High School Conductivity Project
Two high school students, Nick and Nikita, were supervised to study the effects our Sepcon membranes had on potential charge based separations. Using standard 30 nm cutoff Sepcons and the pressure cell, they performed a set of experiments with high (1 M) and low concentration (100 mM) KCl. They measured the conductivity of the filtrate and retentate after pushing the KCl solution through the Sepcons at 3 psi. Below is the result of these experiments:
Something that was also strange from this data is that the filtrate and retentate concentrations increased from the original concentrations, which could have simply been a mistake made by these students, but is hard to explain if it was no a mistake. Performing a t-test found a value of p=0.0028 at high concentrations and p=0.90 at low concentrations. Since p<.05 at high concentrations, we can say that the filtrate has a significantly lower conductivity than the retentate. At low concentrations, this is not the case and we cannot say that there is a statistical difference. This means that at high concentrations we are possibly seeing charged based separation of KCl ions through our membranes, and charged ions may be being blocked from flowing through our membranes. This study has provided as with some insight into this being possible, but needs further attention and study before any significant conclusions can be made.