Variable Responsive Wettability Films via Electrospinning Induced by Solvents
Figure 4
The diagram of mechanism of the various wetting properties of the as-prepared electrospun films. (a), (b), and (c) represent films IV, V, and VI in which the solvent of precursor solution is DMF, CH2Cl2, and THF, respectively. PS mainly formed the fabric structures of the composited films, while the spheres which represent PNIPAAm are distributed differently in composite films IV, V, and VI. The chain diagram represents the idealized conformation between the PNIPAAm chain and solvent molecules in precursor solutions. The polar solvent DMF is likely to form intermolecular hydrogen bonding with PNIPAAm chain. Inversely, the PNIPAAm chain forms easily intramolecular hydrogen bonding when the nonpolar solvent CH2Cl2 is used. There is not evident hydrogen bonding interaction in the PNIPAAm/PS/THF precursor solution.
