C60 In Solution Research Articles

Behavior of fullerene C60 in xylene-dimethylformamide binary solvents

The formation of colloidal species of fullerene C60 in two component (xylenedimethylformamide) organic solvents was studied for the first time. The results of the study of the refractive index and UV-visible spectra of C60 solutions were accompanied by an analysis of the particle size using the dynamic light scattering (DLS) method. A correlation has been established between the change in the refractive index of the solution and the degree of selforganization of fullerene molecules in solution at different concentrations and storage periods. It is shown that in the xylene-dimethylformamide binary system, the absorption spectra of C60 (~0.22 mg/ml) do not retain spectral features in a pure solvents when the solution is stored after 5 days. It has been established that, over time, the C60-xylene-dimethylformamide solution becomes polydisperse, and the sizes of the resulting fullerene nanoaggregates depend on the initial C60 concentration.

Cationic peptides as promising compounds for the treatment of bacterial complications in atopic dermatitis: Antibacterial activity assessment

BACKGROUND: The decrease in the effectiveness of antibiotics against the background of resistance of microorganisms aggravates the therapy of atopic dermatitis complicated by bacterial infection and actualizes the development of new antimicrobial agents.
 AIM: To develop, synthesize, and evaluate the antibacterial activity of cationic peptides and an aqueous solution of fullerene C60 to create drugs based on them that will have a spectrum of biological activity, including anti-inflammatory, antiallergic, and antibacterial activities.
 MATERIALS AND METHODS: This study analyzed the developed linear and dendrimer cationic peptides, whose structure was confirmed by matrix-assisted laser desorption ionization–time of flight mass spectrometry. An aqueous solution of fullerene C60 was obtained using a uniquely developed and patented technology. Antibacterial activity was assessed by diffusion into agar using disks (screening) and serial dilution, which was used to determine the minimum bactericidal concentration of the studied compounds.
 RESULTS: Moreover, 42 cationic peptides with various structures were developed and synthesized. The molecular weight of the peptides did not exceed 5,000 Da. They contained 7–25 amino acids with charges from +5 to +16. Screening was carried out through diffusion into agar using disks and revealed 15 peptides that showed activity against Escherichia coli Dh5a. Thus, using the method of counting colonies, the peptides AB-14, AB-17, and AB-18 showed bactericidal activity relative to E. coli Dh5a in concentrations of 0.03, 0.15, and 0.74 mM, respectively, which exceeded that of ampicillin (0.74 mM) several times. Analysis of an aqueous solution of fullerene C60 did not reveal its antibacterial activity.
 CONCLUSIONS: The antibacterial activity of the resulting peptides makes them promising for the development of antibacterial therapeutic agents.

Interaction of Molecules in Solutions of C60 in Polar Solvents

The features of fullerene C60 in N-methyl-2-pyrrolidone (NMP) solutions and NMP/water solvents were studied using optical absorption spectroscopy, dynamic light scattering (DLS) and atomic force microscopy (AFM). When 30% distilled water was added to the C60/NMP solution, a bathochromic shift (by ~9 nm) and a hyperchromic effect for the characteristic absorption maximum (~331 nm) for the solution, as well as a relatively weak and broad new absorption region around 440 nm, were found. These optical changes are explained by the partial destruction of C60-C60 and C60-NMP complexes when water is added to the solution, and the formation of new C60-water complexes or mixed solvate shells of C60-NMP and C60-water during their reorganization. It was determined that at a constant concentration of C60 in solutions, the maximum hydrodynamic diameter of the synthesized fullerene nanoaggregates in a C60/NMP solution is ~23 nm, and in a C60/NMP/water solution is ~33 nm.

Thermal treatment of water-soluble particles formed by compounds composed of carbon nanobelts and C60 molecules

It was previously shown that spherical particles are self-assembled by compounds composed of C60-(6,6)CNB-C60, where CNB stands for “carbon nanobelt”, by mixing two individual solutions of C60 and (6,6)CNB molecules dissolved in 1,2-dichlorobenzene at room temperature. The particles are monodisperse in water thanks to their high absolute value of the zeta potential in water. In this report, we investigate the effect of thermal treatment of the particles on some changes in the physical properties and structures. We find that the particles become electrically conductive after thermal treatment at 600 °C for 1 h. We suppose that the change in the electrical characteristics might have been caused by the structural change of (6,6)CNBs into opened-up ribbons composed of fused benzene rings, which construct networks supported by C60 molecules in the particles, judging by the change in the absorption and mass spectra of the particles after thermal treatment and analysis of a possible change in the structure of C60-(6,6)CNB-C60 based on quantum chemical calculations employing the PM6 method, with which it is known that nanostructures such as carbon nanotubes (CNTs) and (6,6)CNBs can be correctly estimated.

