Using contact angle measurement technique for determination of the surface free energy of B-SBA-15-x materials

Abstract Pure and boron-containing, Santa Barbara Amorphous (SBA-15) mesoporous materials and B-SBA-15-x (x is molar ratio of Si/B = 50, 30, 10), were synthesized via a direct hydrothermal method. Samples were characterized by XRD, BJH pore size distribution and SEM techniques. A contact angle technique was used to determine surface free energy and its dispersive and polar components. For this purpose, ethylene glycol (EG), di-iodomethane (DIM), formamide (FA) and water were used as model liquids to detect the contact angles. The OWRK/Fowkes approach was used to calculate the surface free energy values. Total surface free energy ( γ S ) values of pure SBA-15 and B-SBA-15-50, B-SBA-15-30, B-SBA-15-10 were calculated as 64.365, 63.545, 63.490 and 64.218 mJ/m2 at room temperature, respectively. The main results of the study can be summarized as follows: (i) The contact angle measurement technique is suitable for determining the total surface free energy ( γ S ) and its dispersive and polar components ( γ S d and γ S p , respectively) of SBA-15 mesoporous materials and (ii) Addition of boron did not have a significant impact on the characteristic structure of SBA-15.