Layer‐by‐layer approach to enable polyamide formation on microporous supports for thin‐film composite membranes
Layer‐by‐layer approach to enable polyamide formation on microporous supports for thin‐film composite membranes
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逐层方法可在薄膜复合膜的微孔支撑物上形成聚酰胺
DOI：
10.1002/app.51201
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发表时间：
2021
影响因子：
3
通讯作者：
Geise, Geoffrey M.
中科院分区：
文献类型：
--
作者：
Agata, Wendy‐Angela Saringi;Thompson, Joseph;Geise, Geoffrey M.
聚酰胺薄膜复合膜(PA-TFC)实现了大规模海水淡化。界面聚合(IP)用于制备PA-TFC膜，但它可能会限制单体的使用范围，这阻碍了向先进膜的发展。逐层(LBL)连续沉积可以克服传统IP过程的动力学和热力学限制，以促进不同的共聚单体进入膜。选择层需要沉积在微孔载体上，但在微孔载体上沉积LBL涂层往往会导致膜缺陷。在载体和LBL聚酰胺层之间使用聚乙烯醇(PVA)底漆可以防止缺陷的形成。讨论了由PVA引发的、基于LBL的三层PA-TFC膜的透水性和盐截留率，并与没有PVA引发剂的膜和商用膜进行了比较。传质阻力是使用串联阻力模型分析的，与聚酰胺层相比，传质阻力似乎很小，甚至可以忽略不计。报道了通过LBL将磺化共单体引入到聚酰胺中。PVA底漆层和LBL连续沉积的组合可以扩大相对于传统IP工艺制备的聚酰胺膜可使用的共聚单体的范围。
Polyamide thin‐film composite (PA‐TFC) membranes make large‐scale desalination effective. Interfacial polymerization (IP) is used to make PA‐TFC membranes, but it may limit the range of monomers that can be used, which hinders progress toward advanced membranes. Layer‐by‐layer (LbL) sequential deposition could circumvent kinetic and thermodynamic limitations of the conventional IP process to facilitate incorporation of different co‐monomers into the membrane. The selective layer needs to be deposited onto a microporous support, but depositing LbL coatings on microporous supports often results in defective membranes. Using a poly(vinyl alcohol) (PVA) primer between the support and the LbL polyamide layer may prevent defect formation. The water permeance and salt rejection of a three layer, PVA‐primed, LbL‐based PA‐TFC membrane are discussed and compared to a membrane made without the PVA primer and a commercially available membrane. Mass transfer resistances are analyzed using a series resistance model and appear to be small or even negligible compared to that of the polyamide layer. Incorporation of a sulfonated co‐monomer into the polyamide via LbL is reported. The combination of a PVA primer layer and LbL sequential deposition may expand the range of co‐monomers that could be used relative to polyamide membranes prepared by the conventional IP process.