The Synthesis of C70 Fullerene Nanowhiskers Using the Evaporating Drop Method

Semiconductor nanowhiskers, particularly nanostructured whiskers based on zero-dimensional (0D) C70 fullerene, are being actively discussed due to the great potential of their application in modern electronics. For the first time, we proposed and implemented a method for the synthesis of nanostructured C70 fullerene whiskers based on the self-organization of C70 molecules during the thermal evaporation of C70 droplets on the substrate surface. We found that the onset of the synthesis of C70 nanowhiskers upon the evaporation of drops of a C70 solution in toluene on the substrate surface depends on the substrate temperature. We have provided experimental evidence that an increase in both the C70 concentration in the initial drop and the substrate temperature leads to an increase in the geometric dimensions of C70 nanowhiskers. The obtained results provide useful vision on the role of solute concentration and substrate temperature in the synthesis of one-dimensional materials.

Architected C70/Graphene Oxide Composites Prepared under Continuous Flow in a Vortex Fluidic Device: Implications for Supercapacitors

Graphene oxide (GO) and fullerene C70 form architected-like C70/GO structures in high yield under continuous flow processing in a vortex fluidic device (VFD). The composite material forms within high-shear regimes in the thin film microfluidic platform, in the absence of surfactants, and indeed in the absence of any auxiliary substances. The structures form on intense micromixing of an o-xylene solution of C70 and a colloidal suspension of GO in dimethylformamide (DMF) at ambient conditions, with the liquids delivered through jet feeds at the same flow rate to the hemispherical base of the rapidly rotating quartz tube in the VFD, which is tilted at 45°. The particle sizes range from 0.5 to 3 μm, with their structure and properties explored using scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, X-ray powder diffraction, and Raman spectroscopy. The mechanism of formation of the architected-like structures is consistent with the general model of fluid flow in the VFD and arises from localized high-shear temperature regimes driving desolvation as the nucleation and growth step for crystallizing the fullerene component, which are then capped with GO.

Photocurrent Generation Properties of Half-Photocell Consisting of Electropolymerized Hierarchical Polythiophene Thin Films as Photoexciting Electron Donor and C60 as Electron Acceptor

Polybithiophene/poly(3,4-ethylenedioxythiophene)/indium-tin-oxide coated transparent glass electrodes were prepared by sequential electrochemical polymerization with cyclic voltammetry. The thickness of polybithiophene films was varied by the scan rate of applied potentials during polymerization. Obtained hierarchical polythiophene films were characterized by absorption spectra, fluorescence spectra, scanning electron microscopy, laser microscopy, and atomic force microscopy. Half-photocell properties of the hierarchical polythiophene thin films were evaluated by a three-electrode electrochemical cell in CH2Cl2 solution of electrolyte and C60 as a sacrificial electron acceptor under irradiation of monochromatic light. The thickness and absorbance of hierarchical polythiophene thin films increased by decreasing of scan rate of applied potentials during the polymerization of polybithiophene. While, maximum peaks of fluorescence intensity and internal quantum yield of cathodic photocurrent were observed at 20 nm thickness of polythiophene film under irradiation from the glass side of the transparent electrode. Almost maximum external quantum efficiencies of cathodic photocurrent were observed from 20 nm to 1.5 μm thicknesses of polythiophene films. These tendencies suggest that CH2Cl2 solution of C60 and electrolyte penetrate into the polybithiophene layer up to 1.5 μm.

