Khan Bushra, Haider Sajjad, Khurram Rooha, Wang Zhan, Wang Xi
College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
School of Humanities and Social Sciences Macao, Polytechnic Institute, Macao 999078, China.
Membranes (Basel). 2020 Jul 10;10(7):150. doi: 10.3390/membranes10070150.
The UF membrane with a narrow and uniform pore size distribution and a low tendency to foul has significant applications in wastewater treatment. A major hindrance in the preparation of the UF membrane with these features is the lack of a scalable and economical membrane fabrication method. Herein, we devise a new strategy to prepare a high-quality polyvinylidene fluoride/polymethyl acrylate/cellulose acetate (PVDF/PMMA/CA) blend UF membrane via a combination of the etching mechanism with the traditional Loeb-Sourirajan (L-S) phase inversion method. Different concentrations of silicon dioxide (SiO) nanoparticles (NP) in the membrane matrix were etched by using a 0.2 M hydrofluoric acid (HF) solution in a coagulation bath. This strategy provided the membrane with unique features along with a narrow and uniform pore size distribution (0.030 ± 0.005 μm). The etched membrane exhibits an increase of 2.3 times in pure water flux (PWF) and of 6.5 times in permeate flux(PF), with a slight decrease in rejection ratio (93.2% vs. 97%) when compared to than that of the un-etched membrane. Moreover, this membrane displayed outstanding antifouling ability, i.e., a flux recovery ratio (FRR) of 97% for 1000 mg/L bovine serum albumin (BSA) solution, a low irreversible fouling ratio of 0.5%, and highly enhanced hydrophilicity due to the formation of pores/voids throughout the membrane structure. The aforementioned features of the etched membrane indicate that the proposed method of etching SiO NP in membrane matrix has a great potential to improve the structure and separation efficiency of a PVDF/PMMA/CA blend membrane.
具有狭窄且均匀孔径分布以及低污染倾向的超滤膜在废水处理中具有重要应用。制备具有这些特性的超滤膜的一个主要障碍是缺乏可扩展且经济的膜制造方法。在此，我们设计了一种新策略，通过蚀刻机制与传统的洛布 - 苏里亚南（L - S）相转化法相结合来制备高质量的聚偏氟乙烯/聚甲基丙烯酸甲酯/醋酸纤维素（PVDF/PMMA/CA）共混超滤膜。在凝固浴中使用0.2M氢氟酸（HF）溶液蚀刻膜基质中不同浓度的二氧化硅（SiO₂）纳米颗粒（NP）。该策略赋予了膜独特的特性以及狭窄且均匀的孔径分布（0.030±0.005μm）。与未蚀刻的膜相比，蚀刻后的膜纯水通量（PWF）增加了2.3倍，渗透通量（PF）增加了6.5倍，截留率略有下降（93.2%对97%）。此外，该膜表现出出色的抗污染能力，即对于1000mg/L牛血清白蛋白（BSA）溶液的通量恢复率（FRR）为97%，不可逆污染率低至0.5%，并且由于在整个膜结构中形成了孔隙/空隙，亲水性大大增强。蚀刻膜的上述特性表明，在膜基质中蚀刻SiO₂ NP的 proposed方法在改善PVDF/PMMA/CA共混膜的结构和分离效率方面具有巨大潜力。
