Nanofiltration Membranes with Modified Active Layer Using Aromatic Polyamide Dendrimers
Nanofiltration Membranes with Modified Active Layer Using Aromatic Polyamide Dendrimers
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DOI：
10.1002/adfm.201201004
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发表时间：
2013-02-05
影响因子：
19
通讯作者：
Moore, Jeffrey S.
中科院分区：
文献类型：
--
作者：
Gao, Yuan;de Jubera, Ana M. Saenz;Moore, Jeffrey S.
据报道，用形状持久的树枝状分子对商业纳滤（NF）膜（TFC-S）进行了修饰。两亲性芳香族聚酰胺树枝状聚合物 (G1G3) 通过不同的方法合成，并通过直接渗滤用于膜活性层改性。通过紫外-可见光谱分析从渗滤实验中收集的渗透样品，以监测树枝状聚合物的生成对渗滤行为和活性层改性的影响。通过卢瑟福背散射光谱法和原子力显微镜技术对改性膜进行进一步表征，发现原始 TFC-S NF 膜活性层内树枝状聚合物的积累水平相对较低，随后在活性层顶部形成纯芳族聚酰胺树枝状聚合物涂层。 PES-PVA 超滤膜用作对照膜支撑物（无 NF 活性层），表明树枝状聚合物和支撑物之间的结构相容性在膜改性过程中起着重要作用。改性 TFC-S 膜的性能根据对具有一定分子大小和化学性质的各种水污染物的截留能力进行评估。由于水通量与活性层的厚度成反比，因此针对特定污染物沉积的树枝状聚合物的量进行了优化，以提高溶质截留率，同时保持高水通量。
The modification of a commercial nanofiltration (NF) membrane (TFC-S) with shape-persistent dendritic molecules is reported. Amphiphilic aromatic polyamide dendrimers (G1G3) are synthesized via a divergent approach and used for membrane active layer modification by direct percolation. The permeate samples collected from the percolation experiments are analyzed by UV-visible spectroscopy to monitor the influence of dendrimer generations on percolation behavior and active layer modification. Further characterization of modified membranes by Rutherford backscattering spectrometry and atomic force microscopy techniques reveals a relatively low-level accumulation of dendrimers inside the original TFC-S NF membrane active layer and subsequent formation of a coating of pure aramide dendrimers on top of the active layer. A PES-PVA ultrafiltration membrane is used as a control membrane support (without an NF active layer) showing that structural compatibility between the dendrimers and support plays an important role in the membrane modification process. The performance of the modified TFC-S membrane is evaluated on the basis of the rejection abilities for a variety of water contaminants having a range of molecular size and chemistry. As the water flux is inversely proportional to the thickness of the active layer, the amount of dendrimers deposited for specific contaminants are optimized to improve the solute rejection while maintaining high water flux.