TiO2 Hollow Nanospheres Research Articles

Polymer-induced generation and characterization of electrophoretic properties of hollow TiOX nanospheres for electronic paper

Hollow TiOX nanospheres have been successfully prepared using hollow core–double shell latex particles (poly(styrene-co-methyl methacrylate-co-butyl acrylate-co-methacrylic acid) (abbreviated in poly(St-co-MMA-co-BA-co-MAA)) as template, which involves the deposition of inorganic coating on the surface of hollow core–shell latex particles and subsequent removal of the latex by calcinations in air or ammonia gas. Ti(OBu)4 was used as precursor for the preparation of hollow TiOX nanospheres. TEM of white hollow core–double shell polymers particles with an aperture of approximately 225nm displays the perfect characteristic hollow nanospheres structure of primary core–double shell particles. The formation of TiOX was confirmed by XRD analysis and hollow structure of the particles was revealed by transmission electron microscopy (TEM). When the calcined temperature was at 800°C, hollow TiO2 nanospheres were arranged regularly with the diameter range of 130–170nm. The electrophoretic properties were characterized by JS94J micro-electrophoresis apparatus. The electrophoretic mobility of white TiO2 and black TiO hollow spheres in tetrachloroethylene were 1.09×10−5 and 3.12×10−5cm2/Vs, and the zeta potentials were 7.10 and 20.24mV, respectively. The results show that white TiO2 particles and black TiO hollow nanoparticles are suitable as electrophoretic particles and possess the application potential in the future electrophoretic display.

Hollow Titania Spheres with Movable Silica Spheres Inside

We demonstrate a flexible method for preparing hollow TiO2 nanospheres with movable silica nanoparticles inside (HTNMSNs). In this method, we used monodisperse silica--polystyrene core--shell nanospheres (SiO2-PS-CSNs) sulfonated as templates and prepared the composite shell consisting of TiO2 and sulfonated polystyrene (SPS) through adsorbing or depositing tetrabutyl titanate gel into the SPS shell. Finally the HTNMSNs were obtained after removal of all polymers in the composite nanospheres by dissolution or calcinations. We investigated the dependence of the morphologies of HTNMSNs on the thickness of PS shells and the size of SiO2 cores and prepared rare earth doped HTNMSNs by a sol-gel process.

Preparation of Hollow Anatase TiO2 Nanospheres via Ostwald Ripening.

In this work, we report a simple "one pot" approach to prepare hollow anatase TiO2 nanospheres via Ostwald ripening under hydrothermal conditions. Inner nanospace and highly organized crystallites in the shell structure and surface regions can be created with a wide range of controlling parameters. The formation mechanism has been investigated with TEM/ED/SEM/EDX/XRD/XPS methods. The approach shows a high versatility for structural engineering of various targeted morphological products, including inner material refills.