DescriptionProton (H+) transport in membranes and solid electrolytes leads to their potential use in fuel cells and chemical sensors. Phenyl and zirconia modified phosphosilicate gels were successfully synthesized and demonstrate interesting properties that suggest that these materials have future use as proton conductors. The amount of substitution and the amount of zirconia have been varied. Conductivity measurements using a Four-Point Probe were used to determine the effects of the substitutions on proton conduction in the gel samples. The highest value of conductivity was 1.48E-05 S/m for the sample with 5 wt.% PhTES and 5 wt.% TPZr (5PPS-5Z). The molecular structure of the gels was investigated using FTIR and Raman spectroscopy, to identify hydroxyls and phenyl groups, and the presence of bridging oxygen bonds in the samples. The FTIR transmission spectra explain the nature of the functional groups that are present in the three samples and the Raman spectra display the characteristic peaks for a silica and phosphate network. The samples were also subjected to nanoindentation, it was observed that samples with phenyl substitutions showed some plasticity, while samples without phenyl substitution were brittle. The results of the BET analysis indicate that all three samples have minimal surface area that is accessible to nitrogen. The pore volume is also very low, indicating that the compositions with and without phenyl substitutions have almost no measurable pore volume. The water adsorption studies for samples at 99 % RH for about one hour show a steady increase in the samples mass. The samples, despite being phenyl modified are still able to take in water. The substitution of a phenyl group on the silica precursor as well as the addition of zirconium (IV) ions in the formulation of phosphosilicate gels for proton conduction has interesting effects on the mechanical, structural, thermal and transport properties.