Application of pH-responsive functionalized hollow mesoporous organosilica nanoparticles for wood preservation

Plant-derived preservatives exhibit excellent antifungal effects. However, their antifungal active ingredi-ents can easily leach out. A properly designed functional response system can help realize the responsive release of preservatives and reduce leaching. Herein, the pH-responsive preservatives delivery system was designed and synthesized. The preservative (Forsythia) was encapsulated with hollow mesoporous organosilica nanoparticles (HMONs), and carbon quantum dots (CQDs) were employed as mesoporous plugging agents. Forsythia's release was achieved by grafting pH-sensitive chemical bonds on the surface of the carrier. X-ray photoelectron spectroscopy and antifungal results showed that the pH-responsive switch was successfully broken. After 12 weeks of soil-jar incubation, the weight loss rate of treated wood was 2 % +/- 0.5 %. The leaching of Forsythia-HMON-CQDs was lower than that of Forsythia under the same concentration. The design of the system reduced the leaching of Forsythia and extended the service life of wood. In addition, the system was also applicable to ammoniacal copper quat (ACQ). Forsythia-HMON- CQDs showed an outstanding fixation effect and antifungal ability, and its fluorescence can be used to track distribution in wood. This system can be extensively employed in protecting antifungal active ingredients and demonstrates an effective strategy for developing potential bio-based wood preservatives. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).