Three kinds of new 4ZnO center dot B2O3 center dot H2O nanostructures of bunch-, chrysanthemum-, and plumy-like morphologies have been synthesized under hydrothermal conditions at 140 degrees C in the presence of ethanol. The as-synthesized products were characterized by the chemical analysis, TG, XRD, FT-IR, SEM and TEM. All the synthesized 4ZnO center dot B2O3 center dot H2O nanostructures consist of nanoribbons. A series of control experiments confirmed that the morphologies of the products were influenced by the reaction time, temperature, and the presence of the surfactant of PEG-300. Furthermore, the flame retardant properties of the synthesized 4ZnO-B2O3.H2O nanostructures were investigated by the thermal analysis method, demonstrating that they had the better behaviors than the non-nanostructure sample. (C) 2011 Elsevier B.V. All rights reserved.