Effect of surfactants in synthesis of CsH2PO4 as protonic conductive membrane

Cesium dihydrogen phosphate (CDP) powders were synthesized by cetyltrimethylammoniumbromide (CTAB), polyoxyethylene-polyoxypropylene (F-68) and mixture of both surfactants F-68: CTAB with two molar ratios 0.06 and 0.12 as surfactant solutions at room temperature. The synthesized CsH₂PO₄ is characterized by ICP, XRD, TEM, SEM, FT-IR, BET and IS techniques. Based on the width of the (011) XRD diffraction peak and BET measurement, the average size of nanoparticles was ∼ 10 nm in diameter, while the TEM images indicate smaller size than both techniques. The analysis reveals existence of P and Cs with mole ratio 1.02 ± 0.03 which is compatible to molar ratio CsH₂PO₄ formula. The experimental results show that the conductivities increase in the order of CDP_CTAB > CDP_{(F-68: CTAB)0.12} > CDP_{(F-68:CTAB)0.06} > CDP_F-68. The sequence of increasing conductivity is in accordance with the ion exchange capacities of the samples that has direct proportional effect on the proton mobility of samples. Indeed CTAB as cationic surfactant shows the highest proton mobility in the as-obtained samples.