C60 In Solution Research Articles

Self-Assembled Corn-Husk-Shaped Fullerene Crystals as Excellent Acid Vapor Sensors

Low-molecular-weight acid vapors cause aging and destruction in material processing. In this paper, facile fabrication of novel corn-husk-shaped fullerene C60 crystals (CHFCs) through the dynamic liquid–liquid interfacial precipitation method is reported. The CHFCs were grown at the liquid–liquid interface between isopropyl alcohol (IPA) and a saturated solution of C60 in mesitylene under ambient temperature and pressure conditions. The average length, outer diameter, and inner diameter of CHFCs were ca. 2.88 μm, 672 nm, and 473 nm, respectively. X-ray diffraction (XRD) analysis showed the CHFCs exhibit a mixed face-centered cubic (fcc) and hexagonal-close pack (hcp) crystal phases with lattice parameters a = 1.425 nm, V = 2.899 nm3 for fcc phase and a = 2.182 nm, c = 0.936 nm, a/c ratio = 2.33, and V = 3.859 nm3 for hcp phase. The CHFCs possess mesoporous structure as confirmed by transmission electron microscopy (TEM) and nitrogen sorption analysis. The specific surface area and the pore volume were ca. 57.3 m2 g−1 and 0.149 cm3 g−1, respectively, are higher than the nonporous pristine fullerene C60. Quartz crystal microbalance (QCM) sensing results show the excellent sensing performance CHFCs sensitive to acetic acid vapors due to the enhanced diffusion via mesoporous architecture and hollow structure of the CHFCs, demonstrating the potential of the material for the development of a new sensor system for aliphatic acid vapors sensing.

Study of stabilization of self-assembly processes in fullerene C60 solution

The dynamics of changes in the values of the refractive index of solutions of C60 in xylene at various concentrations has been studied by the refractometric method. It was found that the deviation from the linear form of the dependence of the refractive index on the C60 concentration occurs at a C60 concentration of 1.8 mg/ml. The deviation is associated with the largest number of molecular interactions between C60−C60 and the formation of large nanoclusters on their basis in solution. It was found by the dynamic light scattering (DLS) that the final size of C60 nanoclusters in solution depends on the initial concentration of the solute. A higher initial concentration of C60 leads to the synthesis of nanoclusters with a larger diameter. Using the method of optical spectroscopy, the processes of self-organization of fullerene C60 molecules in a xylene solution in time are studied. The character of stability of synthesized fullerene nanoclusters in solution is discussed. The results obtained are of particular importance for numerous applications of nanotechnology for understanding self-assembly processes and the development of new nanomaterials.

Fullerene C60 spectroscopy in [BMIM][PF6] ionic liquid: Molecular dynamics study using polarization effects

We employ molecular dynamics (MD) simulations to assess the electrical behavior of the atomic charges of a fullerene immersed in an ionic liquid (and water). From solute-solvent configurations and DFT calculations, we obtained the atomic charges and the dipole moment in each stage of MD-simulation. Through an iterative process alternating MD-simulations and DFT calculations we obtained the convergence of the C60 dipole moment in solution. A complete analysis of the behavior of atomic charges is presented comparing the impact on the solute-solvent structure, where we highlight the importance of the complete polarization of the solute in solution. To observe the impact of electronic C60-solvente interaction on spectroscopy results we performed nuclear magnetic resonance (NMR) and absorption spectra quantum calculations, using GIAO-DFT and TD-DFT methodology. The results indicate a smaller chemical shift, δ(13C) and a more intense electronic transition band for the fully polarized C60 in solution.

A series of nanoscaled Pt(0)‐phosphorus ylide complexes based on [60]fullerene: Synthesis, characterization, and in vitro biological assessments

