Effect of solvent type on the formation of tubular fullerene nanofibers

1D Fullerene C₆₀ nanofibers (FNFs) were prepared via liquid-liquid interfacial precipitation (LLIP) using toluene, m-xylene, pyridine and/or N-methyl-2-pyrrolidone (NMP) as solvents and isopropyl alcohol as the precipitation agent at 8 °C. C₆₀-saturated solutions were exposed to visible light to promote the growth of FNFs. When the solvents were toluene and m-xylene, it was difficult to synthesize hollow C₆₀ fullerene nanotubes (FNTs). By contrast, the hollow FNTs were easily grown in the C₆₀-pyridine solution or C₆₀-NMP solution upon exposure to visible light. It is found that there is a critical correlation between the adducts of the solvents with C₆₀ molecules and the tubular structure of FNFs.     

Fullerene containing polymers: a review on their synthesis and supramolecular behavior in solution

Due to the theoretical importance and potential applications of fullerene, numerous fullerene derivatives have been developed to enhance its solubility and processability. This article provides an overview on fullerene containing polymers, from synthesis to their physicochemical properties in solution. Due to the unique chemical structure of fullerene, different fullerene containing polymeric architecture can be synthesized through various kinds of conjugating techniques, where fullerene can be located either on the backbone or the branch chain. Recently, the successful development of azido coupling and atom transfer radical addition (ATRA) makes it possible to synthesize "controlled" and well-defined fullerene containing polymers. Experimental results indicated that fullerene containing polymers not only increase the solubility of fullerene in solution, but also retain the conjugating properties of fullerene molecules. By blocking well-defined functional polymers onto fullerene molecules, different types of stimuli-responsive amphiphilic systems can be achieved. However, the large bulk volume and high hydrophobicity of fullerene gives rise to the large aggregates with different morphologies produced in solution, which can be tuned by changing external stimuli, such as pH, temperature, salt, and co-solvents. Interestingly, fullerene containing anionic polymers could induce the formation nano-scale fractal pattern, but not fullerene containing cationic polymers, which is evident from morphological studies.     

富勒烯生物分子衍生物的合成与生物学效应研究

富勒烯具有独特的物理化学性质,是药物设计的理想基体.将富勒烯与各种生物分子进行连接,能改善富勒烯在极性溶剂中的溶解度,得到的新化合物具有富勒烯与生物分子的双重特性,因而具备生物分子的原有功能或产生一些新的生物活性,近年来引起越来越多的关注.综述了富勒烯与氨基酸、肽、寡糖、卟啉等生物分子的最新合成及生物学方面的研究进展.展望了富勒烯生物分子的研究方向和应用前景.     

Interfacial dispersion of poly(N-isopropylacrylamide)/ gold nanocomposites

The nanoparticle dispersity and interfacial property could be considered as a basis of their further application in the nanostructured materials. In this paper, the dispersity and interfacial phenomena of poly(N-isopropylacrylamide) modified gold nanoparticles were investigated. Firstly, such polymer/gold nanocomposites were demonstrated to have a good dispersity in water, tetrahydrofuran, alcohols and also chloroform, so they were used to entrap fluorescent dye-labelled lipids in chloroform as nanocontainers and subsequently delivery the fluorescent lipids into water as nanocarriers. Secondly, when the nanocomposites in water/chloroform mixture were heated above 35 degrees C, the nanocomposite particles could be partially transferred from water into chloroform across the interface, and they would come back into water again as cooling, displaying a reversible thermal response. Moreover, such polymer/gold nanocomposites at the immiscible water/toluene fluids preferred to assembly into 2-dimensional membranes with variable density at the water/oil interface. The special dispersion properties of the poly(N-isopropylacrylamide)/gold nanocomposites provide many potentials in the future.     

Nanoencapsulation of [60] fullerene by a novel sugar-based polymer

[60] Fullerene has been nanoencapsulated by the formation of an inclusion complex with a beta-cyclodextrin-containing lactose copolymer. The cyclodextrin polymer was synthesized by reaction of beta-cyclodextrin chlorotriazine with beta-lactose, and the polymer was highly soluble in water. Encapsulation of the carbon allotrope was achieved by forming a stable inclusion complex between the water-soluble cyclodextrin and [60] fullerene by a new synthetic procedure. Preliminary studies indicate that this complex has potential for biomedical applications because of its radical scavenging properties.     

Glucose/Fe-doped C70 fullerene hybrid biosensor: theoretical study

Abstract

The interaction between glucose molecule and C70 fullerene (pristine and Fe-doped) was investigated with the aid of density functional theory. Our results provide useful information that uncover the chemical and biological activities of C70 when interact with glucose molecule. To mimic real situations, all possible configurations of glucose with respect to fullerene were investigated under both vacuum and distilled water mediums. As expected, no significant change in the calculated energy gaps for all pristine configurations regardless the simulated medium, which indicates that the interaction between glucose molecule and pristine Fullerene is weak physisorption. However, doping fullerene with Fe atom significantly reduced the energy gap for all configurations of the complex which in turn offers an advantage over pristine fullerene for measuring glucose in real situations such as blood.     

