Controlling The Morphology Of The Tetragonal Phase Of Barium Titanate Preparation And Response Properties Of The Electric Field

The barium titanate (BT) particles in tetragonal crystal structure with novel shape were synthesized by a simple hydrothermal method via controlling reaction conditions. Meanwhile, the reaction parameters were also optimized. The as-prepared particles were characterized by XRD, Raman, SEM and Contact Angle. On this basis, the different kinds of BT particles were dispersed in gelatin/glycerol/water mixture system, cured with or without an external dc electric field (1.2kV/mm), A-elastomers (cured without any electric field) and B-elastomers (cured with1.2kV/mm electric field) were prepared. Finally the difference in modulus of a pair of A and B-elastomers were explored and there out the electric response of BT particles were investigated indirectly. The specific contents are as follows:1. Using barium nitrate, tetrabutyl titanate as raw materials, two novel different morphologies of BT particles were synthesized by surfactant-free, simple hydrothermal method via controlling the reaction temperature, time and pH. The as-prepared particles were characterized by XRD, Raman, SEM and Contact Angle. The results show that the crystal phase of BT is tetragonal phase structure when it was prepared at220～240℃for24h. Moreover, the additive time and concentration of KOH solution were vital to the morphology of the barium titanate. The tetragonal BT particles with different morphology possess different tetragonality, surface hydrophilicity and dielectric property.2. BT particles with walnut-like, hollow daisy-like and spherical shapes were prepared by amorphism TiO2and barium hydroxide. XRD, Raman, SEM were used to analyse the structure and morphology of samples. The results show that BT particles which prepared at different conditions are tetragonal phase structure, and the additives play an important role in the morphology.3. In order to compare the surface hydrophilic of tetragonal BT particles, the water contact angle of the particles were tested. The results show that they are all less than30±5°, and means that they all possess predominant surface hydrophilic capacity. The dielectric property of particles reveals that there is a certain relationship between the tetragonality and the dielectric constant. 4. To study the response behavior of different BT particles, BT/gelatin/glycerol complex elatomers’ mechanical properties were tested, indicating that the tetragonal BT particles indeed have stronger response ability, and particles tetragonality, surface hydrophilicity, dielectric properties all have a certain effect on the electric field response performance.