AbstractHerein, A type of Pt(0) complexes based on fullerene C60 including phosphorus ylides as monodentate ligands, [(η2‐C60)Pt(Y1–4)2] (Y1 = PPh3CHC(O)C6H4‐p‐NO2, Y2 = PPh3CHC(O)C6H4‐p‐CH3, Y3 = (p‐tolyl)3P‐CHC(O)C6H4‐p‐NO2, Y4 = (p‐tolyl)3P‐CHC(O)C6H4‐p‐CH3), were synthesized via adding of related monodentate phosphorus ylide to toluene solution of C60 and Pt (dba)2 (dba = dibenzylideneacetone). The structures were identified using IR, NMR (1H, 13C, and 31P), UV–visible, ESI‐MS, and EDX spectroscopies, thermal curve TGA, and electron microscopic images (scanning electron microscopy, SEM, and transmission electron microscopy, TEM). The molecular structure of complexes clearly shows that two ylidic ligands in a cis configuration and two hexagons of C60 in the junction[6,6] coordinate to Pt(0) metal center. These complexes were treated as biological agents in antibacterial, antioxidant, and anticancer assessments. Three Gram‐negative (Escherichia coli, Salmonella typhimurium, and Shigella dysenteriae) and three Gram‐positive bacteria (Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus) were used for antibacterial investigation. The activities of complexes against cancer cells were also tested using AGS (gastric carcinoma), A549 (non‐small lung carcinoma), and MCF‐7 (breast carcinoma) cell lines. All biological studies on synthesized nanocomplexes showed promising effects in comparison with standards.

Еffect of fullerene C60 on the diffusion of organic solvents' molecules

The results of studying the dynamics of molecules of solutions of fullerene C60 in benzene and toluene are presented. The studies were carried out by the method of quasi-elastic scattering of slow neutrons. The following were determined: the total self-diffusion coefficient D, its collective Dcoll and single-particle Ds-p contributions, and molecule relaxation time τ0 before and after the dissolution of fullerene. It is necessary to pay attention to the fact that in our case a kind of neutron contrast experiment takes place. The significant difference (more than ten times) in the cross-sections for an incoherent scattering of neutrons by hydrogen and carbon nuclei made it possible to obtain diffusion parameters that characterize the dynamics of solvent molecules exclusively. It turned out that the intensity of diffusion movements of solvent molecules is almost ten times higher than the mobility of fullerene molecules.

ИЗМЕНЕНИЕ БЕЛКОВО-АЗОТИСТОГО ОБМЕНА У ЛАБОРАТОРНЫХ ЖИВОТНЫХ ПОД ДЕЙСТВИЕМ ВОДНОГО РАСТВОРА ФУЛЛЕРЕНА С60

The active use of fullerene C60 in veterinary medicine has a positive effect on the functions of hepatocytes, promotes the restoration of metabolic processes in the gastrointestinal tract, improving metabolic and redox processes in the body, reducing inflammatory and fibrosing processes in the liver. The aim of the work was to change the protein-nitrogen metabolism in laboratory animals under the action of an aqueous solution of fullerene C60. For the research, 3 groups of white rats were formed. It was found that after the introduction of the studied compounds, we observed changes in the parameters of protein-nitrogen metabolism, which were expressed in an increase in the level of total protein, urea, ammonia and urea in the blood serum of white rats. However, there was a decrease in the concentration of glutamine. The change in the content of albumins in the blood serum by 8.6-10.1 % and globulins by 6-6.5 % was also found. The results obtained indicate a positive effect of C60 fullerene solutions on the animal body.

Kinetic Processes in Fullerene Solutions

In solutions, fullerenes, carbon nanoparticles with size of the order of one nanometer, exhibit a number of interesting properties and kinetic effects. A large part of these effects is connected with the ability of these macromolecules to form aggregates (or clusters), in which the nanoparticles are bound together by dispersion interactions. In this review, we present results of modeling of the kinetics of clusters formation and growth in fullerene C60 solutions of different polarity. The basic approach is the numerical solution of a system of kinetic equations of nucleation theory, applied here for the description of aggregation of fullerenes and accompanying effects. The non-monotonous time dependence of fullerene concentration during dissolution was investigated. A molecular-colloidal solution transition in polar systems is described. In addition, a model description of the critical effect of cluster decomposition after water addition to certain fullerene solutions is presented.

Fullerene production management system used for creation of hydrated solutions

The use of hydrated solutions of fullerene C60 in the food industry is considered. The features of the synthesis of fullerenes C60 by the method of plasma evaporation of graphite raw materials are presented. The structure of a complex mathematical model is proposed which allows one to relate the process of the formation of carbon nanostructures (CNS) in a plasma with the synthesis conditions, which allows one to determine the process conducting conditions with the maximum yield of the final product. An automated information management system (AIMS) for the production of fullerenes has been developed, which allows, based by numerical calculations using a complex mathematical model, to determine rational technological parameters for the graphite raw materials used and the synthesis method. The architecture of an automated information system for managingthe synthesis of carbon nanostructures is presented. The description of the interaction modules and subsystems of the control system is given. The scheme of interaction of elements of an automatedinformation management system in the process of collecting and processing information is presented. The developed automated information management system allows you to control the process of synthesis of carbon nanostructures in automatic or manual mode, monitor technological parameters in real time, calculate control actions and stabilize parameters, process the received data and present it to the user in the form of tabular or graphical information.

