Three-Dimensionally Branched Titanium Dioxide with Cheek-Brush Morphology: Synthesis and its Application to Polymer Composites

Abstract

Nanofiber bundles of TiO 2 with a unique cheek-brush morphology were prepared by simple, rapid, one-pot, single-step, and template-free solvothermal treatment of a titanium alkoxide and aromatic ester in methanol. The solvothermal reaction was performed by heating a mixture of titanium tetraisopropoxide and dimethyl phthalate in methanol to 300 8C. The precursor solution had to be kept at room temperature for 20 min before heating the solution to obtain a cheek-brush morphology. The heating rate (5-6 8C/min), final reaction temperature (300 8C), and holding time at the final temperature (10 min) were also crucial for formation of the cheek-brush morphology. A systematic study of additives in the precursor solution showed that aromatic esters such as diethyl phthalate and methyl benzoate gave cheek-brush morphologies. The cheek-brush TiO 2 assemblies were used to crosslink a poly(N-isopropylacrylamide) hydrogel; the brushes enhanced the physical adhesion properties of the hydrogel. The hydrogel prepared from a 20wt% polymer containing 0.02wt% of the cheek-brush TiO 2 assemblies had an 11 % and 9.1 % higher ultimate tensile strength and elongation ability, respectively, compared with a prototype hydrogel without a crosslinker. A hydrogel prepared using TiO 2 spheres of a similar size had an 11 % and 18 % lower ultimate tensile strength and elongation ability, respectively, compared with the prototype hydrogels. Scheme 1. Solvothermal synthesis of spherical TiO 2 nanoassemblies.[a] F.

Nanoscale Effect of Zirconia Filler Surface on Mechanical Tensile Strength of Polymer Composites

“…In the anode material, Nb 2 O 5 -TiO 2 MARIMO increased the current capacity and lifetime of the batteries [38]. Additionally, TiO 2 nanofiber bundles with a cheek brush morphology enhanced the mechanical strength of a polymer hydrogel when used as a filler [39].…”

Rapid One-Pot Solvothermal Batch Synthesis of Porous Nanocrystal Assemblies Composed of Multiple Transition-Metal Elements

“…To overcome the limitations of traditional solution-based syntheses of transition-metal composite oxides with multiple metal components, herein, we demonstrate a rapid one-pot synthetic approach based on a rapid-heating technique in a batch-type reactor to prepare porous metal oxides containing multiple transition-metal species (Figure a). Recently, we demonstrated a new synthetic approach to fabricate porous metal oxides using an alcohol-based solvothermal reaction. − In our method, the methanol-based solvothermal reaction was conducted in a closed reactor consisting of an SUS-316 stainless steel tube with pressure-resistant caps (Figure b). The inner temperature was traced by a thermocouple.…”