Synthesis, Properties, and Applications of Carbon Nanotubes: An Overview

Abstract

The current study attempts to review the literature concerning the synthesis, properties, and application of carbon nanotubes (CNTs). The methods used to produce carbon nanotubes include laser ablation, electric arc discharge, chemical vapor deposition, plasma-enhanced chemical vapor deposition, pulsed laser deposition, use of low-frequency ultrasound waves, heating a bulk polymer, and bulk sputtering. CNTs have excellent mechanical and thermal properties that strongly depend upon their structure. Functionalized magnetic CNTs are involved in magnetic force microscopy used in biomedicine. The liquid and plastic limit of kaolinite can be increased by adding CNTs to it. In the medical field, CNTs have numerous applications including gene delivery to cells, cancer therapy, drug delivery, and tissue regeneration. Their antioxidant nature also enables them to be used in cosmetic products and in the field of dermatology. They are also used to purify the environment, water, and in modern food-packaging technology. The sensors containing CNTs composite pellets are sensitive to gases, such as NH3, CO2, and CO H2O. CNTs are used to construct gas containers for hydrogen storage. They are also considered ideal for structural applications and their properties can be improved by making their composites with metals. Such metals may be introduced into the core of CNTs by different methods including solid-state reaction, arc-discharge method, and electrochemical techniques. The value of absorbed hydrogen gas in CNTs varies between 0.4 and 67 mass %. Recent advances encourage more research on CNTs to increase their clinical applications in the future.