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Composites of polyaniline with synthesized nanostructured titania (TiO₂) and polyaniline with commercial TiO₂ have been in situ synthesized by oxidative chemical polymerization method. Sulfuric acid was used as dopant during the polymerization process. Sol-gel precipitates of nanostructured titania were synthesized by hydrolyzing the mixture of titanium chloride (TiCl₃) and colloidal transparent solution of starch. Composite materials were subjected for comparison to spectroscopic and X-ray diffraction analysis. Strong coupling/interaction of titania with the imine nitrogen in polyaniline confirmed by FTIR spectral analysis. XRD shows the composite of synthesized titania with polyaniline have broaden peak as compared to that of commercial titania with polyaniline indicating particle size in the range of nanometer scale which is supported by 40 nm particle size of the synthesized titania from TEM picture. Increase in conductivity with increasing temperature was observed in both the composite materials.

Polyaniline/LiNi_0.5Gd_0.08Fe_1.92O₄ nanocomposite was synthesized by an in-situ polymerization of aniline in the presence of LiNi_0.5Gd_0.08Fe_1.92O₄ particles. The dielectric properties of the as-prepared polyaniline-based nanocomposite were investigated using an Agilent E4991A RF Impedance/Material Analyzer at room temperature in the frequency range from 1 MHz to 1 GHz. The real (ε') and imaginary part (ε″) of complex permittivity, and dissipation factor (tan δ) were found to be frequency-dependent, which decreased with increasing of frequency. It was shown that ε', ε″ and tan δ of the nanocomposite were lower than those of pristine polyaniline. In order to investigate the dielectric process in detail, the complex electric modulii derived from the complex permittivity were analyzed as a function of the frequency.

The emergence of ferromagnetism in conducting polymers is well known, however, the influence of lattice vibrations has not been analyzed yet. Hereafter, we fill this gap by studying the common effect of strong correlations and lattice vibrations in hole doped conjugated polymers. The results underline that away from system half-filling, the lattice vibrations have negligible effect on the studied ordered phase.

The power spectral density of low frequency resistance fluctuation in heterocyclic conducting polymer thin film resistors was measured at various temperatures and bias current values. An accurate calculation of the background noise was performed in order to correct the measured power spectral densities. A parameter obtained normalizing the voltage power density to the sample volume and d.c. bias is used to compare the tested conducting polymers with various materials used for resistors fabrication.

Lead-based nanocrystals (NCs) are promising materials for high-efficiency solar cells since they are able to generate multiexcitons with high efficiency. One complication of utilizing these NCs is the insulating ligands capping their surfaces. In this paper, we have successfully developed and characterized a phosphonate-functionalized poly-3-hexylthiophene (POP3HT-50) and used it in the direct synthesis of PbS NCs within the polymeric host matrix without extraneous ligands. Devices made of POP3HT-50/PbS nanocomposites show an order of magnitude improvement in η when compared to that reported for a P3HT/PbS device (η = 0.011% versus 0.001%). The improved performance is consistent with better electronic contact between PbS NCs and POP3HT-50.

New hybrid (organic–inorganic) material based on nanocrystalline CdSe capped with EDTA and poly(O-toluidine) doped with camphor sulfonic acid (POT-CSA) is processed from solution and characterized in order to relate the device function (optical absorption, charge separation and transport properties) to active-layer properties and device parameters. POT/CdSe hybrid material has been synthesized using physical mixing method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to investigate the structural and morphological properties. The organic–inorganic composite system was applied as an active device component to demonstrate the electrical memory effects. The device exhibited a nonvolatile, resistive switching performance with a constant ON–OFF current ratio. The nonvolatile behavior was confirmed by applying a 2.5-V read pulse.

