Colloidal assemblies of branched geminis studied by cryo-etch-HRSEM. High-resolution scanning electron microscopy.
Cryo-etch-HRSEM is introduced as a useful method for exploring colloidal systems. The method fast freezes an aqueous sample (to -105 degrees C in 6-7 ms), removes some or all of the surface water by sublimation (etching), and magnifies the resulting colloidal structure by up to a million. Three new structurally similar gemini surfactants served to illustrate the technique. One gemini formed a gel whose delicate fractal-like molecular web could be observed after 10-min etching. A second formed a coacervate with a more hydrated porous structure. The third displayed a "bumpy" surface consistent with spherical vesicles projecting from the vitreous ice. The information-content of cryo-etch-HRSEM is pictorial but distinctive in nature.
Menger
Fredric M
FM
Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA. menger@emory.edu
Seredyuk
Victor A
VA
Apkarian
Robert P
RP
Wright
Elizabeth R
ER
D008823:Micelles; D008855:Microscopy, Electron, Scanning / Q000379:methods; D013501:Surface-Active Agents / Q000737:chemistry*
D008823:Micelles; D013501:Surface-Active Agents