In this study, the relationship between transport performance of Cr(VI) through PVDF-co-HFP based ionic polymer inclusion membranes (IPIM), alkyl chain length of symmetric imidazolium bromide based room temperature ionic liquids (RTILs) and morphological changes of these IPIMs has been comprehensively described. Butyl, hexyl, octyl, and decyl substituted RTILs containing IPIMs were prepared in different compositions and their effectiveness on Cr(VI) transport was experimentally optimised. In optimum conditions, the initial mass transfer coefficient (J(o)) value of Cr(VI) was found as 5.0 x 10(-6) mols(-1) m(-2), and also, we found that the optimised process is significantly selective for chromium in existence the other heavy metal ions. Morphological and structural characterizations of IPIMs have been performed before and after Cr(VI) transport to illuminate the morphological and the structural changes. Also, the additional plasticizing effect of RTILs as an unusual morphological phenomenon have come forward. In today's industrialised world, the demand for environmentally friendly processes for removal or recycle of toxic substances by simpler and cheaper ways have been increasing day by day. As a result, our developed and optimised membrane-based process seems to be overcome some Cr(VI) dependent environmental and industrial difficulties. (C) 2016 Elsevier B.V. All rights reserved.