Carboxylic multi-walled carbon nanotubes are widely used in various fields due to their unique properties. In materials science, they enhance the mechanical strength and electrical conductivity of composites, making them ideal for lightweight, durable materials in aerospace and automotive industries. In electronics, they are utilized in sensors, transistors, and conductive films due to their high surface area and electrical properties. In biomedical applications, their functionalized surface allows for drug delivery systems, bioimaging, and tissue engineering scaffolds. Additionally, they are employed in environmental applications for water purification and pollutant adsorption, thanks to their high surface reactivity and adsorption capacity. Their versatility makes them a valuable component in advanced technological and scientific applications.