Ordered nanostructures from self-assembly of rod–coil oligomers with n-shaped rod and dendritic poly(ethylene oxide) coil segment

Abstract

The n-shaped rod–coil molecules consisting of an anthracene unit and two biphenyl groups connected by acetylenyl bonds as a conjugated rod segment and dendritic poly(ethylene oxide)s with different cross-sectional areas were synthesised. These new molecular structures were characterised by using ¹H NMR and MALDI-TOF-MS. The self-assembly of these molecules in the bulk state and in aqueous solution was investigated using differential scanning calorimetry, X-ray diffraction and transmission electron microscopy (TEM). In the bulk state, molecule 1a with a linear coil segment, self-organised into lamellar crystalline structures, whereas molecules 1b and 1c with di- and tetra-branched dendritic wedges did not solidify at room temperature. Dynamic light scattering and TEM experiments reveal that in aqueous solution, the molecules exhibit a strong tendency to organise into the thread-like fibres along the axial direction of cylindrical micelles or into the wide fibroid bundles via the aggregation of cylindrical micelles as the cross-sectional area of the dendritic coil segments increases.

Keywords::

• self-assembly
• dendrimer
• n-shaped
• rod–coil
• cylindrical micelle

Notes

^1. Equally contributed to this work.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [Nos 21164013 and 21304009], Jilin Provincial Science & Technology Department [No. 201115225], the National Key Technologies R&D Program of China during the 12th Five-Year Plan Period [No. 2012BAD29B06], the Food Safety Key Laboratory of Liaoning Province [No. LNSAKF2011025] and the Scientific Research Foundation for the Doctoral Program of Bohai University [No. 2011016].