Electron transfer and energy exchange between a covalent organic framework and CuFeS nanoparticles.

CuFeS is a prominent chalcogenide that possesses similar optical properties and a significantly lower cost, compared to gold. Additionally, covalent organic frameworks are a class of materials at the forefront of current research, mainly used as photoactive components and porous absorbers. Hence, in this work, hydrophilic CuFeS particles are coupled with multi-functional covalent organic frameworks through ionic bonding to produce a hybrid material with unique and optimized properties.

Photocatalytic degradation of organic micropollutants under UV-A and visible light irradiation by exfoliated g-CN catalysts.

In the present study, the photocatalytic performance of exfoliated graphitic carbon nitride (g-CN) catalysts, with enhanced properties and response in UV and visible light irradiation, was evaluated for the removal of selected contaminants i.e., diuron, bisphenol A and ethyl paraben.

Electrochemical deposition of highly hydrophobic perfluorinated polyaniline film for biosensor applications.

Highly hydrophobic perfluorinated polyaniline thin films with water contact angle of ∼140° and low internal resistance properties are prepared through electrochemical polymerization. UV-visible spectroscopy demonstrates a gradual evolution of the polaron band which indicates the electronic conductive properties of the polymers. Simultaneous possession of the water-repelling property and electron conductivity for superhydrophobic perfluorinated polyaniline leads to a unique polymer that is suitable as a solid contact in ion-selective electrodes for monitoring of pH changes during early stages of inflammation and septic shock.

Exploring seebeck-coefficient fluctuations in endohedral-fullerene, single-molecule junctions.

For the purpose of creating single-molecule junctions, which can convert a temperature difference Δ into a voltage Δ the Seebeck effect, it is of interest to screen molecules for their potential to deliver high values of the Seebeck coefficient = -Δ/Δ. Here we demonstrate that insight into molecular-scale thermoelectricity can be obtained by examining the widths and extreme values of Seebeck histograms. Using a combination of experimental scanning-tunnelling-microscopy-based transport measurements and density-functional-theory-based transport calculations, we study the electrical conductance and Seebeck coefficient of three endohedral metallofullerenes (EMFs) ScN@C, ScC@C, and ErN@C, which based on their structures, are selected to exhibit different degrees of charge inhomogeneity and geometrical disorder within a junction.

Copper Coordination and the Induced Morphological Changes in Covalent Organic Frameworks.

In this work, we reveal the coordination of copper ions absorbed by a series of covalent organic frameworks. The frameworks were synthesized through the nucleophilic substitution of either cyanuric chloride or phosphonitrilic chloride trimer by 4,4'-bipyridine, and they were utilized as absorbers for the removal of copper ions from aqueous solutions. The exfoliated counterpart of the layered network was compared to the bulk materials in terms of the copper retention capacity and efficiency.

CF -Bridged C Fullerene Dimers and their Optical Transitions.

Fullerene dyads bridged with perfluorinated linking groups have been synthesized through a modified arc-discharge procedure. The addition of Teflon inside an arc-discharge reactor leads to the formation of dyads, consisting of two C fullerenes bridged by CF groups. The incorporation of bridging groups containing electronegative atoms lead to different energy levels and to new features in the photoluminescence spectrum.

Long Stokes shifts and vibronic couplings in perfluorinated polyanilines.

We report the effect of surfactant addition on the optical properties of perfluorinated polyanilines synthesized through liquid-liquid interfaces. We obtained very long Stokes shifts, 205 nm, for oligomers derived from a hydrofluoroether-water system in the presence of Triton X-100 as a surfactant, and vibronic fine features from a toluene-water system.

Ultra-stiff large-area carpets of carbon nanotubes.

Herewith, we report the influence of post-synthesis heat treatment (≤2350 °C and plasma temperatures) on the crystal structure, defect density, purity, alignment and dispersibility of free-standing large-area (several cm(2)) carpets of ultra-long (several mm) vertically aligned multi-wall carbon nanotubes (VA-MWCNTs). VA-MWCNTs were produced in large quantities (20-30 g per batch) using a semi-scaled-up aerosol-assisted chemical vapour deposition (AACVD) setup. Electron and X-ray diffraction showed that the heat treatment at 2350 °C under inert atmosphere purifies, removes residual catalyst particles, and partially aligns adjacent single crystals (crystallites) in polycrystalline MWCNTs.

Mapping and Tuning the Fluorescence of Perfluorinated Polyanilines Synthesized through Liquid-Liquid Interfaces.

A series of light-emitting perfluorinated polyanilines were synthesized by the oxidative polymerization of 3-perfluorooctyl aniline through a variety of aqueous/organic interfaces. According to the interfacial tension between the two solvents (the organic being chloroform, dichloromethane, perfluorinated ether, toluene, or o-dichlorobenzene), we obtain distinctive classes of materials based on the crystal packing, protonation, and oxidation state of the polymeric chains. We distinguish between soluble fractions with a distinctive, strong, and red-shifted photoluminescence pattern and an insoluble precipitate which can be subsequently solubilized in a mixture of acetone and toluene.

