NaOH浓度对纳米Fe_3O_4/纤维素复合膜结构和性能的影响

Effects of NaOH Concentration on Structure and Properties of Nano-Fe_3O_4/ Cellulose Composite Membrane

以N-甲基吗啉-N-氧化物(NMMO)天然纤维素膜为基材,NaOH为沉淀剂,利用原位共沉淀法制备出纳米Fe_3O_4/纤维素复合膜,通过X射线衍射光谱(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)、热重分析(TGA)仪和振动样品磁强计(VSM)研究了NaOH浓度对复合膜结构及性能的影响。结果表明:球形纳米Fe_3O_4能均匀分散并固定在纤维素膜基体上,且随NaOH浓度的增加,Fe_3O_4晶粒尺寸逐渐增大。复合薄膜红外谱图显示纳米Fe_3O_4与纤维膜之间形成较强的界面结合力。随NaOH浓度的从1.0 mol/L增加到3.0 mol/L,复合膜的热稳定性逐渐增强,其热失重残留量由19.3%提高到23.8%。VSM研究表明Fe_3O_4/纤维素复合膜具有良好的超顺磁性,NaOH浓度的增加能够提高复合膜的磁性能。

Using NMMO-cellulose memberane as matrix and NaOH as precipitant, Fe3O4/cellulose composite membranes were prepared by in-situ co-precipitation method. The effects of NaOH concentration on the structure and properties of composite membranes were studied by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, Fourier transform infrared spectrometer（ FT-1R）, thermal gravimetric analyzer （TGA） and vibration sample magnetometer（VSM）. Results showed that the spherical magnetic Fe304 nanopartieles were dispersed uniformly and immobilized in the cellulose membranes, and the crystallite size of Fe304 on the surface of composite membrane increased with NaOH concentration increasing. FT-IR spectra showed that there were good interactions between cellulose and Fe304 in the membranes.The thermal stability of the composite membrane increased with the increase of NaOH concentration from 1.0 mol/L to 3.0 mol/L, and the residue rate of composite membrane increased from 19.3 % to 23.8 %. VSM showed that Fe304/cellulose composite membranes showed good superparamagnetic property, and magnetic properties of the composite membrane improved by increasing the NaOH concentration.