Nowadays, excess quantities of industrial waste acid with low concentration have become not only a serious threat to environment but also a huge resource waste. Electrodialysis (ED) should have played important roles therein. However, the substantial proton leakage of anion exchange membrane (AEM) seriously deteriorates its work performances. In this report, the water uptake of AEM is controlled for alleviating the problem by material selection, for example, hydrophobic skeleton and weakly basic anion exchange groups. Of note, two kinds of membrane structures are designed and investigated. One is the semi interpenetrating network which is achieved by blending PVDF with DMAEMA and DVB copolymer, the other is a so-called microphase-separated structure which is driven by the polarity difference of segments of the side-chain-type membrane material, PVDF-g-PDMAEMA. Series of electrodialysis experiments confirm that the as-prepared AEMs do exhibit remarkable acid block property. In particular, PVDF-g-PDMAEMA AEM displays more outstanding comprehensive properties, such as area electrical resistance, anti-swelling and limiting current densities. Based on comparison of results achieved in electrochemical characterizations, morphology observations and measurements of water uptake and acid adsorption, it is concluded that the microphase separation of the hydrophilic and hydrophobic segments contributes to the formation of ion nanochannels and then induces some consequential confinement effects. (C) 2017 Elsevier B.V. All rights reserved.