Viscous behaviour of o-xylene/fullerene C60 solutions

The results of an investigation of the viscosity of fullerene C60 in o-xylene solutions are presented. An experimental study of the viscosity was performed by a capillary method within a fullerene mass concentration range of 0–0.55% and a temperature range 273 K - 353 K. Viscosity measurements were performed in the range of parameters where the objects of study were in a state of molecular solution. As a result, we found that fullerene C60 increased the viscosity of o-xylene. The temperature and concentration dependences of the viscosity, the activation parameters of the viscous flow and the volume fluctuations of the examined solutions were analysed. In addition, an analysis of the dependences of the viscosity, free activation energy and activation enthalpy on volume fluctuations was performed and presented. It was shown that solutions of o-xylene/C60 exhibit behaviour that is thermodynamically similar to that of pure o-xylene. It was also found that zones with extreme increases in the viscosity, free activation energy, activation enthalpy and volume fluctuations of o-xylene/C60solutions compared to those of pure o-xylene appear in the vicinity of mass concentrations of fullerene C60 equal to 0.05%.

Спектральное исследование фотодинамических процессов в системе C-=SUB=-60-=/SUB=--(н-метилпирролидон)-кислород

The processes of photoexcitation and energy transfer in an air-saturated solution of fullerene C60 in n-methylpyrrolidone are studied. With femtosecond laser pumping at a wavelength л(p) = 520 nm, transient absorption spectra were obtained in the range 470-750 nm. Broadband absorption is observed at л > 650 nm as a result of aggregation of fullerene molecules, characterized by a short decay time of the picosecond scale. The analysis of the time dependencies indicates the presence of several processes. Within the proposed interpretation, we state a remarkable reduction in the time of singlet-triplet intersystem crossing with an increase of nanocluster size while the rapid quenching of the singlet state varies only slightly. The quantum yield of the triplet state can therefore increase, reaching 0.14. The phosphorescence spectra of singlet oxygen with a maximum at л = 1276 nm were measured with LED excitation at various wavelengths in the range 370-625 nm. The lifetime and quenching rate constant of singlet oxygen in n-methylpyrrolidone are determined. The combined quantum yield of triplet fullerene and singlet oxygen in n-methylpyrrolidone is estimated as 0.74. The efficiency spectra of the singlet oxygen photosensibilization in the C60-(n-methylpyrrolidone)-oxygen system are obtained, indicating the increasing role of large nanoclusters in this process during aging of the solution.

Density, specific heat capacity and viscosity of fullerene C60 solutions in tetralin

By combination of thermophysical and optical properties the solutions of tetralin with nanoparticles such as fullerene C60 can be considered as promising heat transfer agents for solar energy. The paper presents the results of experimental investigation for the density, viscosity and specific heat capacity of tetralin / fullerene C60 solutions. The study was performed in the temperature range 237…434 (K) and concentrations of fullerene C60 up to 1.043 (wt.%). The obtained results have shown an increase in the density and viscosity, as well as a decrease in the specific heat capacity of tetralin after adding C60. The obtained temperature dependences for the thermophysical properties of tetralin / C60 solutions are equidistant to theirs for tetralin. Obtained data on the density and viscosity were accurately fitted by a few-constant correlations for non-associated substances. The experimental data on the specific heat capacity of both tetralin and tetralin / C60 solutions indicate to significant effect of supramolecular structures in a liquid phase of aromatic hydrocarbons on this property. This effect is most significant in the temperature region close to the triple point. A new correlation for predicting the specific heat capacity of aromatic hydrocarbons containing fullerene C60 on the boiling line using a limited initial empirical data is proposed.

