Before the actual crystallization, both bulk C30d and the C30d molecules incorporated into the lipid membranes transition through a rotator phase. According to literature, the high-temperature peak in the heat capacity should signify the transition from liquid to the RIV rotator phase . The RIV phase is then expected to transform into the RIII phase if the sample is cooled further. However, we do not see any indication of a rotator-rotator transition in bulk C30d. This is not unexpected, since the latent heat involved in this transition would be very small . Consequently, we cannot determine which rotator phase is adopted at any given temperature, and whether both rotator phases can be formed in the lipid membrane. Upon further cooling, at about 54 • C (according to DSC), the C30d molecules that had initially anisotropic motions in the lipid membrane, and that formed a rotator phase, crystallize. Notably, this transition happens at a different temperature than for bulk C30d. With 2 H NMR, the crystallization is already observed at 58 • C (Fig. ). This discrepancy between DSC and NMR is easily explained by the acquisition time needed for the 2 H NMR spectra presented in Figure , ranging from 14 to 24 hours, resulting in a very small, effective cooling rate. DSC scans however were conducted at cooling rates of 2 • C/min and thus the DSC transition temperatures can be expected to be lower than those obtained from 2 H NMR . Furthermore, our 2 H NMR results have a relatively low temperature resolution (about ±1 • C). This makes it difficult to detect slight shifts of the crystallization temperature such as the one between bulk and incorporated C30.