A Remarkable Elevation of Freezing Temperature of CCl₄ in Graphitic Micropores

The freezing behavior of CCl 4 confined in graphitic micropores of activated carbon fibers (ACFs) was examined by use of differential scanning calorimetry over the temperature range of 180 to 320 K. For ACF of average pore width, w = 1.1 nm, we observed a clear peak showing that the freezing temperature is 299 K. The freezing temperature was elevated by 57 K. However, the enthalpy of freezing was only 1.0% of that of the bulk liquid CCl 4 to an fcc solid phase. CCl 4 confined in micropores of w = 0.80 nm had a more diffuse DSC peak, providing a similar elevation of the freezing temperature and an even smaller freezing enthalpy of 0.5% of the bulk value.