Measurement of Specific Surface Area of Silica Gel Using a Paper-Based Microscale Laboratory

We describe the measurement of the specific surface area of silica gel via solution adsorption method using paper-based microscale laboratory. The students utilized microfluidic paper-based analytical devices, plotted a calibration graph, and quantified the methylene blue content after adsorption by silica gel. This experiment has the advantages of low cost, fast speed, easy operation, and environmental friendliness compared to using a UV-visible spectrophotometer to determine the specific surface area. A total of 108 students majoring in chemical education participated in this practice in the sixth semester, and all students completed the experiment within 3 h. Of the total number of students participating, 85.2% of participants obtained a specific surface value with a relative error < 30%, and 94.4% of them obtained a calibration curve with a determination coefficient > 0.96. The study demonstrates the feasibility of adopting this modified laboratory experiment in physical chemistry teaching laboratories. The students ' responses to a questionnaire and their experimental reports indicated a high degree of student satisfaction, interest, and skill development after performing this experiment.