Packing structures and orientation of sexithiophene (6T) molecules on Ag (111) surface are investigated by molecular dynamics (MD) simulations and quantum chemical calculations. Both the cluster and the slab models are employed. The density functional theory and molecular mechanism calculations demonstrate a weak physisorption and little site-preference in thiophene/Ag (111) system. The MD simulations show that in the first layer close to the surface, the nearly coplanar 6T strips lie parallel with long axes deviating from direction about 20° – 30° and 75° – 90°. The average adsorption height of the monolayer is about 3.2 Å with most of the sulfur atoms in thienyl rings sitting on the bridge site of Ag (111) surface. The 6T molecules tend to take tilted orientations when they are far away from the surface. The packing structures of 6T layers deposited on the surface resulted from the competition between the molecule–substrate and intermolecular interactions.

High quality poly(5-cyanoindole) (P5CI) films were electrosynthesized by direct anodic oxidation of 5-cyanoindole on stainless steel sheet in the mixed electrolytes of boron trifluoride diethyl etherate (BFEE) and diethyl ether (EE) (by volume 1:1) + 0.05 mol L^-1Bu₄NBF₄. The film formed can be peeled off the electrode into freestanding films. The addition of EE into BFEE can improve the solubility of monomer. P5CI films obtained from this medium showed excellent electrochemical behavior with conductivity of 10^-2S cm^-1. Structural studies showed that the polymerization of 5-cyanoindole occurred at the 2,3 position. As-formed P5CI films were thoroughly soluble in strong polar organic solvent dimethyl sulfoxide (DMSO) while partly soluble in tetrahydrofuran (THF) or acetone. Fluorescence spectral studies indicated that P5CI was a good blue-light emitter.

A novel catalytic route for the synthesis of a water-soluble and electrically conducting polypyrrole (PPy) in the presence of sulfonated polystyrene (SPS) is presented. Anionic water-soluble transition-metal tetrasulfonated porphyrins (TSPP) were used to catalyze the polymerization. The reactions were carried out with different monomer, catalyst, template and initiator concentrations and the optimum conditions are reported. Also various pH values ranging from 1 to 4 were investigated. The absorbance of the polaron bands at different pH values demonstrates that pH 2 is the best condition for polymerization. Precipitation or "salting out" phenomenon was highly dependent on the mentioned factors. The formation of PPy was confirmed by UV-vis and FT-IR spectroscopy. Cyclic voltammetry (CV) showed that the synthesized polymer has convenient electroactivity. Furthermore, the presence of SPS that serves as a charge-compensating dopant in this complex provides a unique combination of properties such as processability and water solubility.

Conducting polymer (CP) is an electroactive polymer that displays specific electronic properties, including conductivity. The utility of CP-based soft actuators in various biomedical applications has recently been motivated due to their low voltage-driven specialty compared to the widely used high voltage-driven dielectric elastomers. In some biomedical applications, highly delicate CP actuators may be torn or damaged for unknown reasons. In this regard, this study develops a tear fracture model for fiber-reinforced CP actuators to investigate a specific fracture test of mode III, namely, the trousers test, which involves pulling two legs of a cut specimen horizontally apart. The development of the tear fracture model adopts a well-known Griffith criterion along with the thermodynamically consistent continuum mechanics approach. Additionally, prominent strain energy capturing elastomer strain-stiffening at a moderate strain range is used in conjunction with an empirically established correlation to couple the two internal phenomena, ion diffusion and mechanical deformation of the CP actuators. Later, the effects of various electrical and geometrical parameters on the tearing of the actuator are also addressed.

This work presents new bulk p-n hetero-junction where iodine doped TiO₂ (I-TiO₂) acts as n and poly(3, 4-ethylenedioxy- thiophene):polystyrenesulphonate (pEDOT:PSS) as p-element. Heterogeneous films were obtained by means of potentiostatic polymerization of monomer on the metal electrode in presence of suspended I-TiO₂ particles in the electrolyte, (applied potentials in a range of 0.8–1.1 V versus Ag/AgCl/0.1 M KCl). The procedure brings about hybrid films where I-TiO₂ particles are uniformly incorporated into the bulk polymer matrix. An incorporation of I-TiO₂ into the pEDOT:PSS matrix causes increase in the measured current under visible light illumination.

