School of Chemical, Petroleum and Gas Engineering, Iran University of Science and Technology, Tehran, Iran.
Sci Rep. 2023 May 18;13(1):8076. doi: 10.1038/s41598-023-35027-5.
This work presents a modified polyvinylidene fluoride (PVDF) ultrafiltration membrane blended with graphene oxide-polyvinyl alcohol-sodium alginate (GO-PVA-NaAlg) hydrogel (HG) and polyvinylpyrrolidone (PVP) prepared by the immersion precipitation induced phase inversion approach. Characteristics of the membranes with different HG and PVP concentrations were analyzed by field emission scanning electron microscopy (FESEM), Atomic force microscopy (AFM), contact angle measurement (CA), and Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The FESEM images showed an asymmetric structure of the fabricated membranes, and possessing a thin dense layer over the top and a layer finger-like. With increasing HG content, membrane surface roughness increases so that highest surface roughness for the membrane containing 1wt% HG is with a Ra value of 281.4 nm. Also, the contact angle of the membrane reaches from 82.5° in bare PVDF membrane to 65.1° in the membrane containing 1wt% HG. The influences of adding HG and PVP to the casting solution on pure water flux (PWF), hydrophilicity, anti-fouling ability, and dye rejection efficiency were evaluated. The highest water flux reached 103.2 L/m h at 3 bar for the modified PVDF membranes containing 0.3 wt% HG and 1.0wt% PVP. This membrane exhibited a rejection efficiency of higher than 92%, 95%, and 98% for Methyl Orange (MO), Conge Red (CR), and Bovine Serum Albumin (BSA), respectively. All nanocomposite membranes possessed a flux recovery ratio (FRR) higher than bare PVDF membranes, and the best anti-fouling performance of 90.1% was relevant to the membrane containing 0.3 wt% HG. The improved filtration performance of the HG-modified membranes was due to the enhanced hydrophilicity, porosity, mean pore size, and surface roughness after introducing HG.
本工作采用浸没沉淀相转化法制备了一种改性聚偏二氟乙烯（PVDF）超滤膜，该膜共混了氧化石墨烯-聚乙烯醇-海藻酸钠（GO-PVA-NaAlg）水凝胶（HG）和聚乙烯吡咯烷酮（PVP）。通过场发射扫描电子显微镜（FESEM）、原子力显微镜（AFM）、接触角测量（CA）和衰减全反射傅里叶变换红外光谱（ATR-FTIR）分析了不同 HG 和 PVP 浓度的膜的特性。FESEM 图像显示了所制备的膜的不对称结构，在顶部具有一层薄而致密的层，而在底部具有一层指状层。随着 HG 含量的增加，膜表面粗糙度增加，因此含有 1wt%HG 的膜的表面粗糙度最高，Ra 值为 281.4nm。此外，膜的接触角从裸 PVDF 膜的 82.5°降至含 1wt%HG 的膜的 65.1°。评估了向铸膜液中添加 HG 和 PVP 对纯水通量（PWF）、亲水性、抗污染能力和染料截留效率的影响。对于含有 0.3wt%HG 和 1.0wt%PVP 的改性 PVDF 膜，水通量最高可达 103.2L/m h，压力为 3bar。该膜对甲基橙（MO）、刚果红（CR）和牛血清白蛋白（BSA）的截留效率均高于 92%、95%和 98%。所有纳米复合膜的通量恢复率（FRR）均高于裸 PVDF 膜，最佳抗污染性能为 90.1%，与含有 0.3wt%HG 的膜有关。HG 改性膜的过滤性能得到改善是由于引入 HG 后，膜的亲水性、孔隙率、平均孔径和表面粗糙度得到提高。
