Efficient determination of crystallisation and melting points at low cooling and heating rates with novel computer controlled equipment

摘要

We studied melting and solidification points of 14 pure solvents and two ionic liquids with a recently constructed automatic computer-controlled equipment, which is able to record simultaneously temperature–time functions of up to 30 samples at very low heating and cooling rates down to 1.5 K · h?1. The effects of viscosity of the studied samples and of carbon fibres as an added crystallisation aid were also investigated. Equilibrium temperatures for the solid–liquid phase transition are in accordance with literature for materials that were often checked, such as acetonitrile, showing the quality of our new equipment, whereas the value of the transition temperature of some other materials differed from published results. It is shown that both the viscosity of the material and carbon fibres as crystallisation aids have an effect on supercooling. The value given for the equilibrium point of the ionic liquid trioctylmethylammonium trifluorocetate Ttr = (285.62 ± 0.1) K is new.