Synthesis and solution rheology of adenine-containing polyelectrolytes for electrospinning

Conventional free radical copolymerization of 9-vinylbenzyladenine (VBA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) with subsequent protonation afforded the synthesis of adenine-containing polyelectrolytes. All adenine-containing polyelectrolytes exhibited classical polyelectrolyte solution rheological behavior with scaling factors near 0.6 and 1.6 in the semidilute unentangled and semidilute entangled regimes, respectively. However, the adenine-containing polyelectrolytes deviated from polyelectrolyte behavior in the concentrated regime with increasing scaling factors as adenine-incorporation increased due to intermolecular association. The electrospinning behavior exhibited a strong dependence on adenine incorporation. Higher adenine-incorporation decreased the normalized concentration for fiber formation from 4.5Ce for PDMAEMA•HCl to 2.9Ce for 35 mol% VBA. The required zero-shear viscosities for electrospinning were 312 cP for PDMAEMA•HCl and 116 cP for the 35 mol% VBA copolymer. Increasing the adenine concentration also increased the fiber diameters presumably due to adenine–adenine interactions. These adenine-decorated electrospun mats exhibit potential in a variety of applications including filtration, purification, and tissue scaffolding.