Institute of Materials Science and Technology, Analysis and testing center, Sichuan University, Chengdu 610064, P. R. China.
Nanoscale. 2019 Apr 11;11(15):7166-7175. doi: 10.1039/c9nr00621d.
The stability of superhydrophobicity is crucial for the long-term application of an oil/water separation membrane in harsh environments such as high temperatures and various aggressive solvents. However, achieving such a stable superhydrophobic membrane remains a challenge. In this study, high performance fibrous oil/water separation membranes with a highly stable superhydrophobicity were fabricated by designing a functional polymer containing hydroxyl units. The reaction of hydroxy groups in poly(arylene ether sulfone) with octadecyltrichlorosilane (OTS) produces stable covalent interactions, which greatly enhance the stability of OTS on the PAES-OH (polyarylene ether sulfone containing hydroxy units) fibrous membrane fabricated by electrospinning, thus improving the stability of superhydrophobicity of the membrane. The stability of the OTS layer was characterized by FT-IR, SEM and water contact angle measurement. The results suggest that OTS is highly stable on a PAES-OH membrane, while OTS on a polyethersulfone (PES) fibrous membrane is detached from the fiber during ultrasonic cleaning. The obtained membrane is superhydrophobic, with a water contact angle (CA) as high as 159.2° and a threshold sliding angle (TSA) as low as 7.8° even after ultrasonic cleaning for 3 h. In addition, the oil/water separation experiments indicate that this membrane has an excellent performance in the separation of oil from oil/water mixtures, and oil/water emulsions: the gravity driven flux is 7260-8720 L (m2 h)-1 and the water rejection is over 99%. This study provides a new approach for fabricating oil/water separation membranes with highly stable superhydrophobic properties from the perspective of designing new polymers.
超疏水性的稳定性对于在高温和各种腐蚀性溶剂等恶劣环境下长期应用油水分离膜至关重要。然而，实现这种稳定的超疏水性膜仍然是一个挑战。在这项研究中，通过设计含有羟基单元的功能性聚合物，制备了具有高稳定性超疏水性的高性能纤维状油水分离膜。聚(芳醚砜)中的羟基与十八烷基三氯硅烷（OTS）反应生成稳定的共价键相互作用，这极大地增强了 OTS 在由静电纺丝制备的含有羟基单元的聚芳醚砜（PAES-OH）纤维膜上的稳定性，从而提高了膜的超疏水性稳定性。通过傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）和水接触角测量对 OTS 层的稳定性进行了表征。结果表明，OTS 在 PAES-OH 膜上高度稳定，而在聚醚砜（PES）纤维膜上的 OTS 在超声清洗过程中从纤维上脱落。所得到的膜具有超疏水性，水接触角（CA）高达 159.2°，即使在超声清洗 3 小时后，阈值滑动角（TSA）也低至 7.8°。此外，油水分离实验表明，该膜在油水混合物和油包水乳状液的分离中具有优异的性能：重力驱动通量为 7260-8720 L/（m2·h），水截留率超过 99%。本研究从设计新型聚合物的角度为制备具有高稳定性超疏水性的油水分离膜提供了一种新方法。
