High-pressure Raman studies up to 0.84GPa are performed on oleic acid.Spectral analysis indicates that oleic acid undergoes a pressure-induced phase transition in the 0.29–0.36GPa range.Only one high-pressure phase below 0.84GPa is present,in which the polymethylene chains take the ordered all-trans conformation,with the methyl end of the chains exhibiting the ordered chain-end conformation and the olefin group taking the skew-cis-skew’conformation.The conformational characters of the oleic acid molecule show that the high-pressure phase is the same as the low-temperature crystalline𝛾phase.The pressure-induced phase transition is typical of first-order transitions and the transition path during compression is different from that during cooling.
展开▼
机译：Temperature‐dependent structural variations of water and supercooled water and spectral analysis of Raman spectra of water in the OH‐stretching band region and low‐frequency region studied by two‐dimensional correlation Raman spectroscopy
