Accessing Frank-Kasper Phases via Blending of Architecturally Distinct and Sustainable Sugar-Based Block Co-Oligomers

Sugar-based block co-oligomers (BCOs), composed of polar oligosaccharide and nonpolar hydrocarbon blocks, have emerged as a promising platform for generating complex, thermally stable nanostructures with ultrasmall feature size, including network and Frank-Kasper (FK) phases. Here, we show that the blending of chemically distinct sugar-based BCOs offers an effective alternative to precision synthesis for tuning self-assembly in this class of sustainable materials. We investigate the binary blends of glucose-(solanesol)₂ (Glc₁-(Sol)₂, G1) and 1,3-(maltose)₂-(solanesol)₂ (1,3-(Glc₂)₂-(Sol)₂, CIS), which possess AB₂ and A₂B₂ architectures, respectively. While neat G1 and CIS individually formed dodecagonal quasicrystal (DDQC)/body-centered cubic (BCC) and lamellar/hexagonally perforated layer morphologies, their blends exhibited emergent micelle packing structures, including FK σ and A15 phases. Notably, thermal processing of these blends further induced the formation of Laves C14 and C15 phases. The Laves phase formation was attributed to micelle swelling and increased polydispersity driven by thermal caramelization of the sugar blocks. This work demonstrates that physical blending, combined with thermal modulation, enables access to the full spectrum of FK phases reported in block copolymers. These findings establish sugar-based BCOs as versatile and sustainable platforms for engineering soft-matter lattices through simple processing strategies.