Five synthetic β-d-maltosides derived from Guerbet branched alcohols, whose total hydrocarbon chain length ranged from C to C, were synthesized to a high anomeric purity, and their thermal properties, liquid-crystalline phases, and structures were characterized using differential scanning calorimetry, optical polarizing microscopy, and small-angle X-ray scattering. Thermal investigations of all anhydrous Guerbet maltosides showed that they do not form solid crystals but undergo a glass transition upon temperature change in the range of 35-53 °C. The glassy crystalline structure turns into the liquid-crystalline structure upon heating or addition of water. In thermotropic studies, the lamellar phase formation is prominent in shorter-chain-length analogues, whereas the longer-chain compounds exhibit a more frustrated form of self-assembly in the formation of a metastable state, polymorphism, and inverse bicontinuous cubic structure ( Ia3 d). The excess water conditions show that the phase formation is dominated by the lamellar phase for the longer-chain compounds. Normal micellar solution was observed in the shortest-chain-length maltosides because of the enlargement of hydrated maltose headgroups. The self-assembly of both dry and fully hydrated Guerbet maltosides, which exhibited glass-forming abilities and showed surface activity and also the ability to act as membrane-stabilizing compounds, makes them ideal candidates for practical use in industry as well as biomedical research.

This work investigates the head group region of the inverse and normal bicontinuous cubic phases (Ia3d space group) of the glucopyranoside/water system using 2-(2′-hydroxyphenyl)benzoxazole and its derivatives as fluorescent probes.