File Name : figs1.pdf Caption : figure s1. sem images of pbs File Name : figs2.pdf Caption : figure s2. volumic distribution of dispersed particle size of pbs in water File Name : figs3.pdf Caption : figure s3. pictures of (a) pellet, (b) pellet with electrode, (c) mould made of pla, and (d) mould filled with sample powder. File Name : figs4.pdf Caption : figure s4. conductivities of samples prepared by moulding (red bars), pellet method (dark grey bars), and value from reference (light grey bars). File Name : figs5.pdf Caption : figure s5. proton conductivities of pbas with and without surface modification at room temperature, 90rh% : (a) mnpba, (b) cupba File Name : figs6.pdf Caption : figure s6. water adsorption isotherm of pb-sm26 at 25˚c