pH
ASSUMPTION: If any changes in the dimensions and/or surface are observed then the pH of solution degrades tested material.
3 pieces of each material were suspend in sealable bottles. Each bottle was filled with solutions of pH 5.0; 7.0 and 9.0. The tested material was outlined on a previously prepared paper sheet and a 3d photo of the fresh piece (3d microscope) was taken. The test run for 21 d. The bottles were opened and the materials were inspected every 2 to 3 days. Any changes observed were recorded (pictures with 3d microscope/measurements on previously used paper sheet) and noted in the dedicated table/file.