Construction of Supramolecular Assemblies from Self‐Organization of Amphiphilic Molecular Isomers. Issue 16 (29th July 2016)

• Record Type: Journal Article
• Authors: Li, Zhaohua; Yang, Yuntian; Wang, Yanqiu; Chen, Tie; Jin, Long Yi; Lee, Myongsoo
• Is Part Of: Chemistry, an Asian journal. Volume 11:Issue 16(2016)
• Page Start: 2265
• Page End: 2270
• Publication Date: 2016-07-29
• Subjects: amphiphiles -- coil-rod-coil structures -- nanofibers -- nanostructures -- self-assembly; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201600683
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: Amphiphilic coil‐rod‐coil molecules, incorporating flexible and rigid blocks, have a strong affinity to self‐organize into various supramolecular aggregates in bulk and in aqueous solutions. In this paper, we report the self‐assembling behavior of amphiphilic coil‐rod‐coil molecular isomers. These molecules consist of biphenyl and phenyl units connected by ether bonds as the rod segment, and poly(ethylene oxide) (PEO) with a degree of polymerization of 7 and 12 as the flexible chains. Their aggregation behavior was investigated by differential scanning calorimetry, thermal optical polarized microscopy, small‐angle X‐ray scattering spectroscopy, and transmission electron microscopy. The results imply that the molecular structure of the rod building block and the length of the PEO chains dramatically influence the creation of supramolecular aggregates in bulk and in aqueous solutions. In the bulk state, these molecules self‐organize into a hexagonal perforated lamellar and an oblique columnar structure, respectively, depending on the sequence of the rod building block. In aqueous solution, the molecule with a linear rod segment self‐assembles into sheet‐like nanoribbons. In contrast, its isomer, with a rod building block substituted at the meta ‐position of the aryl group, self‐organizes into nanofibers. This is achieved through the control of the non‐covalent interactions of the rod building blocks. Abstract : Hot rods : Self‐assembling behavior of amphiphilic coil‐rod‐coil molecular isomers, consisting of biphenyl and phenyl units, incorporating p ‐aryl or m ‐aryl groups in the middle of the rod segments was investigated in bulk and in aqueous solutions. The experimental results suggest that the sequence of the rod building block dramatically influences self‐assembly of the rod‐coil molecular system.