Study of the interactions of the hazardous amoxicillin antibiotic inside the MCM-41/CTA hydrophobic cavities

In this work, it was studied the interaction of the hazardous antibiotic amoxicillin (AMX) molecules inside the mesocavities of a composite MCM-41/cetyltrimethylammonium (MCTA). MCTA with low surface area (5 m2  g−1) showed high sorption efficiency of AMX (55 mgAMX g−1) comparable with high surface area activated carbon (980 m2 g−1). Positron annihilation spectroscopy and isosteric heats suggested that the AMX molecules are not adsorbed by a classical surface process but are attracted and trapped by the CTA C18 hydrophobic chains inside the MCM-41 mesocavities. Preliminary kinetic data suggests that the AMX sorption process takes place in three stages, the external adsorption, interaction with the CTA molecules and diffusion inside the mesocavities.