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Abstract

Irradiation of solutions of photochromic spiropyrans in nonpolar solvents initiates a succession of spontaneous chemical and physical transformations, resulting in the appearance of colloidal spherical particles, globules, of very complex structure. They are composed of highly dipolar crystalline nuclei surrounded by amorphous envelopes. Due to their large permanent dipoles the globules are aligned in linear beaded structures in a constant electric field. Macroscopically these structures look like colored threads, extending along the electric lines of force. The globules and threads reveal properties associated both with crystals (optical and electric anisotropy, discrete X-ray diffraction) and with amorphous materials (droplike form, fluidity). The globules grow stepwise, resulting in the appearance of several generations of threads with discrete increasing sizes of globules. The quasi-crystalline globules mimic the organization of biomembranes.