Temperature and pH-Responsive Smart Carbon Nanotube Dispersions

Carbon nanotubes (CNTs) are a family of all-carbon quasi one-dimensional nanomaterials that are highly hydrophobic and typically aggregated in bundles. Recent accomplishments in dispersing CNTs in aqueous solutions open possibilities for their new applications in biomedicine. In many occasions, biological and biomedical applications demand an actuation mechanism; thus, it is highly desirable to control the dispersion and aggregation of CNTs in aqueous solutions with external stimuli. Here, we report two “smart” single-walled CNT (SWNT) aqueous dispersions that respond to temperature and pH changes through environment-responsive polymers, poly (N -isopropylacrylamide) (PNIPAAm) and Poly-l -lysine (PLL).