SMALL MOLECULAR LUMINESCENT GELLING AGENT 2,3-BIS-N-DECYLOXYANTHRACENE - RHEOLOGICAL AND STRUCTURAL STUDY

Luminescent organogels in decane and alcohol solvents of a small molec ule, 2,3-bis-n-decyloxyanthracene (DDOA), have been studied by theolog y and small-angle neutron scattering techniques. When the temperature of a binary DDOA/hydrocarbon or alcoholic solution is lowered, a sharp sol-to-gel transition is observed during the kinetics of DDOA aggrega tion. A thermoreversible solid-like viscoelastic material with a large yield stress (sigma approximate to 550 Pa at C = 1% wt) is obtained. The elasticity of the 3D network (G' approximate to 10(4) Pa at C = 1 % wt) suggests the existence of numerous and/or strong junction zones as found in some crystalline gels, The scattering experiments have dem onstrated the existence of an interface of large bundles of particles with the solvents. If a fiber morphology is considered, the diameters range from ca. 100 to at least 500 Angstrom, in agreement with previou s electron microscopy experiments. The DDOA gel crystallinity is corre lated with the hexagonal ordering of the related crystalline powder. ( C) 1995 Academic Press, Inc.