同轴静电纺丝法制备多孔镁铝尖晶石纤维

摘要

To prepare porous magnesium aluminate spinel fibers,anhydrous magnesium chloride,anhydrous aluminum chloride and anhydrous ethanol were used as starting materials,and methylene chloride was used as the solvent to prepare dry gel by the nonhydrolytic sol-gel method firstly.Then the dry gel was added with N,N-dimethylformamide (DMF) as the diluent and polyvinylpyrrolidone (PVP) as the spinning aid to prepare electrospinning precursor solution.At last the precursor fibers obtained from the magnesium aluminate gel-PVP precursor solution by coaxial electrospinning technology with multi-needles were calcined at 900 ℃ to obtain the final fibers.X-ray diffraction analysis (XRD) and scanning electron microscope (SEM) were used to study the influences of the PVP additions (3,4,and 5 g),cation concentrations (0.216,0.288,and 0.360 mol · L-1),electrospinning voltages (22,24,and 26 kV) and feeding rates of liquid paraffin (0.1,0.3,and 0.5 mL · h-1) on the phase composition and morphology of porous magnesium aluminate spinel fibers.The results show that continuous magnesium aluminate spinel fiber with obvious porous structure can be obtained when the PVP addition is 4 g,the cation concentration is 0.288 mol · L-1,the electrospinning voltage is 24 kV,and the feeding rate of liquid paraffin is 0.3 mL · h-1.%为制备多孔镁铝尖晶石纤维,首先以无水氯化铝、无水氯化镁、无水乙醇为原料,二氯甲烷为溶剂,采用非水解溶胶-凝胶法制备出干凝胶,再引入纺丝助剂聚乙烯吡咯烷酮(PVP)和助溶剂N,N-二甲基甲酰胺(DMF)制成静电纺丝溶液,利用多针头同轴静电纺丝法制备镁铝尖晶石凝胶-PVP前驱体纤维,经900℃煅烧合成出多孔镁铝尖晶石纤维.借助XRD和SEM研究了PVP用量(3、4和5 g)、阳离子浓度(0.216、0.288和0.360 mol·L-1)、静电纺丝电压(22、24和26 kV)及内液流速(0.1、0.3和0.5 mL· h-1)对多孔镁铝尖晶石纤维相组成和形貌的影响.结果发现:当PVP用量为4 g,阳离子浓度为0.288 mol·L-1,纺丝电压为24 kV,内液流速为0.3 mL·h-1时,纤维物相为纯镁铝尖晶石相,纤维连续,并呈现明显的多孔结构.