https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:55755 Wed 19 Jun 2024 16:05:29 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32171 Tue 28 Jan 2020 10:40:24 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:51616 Tue 12 Sep 2023 13:49:36 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:43837 Tue 04 Oct 2022 11:46:28 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:37211 a]P) in soils. In this study, we investigated the influence of pH, EC and ageing on the extractability of B[a]P in two contracting soils (varied largely in soil texture, clay mineralogy and organic carbon content) over 4 months. Dilute sodium hydroxide (0.2 mol L^-1) and sodium chloride (0.1 mol L^-1) solutions were used to adjust soil pH and EC either separately or simultaneously. Extractability of B[a]P in these soils was monitored using a mild solvent extraction using butanol (BuOH, end-over-end shake over 24h), and an exhaustive mix-solvent extraction using dichloromethane/acetone (DCM/Ace, v:v = 1:1) facilitated by sonication and a subsequent NaOH saponification method following the DCM/Ace extraction. Results showed that increased pH and/or EC significantly increased the B[a]P extractability in the sandy soil (GIA). Variance analysis of contribution of pH and/or EC modification and ageing time on changes in B[a]P extractability indicated that in GIA > 55% and over 25% of the changes in B[a]P extractability was attributed to increased pH&EC and pH only respectively. While ageing resulted in >85% of the change in B[a]P extractability in the clayey soil (BDA), following by increased pH&EC (contribution < 15%). Large amount of non-extractable residue (NER) were formed over the ageing period, up to 95% and 79% in GIA/BDA and its modified soils, respectively. Significant correlations were observed between B[a]P BuOH extractability and the exhaustive sequential extraction using DCM/Ace followed by NaOH saponification for all soils (p < 0.001). With slopes of the correlations close to 1, our results indicated that the simple mild solvent BuOH extraction was equivalent to the complex sequential DCM/Ace and NaOH saponification extraction in these soils.]]> Thu 30 Mar 2023 09:35:27 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:47297 Thu 27 Jul 2023 11:25:51 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:44820 Mon 24 Oct 2022 09:38:27 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:41550 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.]]> Fri 05 Aug 2022 14:23:34 AEST ]]>