摘要
针对磁力搅拌器制备纳米材料时存在粒径分布宽、分散不均匀的问题,采用撞击流-旋转填料床结合化学共沉淀法,以Fe(NO_3)_3·9H_2O、Co(NO_3)_2·6H_2O、NaOH为原料制备CoFe_2O_4纳米颗粒。研究了转速、液体流量、NaOH浓度以及晶化时间对CoFe_2O_4纳米颗粒粒径的影响;并与磁力搅拌器制备的CoFe_2O_4纳米颗粒在磁性能方面进行了对比。采用X射线衍射仪(XRD)、傅里叶红外光谱仪(FTIR)、透射电镜(TEM)、纳米粒度仪及振动样品磁强计(VSM)对产物的粒径形貌及磁性能进行表征。结果表明:CoFe_2O_4纳米颗粒的粒径随转速、液体流量和NaOH浓度的增加而减小,但随晶化时间的增加而增大。最佳工艺条件为:转速900r/min,液体流量60L/h,NaOH浓度3mol/L,晶化时间6h。此条件下制备的CoFe_2O_4纳米颗粒的粒径约为20nm,饱和磁化强度为75.43emu/g,较磁力搅拌器提高40%。
Nanoparticles prepared by magnetic stirrer tend to have a wide particle size distribution and uneven dispersion.In order to address these problems,CoFe2O4 nanoparticles were prepared by chemical coprecipitation in impinging stream-rotating packed bed(IS-RPB)using aqueous solutions of Fe(NO3)3/Co(NO3)2 and NaOH as raw materials.The effects of rotational speed,liquid flow rate,NaOH concentration and crystallization time on the particle size of CoFe2O4 nanoparticles were examined,and their magnetic properties were compared with that prepared by magnetic stirrer.The particle size,morphology and magnetic properties of as prepared nanoparticles were characterized by X-ray diffraction(XRD),fourier infrared spectroscopy(FTIR),transmission electron microscopy(TEM),nanoparticle size analyzer and vibrating sample magnetometer(VSM).The results showed that the particle size of CoFe2O4 nanoparticles decreases with the increase of rotational speed,liquid flow rate and NaOH concentration,but increases with the increase of crystallization time.The optimum operating conditions are as follows:rotational speed 900r/min,liquid flow rate 60L/h,NaOH concentration 3mol/L,and crystallization time 6h.CoFe2O4 nanoparticles prepared under optimum operating conditions have an irregular shape with an average diameter of about 20nm and a saturation magnetization of 75.43emu/g,which is 40%higher than that prepared by magnetic stirrer.
作者
祁贵生
武晓利
刘有智
郑奇
郭林雅
QI Guisheng;WU Xiaoli;LIU Youzhi;ZHENG Qi;GUO Linya(Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering,North University of China,Taiyuan 030051,Shanxi,China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2018年第5期1680-1686,共7页
Chemical Industry and Engineering Progress
关键词
超重力
化学共沉淀
撞击流-旋转填料床
铁酸钴
纳米粒子
high gravity
chemical coprecipitation
impinging stream-rotating packed bed
cobalt ferrite(CoFe2O4)
nanoparticles
