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Highly charged fullerene anions electrochemically stabilized by anionic polymers. In this study, we propose the overcoating of In this study, we propose the overcoating of anionic polymers as a possible solution to the dissolution problem.
Fullerene was chosen as a model redox-active molecule due to its ability to accept multiple electrons. The barrier function of two anionic polymers was evaluated by monitoring the peak currents for the redox reactions of fullerenes using cyclic voltammetry.
Nafion exhibited a better barrier effect on the dissolution of fullerene species and stabilized up to four and five redox reactions of C 60 and C 70 , respectively. On the other hand, although sulfonated polystyrene-block-poly ethylene-ran-butylene -block-polystyrene showed a more negative cathodic limit in the electrochemical potential window, the dissolution of fullerene species occurred as fast as for uncovered fullerene thin films.
Save to Library. However, surface modification of fullerene cages with various functional groups can lead to the destruction of their original structures. Herein, we report a simple approach for controlling the electrochemical properties of fullerene thin films formed on Au electrodes in various ionic liquids ILs.
A total of eight reversible redox couples for six reductive and two oxidative processes were observed for fullerenes in ammonium- and pyrrolidinium-based ILs.
The redox potentials, the differences between two successive redox potentials, the average values of these potential differences for fullerene reduction, and the electrochemical band gaps of fullerene films in various ILs were found to depend on the cation and its alkyl chain length, the anion, and the chemical structure of the fullerene. Highly charged C70 anions were reduced more easily than C60 anions.
An increase in the alkyl chain length of the cation led to an increase in the average potential difference between two successive redox potentials for fullerene reduction. The results indicate that the electrochemical band gaps of fullerenes can be manipulated using ILs with appropriate anions, which can be determined based on the size of the anion and the charge distribution.
They have unique properties such as high thermal and chemical stability, negligible vapor pressure, and a wide electrochemical potential window, which differentiate them from They have unique properties such as high thermal and chemical stability, negligible vapor pressure, and a wide electrochemical potential window, which differentiate them from conventional liquids such as water and organic solvents.
In particular, they are promising replacements for conventional liquids in rechargeable batteries and fuel cells, electrodeposition, electropolymerization, and electrosynthesis, because they avoid some of the disadvantageous properties of conventional liquids, such as the narrow electrochemical potential window of water and high flammability of organic solvents.
The contents in each chapter are briefly summarized as follows: In Chapter 1, general introductions, physicochemical parameters of ILs, and their cation and anion dependencies are described. Recent advances in the electrochemical applications of ILs are also introduced.
The backgrounds of issues focused in this study are also explained in Chapter 1. Finally, the aims and construction of the thesis are outlined. In Chapter 2, the electrochemical behaviors of various ILs on Au single crystal electrodes are explored. It was further determined that the electrochemical behaviors of ILs in the electrical double-layer regions are strongly dependent on the crystallographic orientations of Au.
From the electrical charge consumed during the negative scan, it was inferred that the irreversible cathodic peak is attributable to the reductive desorption of iodine adsorbed on Au single crystal electrodes. Scanning tunneling microscopy and ex situ X-ray photoelectron spectroscopy revealed that the iodine adlayer is formed when the Au single crystal electrodes are immersed into 1- alkylmethylimidazolium iodide, and the imidazolium cations replace the iodine adlayer after the reductive desorption of iodine.
In Chapter 4, the relationship between the diffusion coefficients of metallocene and the viscosities of ILs are resolved using the Stokes-Einstein equation and its modified versions. The electrochemical behaviors of metallocene in 1-alkylmethylimidazolium bis trifluoromethylsulfonyl amides were studied, and the activation energies for the diffusion of metallocene in the ILs increased with an increase in the alkyl chain length of the 1-alkylmethylimidazolium cation.
