Biodegradable poly(ϵ‐caprolactone) (PCL) has been covalently grafted onto the surfaces of multiwalled carbon nanotubes (MWNTs) by the “grafting from” approach based on in‐situ ring‐opening polymerization of ϵ‐caprolactone. The grafted PCL content can be controlled easily by adjusting the feed ratio of monomer to MWNT‐supported macroinitiators (MWNT‐OH). The resulting products have been characterized with Fourier‐transform IR (FTIR), NMR, and Raman spectroscopies, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). After PCL was coated onto MWNT surfaces, core/shell structures with nanotubes as the “hard” core and the hairy polymer layer as the “soft” shell are formed, especially for MWNTs coated with a high density of polymer chains. Such a polymer shell promises good solubility/dispersibility of the MWNT–PCL nanohybrids in low‐boiling‐point organic solvents such as chloroform and tetrahydrofuran. Biodegradation experiments have shown that the PCL grafted onto MWNTs can be completely enzymatically degraded within 4 days in a phosphate buffer solution in the presence of pseudomonas (PS) lipase, and the carbon nanotubes retain their tubelike morphologies, as observed by SEM and TEM. The results present possible applications for these biocompatible PCL‐functionalized CNTs in bionanomaterials, biomedicine, and artificial bones.
Carbon nanotubes have been shown to efficiently quench luminescence from conjugated polymers when incorporated in a composite. However, shown here is an up to 100-fold increase in the visible photoluminescence signal from fluorescent chromophores in nylon 10,10 by incorporating multi-walled carbon nanotubes (MWCNTs). Using 325- and 488-nm excitation the optical absorption by MWCNTs embedded within the polymer matrix is demonstrated, followed by efficient excitation-energy transfer to emissive chromophores intrinsic to the polymer but only when the MWCNTs are acid functionalized. Furthermore, the MWCNTs are shown to significantly retard photobleaching of fluorescent centers in the nylon composites. These remarkable properties greatly advance the prospects of utilizing MWCNTs in organic solar cells and electroluminecent devices to improve performance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.