Changes in permselectivity of radiation-grafted anion-exchange membranes with different cationic headgroup chemistries are primarily due to water content differences
Changes in permselectivity of radiation-grafted anion-exchange membranes with different cationic headgroup chemistries are primarily due to water content differences
复制标题
具有不同阳离子头基化学性质的辐射接枝阴离子交换膜的选择性渗透性的变化主要是由于水含量的差异
DOI：
10.1039/d3ma00082f
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发表时间：
2023
影响因子：
5
通讯作者：
Chakraborty A
中科院分区：
文献类型：
--
作者：
Chakraborty A
在先前的论文[Bance-Soualhi等人，杰·板牙。A，2021，9，22025]，我们表明辐射接枝的阴离子交换膜（RG-AEM）的交联对于获得足够高的表观选择性渗透率以用于诸如（反向）电渗析的应用是必要的。然而，先前研究中的一个单独结果表明，具有不同阳离子头基的可比AEM（类似的离子交换容量、IEC和骨架化学）可能会在选择渗透性和电导率之间产生不同的平衡。这项简短的后续研究比较了一系列非交联RG-AEM的渗透选择性和Cl−电导率，这些RG-AEM具有脂肪族季铵头基（N-苄基-N-甲基哌啶鎓，MPIP和苄基三甲基铵，TMA）或芳香族阳离子头基（N-苄基吡啶鎓，PYR或1-苄基-2，3-二甲基咪唑鎓，NH 4）。我们表明，在头基化学的变化修改的RG-AEM的选择渗透性-电导率平衡，但这主要是由于不同的头基诱导不同的固有水含量：较高的水含量RG-AEM产量较低的选择渗透性。如从该水含量观察所预期的，较高的IEC变体产生具有较低的选择性渗透率的RG-AEM。将N，N，N′，N′-四甲基己烷-1，6-二胺-（TMHDA）基离子交联添加到基于DMI的RG-AEM中也提高了选择渗透性，证实了先前研究的观察结果也适用于芳香族头基RG-AEM。总之，含有咪唑鎓型头基沿着且具有最佳量的离子交联的高IEC AEM可能是有希望的，并且值得更多的研究（即，将RG-AEM与含有这些属性的更便宜、更可扩展的非RG类似物进行比较）。
In a prior paper [Bance-Soualhi et al., J. Mater. Chem. A, 2021, 9, 22025], we showed that the crosslinking of radiation-grafted anion-exchange membranes (RG-AEM) was necessary to obtain high enough apparent permselectivities for use in applications such as (reverse)electrodialysis. However, a separate result in this prior study suggested that comparable AEMs (similar ion-exchange capacity, IEC, and backbone chemistry) with different cationic headgroups may yield different balances between permselectivity and conductivity. This short follow-up study compares the permselectivities and Cl− conductivities of a series of non-crosslinked RG-AEMs with either aliphatic quaternary ammonium headgroups (N-benzyl-N-methylpiperidinium, MPIP, and benzyltrimethylammonium, TMA) or aromatic cationic headgroups (N-benzylpyridinium, PYR, or 1-benzyl-2,3-dimethylimidazolium, DMI). We show that a change in the headgroup chemistry modified the permselectivity-conductivity balance of the RG-AEM, but this was primarily due to the different headgroups inducing varying intrinsic water contents: higher water content RG-AEMs yield lower permselectivites. As also expected from this water content observation, higher IEC variants yielded RG-AEMs with lower permselectivities. The addition of N,N,N′,N′-tetramethylhexane-1,6-diamine-(TMHDA)-based ionic crosslinking to a DMI-based RG-AEM also raised permselectivity, confirming the observation of the prior study also applies to aromatic headgroup RG-AEMs. In summary, high IEC AEMs containing imidazolium-type headgroups along with an optimal amount of ionic crosslinking could be promising and warrant more study (i.e. a comparison of RG-AEMs with cheaper, more scalable non-RG-analogues that contain these attributes).