纳米级Fe_(3)O_(4)@SiO_(2)@mSiO_(2)粒子的微流控合成及其有机污染物的吸附分离应用

Microfluidic synthesis of Fe_(3)O_(4)@SiO_(2)@mSiO_(2) nanoparticles used for the removal of organic pollution

多孔二氧化硅作为良好的有机物吸附材料已经用于废水的处理,此外结合具有超顺磁性的Fe_(3)O_(4)纳米粒子,使材料具有了吸附分离的新特性.采用了微流控技术,搭建了基于液滴反应的微流控装置,高效、快速地合成了纳米级四氧化三铁@二氧化硅@多孔二氧化硅(Fe_(3)O_(4)@SiO_(2)@mSiO_(2))结构的粒子,以亚甲基蓝(MB)为模型,检测粒子的吸附能力.通过透射电子显微镜(TEM)、傅立叶红外光谱(FTIR)、多功能振动样品磁强计(VSM)、粉末X-射线衍射(XRD)等表征手段,对Fe_(3)O_(4)@SiO_(2)@mSiO_(2)纳米粒子进行了形貌、成份、磁学特性及表面性能的表征.Fe_(3)O_(4)@SiO_(2)@mSiO_(2)纳米粒子对MB吸附实验,在pH 10左右,可达到最大吸附量为101.9 mg/g,重复使用四次后吸附效率可达到88%.

Porous silica nanoparticles,as an excellent adsorbent,has been widely used in the removal of organic dyes.To facilitate the adsorption and separation in wastewater treatment,we synthesized novel nanoparticles to combine the advantages of porous silica nanoparticles with super-paramagnetism of Fe_(3)O_(4) nanoparticles.In this paper,we built a microfluidic device based on a droplet reaction to efficiently and rapidly synthesize composite nanoparticles with the structure of Fe_(3)O_(4)@SiO_(2)@mSiO_(2).Moreover,methylene blue(MB)was explored as the model to measure the removal efficiency of our homemade composite nanoparticles.By means of transmission electron microscopy(TEM),Fourier infrared spectroscopy(FTIR),vibrating sample magnetometer(VSM),powder X-ray diffraction(XRD),the morphology,composition,magnetic properties,and surface property of Fe_(3)O_(4)@SiO_(2)@mSiO_(2) nanoparticles were characterized.The maximum adsorption capacity of MB reached 101.9 mg/g in solutions(pH 10),and the adsorption efficiency reached 88%after four times usage.