Polyfunctional Fullerene Derivatives as UV-MALDI Matrices to Detect Peptides and Proteins

Fullerene derivatives with polyfunctional groups were synthesized and used as matrices in UV matrix-assisted laser desorption ionization (UV-MALDI) to detect polar biomolecules such as peptides and proteins. The fullerene derivatives are N,N-dimethylformamide (DMF) or water soluble. The matrix solutions (in DMF or water) can mix well with the aqueous solution containing the analyte. Visual observation with the assistance of magnifying glasses indicated that after drying, a homogenous sample solution was produced on the sample probe. MALDI/time-of-flight (MALDI/TOF) analyses results demonstrate that strong signals from peptides and proteins can be obtained. The fact that a homogenous sample solution was produced on the sample probe accounts for why the analyte's signals were detected everywhere on the probe.     

INHIBITORY EFFECT OF FULLERENE DERIVATIVES ON GLUTATHIONE REDUCTASE

Fullerene derivatives which have carboxylic acid moiety effectively inhibited glutathione reductase activity. Preincubation of the reductase and fullerene derivative at 37°C enhanced the inhibition activity.     

INHIBITORY EFFECT OF FULLERENE DERIVATIVES ON GLUTATHIONE REDUCTASE

Fullerene derivatives which have carboxylic acid moiety effectively inhibited glutathione reductase activity. Preincubation of the reductase and fullerene derivative at 37°C enhanced the inhibition activity.     

Reaction of [60]fullerene With Triethylamine

[60]Fullerene reacts with neat triethylamine via an electron transfer involving an intermediate C60-radical-anion, to give a salt-like product. This decomposes to [60]fullerene upon either heating, or treatment with ultrasound. EI mass fragmentation of the product indicates an intramolecular abstraction of H from C₂H₅ by the [60]fullerene moiety.     

Fullerene Production in a Graphite Tubular Reactor

Effects of operational parameters on the production yield of fullerenes have been detailed by many researchers and up to 20% fullerene yields were attained at optimized pressure, current, and electrode gap. Many of the tests were carried out under static helium pressure and no reference was made to helium flow during the arcing process. It is, however, known that helium flow enhances the fullerene yield. In this study, a tubular graphite reactor was placed into a stainless steel chamber and the arc was generated inside the tubular reactor. Fresh helium was fed at one end of the tubular reactor and vacuum was applied to the other end. Changing the helium flow rate affected the residence time of the particles in the reactive zone. Fullerene yields were obtained to be as high as 32%, which is much above the literature stated values.     

Influence of C60 and Fullerene Soot on the Oxidation Resistance of Vegetable Oils

The influence of fullerene soot as well as pure C₆₀ on the oxidation stability of rapeseed oil is studied. Fullerene soot (C₆₀ content between 0-6 wt.%) was synthesized by using a carbon arc method. Differential scanning calorimetry was applied to estimate the oxidation induction time of fullerene-oil composites. The addition of fullerene soot significantly hampered the peroxide formation thus increasing of oxidation stability of tested oils.     

Decrease in Fullerene Productivity Due to Air Leakage in Carbon Arc Method

Fullerene productivity was investigated in the carbon arc discharge method when air was deliberately introduced into He-filled arc apparatus. Values of fullerene yield and production rate did not vary until the air leakage rate, denned as an increase in the ratio of air partial pressure relative to He pressure, was 0.2%/min. Fullerene productivity drastically decreased when the air leakage rate increased above 0.2%/min. Emission spectroscopic measurement of the arc plasma suggested the possibility that this decrease in productivity was related to an increase in the formation of carbon-air combined molecular species, e.g., CN, in the plasma.     

Atmospheric pressure photoionization mass spectrometry of fullerenes

Atmospheric pressure photoionization (APPI) was evaluated for the analysis of fullerenes. An important response improvement was found when using toluene mediated APPI in negative mode if compared with other atmospheric pressure ionization (API) sources (electrospray and atmospheric pressure chemical ionization). Fullerene APPI negative mass spectra were dominated by the isotopic cluster of the molecular ion, although isotopic patterns for M+1, M+2, and M+3 ions showed higher than expected relative abundances. These discrepancies are explained by the presence of two isobaric ions, one due to (13)C and the other due to the addition of hydrogen to a double bond of the fullerene structure. Triple quadrupole tandem mass spectrometry, ultrahigh resolution mass spectrometry, and accurate mass measurements were used to confirm these assignments. Additionally, cluster ions M+16 and M+32 were characterized following the same strategy. Ions due to the addition of oxygen and alkyl additions were attributed to the presence of methanol in the mobile phase. For the fast chromatographic separation of fullerenes (less than 3.5 min), a sub-2 μm C18 column and isocratic elution (toluene/methanol, 45:55 v/v) was used. Highly selective-selected ion monitoring (H-SIM) mode (mass resolving power, >12,500 fwhm) was proposed monitoring the two most intense isotope ions in the [M](-?) cluster. Method limits of quantitation down to 10 pg L(-1) for C(60) and C(70) fullerenes and between 0.75 and 5.0 ng L(-1) for larger fullerenes were obtained. Finally, the ultrahigh performance liquid chromatography (UHPLC)-APPI-MS method was used to analyze fullerenes in river and pond water samples.     

