title: The investigation on the pressure-induced phase transition in linoleic acid by in situ Raman spectroscopy.
abstract: With diamond anvil cell as a high-pressure apparatus, the in situ Raman spectra of linoleic acid from normal pressure to 1.29 GPa were measured to investigate the effect of pressure on the structural changes. In the pressure ranges of 0.07-0.12 GPa and 0.31-0.53 GPa, the significant changes in Raman spectra show that linoleic acid undergoes two pressure-induced phase transitions. Spectral analysis indicates that the polymethylene chain of linoleic acid molecule transforms from the disordered gauche conformation to the ordered trans conformation in the range of 0.07-0.12 GPa. And the polymethylene chain of linoleic acid molecule remains the ordered trans conformation whereas the conformation of the olefin group significantly changes and the degree of conformational order increases in the range of 0.31-0.53 GPa. The pressure-induced phase transitions in linoleic acid are reversible.
authors.affiliation: Department of Physics, Changchun University of Science and Technology, Changchun 130022, China. Electronic address: bnucarol@163.com.
authors.forename: Fan
authors.initials: F
authors.lastname: Ya
authors.affiliation: National Engineering Research Center for Rare Earth Materials, General Research Institute for Nonferrous Metals, Beijing, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Jing
authors.affiliation: College of Physics, Jilin University, Changchun 130012, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Da-Peng
mesh_terms: D019787:Linoleic Acid / Q000737:chemistry*; D044367:Phase Transition; D011312:Pressure; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D019787:Linoleic Acid
keywords: In situ Raman spectroscopy; Linoleic acid; Pressure-induced phase transition