We report the properties of organogels comprised of organic liquids and low molecular mass organogelators (LMOGs) based on nitrogen-containing derivatives of (R)-12-hydroxyoctadecanoic acid ((R)-HSA). The LMOGs are 6 primary and secondary (N-propyl and N-octadecyl) amides and amines of (R)-HSA and the ammonium carbamate salt of the amine, 18-aminooctadecan-7-ol. Some of the LMOGs are extremely efficient, requiring less than 1 wt % in order to gelate several organic liquids at room temperature. Optical polarizing micrographs of gels with 2 wt % of an LMOG in silicone oil, hexane, CCl4 and DMSO show smaller and larger spherulites, respectively, for preparations by fast- and slow-cooling protocols of their sols. X-ray studies have been conducted for the silicone oil gels to elucidate the structures of the fibrous networks responsible for immobilization of the liquid components. They indicate lamellar molecular packing within the fibers of the 3-dimensional LMOG networks. Rheological measurements of representative derivatives of (R)-HSA in their 2 wt % silicone oil gels were also made. Some of the gels were highly thixotropic and exhibited very fast recovery times after being destroyed by high shear. Correlations between the molecular structures of the LMOGs and the properties of their gels, including critical gelator concentrations, periods of stability, and gel-sol transition temperatures will be presented.

We thank the National Science Foundation for its support of this research and Prof. Dan Blair for the use of his rheometer.