Advances in Applied NanoBio-Technologies 2022, Volume 3, Issue 1, Pages: 65-71 65 Adv. Appl. NanoBio Tech. ISSN: 2710-4001 Investigation of potential curves of carbon nanotubes: A mini-review Behnam Esfandiari * , Majid Monajjemi, Hossein Aghaie Islamic Azad University Science and Research, Tehran Abstract Received: 05/01/2022 Accepted: 26/01/2022 Published: 20/03/2022 The theoretical study of Reactions of single-walled carbon nanotubes has the largest share compared to thermodynamic potentials of these materials. Thermodynamics of free enthalpy energy and Gibbs of single-walled carbon nanotubes in different types (armchair, zigzag, chiral (n>m), and chiral (n<m)) was studied. Mass values of these thermodynamic potentials were calculated by PM3 using the basis of quasi-experimental calculations. These values were used to investigate the relationship between thermodynamic potentials and the diameter and length of the nanotube. The purpose of this theoretical study is to investigate the effect of diameter and length of these nanotubes on their thermodynamic potentials. The findings show that the thermodynamic potentials of single-walled carbon nanotubes increase with increasing each of the length or diameter parameters. The amount of free energy of Gibbs obtained emphasizes the fact that the stability of single-walled carbon nanotubes increases with increasing diameter and length. Keywords: Thermodynamic potentials; Carbon nanotubes; Theoretical predictions 1 Introduction Piping a hexagonal grid along different directions to make extremely long single-walled carbon nanotubes shows that all these pipes not only have a helical symmetry, but also have a transfer symmetry along the axis of the pipe. Also, many of them have central symmetry around this axis. This structure allows a single-walled carbon nanotube to be named with an integer pair. Carbon nanotubes are one of the basic elements in nanotechnology that have been extensively studied. The potential applications of this substance have led many researchers in various fields of science to research them. In general, research in this field can be divided into two categories: theoretical and experimental research. Functionalization of nanotubes and finding new methods for their purification are among the most important experimental activities. Almost all theoretical research on nanotubes has been devoted to the study of their covalent and non-covalent functionalization. The simplicity of calculations when using single-walled carbon nanotubes (SWNTs) along with their basic and unique applications has led to the further use of these nanotubes in theoretical studies. The interaction of small molecules such as O2, N2, NO2 and groups such as NH2, OH, CH3, COOH, the fluorination reactions (hydrogenation) and hydrogenation of SWNTs were studied theoretically. In addition, the types of ring-forming reactions in SWNTs were theoretically investigated. Corresponding: Behnam Esfandiari. Islamic Azad University Science and Research, Tehran Email: Esfandiari1516@gmail.com As mentioned, most theoretical studies have investigated the reactions of single-walled carbon nanotubes and the thermodynamic potentials of these materials have received less attention. This study investigates two thermodynamic potentials of SWNTs, namely enthalpy (H) and Gibbs free energy (G) for single-walled nanotubes. Carbon nanotubes often refer to single- walled carbon nanotubes (SWCNTs) with diameters in the range of one nanometer. They were discovered in 1993 separately by Ijima, Ichihashi, and Beethoven et al. Single-walled carbon nanotubes are one of the carbon deformations and mediate between fullerene and planar graphenes. Single-walled carbon nanotubes can be thought of as slices of a hexagonal lattice of carbon atoms perpendicular to one of the Bracket lattice vectors to form a hollow cylinder, however, they are not made this way. Carbon nanotubes are hollow ring structures composed of carbon atoms that can be arranged in single or multi-walled form, and also have metallic and quasi- conductive properties. Carbon nanotubes also referred to as multi- walled carbon nanotubes (MWCNTs) consist of nested single- walled carbon nanotubes which join together in a tree-like ring structure by weak van der Waals forces. These tubes are very similar to the direct and parallel carbon layers of Oberlin, Endo and Kuyama which are cylindrically arranged around a hollow tube. Also, multi-walled carbon nanotubes sometimes refer to two-walled and three-walled carbon nanotubes. Carbon nanotubes can also refer to tubes with an indeterminate carbon wall structure and a diameter of less than 311 nm. Such tubes were discovered in 3992 by Raduskovic and Lukjanovich. The length of a carbon nanotube produced by