posted on 2024-01-03, 17:05authored bySoumi Das, Caini Zheng, Timothy P. Lodge, J. Ilja Siepmann, Mahesh K. Mahanthappa, Michelle A. Calabrese, Theresa M. Reineke
Bicontinuous
thermotropic liquid crystal (LC) materials, e.g.,
double gyroid (DG) phases, have garnered significant attention due
to the potential utility of their 3D network structures in wide-ranging
applications. However, the utility of these materials is significantly
constrained by the lack of robust molecular design rules for shape-filling
amphiphiles that spontaneously adopt the saddle curvatures required
to access these useful supramolecular assemblies. Toward this aim,
we synthesized anomerically pure Guerbet-type glycolipids bearing
cellobiose head groups and branched alkyl tails and studied their
thermotropic LC self-assembly. Using a combination of differential
scanning calorimetry, polarized optical microscopy, and small-angle
X-ray scattering, our studies demonstrate that Guerbet cellobiosides
exhibit a strong propensity to self-assemble into DG morphologies
over wide thermotropic phase windows. The stabilities of these assemblies
sensitively depend on the branched alkyl tail structure and the anomeric
configuration of the glycolipid in a previously unrecognized manner.
Complementary molecular simulations furnish detailed insights into
the observed self-assembly characteristics, thus unveiling molecular
motifs that foster network phase self-assembly that will enable future
designs and applications of network LC materials.