Effect of extract of cryopreserved piglets skin fragments and aqueous colloidal solution of fullerene C60 on epidermis morphology in cold skin wound

Effect of extract of cryopreserved piglets skin fragments and aqueous colloidal solution of fullerene C60 on epidermis morphology in cold skin wound

Size selective supramolecular interaction upon molecular complexation of a designed porphyrin with C60 and C70 in solution

The present work reports the case study on molecular complexation of a designed porphyrin, namely, 10,20-Bis(trans-1-amino-2-phenylethyl)-porphyrin-ZnII (1) with fullerenes C60 and C70 in toluene and 1,2-dichlorobenzene (DCB). As evidenced from both UV–vis and steady state fluorescence studies, the interaction is considered to be purely non-covalent in nature. Calculation of the binding constants value (K) of the C60 (i.e., KC60-1 = 3675 dm3·mol−1 in toluene and 4050 dm3·mol−1 in DCB) and C70 complexes of 1 (i.e., KC70-1 = 18,630 dm3·mol−1 in toluene and 20,105 dm3·mol−1 in DCB) reveal that size selective non-covalent interaction prevails in present work as selectivity of binding between C70 and C60 (KC70/KC60) is estimated to be same, i.e., KC70/KC60 ~ 5.1 measured both in toluene and DCB. Steady state fluorescence measurements elicit that the quenching of fluorescence of 1 in presence of C70 in DCB occurs via both static and dynamic quenching pathway. The values of kCSs (and φCSs) for the C60-1 and C70-1 systems are evaluated to be 8.95 × 106 s−1 (and 0.037) and 2.10 × 107 s−1 (and 0.083) in DCB, respectively, which provides very good support in favour of charge separation as well as formidable quenching in case of C70-1 system compared to C60-1 system. Explicit DFT calculations in vacuo predict the geometry on orientation of bound guest (here fullerenes) with the donor (here 1) and extend very good thermodynamic support in favour of the high value of K for the C70-1 system compared to C60-1 system with the help of theoretically calculated heat of formation (ΔHf0) value of such systems, i.e., ΔHf0 (C60-1) = −2.338 kcal·mol−1 and ΔHf0 (C70-1) = −42.802 kcal·mol−1 (side-on orientation of C70).

The interplay of enthalpic/entropic factors in nanoparticles' aggregation in solution: The case of fullerene C60

In the present work we accomplished analysis of interplay of enthalpic (van der Waals and electrostatic) and entropic (solvophobic) factors into the aggregation process of fullerene C60 in solution. We showed that in order to maintain the fullerene clusters stable their internal structure must be irregular, viz. dense packing of fullerene molecules inside (the nucleus) and loose packing on the outer shell. The stabilization of the nucleus is governed by van der Waals factor with negligible contribution from electrostatics, whereas the stability of the outer shell is mainly determined by electrostatics. We demonstrated, that the outer shell of clusters is made of the fullerene mantle with water molecules incorporated, required for reduction the electrostatic repulsion of surface charges. Such irregularity enabled to explain the origin of well-known intrinsic fractality of large fullerene clusters, the existence of barrier of solvent polarity required to maintain the clusters stable, and predicted the attenuation of the aggregation constant for large clusters. And, finally, we showed that fullerene binding to clusters is accompanied by small magnitude of van der Waals and electrostatic interactions, thus explaining the purely entropic character of fullerene aggregation with nearly zero experimental enthalpy change.

Direct transformation of AgNO3 complex encapsulated Fullerene (C60) microcrystal on solid silver Nitrate Crystal without organic Ligands

We observed the unusual crystal transformation from solid AgNO3 to Ag(I)‐encapsulated fullerene (C60) microcrystal by a coordination‐driven crystallization, when casting C60 solution on AgNO3 crystal. The strong binding of Ag+‐C60 ruptures electrostatic interactions within AgNO3 lattice, forming a binary hybrid material, which was characterized by XRD, Raman spectroscopy and mass spectrometry. Our results support the fact that AgNO3 crystal can directly interact with fullerene C60 molecules, other than through solvated metal cations. Two major factors, namely sturdy Ag+‐olefin interaction and an enclosed cage effect play the dominating roles in crystal transformation. Adding to the regular solution‐based crystallization, this facial protocol is expected to render an additional dimension in fabrication of exohedral metallofullerene architecture, regardless of solubility of metal cation in anti‐solvent.

The formation of self-assembled structures of C60 in solution and in the volume of an evaporating drop of a colloidal solution

The results of experiments on the self-aggregation of C60 fullerene molecules both inside a two-component solvent (xylene/tetrahydrofuran) and in the volume of an evaporating drop of C60 colloidal solution on a flat substrate surface are presented. The investigations of C60 solutions using dynamic light scattering, transmission electron microscopy and UV–Vis absorption spectroscopy methods revealed the possibility of synthesis of fractal nanoaggregates with a diameter of up to ~135 nm at low concentrations of C60 in the solutions. The final geometric dimensions of C60 nanoaggregates were determined by the initial concentration of fullerene in the solvent medium. Using the scanning electron microscopy method, we have shown that in an open dissipative system – in the volume of an evaporating droplet of the colloidal solution of fullerene C60 sessile on the surface of a flat glass substrate, large quasispherical nanoaggregates with an average diameter of ~380–800 nm are formed. The physical features and regularities that characterize the processes of self-aggregation of fullerene particles in the volume of a drying drop were determined.

