Phase Separation in the Organic Solid State: The Influence of Quenching Protocol in Unstable n-Alkane Blends

ABSTRACT Blends of normal alkanes form lamellar structures, when quenched from the melt, in which the separation of the individual chains may be controlled by the chain-length mismatch, molar composition, isotopic substitution and confinement. 2:1 C28H58:C36D74 mixtures have been investigated after subjection to a cooling rate varying over three orders of magnitude and intermediate annealing prior to reaching ambient. Quenching at 100°C/min yields similar behaviour to intermediate annealing between the pure components' melting points. Slow cooling at 0.1°C/min generates significantly greater ordering and behaviour comparable to that obtained from annealing mid-way between the mixing transition and the C28H58 melting point.