Chem. J. Chinese Universities ›› 2022, Vol. 43 ›› Issue (8): 20220144.doi: 10.7503/cjcu20220144

• Physical Chemistry • Previous Articles     Next Articles

Effects of Amine Structures on the pH Window of Oleic Acid Vesicle

LI Lei1,2, FANG Yun2(), XIA Yongmei1(), FAN Mengqi2, FAN Ye2   

  1. 1.State Key Laboratory of Food Science and Technology
    2.Key Laboratory of Synthetic and Biological Colloids,Ministry of Education,School of Chemical and Material Engineering,Jiangnan University,Wuxi 214122,China
  • Received:2022-03-07 Online:2022-08-10 Published:2022-04-28
  • Contact: FANG Yun,XIA Yongmei E-mail:yunfang@126.com;ymxia@jiangnan.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21606107);the National Key Research and Development Program of China(2017YFB0308705)

Abstract:

The pH window of oleic acid vesicle(OAV) was defined by laser Tyntall effect and turbidity observation, and effects of amine structure on the pH window were investigated involving in spacer lengths of diamines, numbers of amino groups in polyamines, alkyl chain lengths of primary fatty amines and quaternization. It is found that diamines and polyamines could mostly extend the pH window of OAV into the alkaline region, while primary fatty amines and dodecyltrimethylammonium bromide(DTAB) could result in a new metastable to stable vesicular phase at the low pH region besides the above window extension. Regulation of the pH window of OAV driven by amines is generally relying on transformation between protonation and deprotonation of amino groups under different pH, while cooperating with hydrophobic interaction of fatty amines or electrostatic attraction of DTAB. Thermodynamic parameters for molecular interactions and binding energy calculation show that the non-covalent bonding of diethyle-netriamine, as a representative of diamines or polyamines, with the OAV surface is dominated by hydrogen bond or ion-dipole interaction, which has weaker effect on the pH window of OAV than the hydrophobic co-assembly with primary fatty amines or electrostatic attraction with DTAB.

Key words: Fatty acid vesicle, Oleic acid, Amine, pH window, Tyntall effect

CLC Number: 

TrendMD: