Synthesis Of Novel Amphiphiles And Their Application In Preparation Of Mesoporous Materials

Ordered porosity,high BET specific surface area,excellent stabiity and biocompatibility endow mesoporous materias great potential in many fileds,such as catalysis,absorption,drug dilivery.In the soft-template method which is used most widely,the stucture of amphipathic molecules influences their self-assembling behavior in aqueous solution and then influences the porosity structure and morphology of mesoporous materials.Though the method has been investigated for a long time that the amphiphiles are used as structure-directing agents to prepare mesoporous materials,it has not been researched that how molecular structure of amphiphiles influences the preparation of mesoporous silica.Based on rational design,two kinds of amphiphiles were synthesied whose polar head groups linked to the tail chains through covalent bonds and non-covalent bonds.It has been conducted to explore the influence of molecular structure on the preparation of mesoporous materials by alterring the polar head group and chain structure of every kind of amphiphiles.Two parts of work were finished as follows:Firstly,pyrrole-containing amino acid amphiphiles were synthesised with their polar head group as Aspartic acid,Glutamic acid,Tryptophan,Phenylalanine respectively,which was linked to tail chain by covalent bond.Mesoporous silica with different porosity and morphology were prepared in the same experimental condition using four kinds of surfactants as structure-directing agents respectively.In condition of the optimal concentration,mesoporous silica were prepared with structure of radial pores-containing hollow vesicles,2D hexagonal phase pores-containing films,onion pores-containing spheres,onion pores-containing spheres respectively.The results proved that the head group of surfactants influences the porosity and morphology of mesoporous silica and the laminar pores were prepared easily by using head group with conjugate ? bonds tentatively.Besides the pyrrole groups in the amphiphiles were oxidative polymerized and carbonized to prepared polypyrrole derivatives and carbon materials.Secondly,pyrrole-containing imidazolium ionic liquid amphiphiles with different counter ions and chain structure were synthesised using the counter ions-exchangeable property of ionic liquid amphiphiles whose polar head groups linked to the tail chains through non-colavent bonds.Aspartic acid,Lysine,Tryptophan,naphthoic acid,ptoluenesulfonic acid were selected as the source of counter ions.In the same experimental condition,mesoporous silica with 2D hexagonal phase pores,laminar pores,cubic bicontinuous phase pores were prepared respectively using amphiphiles with different head groups and chain structure,which proved that the head groups and chain sturcture of amphiphiles influenced the preparation of mesoporous silica and the head group with conjugate ? bonds prefered the laminar pores ulteriorly.