Temperature Dependent Swelling Transitions of Hummers Graphite Oxide in Liquid 1‐Alcohols

Abstract

Graphite oxides (GO) swell in liquid alcohols with significant expansion of c‐lattice. However, temperature‐dependent swelling of Hummers GO (HGO) has so far been reported only for methanol and ethanol. Here, HGO swelling in liquid 1‐alchohols (C1 to C22 according to the number of carbons) is studied as a function of temperature using in situ synchrotron radiation XRD. Swelling transitions never previously observed for HGO in any kind of polar solvents are found, enthalpy of these transition and compositions of HGO‐Cx solid solvates near the point of solvent melting reported. Swelling transitions from low temperature to high‐temperature phase are found for HGO in C10–C22 alcohols, similarly to earlier reported transitions in Brodie graphite oxide (BGO). The transitions correspond to a strong change of inter‐layer distance correlating with the alcohol molecules length and change in molecules orientation from perpendicular to parallel to GO planes (Type II transitions). However, Type I swelling transitions (related to insertion/removal of one layer of alcohol molecules) reported earlier for BGO are not found in HGO. Continuous changes of the d(001) spacing are revealed for HGO immersed in all smaller alcohols in the range C1 (methanol) to C9 (nonanol).