Effect of a compound based on an aqueous solution of fullerene C60 on hematological parameters of white rats

The article is devoted to the study of the effect of a compound based on an aqueous solution of fullerene C60 on the hematological parameters of white rats. The experiment was carried out on three groups of animals. The first group served as a control. The second group was injected with 1 ml of an aqueous solution of Fullerene C60 (1 mg / ml of DV), 150 mg of resveratrol – 25 mg, betoin hydrochloride – 10 mg. The third group received 1 ml of an aqueous solution of Fullerene C60 (1 mg/ml of DV), 2500 mg of resveratrol, 1000 mg of betoin hydrochloride. It was determined that the animals of the second group had a significant increase in the number of erythrocytes by 11.8% and the hemoglobin content by 14.8% relative to the control values. In white rats of the third group, there were no significant differences with the control. In animals of the second group, the number of rod-shaped neutrophils and monocytes increased by 10 and 9.3%, respectively, relative to the control. No significant differences were found in animals of the third group. The number of segmented neutrophils after the introduction of an aqueous solution of fullerene C60 increased by 12.4% (group 2 animals) and 6.1% (group 3 animals). It was revealed that the compound based on an aqueous solution of fullerene C60 has a pronounced effect on the hematological parameters of the body of white rats. The most effective dose was 1 ml of an aqueous solution of Fullerene C60 (1 mg / ml of DV), 150 mg of resveratrol – 25 mg, betoin hydrochloride – 10 mg, after administration of which an increase in the number of erythrocytes by 11.8% and the hemoglobin content by 14.8% relative to the control values, the number of rod-shaped neutrophils and monocytes by 10 and 9.3%, respectively, and the number of segmented neutrophils by 12.4%.

On modeling of the kinetics of aggregation in low-polar C60 solutions

Based on some recent experimental evidence, kinetics of cluster growth in a fullerene C60 low-polar solution are considered within a model based on oxides C60Ox as aggregation initializers. A system of equations for the time-evolution of the cluster-size distribution function is developed. First stage of clusters growth consists in formation of packed small C60 clusters around separate fullerene oxides. For this stage analytical solutions of equations were obtained and compared with numerical results. During the next stages, cluster-cluster aggregation events start to play a role. First numerical results for stage II are obtained and discussed. The results are compared with experimental study of clusters growth in the saturated C60/benzene solution by dynamic light scattering.

Adjuvant effect of dispersed fullerene C60 on the immune response to constructs harboring amino acid and nucleotide sequences of hepatitis C virus nonstructural NS5B protein

A vaccine against hepatitis C has not yet been developed. Recombinant proteins and plasmids encoding hepatitis C virus (HCV) proteins, the components of candidate vaccines, induce a weak immune response and require the use of adjuvants. The aim of the work was to study the adjuvant action of an aqueous solution of fullerene C60 during immunization of mice with HCV recombinant protein NS5B (rNS5B) that is an RNA-dependent RNA polymerase, or with NS5B-encoding pcNS5B plasmid. An aqueous solution of dispersed fullerene (dnC60) was obtained by ultrafiltration. C57BL/6 mice were immunized with rNS5B subcutaneously, pcNS5B intramuscularly mixed with different doses of dnC60 three times, then the humoral and cellular response to HCV was evaluated. Mice immunization with rNS5B in a mixture with dnC60 at doses of 250 g/mouse significantly induced humoral response: a dose-dependent increase in IgG1 antibody titers was 720 times higher than in the absence of fullerene. There was no increase in the cellular response to rNS5B when administered with dnC60. The humoral response to DNA immunization was weak in mice of all groups receiving pcNS5B. The cellular response was suppressed when the plasmid was injected in a mixture with dnC60. Dispersed fullerene dnC60 is a promising adjuvant for increasing the immunostimulating activity of weakly immunogenic proteins including surface and other HCV proteins, important for a protective response. Further research is needed to enhance the ability of dnC60 to boost the cellular immune response to the components of the candidate vaccine.

Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the crystals.

To investigate the host ability of a simple macrocycle, 1,3-phenylene-bridged naphthalene hexamer N6, we evaluated the complexation of N6 with fullerenes in toluene and in the crystals. The complexes in the solid-state demonstrate the one-dimensional alignment of fullerenes. The single-crystals of the C60@N6 composite have semiconductive properties revealed by photoconductivity measurements.

Vortex fluidic high shear induced crystallisation of fullerene C70 into nanotubules.

