Silica nanoparticles as carriers of antifouling ligands for PVDF ultrafiltration membranes
Silica nanoparticles as carriers of antifouling ligands for PVDF ultrafiltration membranes
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DOI：
10.1016/j.memsci.2013.01.029
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发表时间：
2013-04
影响因子：
9.5
通讯作者：
Hao Wu;J. Mansouri;V. Chen
中科院分区：
文献类型：
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作者：
Hao Wu;J. Mansouri;V. Chen
PVDF膜的高度疏水性使其容易结垢，经常使用亲水添加剂来改善其润湿性和结垢性能。另一种减轻污染的方法是通过表面改性来改变膜。在最佳的制膜条件下，由于两亲性添加剂自发迁移到膜上表面，导致所谓的表面偏析，可以实现原位膜表面改性。非极性低表面能聚合物，如聚硅氧烷，可以使表面具有永久的污垢释放能力。然而，由于溶液热力学的不利，它们在相分离过程中不能自发地分离到聚合物-水界面上。虽然一些亲水性聚合物，如聚乙二醇（PEG）可以改善表面亲水性，抑制污染物在表面的吸附和沉积，但它们与膜基质的相容性低，在过滤过程中会导致耗损，这是一个缺点。在这项研究中，采用了一种新的方法，使用纳米颗粒作为防污配体的载体和锚点。通过硅烷偶联剂对商业sio2纳米颗粒进行化学功能化，然后进一步将PEG分子固定在其表面。将改性纳米颗粒直接分散在铸造液中，制备了改性SiO2/PVDF共混膜。结果表明，表面修饰的二氧化硅纳米颗粒作为载体，促进了固定在二氧化硅上的PDMS或PEG分子迁移到膜表面，有助于表面修饰，从而提高膜的抗污性能。
The highly hydrophobic nature of PVDF membranes makes it prone to fouling, and hydrophilic additives are frequently used to improve its wettability and fouling performance. Another approach to mitigate fouling is to alter membrane via surface modification. Under optimum conditions of membrane fabrication, in-situ membrane surface modification may be achieved as a result of the spontaneous migration of amphiphilic additives to the membrane upper surface resulting in so-called surface segregation. Non-polar low surface energy polymers, such as polysiloxane, could render the surface with permanent fouling release ability. However, they cannot spontaneously segregate onto the polymer–water interface during phase separation due to the unfavorable solution thermodynamics. While some hydrophilic polymers such as polyethylene glycol (PEG) may improve the surface hydrophilicity and inhibit the adsorption and deposition of foulant onto surface, their low compatibility with the membrane matrix and consequent depletion during filtration process can be a drawback. In this study, a novel approach was taken to use nanoparticles as carriers and anchors for antifouling ligands. Commercial SiO2nanoparticles were chemically functionalized by silane coupling agents, which were then further used to immobilize PEG molecules on their surface. Modified nanoparticles were directly dispersed in casting solution and modified SiO2/PVDF blend membranes were prepared. The results demonstrated that the surface modified SiO2nanoparticles acted as a carrier that facilitated the migration of PDMS or PEG molecules immobilized on SiO2to the surface of the membrane, contributing to the modification of surface and hence improvement of the membrane fouling resistance property.