The
research presented here reports the surprising observation
that adding glucose and other carbohydrate osmolytes to the polar
phase of water-containing reverse micelles causes the particles to
shrink. This apparent change in reverse micelle size is attributed
to two factors: an increase in the surface area per surfactant molecule
induced by the presence of carbohydrate and changes in the particle
shape eccentricity. The studies reported here not only focus on glucose
but also explore other carbohydrate osmolytes, specifically ethylene
glycol, glycerol, erythritol, xylitol, sorbitol, myo-inositol, and
trehalose, in the nanoconfined environments of reverse micelles. Through
two-dimensional proton nuclear Overhauser enhancement nuclear magnetic
resonance spectroscopy, the osmolytes were determined to reside solvated
in the aqueous interior of the reverse micelles. This paper reports
the loading limit of carbohydrates into AOT [sodium bis(2-ethylhexyl)sulfosuccinate]
reverse micelles, demonstrates the location of the carbohydrates in
the reverse micelles, and shows an unexpected effect where the carbohydrates
add to the reverse micelle volume without causing an apparent increase
in the reverse micelle diameter.