Polyfunctional Fullerene Derivatives as UV-MALDI Matrices to Detect Peptides and Proteins

Abstract

Fullerene derivatives with polyfunctional groups were synthesized and used as matrices in UV matrix-assisted laser desorption ionization (UV-MALDI) to detect polar biomolecules such as peptides and proteins. The fullerene derivatives are N,N-dimethylformamide (DMF) or water soluble. The matrix solutions (in DMF or water) can mix well with the aqueous solution containing the analyte. Visual observation with the assistance of magnifying glasses indicated that after drying, a homogenous sample solution was produced on the sample probe. MALDI/time-of-flight (MALDI/TOF) analyses results demonstrate that strong signals from peptides and proteins can be obtained. The fact that a homogenous sample solution was produced on the sample probe accounts for why the analyte's signals were detected everywhere on the probe.     

Efficient Organic Solar Cells with Non‐Fullerene Acceptors

Fullerene‐free OSCs employing n‐type small molecules or polymers as the acceptors have recently experienced a rapid rise with efficiencies exceeding 12%. Owing to the good optoelectronic and morphological tunabilities, non‐fullerene acceptors exhibit great potential for realizing high‐performance and practical OSCs. In this Review, recent exciting progress made in developing highly efficient non‐fullerene acceptors is summarized, mainly correlating factors like absorption, energy loss and morphology of new materials to their correspondent photovoltaic performance.     

INFLUENCE OF DESIGN AND OPERATIONAL PARAMETERS ON YIELD OF FULLERENES

Fullerene production by arc-discharge method using graphite electrodes has been studied with respect to influence of different design and operational parameters on fullerene yield in a constant arc fullerene reactor. The design parameters like reactor length, diameter, heat transfer area and operational parameters like voltage, current, pressure, coolant flow rate, graphite evaporation rate and electrode diameter etc. have been experimentally studied in detail to establish a relationship between these parameters and fullerene yield. All the parameters affecting the yield have been correlated by dimensional analysis and an equation to calculate the fullerene yield is derived. It was observed experimentally as well as by dimensional analysis that many favorable parameters for getting good yield are linked with other parameters which also get changed if the favorable parameters are changed and thus it is difficult to make a substantial change in the yield of fullerenes.  The relationship established between the yield and parameters is however useful in optimising fullerene yield in a reactor and also helpful in designing a futuristic fullerene reactor of improved yield and productivity. The fullerene yield from different designs of reactors is obtained in the range of 4% to 20%.     

Fullerene/A5083 composites fabricated by material flow during friction stir processing

Fullerene was successfully dispersed into A5083 by friction stir processing (FSP). Dispersion of the fullerene enhanced the grain refinement by recrystallization during the FSP and the grain size reached ∼200 nm. The hardness was also remarkably increased by both the grain refinement and the dispersion of the fullerene molecules.In this study, material flow during the FSP was investigated with respect to the dispersion of the fullerene. It was revealed that the formation mechanism of the “onion ring” was closely related to the convectional flow induced by the shoulder of the rotating tool. This material flow by the shoulder is very important when fabricating the surface composites by the FSP in order to provide a uniform dispersion of the reinforcement.     

Size-controlled recrystallization of fullerene by gas–antisolvent process

Gas–antisolvent (GAS) process using CO₂ successfully prepared crystals of fullerene (C₆₀) from a toluene solution through a precipitation. Particle sizes of precipitated C₆₀ could be easily controlled by changing the initial pressurization rate of CO₂, the temperature at the initial pressurization, and the quantity of C₆₀. Fullerene particles obtained by GAS method had regular octahedral shapes, whereas the particles obtained by adding liquid ethanol as an antisolvent to C₆₀ solution did not have such shape. Particle sizes could be changed in a range of 1.0–8.5 μm by GAS method; they were wider than the range of particles obtained by ethanol addition (0.7–1.8 μm).     

120 keV Ar ion-induced red and blue shift of SPR Wavelength of Au nanoparticles in fullerene C60

Journal of Materials Science: Materials in Electronics - Au nanoparticles are synthesized in a fullerene C60 matrix using the thermal co-evaporation technique. Fullerene C60 is chosen due to its...