聚醚砜/微纳纤维素复合膜材料的光谱表征与性能研究

Study on Spectroscopic Characterization and Property of PES/Micro-Nano Cellulose Composite Membrane Material

采用FTIR表征了聚醚砜/微纳纤维素复合膜材料的官能团特征,利用XRD分析了复合膜材料的结晶度变化情况。研究了微纳纤维素质量分数的变化对膜亲水性能的影响。通过SEM观察了复合膜支撑层的膜结构。结果表明,复合膜材料同时具有聚醚砜、微纳纤维素红外特征峰,且没有新峰出现,说明复合膜中微纳纤维素与聚醚砜为氢键缔合作用,无新官能团的产生,达到分子水平的相容。微纳纤维素的存在使得复合膜结晶性能增强,结晶度从37.7%增大至47.9%。随着微纳纤维素质量分数的增加,复合膜对水的范德华力和氢键力增强,亲水角从55.8°下降至45.8°,表面能从113.7 mN.m-2增加到123.5 mN.m-2,从而提高了复合膜材料的亲水性。复合膜多孔支撑层表面孔数较多,孔径有所增大,膜孔分布较为均匀。

In the present paper, the functional groups of PES/micro-nano cellulose composite membrane materials were characterized by Fourier transform infrared spectroscopy （FTIR）. Also, changes in crystallinity in composite membrane materials were analyzed using X-ray diffraction （XRD）. The effects of micro-nano cellulose content on hydrophilic property of composite membrane material were studied by measuring hydrophilie angle. The images of support layer structure of pure PF_.S membrane mate- rial and composite membrane material were showed with scanning electron microscope （SEM）. These results indicated that in the infrared spectrogram, the composite membrane material had characteristic peaks of both PES and micro-nano cellulose without appearance of other new characteristics peaks. It revealed that there were no new functional groups in the composite membrane material, and the level of molecular compatibility was achieved, which was based on the existence of inter-molecular hydrogen bond association between PES and micro-nano cellulose. Due to the existence of micro-nano cellulose, the crystallinity of com- posite membrane material was increased from 37.7~ to 47.9~. The more the increase in micro--nano cellulose mass fraction, the better the van de waal force and hydrogen bond force between composite membrane material and water were enhanced. The hydrophilic angle of composite membrane material was decreased from 55.8°to 45. 8°and the surface energy was raised from 113.7 to 123.5 mN · m^-2. Consequently, the hydrophilic property of composite membrane material was improved. The number of pores in the support layer of composite membrane material was lager than that of pure PES membrane. Apparently, pores were more uniformly distributed.