Smart Thermosensitive Mesoporous Silica Composites for Precisely Triggered Linalool Release

Abstract

To overcome the application limitations of linalool, including its high volatility and poor stability, mesoporous silica MCM-41 was used as the carrier, and N-isopropylacrylamide (NIPAM) was employed as the thermosensitive monomer in this study. Acrylamide (AM) was introduced to modulate the lower critical solution temperature (LCST) of poly(N-isopropylacrylamide) (PNIPAM), while N,N′-methylenebis(acrylamide) (BIS), used as a cross-linking agent, was added to enhance structural stability, thus constructing the MCM-41-PNIPAM thermosensitive composite sustained-release system. Characterization results confirmed the successful synthesis of the target material, whose LCST increased to 82–85 °C with the increasing AM doping ratio. Sustained-release experiments indicated that the release rate of linalool significantly increased when the environmental temperature exceeded the LCST. Antibacterial tests revealed that the composite exhibited a remarkable inhibitory effect on Bacillus subtilis, Staphylococcus aureus, and Escherichia coli following the temperature-triggered release of linalool. Moreover, the antibacterial effect could be precisely controlled by regulating the ambient temperature, thereby modulating the release. This study presents a new strategy for the stabilized application of linalool, achieves an intelligent response effect of “temperature-triggered and on-demand release,” and offered a universal method for constructing intelligent preservation systems.