Preparation of multilayer films using the layer-by-layer (LbL) technique via hydrogen bonding has recently gained increasing research interest and has potential in diverse areas of research, especially in the biomedical field. However, the scope of these hydrogen-bonded multilayer films in separation science is quasi-unexplored. In this work, ultrathin multilayer membranes were prepared by the LbL deposition of tannic acid (TA) and poly(2-alkyl-2-oxazoline)s via hydrogen-bonding (HB) and hydrophobic interactions. The potential of these membranes in aqueous filtrations was demonstrated as they show high retention (>95%) for both positively (malachite green oxalate) (MGO) and negatively charged (Rose Bengal) (RB) dyes and even 95% retention for the much smaller and neutral micropollutant bisphenol A (BPA) (228 g/mol). Nanofiltration (NF) performances of three variants of poly(2-alkyl-2-oxazoline), namely, poly(2-methyl-2-oxazoline) (PMEOx), poly(2-ethyl-2-oxazoline) (PEtOx), and poly(2-n-propyl-2-oxazoline) (PPropOx), were compared revealing an increase in retention and decrease in permeance with increasing hydrophobicity of the poly(2-alkyl-2-oxazoline)s. Even though the reported HB multilayer membranes appear to be promising candidates for aqueous filtrations, their permeance is currently still about an order of magnitude too low for real-life applications due to the formation of rather dense hydrogen-bonded layers.

中文翻译：

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用于水分离的分层组装的氢键合多层聚（2-恶唑啉）膜

使用经由氢键的逐层（LbL）技术制备多层膜近来已引起越来越多的研究兴趣，并且在各种研究领域中具有潜力，特别是在生物医学领域。然而，在分离科学中这些氢键合多层膜的范围尚待探索。在这项工作中，通过氢键合（HB）和疏水作用通过单宁酸（TA）和聚（2-烷基-2-恶唑啉）的LbL沉积制备了超薄多层膜。这些膜在水过滤中的潜力得到了证明，因为它们对正（孔雀石绿草酸盐）（MGO）和负电荷（玫瑰红）（RB）染料均显示出较高的保留率（> 95％），甚至对大多数染料而言仍显示95％的保留率。较小和中性的微污染物双酚A（BPA）（228克/摩尔）。比较了正丙基-2-恶唑啉（PPropOx），发现随着聚（2-烷基-2-恶唑啉）s疏水性的增加，保留率增加，磁导率降低。尽管已报道的HB多层膜似乎有望用于水过滤，但由于形成了相当致密的氢键合层，因此对于现实生活中的应用，其渗透率目前仍约低一个数量级。