Polymer-directed Morphological Control Of Inorganic Materials

The controlled synthesis of inorganic or inorganic/organic hybrid materials with specific shape or highly ordered hierarchical architecture is a key challenge in current materials synthesis and device fabrication. Recently, bio-inspired synthesis strategy has been explored as a promising approach for the morphological control and crystal tectonics. The main contents of our work are summarized as follows:Firstly, PSMA is selected as a crystal modifier, taking advantage of the cooperative effects of related experimental parameters such as the concentration of PSMA, pH value of solution, and molar ratio of cation to anion (R), to control the morphology of inorganic materials, including BaSO₄, SrSO₄, and BaCrO₄, giving rise to the emergence of a variety of interesting morphologies. A series of control experiments have been carried out to understand the morphological change with the variation of experimental conditions. The results indicate that the effect of all those parameters on the morphologies and crystallization of inorganic mineral can be attributed to their influence on the interaction between the carboxylic acid groups of PSMA and the crystal planes of the surface of inorganic mineral. In addition, a preliminary understanding for the formation mechanism of certain wonderful morphology has been proposed on the basis of the experimental results.Secondly, monodispersed quasi-octahedral PbWO₄ crystals have been fabricated via a simple PbWO₄ precipitation reaction in the mixed synthetic system of PVP and CTAB. The cooperative effect of PVP and CTAB is found to be responsible for the morphological transformation process from PbWO₄ pagodas to the unique PbWO₄ quasi-octahedrons. The photoluminescence property for the unique PbWO₄ quasi-octahedrons is observed to be significantly different from that for the PbWO₄ pagodas.Finally, Single crystalline vanadium oxide nanobelts have been synthesized on a large scale by hydrothermal treatment of NH₄VO₃ in the presence of the polymer PEG-4000 at 180℃ for 24 h. The results demonstrate that PEG, pH value and precursor play a critical role important for the formation of single crystalline vanadium oxide nanobelts.