Self-assembled poly(2-ethyl-2-oxazoline)/malonic acid hollow fibers in aqueous solutions

摘要: Abstract Well-defined poly(2-ethyl-2-oxazoline) (PEOX)/Malonic Acid (MA) fibers having hollow tubular morphology were shown to form in aqueous solutions at 25 °C by complexation induced self-assembly between PEOX and MA. The had diameter of ~1–3 μm a wall thickness ~40 nm. Different interactions MA identified for as function pH. At pH2, when both ends protonated, H-bonded was the driving interaction fiber formation. IR data showed -C O band -COOH dried formed pH2. downshift C stretching much 15 cm−1 confirmed complexation. enthalpy determined isothermal titration calorimetry (ITC) −49.39 kJ/mol which is consistent with H-bonding. Thermogravimetric analysis (TGA) two distinct decomposition temperatures one 100 150 °C corresponding other 350–450 °C also indicated presence components fibers. pH4, end protonated ionized, electrostatic carboxylate (–COO−) group amide pH7, formation significantly hindered. results are important understanding role different mechanism pH-responsive have great potential be used biomedical applications drug delivery release purposes.