- Title
- Hollow porous silica nanosphere with single iarge pore opening for pesticide loading and delivery
- Creator
- Nuruzzaman, Md; Ren, Jiawei; Liu, Yanju; Rahman, Mohammad Mahmudur; Shon, Ho Kyong; Naidu, Ravi
- Relation
- ACS Applied Nano Materials Vol. 3, Issue 1, p. 105-113
- Publisher Link
- http://dx.doi.org/10.1021/acsanm.9b01769
- Publisher
- American Chemical Society (ACS)
- Resource Type
- journal article
- Date
- 2020
- Description
- Hollow porous silica nanospheres (HSNs) have unveiled as a potential carrier for pesticide delivery. However, HSNs mostly suffer from postsynthesis loading process of pesticides because of the tiny mesopores onto shell. To eradicate this disadvantage, it was hypothesized that developing a large through hole or pore opening on shells (>10 nm) could be effective for the postsynthesis loading of active molecules onto HSNs using a simple immersion method. We synthesized HSNs with a single large through hole or pore opening on shells (15.95 nm) in an earlier study, which was subsequently termed bowl-structured hollow porous silica nanospheres (BHSNs). In this study, the postsynthesis loading of a model pesticide, namely imidacloprid, onto BHSNs was evaluated via the simple immersion method. It was observed that the presence of a single large pore-opening on the shells of BHSNs facilitated loading of imidacloprid to the inner core or void space of BHSNs. Thermogravimetric analysis (TGA) showed that around 16% imidacloprid molecules were loaded to the BHSNs when acetone was used as a dispersing medium. It was evidenced by differences between weight losses patterns of imidacloprid loaded to BHSNs (imi@BHSNs) from pure imidacloprid. Both adsorption and entrapment mechanisms were effective during loading. FTIR analysis showed that pesticide molecules were adsorbed on BHSNs via hydrogen bonding interaction. The controlled releasing profile of imidacloprid from BHSNs was observed in distilled water at room temperature, except an initial burst release of a small amount (<5%). The controlled release composed of a faster sustained release followed by a slower conditional release due to the deposited and adsorbed imidacloprid. The non-Fickian case II transport mechanism prevailed during transportation of imidacloprid to the release media from BHSNs. We anticipate that this study could provide an important avenue for advancing practical applications of BHSNs in pesticide delivery systems.
- Subject
- ABC triblock copolymer; bowl structure; imidacloprid; nanoencapsulation; nanopesticide; pesticide loading
- Identifier
- http://hdl.handle.net/1959.13/1441859
- Identifier
- uon:41550
- Identifier
- ISSN:2574-0970
- Language
- eng
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