Abstract: As a classical physical chemistry experiment, traditional Fe(OH)₃ colloid electrophoresis has suffered from the following shortcomings, such as the waste of Fe(OH)₃ colloid, the long dialysis operation time, and the lack of inquiry learning. To overcome such shortcomings, we have made the following improvements on the original experiment: 1) realizing the recycling of Fe(OH)₃ colloid by regenerating Fe(OH)₃ colloid waste via colloid redissolution route; 2) improving the purification efficiency of coarse Fe(OH)₃ colloid through optimizing the dialysis procedure; 3) introducing AgI colloid exploratory investigation to enhance the innovation and interestingness of this experiment; 4) introducing paper electrophoresis to cultivate the ability to connect fundamental experiments with practical applications. The above improvements have been fully confirmed and already applied in the colloid electrophoresis experiment performed in our university. As expected, such improvements have aroused enthusiastic responses from the students attended this course, thus providing a valuable reference for us to improve other classical experiments.

Key words: Fe(OH)₃ colloid, Zeta potential determination, Resource recycling, Colloid redissolution method, Silver iodide colloid surface charge analysis