Synthesis And Self-Assembly Of Linear And H-shaped Rigid-flexible Block Oligomer Molecules

Amphiphilic triblock copolymerare promising candidates for applications in the field of supramolecular chemistry,so the supramolecular architectures formed by the self-assembly of block molecules have received great attention.In this paper we synthesized four twist H-shaped target molecules which were connect the rod-coil molecules of center containing hydroxyl with Alpha,Alpha'-Dibromo-p-xylene.These molecules,consisting of a linear type of poly(ethylene oxide)chain and branched poly(ethylene oxide)chain as coil segments.Comparison of the interfacial methyl groups aimed to study the influence of cross sectional area of the flexible chain and the shape of the rod-coil molecules.And some molecules contain p-quinquephenyl groups as rod segments incorporating lateral hydroxyl or methoxyl groups in the center positions and oligo(ethylene oxide)s as the coil segments.The self-assembling behavior of these molecules in bulk and in aqueous solution was investigated by 1H-NMR,TOF-MASS,DSC,POM,SAXS,UV-vis,FL spectroscopy and AFM.Mainly discuss the influence of rigid shape,flexible chain length,flexible clain block volume fraction on the self-assembly behaviors in bulk and in aqueous solution.The results revealed that the lateral methoxyl or hydroxyl groups in the center of the rod segments significantly influence the formation of various supramolecular nano-structures in the bulk state and aqueous solution,via the tuning of noncovalent interactions of the rod building blocks.Although these molecules have the same rod segments,they have different coil segment.In summary,the results described here demonstrate that the ?-? stacking and consequent steric hindrance effects were the primary driving force generally influence the self-assembly behavior of the rod-coil amphiphiles in aqueous solution.