In conjunction with the recent redesign, we decided to look into alternative solutions to use in our fuel cell.  Specifically, we are looking to compare sodium carbonate, sodium chloride, and sodium borate with the currently used urea borate. 

As when initially determining the suitability of materials for this device, we needed to confirm the solutions would not interact with any of the materials used. To do this, we soaked the materials in each of the three solutions. The process was similar to that used in testing materials described in parts 2-1 to 2-5 of the instructions. Unlike when first testing the materials, in this instance we only looked for changes in pH.

As shown in the table above, most of the materials did not react significantly to the different solutions. The only material that showed a significant pattern in changing the pH was silicone, which raised the pH slightly. This is not unexpected, as we did not use silicone in the pervious iteration of the fuel cell because it raised the pH in the initial materials testing as well. We chose to retest because we switched to an aquarium grade silicone to see if that would reduce the reaction, which it seems to have done. Additional testing should be done before we introduce silicone into the fuel cell.

None of the potential solutions show significant reactivity to the main materials used in the fuel cell, with sodium chloride having the smallest change in pH for the materials overall.