Investigations of the Kinetics of Cluster Growth in Fullerene C60 Solutions

Fullerenes tend to form clusters in different solutions. In this work, a brief survey and some results in the field of investigations of the structure and kinetics of clusters growing in C60 solutions are presented. The general character of this phenomenon for fullerenes is emphasized, and the considerations of mechanisms responsible for the formation and growth of clusters are discussed. We distinguish different types of fullerene solvents by the aggregation mechanism. The kinetics of cluster growth measured via the dynamic light scattering is presented. The complicated structure of clusters in different solutions is briefly discussed.

Physicochemical study of water-soluble C60(OH)24 fullerenol

The article presents novel physicochemical data on C60(OH)24 aqueous solutions. Temperature and concentration dependencies of density (ρ) and speed of sound (u) and surface tension (γ) were obtained. Additionally, the study of human serum albumin (HSA) binding to C60(OH)24 fullerenol was conducted, and thermodynamic characteristics of C60(OH)24–HSA binding were calculated. The obtained values of a binding constant demonstrate that the complexes of C60(OH)24 with HSA are stable and HSA can perform transport functions in the bloodstream. Finally, excess thermodynamic functions of C60(OH)24–H2O binary system were calculated under the application of Virial Decomposition Asymmetric Model (VD-AS) and the boundaries of diffusion stability loss were determined. Aqueous solutions of C60(OH)20 are thermodynamically stable up to xdiff = 6.0 · 10−5. Further concentration increase leads to formation of third-order clusters with linear dimensions of thousands of nanometres and phase separation of the aqueous solution.

Vortex-Aligned Ordered Film of Crystalline Fullerene C70 Microtubes with Enhanced Photoluminescence and Photovoltaics Properties

Crystalline fullerene C70 microtubes (FMTs) were produced employing ultrasound-assisted liquid- liquid interfacial precipitation (ULLIP) technique at the interface between fullerene C70 solution in 1,2 dichlorobenzene (DCB) and isopropanol (IPA) at 15 °C. Using the vortex-flow motion of the subphase water (also called Vortex-Langmuir-Blodgett technique), the FMTs were aligned and homogeneous films were prepared at the air-water interface. The aligned FMTs film exhibited enhanced photoluminescence (PL) with PL intensity ~5 times higher than that of the pristine C70. Moreover, the aligned FMT film showed better photovoltaics properties compared with randomly oriented FMTs and pristine C70 film obtained from the spin coating. The compact, directional orientation and proper surface coverage of the FMT film enhanced the charge transport properties in the photovoltaic device.

The effect of fullerene C60 additives on the density of o-xylene

The results of the experimental study of the density of o-xylene/ fullerene C60 solutions in the concentration range 0-0.55 wt.% and temperatures 283-343 K are presented. The density was measured by a pycnometric method with an extended uncertainty of 0.07%. The concentration and temperature dependences of the density of o-xylene/ fullerene C60 solutions were obtained. It was shown that the temperature dependences of the density form a family of almost equidistant straight lines. At the same time, the concentration dependences of the density have a peculiarity that indicates probable structural transformations in the base fluid when a small amount of fullerene C60 is added. It was shown that all concentration dependences of the density of the studied solutions have a minimum in the vicinity of the fullerene concentration of 0.05 wt.% in the entire investigated temperature range. In addition, these dependences consist of two branches with different behavior. Of interest is the phenomenon of the density reduction in the region of small fullerene C60 additives to o-xylene. It is proposed to use an extended scaling model with a universal for non-associated substances crossover function for predicting the density of o-xylene/ fullerene C60 solutions in a wide range of state parameters. Within this model, the pseudocritical parameters of o-xylene/ fullerene C60 solutions were calculated. The authors note that the concentration dependences of the pseudocritical parameters also have a minimum in the vicinity of the fullerene concentration of .0.05 wt.%. The density of o-xylene/ fullerene C60 solutions calculated according to the proposed equations are consistent with the experimental data within the extended uncertainty. The excess molar volume of o-xylene/ fullerene C60 solutions was calculated.