the ecstasy tablet.

Headspace solid-phase microextraction using an electrochemically deposited dodecylsulfate-doped polypyrrole film to determine of phenolic compounds in water

A dodecylsulfate-doped polypyrrole (PPy-DS) film was prepared by electrochemical fiber coating (EFC) technique and applied as a new fiber for headspace solid-phase microextraction (HS-SPME) of phenolic compounds from water samples. Electrochemically polymerized PPy is formed on the surface of a platinum wire and will contain charge-compensating anion (dodecylsulfate) incorporated during synthesis. The efficiency of this fiber for microextraction of phenols was evaluated using a HS-SPME device coupled with gas chromatography-flame ionization detection (GC-FID). The results shows that PPy-DS as a SPME fiber coating is suitable for the successful extraction of phenolic compounds. Parameters like ionic strength, agitation of the sample, sample pH, temperature of the sample, and adsorption/desorption times were studied and optimized to obtain the best extraction results. This method provided good repeatability (R.S.D.s < 7.2%) for spiked water samples. The calibration graphs were linear in the range of 2–100 ng mL −1 with the square of the correlation coefficient R 2 > 0.991 and detection limits were between 0.57 and 1.82 ng mL −1. The capability of PPy-DS to extract phenolic compounds has been compared with the results obtained with literature data for several fibers and this laboratory-made fiber showed comparable analytical parameter for the studied compounds.

Dodecylsulfate-doped polypyrrole film prepared by electrochemical fiber coating technique for headspace solid-phase microextraction of polycyclic aromatic hydrocarbons

The electrochemical fiber coating (EFC) technique was used for the preparation of dodecylsulfate-doped polypyrrole (PPy-DS), and applied as a new fiber for solid-phase microextraction (SPME) procedures. PPy-DS film was directly electrodeposited on the surface of a platinum wire from an aqueous solution containing pyrrole and sodium dodecylsulfate, using cyclic voltammetry (CV). The effect of polymerization conditions and type of dopants on the thermal stability, adhesion and extraction characteristics of the fiber were investigated. The electron microscopy imaging of PPy-DS film suggested that the surface fiber coating was well-distributed with a porous structure. The fiber coating can be prepared easily in a reproducible manner, and it is inexpensive and has a stable performance at high temperatures (up to the 300 degrees C). The extraction properties of the fiber to eight polycyclic aromatic hydrocarbons (PAHs) were examined, using a headspace-SPME (HS-SPME) device coupled with gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The results revealed study shows that PPy-DS as a SPME fiber coating is suitable for the successful extraction of PAHs. The effects of the extraction parameters including exposure time, sampling temperature, salt concentration, and stirring rate on the extraction efficiency have been studied. A satisfactory reproducibility for extractions from spiked water samples at PPb-level with R.S.D. < 7.6% (n = 7) was obtained. The calibration graphs were linear in the range of 0.5-100ng ml(-1) and detection limits for the selected PAHs were between 0.05-0.16 ng ml(-1). Comparing the HS-SPME results for extraction and determination of PAHs using PPy-DS fiber with the corresponding literature data using PDMS fiber shows that the proposed fiber has a better detection limit for low molecular weight PAHs. The life span and stability of PPy-DS fiber is good and it can be used more than 50 times at 250 degrees C without any significant change in sorption properties.

An electrochromic device combining polypyrrole and WO3 II: solid-state device with polymeric electrolyte

Abstract In this work we describe the assembling of a solid-state electrochromic device using, as active materials, an organic conductive polymer and a transition metal oxide. The optically active materials were dodecylsulfate doped polypyrrole and tungsten oxide. The substrates used were glass slides coated with tin-doped indium oxide and the solid elastomeric electrolyte was the copolymer of ethylene oxide and epichlorohydrin containing lithium perchlorate. Initially, we studied separately the materials used to assemble the device and, in sequence, we assembled and characterized the complete devices. The thickness of the polypyrrole and the electrolyte films were varied to obtain the highest chromatic contrast, stability over a high number of redox cycles, and short response times. The characterizations were made by spectroelectrochemistry using the techniques of cyclic voltammetry and chronoamperometry. To illustrate the results obtained, we described two devices with different polypyrrole and electrolyte film thicknesses. The chromatic contrast in the visible and near-infrared wavelength range is 30% and the electric and optical properties of the devices remain unchanged after 1.5×10 4 double potential chronoamperometric steps.

An IR spectroscopic study of the electrochemical reduction of polypyrrole doped with dodecylsulfate anion

In situ transmission IR spectra (4000—450 cm −1) of the oxidized and reduced forms of electrochemically grown polypyrrole films have been recorded. The changes that occurred in the IR spectra of oxidized polypyrrole doped with dodecylsulfate were evaluated as it was progressively reduced electrochemically at constant current. The spectral data were interpreted in terms of changes in bond order and found to be consistent with a quinoid-to-benzoid transition on reduction. Spectral subtractions were used to isolate the spectra of the oxidized and reduced species. The data suggest that the conducting species in dodecylsulfate-doped polypyrrole is the same as that obtained with p-toluenesulfonate and we conclude that the lower conductivity of the former is caused by a lower level of active species, rather than the presence of different charge carriers in the former polymer. The rate of loss of active species on reduction was found to be double the expected rate, consistent with results obtained by other workers. In terms of the polaron/bipolaron concept, we suggest this is consistent with disruption of bipolarons by removal of one positive charge from each as the first step in the reduction. We also examined the spectra of reduced films that had been exposed to air. The data indicate a shift in bond order towards a quinoid structure but a key part of the spectrum assigned to the α-carbon atoms did not change in proportion to the rest of the spectrum; this suggests that delocalization along the chain through a quinoid structure was not achieved to a significant extent by oxygen doping.

Electrochemical properties of dodecylsulfate-doped polypyrrole films in aqueous solution containing NH 4Cl and ZnCl 2

Dodecylsulfate-doped polypyrrole (PPy) films were electrochemically synthesized in aqueous solution containing sodium dodecylsulfate. In order to examine the applicability of the films to electrode materials, the electrochemical properties and charge-discharge properties were investigated in the aqueous solution containing 0.4 M NH 4Cl and 0.1 M ZnCl 2. From cyclic voltammetric and chronoamperometric results, it was concluded that the good electrochemical reversibility was due to the fast mobilities of NH 4 + and Cl − instead of the dodecylsulfate trapped in the polymer matrix. The charge-discharge tests of the Zn/(NH 4Cl, ZnCl 2)/PPy cell showed an open-circuit voltage of 1.3 V after 80 min, specific capacity of 59 Ah kg −1 and energy density of 77 Wh kg −1.

The role of ion exchange in the redox processes of polypyrrole/dodecyl sulfate films as studied by electrogravimetry using a quartz crystal microbalance

The electrochemical redox mechanism of a dodecyl sulfate-doped polypyrrole was studied in detail by electrogravimetry using a quartz crystal microbalance. In order to distinguish the nature of the inserted/deinserted species, different salts were used as aqueous electrolytes. A quantitative analysis of the results indicated that the surfactant counter anion was trapped in the polymer matrix and that both anions and cations of the electrolyte play an important role in the redox processes. Quantitative calculations showed that the hydration sphere of these ions must be taken into account when dealing with the redox processes of conductive polymers adhered to the surface of electrodes.