From this result, it was presumed that the activation energy for the diffusion of metallocene in the ILs relates to the viscosity of an IL. The product of the Stokes radius of metallocene and the Sutherland coefficient was not dependent exclusively on the viscosity of an IL.
Instead, it was affected by the types of the cations of ILs and temperature. Furthermore, it was demonstrated that the Sutherland equation, which relates the friction coefficient, gives a sufficient explanation for the diffusion of metallocene in ILs.
The multiple redox reactions of fullerene C60 and C70 films prepared on Au single crystal electrodes in ILs are described in Chapter 5. C60 and C70 exhibited eight redox reactions two oxidative and six reductive in pyrrolidinium- and ammonium-based bis trifluoromethylsulfonyl -amide.
It is suggested that the interaction between fullerene species and surrounding ions depend on the types of fullerene and the charge distributed in the fullerene cage. The redox potentials of fullerene films were influenced by the chemical structure of ILs.
For instance, the potential of the sixth reductive process of fullerene in 1-butylmethylpyrrolidinium bis trifluoromethylsulfonyl - amide was approximately 1 V more positive than that obtained in trioctylmethylammonium bis trifluoromethylsulfonyl amide. The influence on the crystallographic orientation of Au, scan rate, temperature, and adlayer thickness of the C60 film on the dissolution speed of C60 molecules in thin films was carefully examined.
Typically, the observation time, in which the ideal six redox waves for the reduction of C60 molecules in a thin film could be detectable, became longer at a high scan rate and a low temperature. The suppression of the diffusion of fullerene films in ILs using ionic polymers are clarified in Chapter 6.
It was found that the solubility of fullerene in ILs can be manipulated by a change in the types of ionic polymers. Nafion-modified fullerene films demonstrated a high stability for multiple reduction of C60 molecules.
Atlas of fullerenes pdf to word
In Chapter 7, research outcomes attained in this study are summarized, along with future prospects for research in the field on ILs. Electrochemical stability of C60 thin film supported on a Au electrode at a pyrrolidinium-based ionic liquid interface.
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The prepared thin film of C60 was characterized by atomic force microscopy and scanning tunneling microscopy, which revealed homogeneous epitaxial growth with approximately 40 layers. The redox states of C60 in [C4mpyrr][Tf2N] can be clearly controlled by the scan rate and temperature.
Vertical phase segregation of hybrid poly 3-hexylthiophene and fullerene derivative composites controlled via velocity of solvent drying. We investigated the processes of phase segregation controlled by velocity of solvent drying in composite materials formed by mixing tert-butylfullerenoacetate TBC-C60 with the conjugated polymer poly 3-hexylthiophene.
When the high When the high boiling solvent 1,2,4-trichlorobenzene TCB was used as solvent to dissolve the composites, we found that vertical phase separation could be induced due to the ultra-slow evaporating velocity of TCB. In contrast, the film cast from o-dichlorobenzene displayed lateral phase segregation. The vertical phase segregation was verified by atomic force microscopy measurements, as well as photoluminescence lifetime lengthening in comparison with the lateral one determined by time-correlated single-photon counting techniques.
Furthermore, external quantum efficiency EQE curves demonstrated different profile shapes when devices were illuminated from either indium tin oxide electrode side or semi-transparent metal electrode one.
In addition, devices based on vertical phase segregation exhibited large open circuit voltage Voc compared with those with laterally segregated structures. The device based on the vertical phase segregation structure with a short circuit current density Jsc of 4. We described a simple model to explain the phase segregation in these blend composites, and showed how the absorption and EQE of the composite devices could be tuned by changing solvent drying velocity.
Conference Paper. Simultaneous ultrasensitive determination of dihydroxybenzene isomers using GC electrodes modified with nitrogen-doped carbon nano-onions. Dihydroxybenzenes DHB isomers are carcinogenic for humans and harm the environment, which is challenging to trace their lowest possible sensing limit as they coexist in their similar chemical structure and characteristics.
