The X-band EPR and magnetic susceptibility in the temperature range 4.2-300 K study of the shungite-I, natural nanostructured material from the deposit of Shunga are reported. Obtained results allow us to assign the EPR signal to conduction electrons, estimate their number, N P , and evaluate the Pauli paramagnetism contribution to shungite susceptibility. A small occupation (*5%) of the localized nonbonding p states in the zigzag edges of the open-ended graphene-like layers and/or on r (sp 2?x) orbitals in the curved parts of the shungite globules has been also revealed. The observed temperature dependence of the EPR linewidth can be explained by the earlier considered interaction of conduction p electrons with local phonon modes associated with the vibration of peripheral carbon atoms of the open zigzag-type edges and with peripheral carbon atoms cross-linking different nanostructures. The relaxation time T 2 and diffusion time T D are found to have comparable values (2.84 9 10-8 and 1.73 9 10-8 s at 5.2 K, respectively), and similar dependence on temperature. The magnetic measurements have revealed the suppression of orbital diamagnetism due to small amount of large enough fragments of the graphene layers.

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Carbon‐containing nanosize solid‐state phase have been produced in the atmospheric pressure microwave (MW) plasma ignited in the gas bubbles in liquid alkanes CnH2n+2 (n = 7, 8, 10, 15, 16). Gas bubbles are generated by flow of argon. According to SEM data, the solid‐state products are represented by particles having dimensions in the range of 100–200 nm. Raman spectra of the sooty‐like unpurified solid products permit to categorize them as sp3+sp2 mixed forms of carbon comprising mainly an “damaged grapheme” along with a “few‐layer” graphite nanoparticles. NMR spectra of the solid products show strong aromatization and formation of various unsaturated molecular fragments. FTIR‐ATR spectra indicate that the carbonaceous nanoparticles are contaminated with minor amounts of different hydrocarbon residues and oxidized species.

An approach to polymer surface modification using self-assembled layers (SALs) of functional alkoxysilanes has been developed in order to improve the printability of silver nanoparticle inks and enhance adhesion between the metal conducting layer and the flexible polymer substrate. The SALs have been fully characterized by AFM, XPS, and WCA, and the resulting printability, adhesion, and electrical conductivity of the screen-printed metal contacts have been estimated by cross-cut tape test and 4-point probe measurements. It was shown that (3-mercaptopropyl)trimethoxysilane SALs enable significant adhesion improvements for both aqueous- and organic-based silver inks, approaching nearly 100% for PEN and PDMS substrates while exhibiting relatively low sheet resistance up to 0.1 Ω/sq. It was demonstrated that SALs containing functional -SH or -NH2 end groups offer the opportunity to increase the affinity of the polymer substrates to silver inks and thus to achieve efficient patterning of highly conductive structures on flexible and stretchable substrates.

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