Comparative study in the identification of liquid to solid transition phase with DSC, Raman spectra analysis and chemiometrics methods applied to phase change materials used for icing-delay in civil engineering infrastructures

Highlights: • PCM are considered to delay ice occurrence in winter maintenance of infrastructure. • DSC, Raman associated with chemiometrics provided the melting temperature. • Results indicated a consistency between the methods. • Some benefits of Raman spectroscopy coupled with chemiometrics were identified. - Abstract: In a costs reduction and comfort requirements context, the use of phase change materials (PCM) is a sustainable and economical answer. For transportation infrastructures and winter maintenance, they avoid ice occurrence or snow accumulation. Their characteristics, and more specifically, the solid to liquid phase transition temperature and enthalpy, are usually obtained through DSC. Raman spectroscopy can bring answers and information on their microstructures. The liquid to solid phase change was investigated on three PCM, a paraffin, formic acid and diluted formic acid. A comparison made on freezing temperature obtained through DSC, Raman spectroscopy associated with chemiometrics indicated a consistency between the methods. Raman spectroscopy coupled with multivariate data analysis allowed the identification of an additional specificity in the freezing process of the paraffin. All methods provided results consistent between each other, although some differences between literature and experimental freezing temperatures of the considered PCM were observed in all cases.