Oleksandra Zavgorodnya

“Practical” Electrospinning of Biopolymers in Ionic Liquids

To address the need to scale up technologies for electrospinning of biopolymers from ionic liquids to practical volumes, a setup for the multi-needle electrospinning of chitin using the ionic liquid 1-ethyl-3-methylimidazolium acetate, [C2 mim]-[OAc], was designed, built, and demonstrated. Materials with controllable and high surface area were prepared at the nanoscale using ionic-liquid solutions of high-molecular-weight chitin extracted with the same ionic liquid directly from shrimp shells.

Polyethylene glycol derivatization of the non-active ion in active pharmaceutical ingredient ionic liquids enhances transdermal delivery

We report the synthesis of four salts composed of the salicylate anion ([Sal]−) paired with tributylammonium ([HN444]+), choline ([Cho]+), 1-methylpyrrolidinium ([HMPyrr]+), and triethylene glycol monomethyl ether tributylammonium ([mPEG3N444]+) cations. Three of the synthesized salts (room temperature liquids [mPEG3N444][Sal] and [Cho][Sal], and a supercooled liquid [HN444][Sal]) belong to the category of ionic liquids (ILs), and one salt (solid [HMPyrr][Sal]) was a crystalline solid. ILs in their neat form were studied for membrane transport through a silicon membrane, and exhibited higher transport compared to a control experiment with sodium salicylate dissolved in mPEG3OH as solvent, but lower membrane transport compared to salicylic acid dissolved in mPEG3OH. The ‘PEGylated’ IL, [mPEG3N444][Sal], crossed the membrane with an ca. ∼2.5-fold faster rate than that of any of the non-PEGylated ILs. This work demonstrates not only that API–ILs can eliminate the use of a solvent vehicle during application and notably transport through a membrane as opposed to a higher melting crystalline salt, but also that the membrane transport can be further enhanced by PEGylation of the counter ions.

Electrospinning Biopolymers from Ionic Liquids Requires Control of Different Solution Properties than Volatile Organic Solvents

We report the correlation between key solution properties and spinability of chitin from the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) and the similarities and differences to electrospinning solutions of nonionic polymers in volatile organic compounds (VOCs). We found that when electrospinning is conducted from ILs, conductivity and surface tension are not the key parameters regulating spinability, while solution viscosity and polymer concentration are. Contrarily, for electrospinning of polymers from VOCs, solution conductivity and viscosity have been reported to be among some of the most important factors controlling fiber formation. For chitin electrospun from [C2mim][OAc], we found both a critical chitin concentration required for continuous fiber formation (>0.20 wt %) and a required viscosity for the spinning solution (between ca. 450–1500 cP). The high viscosities of the biopolymer–IL solutions made it possible to electrospin solutions with low, less than 1 wt %, polymer ...