Fig 11 - uploaded by Oswaldo Luiz Alves
Content may be subject to copyright.
Source publication
We report on the preparation and characterization of two glass/conducting polymer nanocomposites obtained by the in situ oxidative polymerization of pyrrole and aniline inside the pores of Porous Vycor Glass (PVG). Oxidative polymerization of pyrrole was done via Cu2+ cation impregnated in the PVG pores. The polymerization of aniline was undertaken...
Similar publications
Materials have been very important in the history of human endeavors. One of the more important groups of materials in our lives today is composite material. The man made composite material, is a three-dimensional combination of at least two chemically distinct materials, with a distinct interface separating the components, created to obtain proper...
PEDOT is the most popularly used conductive polymer due to its high conductivity, good physical and chemical stability, excellent optical transparency, and the capabilities of easy doping and solution processing. Based on the advantages above, PEDOT has been widely used in various devices for energy conversion and storage, and bio-sensing. The synt...
Novel n-type conducting polymer, poly (p-methylpyridinium vinylene), PMePyV were synthesized by using the quaternization of poly (p-pyridyl vinylene), PPyV and several regiochemical consequences in this polymer were proposed. The electrical, optical, and electrochemical properties of n-type conductive polymer were observed. In addition, a possibili...
Citations
... In situ optical and Raman spectroelectrochemical methods have been very useful for the structural elucidation and study of optoelectronic properties of intrinsically conducting polymers [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] . Surface Enhanced Resonance Raman Spectroscopy (SERS) has been used extensively to study chemically and electrochemically polymerized PPy films [25][26][27]. SERS can be used to identify oxidation (doping) state and * Corresponding author. Tel.: +98 8118270820. ...
Polypyrrole (PPy) and poly(pyrrole-2,6-dimethyl-β-cyclodextrin) [P(Py-β-DMCD)] films prepared by potential cycling in aqueous acidic solutions on indium tin oxide (ITO)-coated glass and gold electrodes were studied by in situ UV-vis and Raman spectroscopy. Characteristic UV-vis and Raman bands were identified and their dependencies on the electrode potential have been discussed. Spectroelectrochemical results reveal differences both in the position of the spectral bands and their potential dependence for PPy and P(Py-β-DMCD) films indicating interactions between polymer chains and CDs during electropolymerization process. The films were also characterized by cyclic voltammetry and FT-IR spectroscopy.
... Porous Vycor glass (PVG), another type of 3-D host, was also used as host to PANI. The PVG is a highly transparent glass to visible light, consisting basically of SiO 2 , with a random network of interconnected three-dimensional pores.[45] The nanocomposites obtained are highly transparent and green. ...
Synthetic MetalsNanostructured Conducting PolymersSpectroscopic TechniquesSpectroscopy of Nanostructured Conducting PolymersConcluding RemarksAcknowledgementsReferences
... Zarbin et al. [27] have shown that the principle bands for a similar copolymer appear at 1317 and 1561cm À1 and are representative of C¼C and CÀC stretching, respectively, which is also an accepted observation from other published studies [28][29][30][31][32][33]. This is assignable to stretching of the phenyl end caps [26] and it is strongly related to the p-p à transition, directly related to the distribution of conjugation lengths [34] which was previously deliberated in the XPS section of this paper. ...
... The broadness of the Raman shifts observed in the region of 1200-1600 cm À1 are attributed to the overlap of the other possible bond attributions, such as, C-N stretching and C-H bending [27]. Other band positions at approximately 1080, 1050, 980 and 940 cm À1 , although weak in intensity, should also be observed indicating the bending of C-H based bonds. ...
Surface characterizations of thin film coatings of carbazole containing random poly(carbazole-co-3-methylthiophene) P[Cz-co-3-MeTh] copolymers on carbon fiber were performed. Coatings with different initial feed ratios of comonomers were electrochemically formed (grafted) onto carbon fibers by constant current electrolysis. The resulting copolymers were characterised with scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The characterization of the thin copolymer films was performed on the surface of the carbon fiber. This allows the relationship between the initial feed ratio of the comonomer, the resulting morphology and the surface structure of these thin film coatings to be investigated. The range of thickness increase (diameter) was from 200 nm to 6.74 μm depending on the polymer and copolymers used.
... Zarbin et al. [30,31] have described the acidic chemical polymerisation of aniline in the porous cavities of Vycor glass (PVG (Corning 7930)), producing the Pani±PVG nanocomposite. The very narrow pore size distribution of the glass prevents the occurrence of intermolecular interactions, structural defects and cross-linking, providing the formation of molecularly isolated polymeric chains. ...
... Therefore, this nanocomposite can be produced with high reproducibility, without modifying the chemical properties of Pani. The reversible colour change of Pani±PVG composite from dark green (emeraldine salt) to dark blue (emeraldine base) when the glass is immersed in acidic solution and basic solution [31,32], respectively, indicates the usefulness of this material as sensing phase for optical pH sensor. ...
... The preparation and characterisation of the Pani±PVG nanocomposite have been already described in details by Zarbin et al. [31]. When a PVG slide is immersed in acidic solution of aniline, the monomer, after diffusion through the pores of the glass, is adsorbed onto the surface as anilinium cation. ...
