Wang Zhe, Zhao Chuchu, Pan Zhijuan
College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, PR China.
College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, PR China; National Engineering Laboratory for Modern Silk (Suzhou), Suzhou 215123, PR China.
J Colloid Interface Sci. 2015 Mar 1;441:121-9. doi: 10.1016/j.jcis.2014.11.041. Epub 2014 Nov 25.
Porous bead-on-string poly(lactic acid) (PLA) nanofibrous membranes (NMs) were fabricated by electrospinning, and the formation mechanism of the membranes was determined in this study. The PLA fibrous morphology, including the fiber diameter, bead size, number of beads, and surface structure of the beads, could be closely controlled by regulating the solvent compositions and the concentrations of the PLA solutions. The filtration performance, which was evaluated by measuring the penetration of sodium chloride (NaCl) aerosol particles with an average diameter of 260nm, indicated that the filtration efficiency and pressure drop for the resultant PLA membranes could be manipulated by modifying the morphology of the fibers. Moderate bead size and quantity contribute to the low pressure drop, and small fiber diameters and nanopores on the beads were conducive to high filtration efficiency. Furthermore, the NM formed from a 5 wt% solution and a solvent mixture containing dichloromethane (DCM)/N,N-dimethylacetamide (DMAC) in a 10/1 ratio of PLA by weight exhibited excellent filtration efficiency (99.997%) and a low pressure drop (165.3 Pa), which are promising characteristics for the membranes' application as filters for respiratory protection, indoor air purification, and other filtration applications.
通过静电纺丝制备了多孔串珠状聚乳酸（PLA）纳米纤维膜（NMs），并在本研究中确定了膜的形成机制。通过调节溶剂组成和PLA溶液的浓度，可以紧密控制PLA纤维形态，包括纤维直径、珠粒尺寸、珠粒数量和珠粒的表面结构。通过测量平均直径为260nm的氯化钠（NaCl）气溶胶颗粒的渗透率来评估过滤性能，结果表明，通过改变纤维形态可以控制所得PLA膜的过滤效率和压降。适中的珠粒尺寸和数量有助于降低压降，而较小的纤维直径和珠粒上的纳米孔有利于提高过滤效率。此外，由5 wt%的溶液和按PLA重量计10/1比例的含有二氯甲烷（DCM）/N，N-二甲基乙酰胺（DMAC）的溶剂混合物形成的NM表现出优异的过滤效率（99.997%）和低的压降（165.3 Pa），这些都是该膜作为呼吸防护、室内空气净化和其他过滤应用的过滤器应用的有前景的特性。
