Biodegradable poly(butylene succinate) nanofibrous membrane treated with oxygen plasma for superhydrophilicity

Abstract

The wettability of materials depends strongly on their surfaces, and endowing them with expected wetting properties promotes their applications in various fields. In this work, the biodegradable and superhydrophilic poly(butylene succinate) (PBS) nanofibrous membranes were fabricated using a combination of electrospinning and oxygen plasma treatment for the first time. The surface morphologies, chemical composition and wettability of the PBS membrane were investigated. It was found that the plasma etched the fiber surface and the etching depth increased with the plasma treatment time. The membrane became superhydrophilic from hydrophobic upon treated with oxygen plasma and the water droplet could completely spread out within 0.5 s, which was mainly attributed to the introduction of oxygen-containing groups by plasma treatment rather than the enlarged surface roughness. Meanwhile, the speed of water spread out on the modified membrane was closely and reversely related to the density of membrane. The wettability differences between nanofibrous membrane and dense films were also pointed out, and the structure had great influence in the performance. Furthermore, the wetting stability of treated membrane was explored by monitoring the evolution of contact angle. The contact angel gradually increased with days due to the decreasing functional groups, and the ageing rate was dependent on the plasma exposure time. Eventhough the wettability of membranes changed fast in the first 10 days, surfaces were still remained moderately hydrophilic (contact angle ~50°) after a month. The investigation concentrated on the wettability of PBS nanofibrous membrane treated with oxygen plasma is beneficial to the creation of materials with desirable properties for various applications.