Plasma-assisted electrospinning: the many facets of a process

In this work, various overlaps between plasma technology and electrospinning process and products are presented. Plasma pre-treatment of polymeric solutions as well as post-treatment of electrospun scaffolds are investigated. Two different polymers are used: Poly-L-lactic acid (PLLA) and Poly(ethylene oxide) (PEO). PLLA electrospun mats are conventionally used for tissue engineering, while PEO mats as nanofibrous separators in lithium-ion batteries. Plasma pre-treatment is used to improve electrospinnability of PLLA in a 100% dichloromethane (DCM) solution avoiding the use of dimethylformamide (DMF)DMF solvent, which may eventually be found in traces in the products but which is conventionally added to increase solution conductivity. SEM images shows that 2 min of plasma treatment of 12 ml of polymeric solution allows the production of good quality nanofibers without defects, while untreated solution cannot be electrospun. Plasma post-treatment is focused on the improvement of electrospun PLLA scaffolds biocompatibility. Finally, results of plasma assisted nanoparticles dispersion in PEO solution is presented: a 3 min plasma treatment of PEO solution followed by 10 min of stirring allows the production of fibers containing well dispersed fumed silica nanoparticles, in contrast with non plasma treated solutions which resulted in fibers containing agglomerates.