Skip to main content
Open Access Publications from the University of California

UC Berkeley

UC Berkeley Previously Published Works bannerUC Berkeley

Structure and Thermodynamics of Hybrid Organic–Inorganic Diblock Copolymers with Salt


We examine the phase behavior of a hybrid organic-inorganic diblock copolymer/salt mixtures. The experimental system comprises poly(ethylene oxide)-block-polyhedral oligomeric silsesquioxane (PEO-POSS) mixed with a lithium bis(trifluoromethane sulfonyl) imide (LiTFSI) salt. Although the diblock copolymers without salt exhibit a classical order-to-disorder transition behavior with increasing temperature, the PEO-POSS/salt mixtures exhibit disorder-to-order transitions with increasing temperature. The analysis of a small-angle X-ray scattering data from the disordered state using Leibler's random phase approximation enables the determination of an effective Flory-Huggins interaction parameter, χ eff , for the electrolytes. Unlike conventional systems, χ eff increases with increasing temperature. A simple expression is proposed to describe the dependence of χ eff on temperature and salt concentration. This enables the calculation of the segregation strength, χ eff N, for both ordered and disordered electrolytes. The composition of the electrolytes is quantified by f EO/LiTFSI , the volume fraction of the salt-containing poly(ethylene oxide)-rich phase. The morphology of electrolytes is presented on a χ eff N versus f EO/LiTFSI phase diagram. Over the values of f EO/LiTFSI studied (0.61-0.91), only two ordered phases were found: lamellae and co-existing lamellae/hexagonally packed cylinders.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View