Blend-electrospun poly(vinylidene fluoride)/polydopamine membranes: self-polymerization of dopamine and the excellent adsorption/separation abilities
Blend-electrospun poly(vinylidene fluoride)/polydopamine membranes: self-polymerization of dopamine and the excellent adsorption/separation abilities
复制标题
DOI：
10.1039/c7ta02845h
复制
发表时间：
2017-07
影响因子：
--
通讯作者：
Fang-fang Ma;N. Zhang;Xiao Wei;Jing‐hui Yang;Yong Wang;Zuowan Zhou
中科院分区：
文献类型：
--
作者：
Fang-fang Ma;N. Zhang;Xiao Wei;Jing‐hui Yang;Yong Wang;Zuowan Zhou
本工作首先将一定量的多巴胺溶解到聚偏二氟乙烯（PVDF）溶液中，然后通过静电纺丝技术制备了纤维膜。然后，聚多巴胺（PDA）在 Tris-HCl 缓冲溶液中发生自聚合。系统研究了PDA在纤维表面的自聚合以及PVDF/PDA膜的微观结构。结果表明，膜的形态取决于缓冲溶液中多巴胺的聚合时间。 PDA均匀涂覆在纤维表面，大大增强了膜的亲水性。使用亚甲蓝（MB）和Cu2+作为探针吸附剂评估PVDF/PDA膜对有机染料和重金属离子的吸附能力。结果表明，PVDF/PDA纤维膜表现出优异的吸附能力，对MB和Cu2+的实验饱和吸附容量分别为172.3和26.7 mg g−1。进一步根据吸附动力学、吸附等温线和热力学参数分析表明，MB的吸附遵循伪二阶模型和Langmuir吸附模型，吸附为自发过程。进一步的结果表明PVDF/PDA膜吸附MB后表现出良好的再生能力。还测量了PVDF/PDA膜的油/水分离能力。 PDA涂层的存在极大地提高了膜的分离效率，根据本工作中采用的测量方法，最大水通量增加至729.3 L m−2 h−1。优异的吸附和分离能力使静电纺PVDF/PDA纤维膜在废水处理中具有巨大的潜在应用前景。
In this work, a certain amount of dopamine was firstly dissolved into the solution of poly(vinylidene fluoride) (PVDF) and then the fibrillar membranes were prepared through an electrospinning technology. Then, the self-polymerization of polydopamine (PDA) was triggered in a Tris–HCl buffer solution. The self-polymerization of PDA on the fiber surface and the microstructure of the PVDF/PDA membranes were systematically researched. The results demonstrated that the morphologies of the membranes were dependent upon the polymerization time of dopamine in the buffer solution. PDA homogeneously coated on the fiber surface, which greatly enhanced the hydrophilicity of the membranes. The adsorption abilities toward organic dyes and heavy metal ions of the PVDF/PDA membranes were evaluated using methylene blue (MB) and Cu2+ as the probe adsorbates. The results showed that the PVDF/PDA fibrillar membranes exhibited excellent adsorption ability and the experimental saturation adsorption capacities were 172.3 and 26.7 mg g−1 for MB and Cu2+, respectively. Further analysis based on adsorption kinetics, adsorption isotherms and thermodynamic parameters showed that the adsorption of MB follows the pseudo second-order model and the Langmuir adsorption model and the adsorption was a spontaneous process. Further results demonstrated that the PVDF/PDA membrane exhibited good regeneration ability after adsorbing MB. The oil/water separation ability of the PVDF/PDA membranes was also measured. The presence of the PDA coating layer greatly enhanced the separation efficiency of the membranes, and the maximum water flux was increased up to 729.3 L m−2 h−1 according to the measuring method applied in this work. The excellent adsorption and separation abilities endow the electrospun PVDF/PDA fibrillar membranes with great potential applications in wastewater treatment.