混有Fe_3O_4纳米颗粒的PDMS薄膜磁力激励变形研究

The research on magnetic force excitation deformation of PDMS membrane which mixed Fe_3O_4 nanoparticles

采用聚二甲基硅氧烷(PDMS)为基体,以经硅烷偶联剂(KH-570)处理过的20nm Fe3O4纳米颗粒为填充物,将这两种材料以不同比例进行混合得到磁性PDMS薄膜,对该磁性薄膜受力进行理论分析,用微米X射线三维成像系统测试同一永磁铁激励下不同半径、支撑腔体不同高度下(磁性薄膜距离永磁铁高度)和Fe3O4纳米颗粒不同质量分数下磁性薄膜的变形大小,以及不同表面磁场强度的永磁铁激励下磁性薄膜的变形大小,通过振动样品磁强计对磁性薄膜样品的磁滞曲线进行了检测,实验结果表明,在相同的激励下半径越大、支撑腔体高度越小、质量分数越大薄膜中心位移越大,不同激励下永磁铁磁场强度越大薄膜中心位移的也越大,与理论分析一致。薄膜变形引起空腔内的体积变化,体积变化证明了薄膜驱动液体的能力,该实验为应用于微流体中的微泵提供了理论依据。

This paper adopt the PDMS as matrix,the Fe3 O4 nanoparticles of 20 nm modified with the silane cou-pling agent (KH-570)as fillers,the magnetic polydimethylsiloxane(PDMS)membrane obtain through two kinds of material which was mixed in different proportions,The stress of magnetic membrane was analyzed the-oretically,then test the deflection of magnetic membrane under the supporting cavity of different radius,differ-ent height of the support cavity(the distance between magnetic membrane and permanent magnet),different magnetic field,different mass fraction of Fe3 O4 nanoparticles with the help of micro X-ray three-dimensional imaging system,the same time hysteresis curve of magnetic was tested to PDMS membrane by vibrating sample magnetometer(VSM).The experiments show under the same excitation,the magnetic membrane center deflec-tion was larger under the condition of supporting cavity of larger radius,shorter height,and bigger mass frac-tion,under the different excitation,the magnetic membrane center deflection increases with the increase of magnetic field intensity,which was consistent with the analysis of theory.At the same time,volume change caused by the center deflection indicates the ability of driving liquid,which provides theoretical basis for the mi-cropump in the application of microfluid.