Pressure-induced Phase Transition in Oleic Acid Studied by Raman Spectroscopy

被引：10

作者：

Fan Ya ^{[1
,2
]}

Zhou Jing ^{[1
]}

Li Shuang ^{[2
]}

Guan Fu-Ying ^{[3
]}

Xu Da-Peng ^{[1
]}

机构：

[1] Jilin Univ, State Key Lab Superhard Mat, Changchun 130012, Peoples R China

[2] Changchun Univ Sci & Technol, Dept Phys, Changchun 130022, Peoples R China

[3] Beijing Normal Univ, Beijing 100875, Peoples R China

来源：

CHINESE PHYSICS LETTERS | 2011年 / 28卷 / 11期

关键词：

LIQUID STRUCTURE; GAMMA FORM; LIPIDS;

D O I：

10.1088/0256-307X/28/11/110702

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

High-pressure Raman studies up to 0.84 GPa are performed on oleic acid. Spectral analysis indicates that oleic acid undergoes a pressure-induced phase transition in the 0.29-0.36 GPa range. Only one high-pressure phase below 0.84 GPa is present, in which the polymethylene chains take the ordered all-trans conformation, with the methyl end of the chains exhibiting the ordered tt 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 crystalline gamma phase. The pressure-induced phase transition is typical of first-order transitions and the transition path during compression is different from that during cooling.

引用

页数：4