摘要
采用静电纺丝法制备了孔径为40～150 nm的PLLA纳米孔结构超细纤维,纳米孔不仅分布在纤维表面,而且存在于纤维内部.通过扫面电镜观察了纤维表面形貌.探讨了混合溶剂二氯甲烷/N,N-二甲基甲酰胺的比例、PLLA浓度、电场强度对PLLA纤维纳米孔大小、分布密度、深度的影响.结果表明通过调节PLLA溶液性质和纺丝参数,PLLA纤维的表面形貌可以在3种状态即光滑无孔、疏浅凹坑、密集深孔之间可控.二氯甲烷/N,N-二甲基甲酰胺比例为1∶4,PLLA浓度9%,电场强度1 kV/cm,环境温湿度分别为30℃和52%,静电纺丝所得PLLA超细纤维表面孔洞直径为150 nm,孔洞分布密集.纳米孔PLLA纤维形成的主要机理是由于静电纺丝过程中溶剂的快速挥发引起纤维表面温度急剧降低导致热致相分离而产生多孔结构.PLLA纤维膜的疏水性与纤维表面孔洞结构密切相关,纤维膜接触角最高可达146.6°.由于PLLA纤维的多孔结构,这种高疏水性的PLLA纤维膜能够快速、大量地吸油,90 s内吸收柴油达到90 g/g,25 min内可以达到145 g/g.
PLLA ultrafine fibers with mesopores of 30 ～ 150 nm were prepared by electrospinning.Their surface morphology was studied using scanning electron microscopy（SEM）.The fiber diameter and morphology could be controlled by adjusting the composition ratio of the dichloromethane（DCM）/N,N-dimethylformamide（DMF） solvent mixture,PLLA concentration and electric filed.Accordingly,fibers with varied surface structure such as smooth surface,shallow pits,or deep pores were obtained.Under optimal electrospinning conditions of DCM/DMF 4 ∶ 1,PLLA concentration of 9 wt%,electric field 1 kV/cm and relative humidity of 52%,dense mesoporous PLLA ultrafine fibers with mean pore diameter of 150 nm were fabricated.Moreover,it showed 3-dimensional inter-connected pore-structure throughout PLLA ultrafine fibers.Most pores were elongated along the fiber axis due to the stretching in the process of electrospinning.The characteristic porous PLLA fiber was formed by a combination of thermal induced phase separation（TIPs） with water assisted breath figure mechanisms,because of the sharp temperature drop caused by the quick solvent evaporation in the electrospinning process.The PLLA fibers with shallow pits or pores of 80 nm in diameter showed water contact angle of 104°,whereas the fibers with deep pores of 150 nm in diameter were highly hydrophobic with water contact angle up to 146.6°.The hydrophobic fibrous mats could quickly absorb oil,90 g/g in 90 s and 145 g/g in 25 min.Their maintaining capacity of oil absorption was 90%.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2010年第10期1193-1198,共6页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号50973019
50843030)
国家重点基础研究发展计划(973计划
项目号2010CB732203)
福建省自然科学基金(基金号2006J0011)资助项目
