A simple experiment for visualizing diffusion

作者:Helseth L E*
来源:European Journal of Physics, 2011, 32(5): 1193-1197.
DOI:10.1088/0143-0807/32/5/007

摘要

We propose a simple and fascinating experiment for studying diffusion in gels using a pH-sensitive dye. By doping agar with methyl red, we obtain a gel which rapidly reacts to changes in pH by changing its absorption spectrum. The pH gradients can be followed using a digital camera, and we demonstrate here that the pH-sensitive colour changes can be used to print colour patterns in the gel which due to diffusion of ions may disappear entirely.

  • 出版日期2011-9