利用膜气液接触器制备纳米材料的研究

利用膜气液接触器制备了纳米CaCO3、SrCO3、Al(OH)3和Al2O3粒子.根据气液反应理论预测了Ca(OH)2浓度、CO2分压等对CO2吸收速率的影响规律,并得到了实验验证.在实验条件下,Ca(OH)2浓度和CO2分压对CaCO3粒子的形貌影响较小,粒径约为70nm.添加PVP和PEG后,粒度降为48nm左右,分散性明显提高.所得SrCO3纳米粒子为球形,粒度均匀,Sr(OH)2浓度对粒子粒度具有明显影响.Al(OH)3粒子为球形,50nm左右,煅烧后得到Al2O3,粒子尺寸增加至70nm左右.反应后用稀盐酸清洗膜使之再生,膜重复使用9次,膜传质系数未见明显降低.

Preparation of nanoparticles with a gas-liquid membrane contactor

Nanosized calcium carbonate,strontium carbonate,aluminium hydroxide and alumina particles were prepared with a gas-liquid membrane contactor.The effects of Ca(OH)2 concentration and CO2 partial pressure on the absorption rate were estimated according to the gas-liquid reaction theory.The theoretical predictions are consistent with the experimental results.In the absence of additives,the particles,about 70 nm in size,are not sensitive to Ca(OH)2 concentration and CO2 pressure.In the presence of PVP and PEG,the particles are well-dispersed and the size can be reduced to 48 nm.The obtained SrCO3 nanoparticles are spherical,uniform in size.The alumina hydrates obtained are amorphous,about 50 nm in size.After calcining at 800 ℃ for 8 h,the amorphous Al(OH)3 converts to alumina and the particles size increases to 70 nm.After reaction,the membrane was washed with dilute hydrochloric and the membrane could be reused for at least 9 times without apparent performance deterioration.