Mesocrystals of vanadium pentoxide : a comparative evaluation of three different pathways of mesocrystal synthesis from tactosol precursors

Abstract

Vanadium pentoxide mesocrystals were synthesized from a mineral liquid crystalline precursor phase, a so-called tactosol. For comparative evaluation of solid formation from that phase, the distance between the vanadium pentoxide particles was lowered by three different modes: (a) by adding a 0.1 M NaCl solution, the electric double layer was compressed and controlled particle aggregation was induced; (b) application of external pressure by ultracentrifugation resulted in particle compression and final crystallization; (c) an acrylic acid/ sulfonic acid copolymer was added to introduce polymer-mediated particle alignment and densification. In all three cases, the preorientation of the particles within the liquid crystal remained, and different mesocrystals were formed. This was demonstrated by comparative analysis of the resulting structures by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and polarization microscopy.