Synthesis of Polydopamine Modified Mesoporous Silica Microspheres for Encapsulation of L-menthol

Abstract

Ordered mesoporous silica materials (OMS) possess high specific surface areas, large pore volume, open channel structure, easily tunable surface functionalities, and good biocompatibility. They have great potential for application in various fields, such as drug delivery, enzyme immobilization, and catalysis. In this study, ordered mesoporous silica microspheres with large pore sizes were synthesized via a non-polar solvent assisted co-assembly method in a water- n-hexane biliquid solution. The obtained mesoporous silica microspheres possess large pore size of 6.9 nm and high surface area of 615 m2/g. Through a nanocasting method, L-menthol was successfully loaded into the mesopores. Through an interface polymerization of dopamine, polydopamine (PDA) was deposited on the external surface of the composite microspheres. By monitoring the weight change of the composite microspheres during treatment by hot air flow, the menthol release behavior was evaluated. As a result of the presence of permeable PDA in shell, the composite microspheres were found to release L-menthol in a controllable way, especially at an appropriate temperature of about 50℃. This study provides an important primary guideline for potential applications of mesoporous silica functionalized with PDA in bio-medicine, adsorption and separation, and so on.