Novel air filtration materials via combined melt-solution electrospinning

摘要

Hierarchically structured nanofibers are gaining attention in the fields of energy and the environment, particularly for air filter and fluid membrane applications. Non-woven fibrous media have been used extensively in air filtration applications and nanofibrous air filters have previously shown grate results for high efficiency air filtration. However, the durability is still questionable because nanofibers form high packing density filtersfeaturing high pressure drop even with the presence of slip flow phenomena. Mixing micro and nano sized structures has been proven to increase the performance of the air filter by allowing a higher surface area to trap more particles and introducing the presence of slip flow at the same time. Synthesis of dual-sized fibrous material using the method of combined melt-solution electrospinning is reported here for the first time. The formation of well-mixed nano- and submicron-size Polyamide (PA 12 and PA 6/6) composites was accomplished simultaniously utilizing melt and sollution electrospinning via custom made electrospinning apparatus. By manipulating the process conditions and the ratios between melt and solution electrospinning, different structures of polimeric mats were achieved. Air filtration parameters were tested and with the particle size of 300 nm filtration efficiency reached up to 89.9 % and pressure drop was 55 Pa. In comparison, uniform nano-fibrous mat formed using only solution electrospinning had higher filtration efficiency of 99.5 % but presure drop was almost 3 times higher at 161 Pa.