The bubble point method is a simple technique to characterise microfiltration membranes. a. What is the bubble point for a membrane with the following pore size distribution using water as the test liquid (water/air=72.8mN/m). b. What is the error if the contact angle between liquid and polymer is not 0 but 20 ? c. Is this possible to characterise an ultrafiltration membrane with the largest active pore size of 1nm with this technique using water as the liquid? d. Is this possible to characterise an ultrafiltration membrane with the largest active pore size of 1nm with this technique using ethanol as the liquid? ( ethanol/air=21.8 mN/m)