**Abstract**

The electrolyte membrane currently being developed is limited to materials that are toxic and expensive. Chitosan as a natural organic polymer supports modification to produce the desired physical and chemical properties, one of which is as solid electrolyte. In the presence of functional groups on chitosan, it is possible to modify it with nanosilica as inorganic filler to improve its characteristics. Incorporation of chitosan matrix with of silane-coupled nanosilica in nanosilica:silane ratio (w/w) are 1:0; 1:0.25; 1:0.50; 1:1; 1:1.50; and 1:2. Evaluation on their properties are both quantitatively (water uptake, tensile strength, proton conductivity, methanol permeability, and selectivity) and qualitatively (functional groups, morphology, topography, and thermal properties). The results show that silane addition to the chitosan-nanosilica membrane in nanosilica:silane as 1:0.50 achieve the best characteristics for polymer electrolyte. The results of functional groups, morphology and topography analysis on selected membranes show that optimum silane addition provides the hydrogen interaction between chitosan matrix and silane-coupled nanosilica so there is an enhanced in membrane properties for electrolyte membrane.

**Keywords:** chitosan matrix modification, polymer electrolyte, silane-coupled nanosilica
