Effect of dispersion state of cloisite15a (r) on the performance of speek/cloisite15a nanocomposite membrane for DMFC application

The introduction of 2,4,6-triaminopyrimi-dine (TAP) into sulfonated poly(ether ether ketone) (SPEEK)/Cloisite15A V R nanocomposite membranes were investigated for the purpose of maintaining low methanol permeability and suppressing swelling in direct methanol fuel cell (DMFC). SPEEK with 63% of degree of sulfona-tion (DS) was prepared by sulfonation of PEEK. Cloisi-te15A (7.5 wt %) along with various weight loading of TAP was incorporated into SPEEK matrix via solution intercalation method. The effect of TAP loading on the SPEEK/Cloisite15A/TAP morphology was studied. The beneficial impact of the SPEEK/Cloisite15A/TAP mor-phology on the physicochemical properties of the mem-brane was further discussed. Swelling behavior, ion exchange capacity (IEC), proton conductivity, and metha-nol permeability of the resultant membranes were deter-mined as a function of Cloisite15A and TAP loadings. Uniform distribution of Cloisite15A particles in the SPEEK polymer matrix in the homogenous SPEEK/Cloisite15A/ TAP nanocomposite membranes was confirmed by scan-ning electron microscopy and X-ray diffraction. The water uptake of the SPEEK nanocomposite membranes decreased dramatically in the presence of TAP. The signifi-cant selectivity of SP/7.5/7.5 nanocomposite membranes could indicate a potential feasibility as a promising electro-lyte for DMFC. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124: 969–977, 2012