XPS raw data from Highly efficient triazolone/metal ion/polydopamine/MCM-41 sustained release system with pH sensitive for pesticide delivery
2018-06-25T10:34:34Z (GMT) by
MCM-41 was prepared through the sol–gel method and encapsulated by polydopamine (PDA) before coordinated with metal ion to form a highly efficient sustained release system (M-PDA–MCM-41) for triazolone delivery. The characterization results confirmed the existence of the coordination bond between the PDA layer and triazolone through the bridge effect from metal ion, which enhanced the interaction between PDA–MCM-41 and triazolone. The adsorption capacity (AC) of Fe-PDA–MCM-41 increased up to 173 mg g–1, which was 160% more than that of MCM-41. The sustained release performance of M-PDA–MCM-41 in different pH values was investigated. Under the conditions of pH ≤7, the release speed of triazolone increased with pH decreasing. Whereas its release speed in the weak base condition was slower than in the neutral condition. Therefore, the as-synthesized system showed significant pH-sensitivity in the sustained release process, indicating that the sustained release system can be well stored in the neutral or basic environment and activated in the acid environment. Their sustained release curves described by Korsmeyer–Peppas equation at pH 7 showed the same behaviour, indicating that PDA decoration or metal ion coordination only increases the steric hindrance and the interaction between carrier and triazolone instead of changing the original structure of the pure MCM material in accordance with XRD and BET analysis results.