Redox-Dependent Franck-Condon Blockade and Avalanche Transport in a Graphene-Fullerene Single-Molecule Transistor.

We report transport measurements on a graphene-fullerene single-molecule transistor. The device architecture where a functionalized C60 binds to graphene nanoelectrodes results in strong electron-vibron coupling and weak vibron relaxation. Using a combined approach of transport spectroscopy, Raman spectroscopy, and DFT calculations, we demonstrate center-of-mass oscillations, redox-dependent Franck-Condon blockade, and a transport regime characterized by avalanche tunnelling in a single-molecule transistor.

Interfacial polymerization of conductive polymers: Generation of polymeric nanostructures in a 2-D space.

In the recent advances in the field of conductive polymers, the fibrillar or needle shaped nanostructures of polyaniline and polypyrrole have attracted significant attention due to the potential advantages of organic conductors that exhibit low-dimensionality, uniform size distribution, high crystallinity and improved physical properties compared to their bulk or spherically shaped counterparts. Carrying the polymerization reaction in a restricted two dimensional space, instead of the three dimensional space of the one phase solution is an efficient method for the synthesis of polymeric nanostructures with narrow size distribution and small diameter. Ultra-thin nanowires and nanofibers, single crystal nanoneedles, nanocomposites with noble metals or carbon nanotubes and layered materials can be efficiently synthesized with high yield and display superior performance in sensors and energy storage applications.

Self-suspended permanent magnetic FePt ferrofluids.

We present the synthesis and characterization of a new class of self-suspended ferrofluids that exhibit remanent magnetization at room temperature. Our system relies on the chemisorption of a thiol-terminated ionic liquid with very low melting point on the surface of L10 FePt nanoparticles. In contrast, all types of ferrofluids previously reported employ either volatile solvents as the suspending media or superparamagnetic iron oxide nanoparticles (that lacks permanent magnetization) as the inorganic component.

Formation mechanism of carbogenic nanoparticles with dual photoluminescence emission.

We present a systematic investigation of the formation mechanism of carbogenic nanoparticles (CNPs), otherwise referred to as C-dots, by following the pyrolysis of citric acid (CA)-ethanolamine (EA) precursor at different temperatures. Pyrolysis at 180 °C leads to a CNP molecular precursor with a strongly intense photoluminescence (PL) spectrum and high quantum yield formed by dehydration of CA-EA. At higher temperatures (230 °C) a carbogenic core starts forming and the PL is due to the presence of both molecular fluorophores and the carbogenic core.

Silver polymeric nanocomposites as advanced antimicrobial agents: classification, synthetic paths, applications, and perspectives.

Utilization of metallic nanoparticles in various biotechnological and medical applications represents one of the most extensively investigated areas of the current materials science. These advanced applications require the appropriate chemical functionalization of the nanoparticles with organic molecules or their incorporation in suitable polymer matrices. The intensified interest in polymer nanocomposites with silver nanoparticles is due to the high antimicrobial effect of nanosilver as well as the unique characteristics of polymers which include their excellent structural uniformity, multivalency, high degree of branching, miscellaneous morphologies and architectures, and highly variable chemical composition.

Fullerol ionic fluids.

We report for the first time an ionic fluid based on hydroxylated fullerenes (fullerols). The ionic fluid was synthesized by neutralizing the fully protonated fullerol with an amine terminated polyethylene/polypropylene oxide oligomer (Jeffamine). The ionic fluid was compared to a control synthesized by mixing the partially protonated form (sodium form) of the fullerols with the same oligomeric amine in the same ratio as in the ionic fluids (20 wt% fullerol).

Organic functionalisation of graphenes.

Graphene sheets derived from dispersion of graphite in pyridine were functionalised by the 1,3 dipolar cycloaddition of azomethine ylide. The organically modified graphene sheets are easily dispersible in polar organic solvents and water, and they are extensively characterised using several spectroscopic and microscopy techniques.

Silver nanoparticles and graphitic carbon through thermal decomposition of a silver/acetylenedicarboxylic salt.

Spherically shaped silver nanoparticles embedded in a carbon matrix were synthesized by thermal decomposition of a Ag(I)/acetylenedicarboxylic acid salt. The silver nanoparticles, which are formed either by pyrolysis at 300 degrees C in an autoclave or thermolysis in xylene suspension at reflux temperature, are acting catalytically for the formation of graphite layers. Both reactions proceed through in situ reduction of the silver cations and polymerization of the central acetylene triple bonds and the exact temperature of the reaction can be monitored through DTA analysis.