Fabrication of a hollow mesoporous silica hybrid to improve the targeting of a pesticide

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 364; pp. 361 - 369
• Main Authors: Gao, Yunhao, Zhang, Yanhui, He, Shun, Xiao, Yanan, Qin, Xueying, Zhang, Yuan, Li, Donglin, Ma, Hongju, You, Hong, Li, Jianhong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-05-2019
• Subjects: Abamectin; Base-triggered release; Bioactivity; Cnaphalocrocis medinalis (Guénee); Field trials; Abamectin; Bioactivity; Base-triggered release; Field trials; Cnaphalocrocis medinalis (Guénee)
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2019.01.105

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•A novel hybrid material was fabricated employing P(GMA-AA) as the gatekeeper of HMS.•Aba-loaded HMS@P(GMA-AA) showed a base-triggered release property.•Aba-loaded HMS@P(GMA-AA) protected Aba from photolysis effectively.•Aba@HMS@P(GMA-AA) possessed satisfactory efficacy on rice leaf folder in practice.
Nanomaterials offer a great opportunity to develop new strategies for designing stimuli-responsive controlled release formulations (CRFs) of pesticides. In this study, a pH sensitive controlled release system, poly(glycidyl methacrylate-co-acrylic acid) (P(GMA-AA)) grafted hollow mesoporous silica (HMS@P(GMA-AA) was fabricated. HMS was fabricated using a hard template and functionalized with 3-(trimethoxysilyl)propyl methacrylate. Then, P(GMA-AA) was grafted onto HMS by seeded precipitation polymerization. Abamectin (aba) was selected as the model pesticide to test the pH-sensitivity property. Detailed investigations showed that Aba@HMS@P(GMA-AA) exhibited a high pesticide-loading efficiency (33 wt%) and superior stability. The release of Aba from Aba@HMS@P(GMA-AA) was pH-dependent. In addition, Aba@HMS@P(GMA-AA) showed a strong combination with rice leaves, mainly benefitting from its low contact angle and high adhesion work on leaves. Bioactivity studies in a greenhouse and the field indicated that Aba@HMS@P(GMA-AA) was more toxic than Aba emulsifiable concentrate (Aba-EC) in controlling rice pest Cnaphalocrocis medinalis (Guénee) larvae, and it possessed long-term efficacy in practice. Importantly, there was no obvious influence on the growth of rice seedlings treated with Aba@HMS@P(GMA-AA). The results suggest that the proposed controlled release system is a promising candidate for the management of pests.