Abstract: Nano barium sulfate was modified with the wet reaction method.Effects of variety of the modifying agent,dosage of the modifying agent,particle size of the nano barium sulfate,modification time,modification temperature and modification speed on the activation degree of the modified nano barium sulfate were investigated.Using infrared spectrometer and thermogravimetric analyzer,the coating condition of modified nano barium sulfate was characterized.Experimental results showed that coupling agent of organic titanate UP-801 is the suitable modifying agent;modification temperature is 80 ℃;dosage of modifying agent is 5%;the modification time is 30 min;modifying rotational speed is 7 000 r/min.Modification of nano barium sulfate suspension with partical size of 34 nm,95.76% activation degree of the nano barium sulfate powder can be acquired.

Key words: nano barium sulfate, surface modification, characterization