Investigation Of The Intermolecular Interaction And Change In Properties Such As Interfacial Chirality At Liquid Interfaces

The interface is the place where many important physical and chemical processes occur.Researches on the interface have been an important subject related to physics,chemistry,environment as well as pharmacy,which is a vital part of the development of modern science.Air/water interface and vesicle interface are two kinds of the most important interfaces.Air/water interface is an ideal place to investigate the symmetry breakdown of supramolecular structure because a variety of chiral control methods such as chiral induction,transmission and amplification occur mainly on air/water interface.Vesicle interface is a vital model of cell membrane simulation,investigation of vesicle interface has opened up a new method for cell membrane research.In a number of interface research methods,Second Harmonic Generation(SHG),which has interface selectivity and sensitivity,makes up for the shortcomings of linear optical methods,and has become widely used in the investigation of air/water interface chirality as well as the molecular transport dynamics on vesicle interface.For the air/water interface part,the SHG method was used to investigate the spontaneous aggregation behavior for malachite green(MG)molecules adsorbed at the air/water interface.Second Harmonic Generation – Linear Dichroism(SHG-LD)technology was used to probe the supramolecular chiral structure of MG formed on the interface.Circular Dichroism as well as molecular field analysis were also carried out for the discussion.This thesis obtained the molecular orientation distribution of MG and discussed the causes of SHG signal fluctuations by using SHG quantitative polarization analysis method.In addition,regulation of supramolecular chiral structure of MG was tried by adding chiral amino acids,surfactants and salt.For the vesicle interface part,this study used 1,2-dioleoyl-sn-glycero-3-phosphorac-(1-glycerol)sodium salt(DOPG)to build vesicle drug release control model,which is one of the major phospholipid molecules that make up the cell membrane.DOPG and amino acids composite vesicles which contained different concentration of Lphenylalanine,L-tyrosine and L-aspartic acid were prepared by thin film hydration method.Vesicle size was characterized and SHG method was used to investigate the molecule adsorption and transport at vesicle surface by using 4-(4-diethylaminostyryl)-1-methylpyridinium iodide(D289)as the probe molecule.The regulation of DOPG membrane permeability by amino acids was probed which supported the investigation of the nosogenesis as well as prevention and cure of amino acid metabolic disease such as phenylketonuria.