Kang D.-Y.Zang J.Wright E.R.McCanna A.L.Jones C.W.Nair S.2019-05-222019-05-22201019360851https://scholars.lib.ntu.edu.tw/handle/123456789/409801Single-walled metal oxide (aluminosilicate) nanotubes are excellent candidates for addressing the long-standing issue of functionalizing nanotube interiors, due to their high surface reactivity and controllable dimensions. However, functionalization of the nanotube interior is impeded by its high surface silanol density (9.1 -OH/nm2) and resulting hydrophilicity. Controlled dehydration of the nanotubes is critical for the success of functionalization efforts. We employ a range of solid-state characterization tools to elucidate dehydration and dehydroxylation phenomena in the nanotubes as a function of heat treatment up to 450 ¢XC. Vibrational spectroscopy (Fourier transform infrared, FT-IR), thermogravimetric analysis-mass spectrometry (TGA-MS), nitrogen physisorption, solid-state NMR, and X-ray diffraction (XRD) reveal that a completely dehydrated condition is achieved at 250 ¢XC under vacuum and that the maximum pore volume is achieved at 300 ¢XC under vacuum due to partial dehydroxylation of the dehydrated nanotube. Beyond 300¢XC, further dehydroxylation partially disorders the nanotube wall structure. However, a unique rehydroxylation mechanism can partially reverse these structural changes upon re-exposure to water vapor. Finally, detailed XRD simulations and experiments allow further insight into the nanotube packing, the dimensions, and the dependence of nanotube XRD patterns on the water content. ? 2010 American Chemical Society.AluminosilicateDehydrationDehydroxylationInorganic nanotubesRehydroxylation[SDGs]SDG6journal article10.1021/nn101211y2-s2.0-78650116108https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650116108&doi=10.1021%2fnn101211y&partnerID=40&md5=adb44b7be6f11244a4700b7bf18c128d