Thin Film Mechano-Energy Induced Slicing of Carbon Nanotubes under Flow

Abstract

Controlling the length of CNTs is important for their applications. As-prepared CNTs are typically nonuniform in length and are entangled, but for applications in electronics and biomedical research in particular, specific lengths are desirable; this has attracted intensified research efforts. We have developed a versatile thin film microfluidic method, which is high in green chemistry metrics, for controlled disentangling and slicing both single-walled CNTs and multiwalled CNTs. The method uses the mechanoenergy generated in a biphasic immiscible mixture of water and o-xylene in a titled vortex fluidic device (VFD) operating at ambient temperature, without the need for using surfactants or other axillary reagents and without the need for applying external fields. Importantly, this simple method can achieve a yield of 93% under continuous flow conditions. The high shear in the dynamic thin film in the VFD is also effective for such processing under continuous flow conditions, such that the method is scalable.