Wang Yi, Fang Zhendong, Zhao Shuaifei, Ng Derrick, Zhang Juan, Xie Zongli
Water Industry and Environment Engineering Technology Research Centre 401311 Chongqing China.
CSIRO Manufacturing Clayton VIC 3168 Australia
RSC Adv. 2018 Jun 20;8(40):22469-22481. doi: 10.1039/c8ra03166e. eCollection 2018 Jun 19.
A new type of polyamide thin-film composite forward osmosis (FO) membranes were prepared by controlling dopamine self-polymerization in the aqueous phase during interfacial polymerization. The as-prepared membranes were investigated by attenuated total reflection Fourier transform infrared, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, atomic force microscopy and water contact angle measurements. The influence of the dopamine self-polymerization degree with different polydopamine particle sizes on membrane morphologies and chemical properties was studied by regulating dopamine concentrations in the aqueous phase. FO performance of the membrane was evaluated under two different modes, active layer facing draw solution (AL-DS) and active layer facing feed solution (AL-FS). The optimized FO membranes achieved a doubly enhanced water flux (22.08 L m h) compared with the control membrane without dopamine incorporation, and a half-reduced reverse salt flux (32.77 mmol m h) with deionized water as the feed and 1 M NaCl as the draw in the AL-FS mode. The optimized FO membrane showed a significantly reduced structural parameter (176 μm) compared with the control membrane (635 μm), indicating the minimised internal concentration polarization. Moreover, the new FO membranes had less flux decline than the control membrane, suggesting the improved antifouling performance of the membrane. Incorporation of dopamine during interfacial polymerization can be an effective strategy to fabricate high-performance FO membranes with excellent antifouling properties.
通过在界面聚合过程中控制水相中多巴胺的自聚合，制备了一种新型聚酰胺薄膜复合正向渗透（FO）膜。采用衰减全反射傅里叶变换红外光谱、X射线光电子能谱、场发射扫描电子显微镜、原子力显微镜和水接触角测量等方法对所制备的膜进行了研究。通过调节水相中多巴胺的浓度，研究了不同聚多巴胺粒径下多巴胺自聚合程度对膜形态和化学性质的影响。在活性层面对汲取液（AL-DS）和活性层面对进料液（AL-FS）两种不同模式下评估了膜的正向渗透性能。与未掺入多巴胺的对照膜相比，优化后的正向渗透膜实现了水通量的双重增强（22.08 L m⁻² h⁻¹），并且在AL-FS模式下，以去离子水为进料液、1 M NaCl为汲取液时，反向盐通量降低了一半（32.77 mmol m⁻² h⁻¹）。与对照膜（635 μm）相比，优化后的正向渗透膜的结构参数显著降低（176 μm），表明内部浓差极化最小化。此外，新型正向渗透膜的通量下降比对照膜少，这表明膜的抗污染性能得到了改善。在界面聚合过程中掺入多巴胺可以成为制备具有优异抗污染性能的高性能正向渗透膜的有效策略。