Polyaniline, poly(o-bromoaniline) and poly(aniline-co-o-bromoaniline)s have been prepared by chemical oxidative polymerization methods. A series of poly(aniline-co-o-bromoaniline) derivatives has been prepared by the chemical oxidative copolymerization of aniline with different mole ratio of o-bromoaniline by varying the feed ratios of the monomers with the introduction of o-bromoaniline units along the polymer backbone. The morphology of each poly(aniline-co-o-bromoaniline) derivative is observed as a porous network of aggregated nanoparticles with each nanoparticle having smaller nanoflake structures. Room temperature electrical conductivity studies reveal that polyaniline has a conductivity value of the order of 10${}^{-3}$S/cm. However, the corresponding poly(aniline-co-o-bromoaniline), with 10% o-bromoaniline content, shows a fivefold increase of the electrical conductivity relative to the polyaniline homopolymer. The different polymer derivatives were characterized by ¹H NMR spectrometry, Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) methods, AC conductivity and dielectric permittivity measurements.

The aim of this review is to provide an up-to-date overview of nanoparticles developed for use as photothermal therapy agents (PTT) over the past five years. The main emphasis is on nanoparticles that absorb near infrared (NIR) light for PTT of cancer. Mild hyperthermia, including drug delivery, versus thermal ablation is also discussed. Recent advances in the synthesis of highly anisotropic novel metal nanoparticles for PTT are described. New metals and metal oxide complexes, as well as the use of quantum dots for PTT and as imaging agents are newer areas of development that are explained. This review also highlights current progress in the development of carbon nanoparticles, including reduced graphene oxide for both thermal ablation as well as drug delivery. The review culminates in the recent use electrically conductive polymer nanoparticles for hyperthermia. The advantages and unique features of these contemporary nanoparticles being used for PTT are highlighted. The goal of the present work is to describe the recent evolution of nanoparticles for NIR stimulated PTT, and highlight the innovations and future directions.

Conductive hydrogels are emerging as an advanced electronic platform for wearable sensors by synergizing the advantageous features of conductivity and flexibility. Especially conductive polymer hydrogels have widespread applications in the fields of catalysis, biomedicine, monitoring, and wearable electronic skin owing to the outstanding strain sensitivity and resilience thereof. Nevertheless, how to maintain the conductivity of hydrogels and electronic skins under strain or deformation remains a significant challenge. To tackle the said bottleneck, a multiple H-bonding MXene-based conductive hydrogel was established in the present study. With the participation of MXene and Fe${}^{2+}$ ions, the hydrogel network was strengthened, which might be attributed to the H-bonding among the polymer chain, MXene, and Fe${}^{2+}$ ions. Meanwhile, the elongation at break and compression modulus of Poly(vinyl alcohol) (PVA)- M3F hydrogels increased to 513% and 85.6kPa compared with the initial PVA hydrogel, respectively. After incorporating Fe${}^{2+}$ ions, the PVA-M3F hydrogels exhibited greater conductivity, which was $7.9\times 10^{-4}$S/cm. Notably, the PVA-M3F hydrogels displayed good resilience, leading to stable conductivity and strain sensitivity. Subsequently, a finger joint was designed to verify the maintenance of conductivity and monitoring behaviors. PVA-M3F conductive hydrogel was found to possess an outstanding capability for electrical signals feedback and was expected to be applied to electronic sensors or monitors. In summary, the introduction of MXene and Fe${}^{2+}$ ions into PVA hydrogels can not only tune the conductivity but also have promising prospects as a countermeasure for wearable electronics.

Light harvesting in photosynthetic purple bacteria is reviewed in detail based on recent advances in structure determination and ultrafast laser spectroscopy. Knowledge obtained from photosynthesis research forms a solid ground for studies of various artificial light harvesting systems. We present our recent research of excitation transfer and charge separation in conjugated polymers. We continue by summarizing our studies of ultrafast photoinduced processes in dye-sensitized nanocrystalline large band-gap semiconductor films – a key part of the Grätzel solar cell. Finally, our recent studies of energy transfer in transition metal supramolecular complexes, a kind of artificial antenna, are presented.