Study On Supramolecular Self-assembly Nanometer Composite System

Hierarchical self-assembled structures which could be found in living systemsshow stimulate responsiveness, complex function and intelligent behavior. So it isimportant to study the mechanism of self-assembly behavior in order to understandthe nature as well as to construct new materials.The first chapter of in this thesis is to synthesis surface-active agent entrappedcompound heteropolyacids SEP-PMo using cationic surfactants CDDA containingbenzoic acid end groups and phosphomolybdic acid (HPMo). The resulting compoundwere characterized by elemental analysis (TA), transmission electron microscopy(TEM) and small angle X-ray scattering (SAXS), differential scanning calorimetry(DSC), polarized light microscopy (PLM) etc. It can be seen from the experimentalresults that during the heating and the cooling cycles, CDDA has a reversible phasetransition, typical liquid crystalline birefringence could be observed under PLM. DSCof SEP-PMo did not show significant phase transition peak, while broken focal conictexture could be observed under PLM. TEM and SAXS results confirm the formationof the lamellar liquid crystal phase structure.In the second part, the above-mentioned surfactant/SEP-PMo heteropolyacidcompound was composed with poly (4-vinyl pyridine)(P4VP) in solution viahydrogen bonding interaction, to obtain a stable supramolecular complexes materials.SAXS, DSC, PLM and other methods have been carried out to study thesupramolecular structure of resulting complex. SAXS of supramolecular complexeswere similar with SEP-PMo, but become more diffuse, indicating that theself-assembled structure of SEP-PMo was partially kept within P4VP.In this section we synthesized two kinds of carbon chain length of smallmolecule4-(3,4,5,-tri decyl alkyl benzoyloxy) phenol and4-(3,4,5-tri dodecylbenzoxy benzoyloxy) phenol, and the their blends with P4VP with hydrogen bondingself-assembly. The compounds were characterized by DSC, SAXS, and FT-IR, etc.The results show that with increasing the amount of small molecules, long rangeordered hexagonal columnar liquid crystalline phase were formed.