Hollow C70 nanotubules are formed under high shear within the thin film of a vortex fluidic device (VFD) without the need for using auxiliary reagents, high temperatures and pressures, and/or requiring downstream processing. This novel bottom-up crystallisation process involves intense micro mixing of two liquids (toluene solution of C70 and anti-solvent, isopropyl alcohol) within a thin film in the VFD to precisely control the hierarchical assembly of C70 molecules into hollow nanotubules. The mechanism of self-assembly was consistent with them being a mould of the high shear double helical topological flow from Faraday waves coupled with Coriolis forces generated within the thin film.

An Organic Molecular Nanobarrel that Hosts and Solubilizes C60

AbstractOrganic cages have gained increasing attention in recent years as molecular hosts and porous materials. Among these, barrel‐shaped cages or molecular nanobarrels are promising systems to encapsulate large hosts as they possess windows of the same size as their internal cavity. However, these systems have received little attention and remain practically unexplored despite their potential. Herein, we report the design and synthesis of a new trigonal prismatic organic nanobarrel with two large triangular windows with a diameter of 12.7 Å optimal for the encapsulation of C60. Remarkably, this organic nanobarrel shows a high affinity for C60in solvents in which C60is virtually insoluble, providing stable solutions of C60.

An Organic Molecular Nanobarrel that Hosts and Solubilizes C60.

Organic cages have gained increasing attention in recent years as molecular hosts and porous materials. Among these, barrel-shaped cages or molecular nanobarrels are promising systems to encapsulate large hosts as they possess windows of the same size as their internal cavity. However, these systems have received little attention and remain practically unexplored despite their potential. Herein, we report the design and synthesis of a new trigonal prismatic organic nanobarrel with two large triangular windows with a diameter of 12.7 Å optimal for the encapsulation of C60 . Remarkably, this organic nanobarrel shows a high affinity for C60 in solvents in which C60 is virtually insoluble, providing stable solutions of C60 .

Effect of fullerene C60 admixture in paraffin wax on the refractive index and phase transition temperatures

The paraffin wax (PW) utilized as a phase change material is promising for thermal energy storage systems. However, the application of this material is limited by itslow thermal conductivity. The fullerene C60 adding in PW can help to eliminate this problem.Therefore, the system PW/C60 is promising for studying its properties.
 The results of an experimental study of the refractive index of solutions of fullerene C60 in PW of 52...54 °C melting point at the ranges of С60content of 0...0.052 wt. %and temperatures of 41…65 °С are presented in the study. The complex character of the concentration dependence of the refractive index on isotherms for the studied thermodynamic systems has been registeredboth in liquid and solid phases.Data on the effect of the C60 content in PW on the temperatures of the start and finish of its phase transition is presented. At C60 content in PW of 0…0.01 wt. % the temperatures of the start and finish of the phase transition decreased, at C60 content of 0.01…0.04 wt. % they increased more than the pure PW temperatures and at C60 content more than 0.04 wt. % they decreased again.
 The obtained effects of a decrease and increase in the refractive index on the isotherms and temperatures of start and finish of PWcrystallizationcan be explained by structural transformations in PW caused by C60 presence. In the authors' opinion, the reason for the extreme behavior of concentration dependence of the refractive index of objects of study is the effect of C60 on the density fluctuations and the quasi-crystalline structure of the liquid and solid phases.These structural transformations in PW cause a similar change inthe concentration dependencies of the temperatures of the start and finish of the phase transition of objects of study.

Investigation of C60/NMP and C60/NMP/xylene solutions by absorption spectroscopy and dynamic light scattering

The behavior of intermolecular interactions in fresh and aged solutions of fullerene C60 in neat N-methyl-2-pyrrolidone (NMP), as well as in NMP/xylene mixed solvents, were studied by the methods of ultraviolet-visible spectroscopy and dynamic light scattering (DLS). It has been experimentally shown that the aging of the C60/NMP solution leads to the disappearance of the characteristic maximum of molecular absorption at ∼330 nm with smoothing, as well as to an increase in the optical absorption intensity. The latter depend on the formation of “C60- NMP”complexes, as well as on the transition of fullerene molecules to the nanocluster state. Increasing the xylene content in the C60/NMP leads to significant changes in charge transfer between solute and solvent (“C60-NMP”, “C60-C60”) at a fixed concentration of fullerene. The latter leads to the reorganization of nanoparticles, which proceeds with the destruction of molecular complexes. In this case, using the DLS method, it was found that the geometric dimensions of the synthesized C60 nanoclusters decrease.