This study This study developed an ultrasensitive and reliable electrochemical scaffold for the individual and sensitive simultaneous determination of DHB isomers. The successful self-assembly of N-CNOs on glassy carbon GC electrode becomes a single, metal-free, economically, and environmentally benign sensor material for the ultrasensitive and simultaneous determination of DHB isomers. The CNO and N-CNOs were initially synthesized through the in-situ flame-pyrolysis technique possessing a high degree of graphitiza-tion, high surface area, excellent surface wettability, and also in high-quantity, adequately characterized using high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman spectral techniques.
The N-CNO modified electrodes were further exploited in practical applications for assessing the level of DHB isomers in industrial effluents. Phthalocyanines Pcs and their derivatives have attracted a lot of attention because of their both biological importance and technological applications.
The properties of Pcs can be tuned by replacing the central atom, by modifying the The properties of Pcs can be tuned by replacing the central atom, by modifying the periphery of phthalocyanine ring, and by changing the meso-atoms.
One more promising pathway for modifying Pcs and their derivatives can be the core-modification, or substitution of the core isoindole nitrogen s by other elements. Motivated by the results obtained for some core-modified porphyrins, we investigated computationally complete core-modification of regular Zn phthalocyanine ZnPc with P and S. Spent lubricating oil sample Shell were reclaimed using some chemical treatments. The carbonaceous residues were The carbonaceous residues were analyzed by EDS for total carbon and oxygen content as well as some wear metals.
It was observed that these materials were enriched in carbon and in. The extended mixing method resulted in the formation of larger dp approximately nm and less negatively charged zeta approximately Genotoxicity of these suspensions was evaluated with respect to human lymphocytes using single-cell gel electrophoresis assay Comet assay.
The assay demonstrated genotoxicity for both types of suspensions with a strong correlation between the genotoxic response and nC60 concentration, and with genotoxicity observed at concentrations as low as 2.
The Olive tail moments OTM for these two concentrations were 1. The results represent the first genotoxicity data for colloidal fullerenes produced by simple mixing in water.
Synthesis of C fullerene nanotubes by the liquid-liquid interfacial precipitation method.
Studies of fullerenes and carbon nanotubes by an extended bond order potential. Although it is known that evaporated metals can penetrate into and through films of organic molecules that are a few nanometers thick, there has been little work aimed at exploring the behavior of the common electrode metals used in Although it is known that evaporated metals can penetrate into and through films of organic molecules that are a few nanometers thick, there has been little work aimed at exploring the behavior of the common electrode metals used in devices based on fullerene derivatives, such as organic photovoltaics OPVs or perovskite solar cells that use fullerenes as electron transport layers.
In this paper, we show that when commonly-used electrode metals e. The plasmonic absorption and scattering from these nanoparticles are readily evident in the optical transmission spectrum, demonstrating that the interpenetrated metal significantly alters the optical properties of fullerene-rich active layers. This opens a number of possibilities in terms of contact engineering and light management so that metal penetration in devices that use fullerene derivatives could be used to advantage, making it critical that researchers are aware of the electronic and optical consequences of exposing fullerene-derivative films to evaporated electrode metals.
The history of a unique stable and soluble complex Pd 2 dba 3 has been considered starting with the classical oxi-dative addition and finishing by the modern synthesis of Pd nanoclusters catalysts absorbed on the carbon and non-carbon The history of a unique stable and soluble complex Pd 2 dba 3 has been considered starting with the classical oxi-dative addition and finishing by the modern synthesis of Pd nanoclusters catalysts absorbed on the carbon and non-carbon polymer supports.
Coordinatively non-saturated Pd 0 particles are used for constructing nanopalladium clusters immobilised which are active as catalysts in the cross-coupling reactions. Natalya Abramova. In recent decades, micro and nanoscale technologies have become cutting-edge frontiers in material science and device developments.
This worldwide trend has induced further improvements in actuator production with enhanced performance.