Sulfonated poly ether ether ketone (SPEEK) based composite cation exchange membranes for salt removal from brackish water

Availability of fresh water is a serious concern due water pollution in these days. Several efforts have been made for water desalination where membrane based technology is considered prominently. Here, we synthesised sulfonated poly ether ether ketone (SPEEK) based functionalized hexagonal boron nitride (SBN) composite cation exchange membranes for water desalination. The morphology of BN and presence of sulfonic acid group are confirmed by TEM analysis. Ionic conductivity for SPEEK membrane is found to be 2.02 x 10(-2) S.cm(-1), which reaches to 4.05 x 10(-2) S.cm(-1) for SBN-10/SPEEK composite membrane. Ion exchange capacity of the SBN-10/SPEEK composite membrane also increased by 40 % and reaches to 1.66 meq.g(-1) as compared to SPEEK membrane. Incorporation of SBN in membrane matrix not only improve the ion exchange capacity and ionic conductivity as well as expand the stability of the membranes. SEM micrograph confirm the uniform distribution of SBN in SPEEK membrane matrix. The composite membranes show the better ion transport properties in term of current efficiency and power consumption during salt removal from brackish water by electrodialysis. For SBN10/SPEEK composite membrane power consumption was 0.75 kW h.Kg(-1) with 98.5 % current efficiency.

Automated summary

The sulfonated poly ether ether ketone (SPEEK) based functionalized hexagonal boron nitride (SBN) composite cation exchange membranes showed improved ion conductivity and ion exchange capacity for water desalination. Incorporation of SBN not only enhanced membrane performance but also increased membrane stability.