Some structural observations of self-assembled, fibrillar gels composed of two-directional bolaform arborols
Arborols are dumbbell shaped molecules (bolaform amphiphiles) in which a hydrophobic spacer separates two hydrophilic end groups. They are a valuable model for naturally occurring fibers, such as actin or amyloid. Applications to materials science can be envisioned. On cooling from warm aqueous or methanolic solutions, arborols spontaneously assemble into long fibers. When the solutions are above a certain concentration that depends on the hydrophilic / hydrophobic balance, this leads to thermally reversible gels stabilized by a mechanism that is poorly understood. With the help of wide-angle X-ray scattering, details of the arborol fiber and gel structure were obtained on wet gels. The characteristic dimensions of the fibers vary in a sensible fashion with the molecular specifics. Solvent character appears to affect the average domain length of arborols stacked into fibers. Fluorescently labeled arborols were prepared. The label does not prevent incorporation into the fibrillar structure, rendering fibril bundles visible in wet gels. Bundles are visible in concentrated gels, but not in less concentrated sols. These results are consistent with observations of dried arborols using atomic force microscopy and with previously published freeze-fracture electron microscopy and small-angle X-ray scattering experiments on dried gels. © 2006 American Chemical Society.
Publication Source (Journal or Book title)
ACS Symposium Series
Sun, J., Yu, K., Russo, P., Pople, J., Henry, A., Lyles, B., McCarley, R., Baker, G., & Newkome, G. (2006). Some structural observations of self-assembled, fibrillar gels composed of two-directional bolaform arborols. ACS Symposium Series, 918, 370-383. https://doi.org/10.1021/bk-2006-0918.ch026