Nanoarchitectonics for Hierarchical Fullerene Nanomaterials

Nanoarchitectonics is a universal concept to fabricate functional materials from nanoscale building units. Based on this concept, fabrications of functional materials with hierarchical structural motifs from simple nano units of fullerenes (C60 and C70 molecules) are described in this review article. Because fullerenes can be regarded as simple and fundamental building blocks with mono-elemental and zero-dimensional natures, these demonstrations for hierarchical functional structures impress the high capability of the nanoarchitectonics approaches. In fact, various hierarchical structures such as cubes with nanorods, hole-in-cube assemblies, face-selectively etched assemblies, and microstructures with mesoporous frameworks are fabricated by easy fabrication protocols. The fabricated fullerene assemblies have been used for various applications including volatile organic compound sensing, microparticle catching, supercapacitors, and photoluminescence systems.

Fluorescent Bis-Calix[4]arene-Carbazole Conjugates: Synthesis and Inclusion Complexation Studies with Fullerenes C60 and C70

Supramolecular chemistry has become a central theme in chemical and biological sciences over the last decades. Supramolecular structures are being increasingly used in biomedical applications, particularly in devices requiring specific stimuli-responsiveness. Fullerenes, and supramolecular assemblies thereof, have gained great visibility in biomedical sciences and engineering. Sensitive and selective methods are required for the study of their inclusion in complexes in various application fields. With this in mind, two new fluorescent bis-calix[4]arene-carbazole conjugates (4 and 5) have been designed. Herein, their synthesis and ability to behave as specific hosts for fullerenes C60 and C70 is described. The optical properties of the novel compounds and their complexes with C60 and C70 were thoroughly studied by UV-Vis and steady-state and time-resolved fluorescence spectroscopies. The association constants (Ka) for the complexation of C60 and C70 by 4 and 5 were determined by fluorescence techniques. A higher stability was found for the C70@4 supramolecule (Ka = 5.6 × 104 M−1; ΔG = −6.48 kcal/mol). Evidence for the formation of true inclusion complexes between the host 4 and C60/C70 was obtained from NMR spectroscopy performed at low temperatures. The experimental findings were fully corroborated by density functional theory (DFT) models performed on the host–guest assemblies (C60@4 and C70@4).

3,6-Fluoren[5]arenes: synthesis, structure and complexation with fullerenes C60 and C70

A new kind of macrocyclic arenes, 3,6-fluoren[5]arenes, were conveniently synthesized in good yields by one-step reaction. 3,6-Fluoren[5]arenes had symmetric pentagon structures with big and rich-electron cavities, which made them form...

PRODUCTION OF NANOMATERIALS FOR APPLICATION AS ADDITIVES

This paper presents the results of the obtained carbon nanostructures by the method of arc synthesis in helium. During the synthesis, the methodology for producing fullerene-containing soot was worked out and the yield of fullerenes was increased by 6% at an optimal current of 180 A and a voltage of 30 V, at a vacuum in the reactor of ~ 0.004 Torr, and helium supply of 0.4 kg / cm2, water temperature of the cooling system ~ 19° C, The obtained nanostructures were subjected to purification by evaporation using a Soxhlet apparatus in 5 cycles. Then the obtained fullerenes C60 and C70 were investigated using analytical instruments confirming their presence. After that, the obtained fullerene mixtures were prepared in suspension and tested on a friction and wear machine. During the experiments, the optimal proportions of mixtures of fullerenes with industrial oils I - 40, as well as additives of metal micropowders were selected. The results of the analysis showed that the addition of fillers reduced friction and wear by 3-4%, which improves the effectiveness of additives from previous studies.