Identification and characterization of aggregates formed by a partly neutralized isophthalic acid derivative in aqueous solution

Fiber-shaped aggregates were obtained from aqueous solutions of 5-octadecyl oxyisophthalic acid neutralized with 1.5 equiv of KOH. The structure of the aggregates in the resulting suspensions was investigated by X-ray and elec tron diffraction (ED) studies; the morphological observations reported here stem from atomic force microscopy (AFM) studies and from polarized optical microscopy (OM). The aggregate formation was examined as a function of the concentration and temperature of the isophthalate solutions or suspensions . The structure elucidation shows that the aggregates consist of crystals a s the smallest subunits. Their structure was determined, and the cell param eters of the unit cell could be established. Furthermore, it is demonstrate d that the material obtained from the aqueous suspensions, by pulling fiber -shaped species mechanically, is a continuous sequence of crystals.