Carboxylic multi-walled carbon nanotubes are widely used in the field of material science for enhancing the mechanical, thermal, and electrical properties of composites. They are incorporated into polymers, metals, and ceramics to create lightweight yet strong materials suitable for aerospace, automotive, and construction industries.

In electronics, these nanotubes serve as conductive additives in batteries, supercapacitors, and sensors, improving energy storage and signal detection capabilities. Their high surface area and functional groups make them ideal for use in electrochemical devices.

In biomedical applications, they are utilized for drug delivery systems due to their ability to attach and transport therapeutic agents. They are also explored in tissue engineering scaffolds to promote cell growth and regeneration.

Additionally, their functionalized surface allows for effective use in environmental applications, such as water purification and pollutant adsorption, where they can remove heavy metals and organic contaminants from aqueous solutions.