Solid-solid phase transition of n-alkanes in multiple nanoscale confinement.
The crystallization behavior of n-C(19)H(40)/SiO(2) nanosphere composites was investigated by a combination of differential scanning calorimetry (DSC) and temperature-dependent X-ray diffraction (XRD). Three kinds of confined alkanes with different solid-solid phase transition supercoolings and a surface (or interface) freezing monolayer of n-C(19)H(40) at the bulk liquid/SiO(2) interface were found in the composites at high SiO(2) loading. The surface freezing monolayer induces the chain packing of bulk alkanes by forming a 2D close-packed arrangement without long-range positional ordering in 3D space. A homogeneous nucleation and growth mechanism is found for the solid-solid transition in confined geometry, in which the supercooling of the transition is sensitive to the confined size.
Jiang
Kai
K
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
Xie
Baoquan
B
Fu
Dongsheng
D
Luo
Faliang
F
Liu
Guoming
G
Su
Yunlan
Y
Wang
Dujin
D