This work describes the preparation of a polyaniline (Pani)–porous Vycor glass (PVG) nanocomposite and its use as sensing phase in an optical fibre pH sensor. Nanocomposites of Pani–PVG were prepared by in situ polymerisation of aniline absorbed inside the pores of a PVG (Corning 7930) with an average porous size of 8nm. The optical sensor was constructed by fixing a PVG slide onto a distal end of bifurcated optical fibre bundle, with a cyanoacrylic resin. The sensor response was found to be reversible in the pH range from 5 to 12 and linear from pH 7.4 to 9.5. Response times of 4, 8 and >16min were obtained for slide thickness’ of 0.5, 1 and 1.5mm, respectively. Changes of temperature, ranging from 20 to 40°C, showed minor effect on the dynamic range. Similarly, the ionic strength (0.15, 0.30 and 0.50moll−1) and the nature of the ions (NaCl, KCl and NaClO4) showed minor influence on the sensor response. Leaching of Pani was not observed and the sensor lifetime was determined as being at least 5 months. These results indicate that a Pani–PVG nanocomposite is suitable for the construction of optical pH sensors, with good analytical performance, since the glass slides can be prepared with good reproducibility and durability.
... 124 Alternatively, conducting polymer can be incorporated into a thin sol-gel film through a "diffuse and polymerize" scheme in which the film is soaked in a solution of monomer, allowing it to penetrate and diffuse throughout the porous structure. [126][127][128][129][130] Electrochemical [126][127][128]130 or chemical 128 polymerization is then used to grow the conductive polymer within the sol-gel. The first reported use of this technique involved the electrochemical growth of polyaniline within a sol-gel film deposited on an underlying ITO electrode. ...
... and thiophene130 derivatives to yield hybrid inorganic-organic composites on electrode surfaces. Other materials have been made by chemically polymerizing aniline or pyrrole within a commercial porous glass.129,131 Sections 1.4.1 and 1.4.2 ...
... SUMMARY OF RESEARCH.1.5.1. Chapter 2. Growth of poly(3,4-ethylenedioxythiophene) (PEDOT) on indiumtin oxide (ITO) electrodes and in sol-gel thin films.While the growth of conductive polymer in sol-gel derived thin films has been demonstrated,[126][127][128][129][130] characterization of the electrochemical properties of the encapsulated polymer (percent redox activity and charge mediation) relative to polymer grown on a bare electrode surface has been inadequate. Likewise, the morphology of thin sol-gel films before and after growth of conductive polymer has not been studied. ...
The efficiency of nerve guide conduits (NGCs) in repairing peripheral nerve injury is not high enough yet to be a substitute for autografts and is still insufficient for clinical use. To improve this efficiency, 3D electrospun scaffolds (3D/E) of poly(l-lactide-co-ε-caprolactone) (PLCL) and poly(l-lactide-co-glycolide) (PLGA) were designed and fabricated by the combination of 3D printing and electrospinning techniques, resulting in an ideal porous architecture for NGCs. Polypyrrole (PPy) was deposited on PLCL and PLGA scaffolds to enhance biocompatibility for nerve recovery. The designed pore architecture of these "PLCL-3D/E" and "PLGA-3D/E" scaffolds exhibited a combination of nano- and microscale structures. The mean pore size of PLCL-3D/E and PLGA-3D/E scaffolds were 289 ± 79 and 287 ± 95 nm, respectively, which meets the required pore size for NGCs. Furthermore, the addition of PPy on the surfaces of both PLCL-3D/E (PLCL-3D/E/PPy) and PLGA-3D/E (PLGA-3D/E/PPy) led to an increase in their hydrophilicity, conductivity, and noncytotoxicity compared to noncoated PPy scaffolds. Both PLCL-3D/E/PPy and PLGA-3D/E/PPy showed conductivity maintained at 12.40 ± 0.12 and 10.50 ± 0.08 Scm-1 for up to 15 and 9 weeks, respectively, which are adequate for the electroconduction of neuron cells. Notably, the PLGA-3D/E/PPy scaffold showed superior cytocompatibility when compared with PLCL-3D/E/PPy, as evident via the viability assay, proliferation, and attachment of L929 and SC cells. Furthermore, analysis of cell health through membrane leakage and apoptotic indices showed that the 3D/E/PPy scaffolds displayed significant decreases in membrane leakage and reductions in necrotic tissue. Our finding suggests that these 3D/E/PPy scaffolds have a favorable design architecture and biocompatibility with potential for use in peripheral nerve regeneration applications.
Organic cathode materials are promising for developing high-energy and high-power Li-ion batteries (LIBs) due to high sustainability, low cost and heavy metal-free features. However, the energy storage of most organic cathodes relies on the electron transfer of a single type of functional group, leading to either a low redox potential or a low capacity. Here we propose a new strategy for the structure design and performance optimization of organic materials. A new organic cathode, dithianon (DTN), containing three functional groups (-S-, C=O, C≡N) in one framework, is reported. The -S- group increases the redox potential to 3.0 V, while C=O and C≡N groups enable three Li-ions involved redox reaction. As a cathode, DTN delivers 270.2 mAh g-1 at 0.5C for 300 cycles. Even at 5C, it still retains 161.5 mAh g-1 after 1000 cycles. The high-capacity, high-power and stable DTN cathode offers great promise for high performance and sustainable LIBs.
