Template Synthesis of Carbonaceous Tubular Nanostructures with Tunable Surface Properties

Uniform, open-ended carbonaceous tubular nanostructures have been synthesized via a hydrothermal route using macroporous anodic alumina membrane (AAO, d ≈ 200 nm) as template and the biomass derivative 2-furaldehyde as carbon precursor. Surface properties and functionality are controllable via selection of postcarbonization temperature, whereby the material shows increasingly hydrophobic, polarizable character as treatment temperature increases. Surface chemistry and carbon condensation were analyzed by a variety of surface sensitive techniques (i.e., FTIR, Raman, XPS), while tube texture, dimensions and uniformity were examined via gas adsorption studies and electron microscopy. Significantly, the presented synthesis allows access to carbonaceous tubular nanostructures with functional pore walls suitable for the introduction of a wide range of important chemical moieties, including as demonstrated here, the successful grafting of thermoresponsive polymers (e.g., poly- N -isopropylacrylamide (PNiPAAm)), providing materials with temperature-dependent hydrophilic−hydrophobic altering behavior and consequent controlled dispersibility in an aqueous phase.