机械力化学合成CaTiO_3纳米晶的研究

研究了采用高能球磨机混合粉磨CaO ,TiO2 的机械力化学变化过程 .发现在一定操作参数 (行星磨公转转速 30 0r/min ,自转 2 0 0r/min)条件下 ,粉磨初期 ( 2h)为无定形形成期 ,混合物颗粒粒度减小 ,晶格畸变 ,转变为无定形 ,并形成CaTiO3 晶核 ;粉磨中期 ( 2～ 10h)为晶粒生长期 ,CaTiO3 晶粒长大 ;粉磨后期 ( 10h以后 )为动态平衡期 ,晶粒生长与粉磨引起的晶粒减小处于动态平衡 ,锐钛矿型TiO2 能够转变为金红石型TiO2 ,具有较好的反应活性 .XRD ,TEM ,FT -IR研究表明 :混合粉磨CaO ,TiO2 可机械力化学合成CaTiO3 纳米晶体 ,晶粒尺寸为 2 0～ 30nm

STUDY ON NANO-CRYSTALLINE CaTiO_3 SYNTHESIZED BY MECHANOCHEMISTRY

The mechanochemisty process occurred during grinding the mixture of CaO and TiO 2 by a plenary_mill was studied under the operating conditions of the mill. The velocity of its revolution and rotation is 300 r/min and 200 r/min respectively. The results show that the process can be divided into three stages: formation of amorphous phase (0-2 h), formation of crystalline phase (2-10 h) and the equilibrium between the growth and decrease of crystalline particles (after 10 h). In the first stage, the particle size of the mixture is decreased, the lattice distorts, the mixture transferrs into amorphous and forms the crystalline nucleus. Then, the crystalline particles of CaTiO 3 grow up. Finally, growing and decreasing of crystalline particle size are in a dynamically balanced state. Anatase can be transferred into rutile and has higher activity comparing with rutile. The crystalline size of nano_sized CaTiO 3 synthesized by the mechanochemistry process is 20 nm to 30 nm identified by XRD, TEM and FT-IR.