Size effects in the heat capacity of modified MWCNTs. (1st December 2021)

• Record Type: Journal Article
• Authors: Bagatskii, M.I.; Jeżowski, A.; Szewczyk, D.; Sumarokov, V.V.; Barabashko, M.S.; Kuznetsov, V.L.; Moseenkov, S.I.; Ponomarev, A.N.
• Is Part Of: Thermal science and engineering progress. Volume 26(2021)
• Publication Date: 2021-12-01
• Subjects: Carbon nanotubes -- MWCNTs -- Heat capacity -- Effects of dimensionality and size; Heat engineering -- Periodicals; Heat engineering; Thermodynamics; Periodicals; 621.402
• DOI: 10.1016/j.tsep.2021.101097
• Languages: English
• ISSNs: 2451-9049

Abstract

Highlights: Quasi-three/two/one – dimensional behavior in heat capacity of MWCNT. Dimensionality effects irrespective of sample modification (grinding or oxidation) Various thermal transport origin depending on the MWCNT outer diameter. Abstract: Carbon nanomaterials with unique physical and chemical properties find practical applications in various fields, such as in new composite materials, nanoelectronics, medicine, etc. The efficiency of using MWCNTs (multiwalled carbon nanotubes) depends on their morphology, structure, the presence of impurities and defects. In this work, the influence of defects and geometric sizes of CVD MWCNTs on their heat capacity was experimentally studied. The heat capacity of MWCNTs modified by grinding and oxidation with different average outer diameters (7.2 and 18 nm) was measured by the thermal relaxation method in the temperature range from 1.8 to 275 K. The effects of size and dimensionality were found. The character of the temperature dependences of the specific heat of ground and ground-oxidized MWCNTs with various diameters differs fundamentally below ≈140 K. The discovered effects are discussed.