Unexpected Colloidal Stability of Fullerenes in Dimethyl Sulfoxide and Related Systems

It is known that fullerenes are poorly soluble in polar solvents, but readily form colloidal solutions in such media. These solutions are typically solvophobic (hydrophobic when prepared in water), that is, thermodynamically unstable colloidal systems with negatively charged particles. To understand the stability factors of a colloidal system, the thresholds for coagulation of a sol or suspension by electrolytes are of key importance. While hydrosols and aqueous suspensions coagulate at concentrations of 1:1 inorganic electrolytes about 0.1-0.2 M, in acetonitrile and methanol, the corresponding critical concentrations of coagulation are ca. 3 orders of magnitude lower. Given the wide variety of properties of organic solvents, it seemed important to complete the picture to study solvents with more basic properties. This is all the more reasonable since electrophilic fullerenes are in fact Lewis acids. Our choice was dimethyl sulfoxide, DMSO, and related solvent systems. The colloidal solutions of fullerenes C60 and C70 in DMSO and N,N-dimethyl formamide, DMF, are unexpectedly easy to prepare by mechanical methods, and addition of water leads to formation of relatively stable organo-hydrosols. UV-visible spectra and dynamic light scattering were used to characterize the solutions of C60 and C70 in DMSO, benzene-DMSO, acetonitrile-DMSO, and benzene-acetonitrile-DMSO systems, as well as in DMF. Our present study demonstrated that, in contrast to organosols in methanol and acetonitrile, colloids of C70 and C60 fullerenes in DMSO and DMF are surprisingly as stable with respect to electrolytes as the corresponding hydrosols are. Such high stability is caused by the non-DLVO interactions, or, in terms proposed by Churaev and Derjaguin, by the so-called structural effect. These results shed light on the nature of the solvation of colloidal fullerene particles in solvents of various chemical natures.

The state of gluconeogenic liver function of white rats under the influence of a nanocomposite aqueous solution of fullerene С60

Biocompatible nanoparticles attract the attention of researchers as a means of correcting a wide range of diseases. The carbonbased nanostructure, fullerene C60, is one of the most promising compounds. However, the use of compounds based on fullerene nanoparticles remains limited. Therefore, the development of domestic innovative medicinal compounds based on fullerenecontaining nanoparticles is one of the priority areas of veterinary medicine. The research was carried out in the laboratory of the Department of "Morphology, Pathology of Animals and Biology" of the Saratov State Agrarian University named after N.I. Vavilov. The first group served as a control. An aqueous solution of fullerene C60 was administered at a dose of 1 ml per (DV 5 mg / kg) 1 kg of body weight (group 2 animals). A compound based on an aqueous solution of fullerene C60 was also introduced, including an aqueous solution of fullerene C60, Lcarnosine and succinic acid in the following ratio of components, wt. / mg: an aqueous solution of fullerene C60 stabilized with pluronic F-127– - 5 ml (5 mg by DV), Lcarnosine -50 mg, succinic acid - 50 mg per 1 kg of body weight (group 3). The studied compounds were administered intramuscularly, once. Glycerin loading was carried out 24 hours after the introduction of the studied compounds. It was found that aqueous solutions of fullerene C60 have a distinct effect on carbohydrate metabolism in the body of white rats. The initial blood glucose level in animals of all groups turned out to be approximately at the same level, but the highest rate of gluconeogenesis was found in animals of group 2. As for the gluconeogenic function of the liver, in animals after the introduction of aqueous solutions of fullerene C60, the increase in newly formed glucose and the rate of gluconeogenesis significantly exceeded the control values. The results obtained indicate a failure in glucose metabolism after the introduction of aqueous solutions of fullerenes.

Refractive and Electrophysical Properties of Dispersed Solutions of Fullerene C60 in Binary Solvents

Refractive and Electrophysical Properties of Dispersed Solutions of Fullerene C60 in Binary Solvents

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.