Effects of organobentonites on imidacloprid release from alginate-based formulation

Structural effects of organobentonites on controlled release of pretilachlor

“…With increasing surfactant loading level in the range studied, both CH 2 asymmetric stretching modes (ν as (CH 2 )) and symmetric stretching modes (ν s (CH 2 )) of the adsorbed surfactant slightly shift from 2929 and 2857 cm −1 (BD 0.6 ) to 2920 and 2848 cm − 1 (BD 1.2 ) for DTMA-bent, and from 2925 and 2852 cm −1 (BH 0.6 ) to 2921 and 2846 cm −1 (BH 1.2 ) for HTMA-bent, close to those of DTMA and HTMA solid (around 2918 and 2848 cm −1 , respectively), indicating that the adsorbed surfactants developed progressively from a less ordered conformation of low packing density to an ordered one of high packing density (Vaia et al, 1994;Zhu et al, 2005Zhu et al, , 2007Zhu et al, , 2008. Similar results were obtained in previous work (Jiang et al, 2015) and in good agreement with other reports (Vaia et al, 1994;Zhu et al, 2005Zhu et al, , 2007Zhu et al, , 2008. Meanwhile, the ratio between the broad peak ascribed to adsorbed hygroscopic water between 3300-3500 cm −1 to the absorption of the structural -OH sharp peak at 3630 cm − 1 of all of the organobentonites decreased compared to the raw bentonite, suggesting an increase in hydrophobicity of bentonite due to the modification (Rytwo et al, 2005).…”

Structure Regulation of Bentonite-Alginate Nanocomposites for Controlled Release of Imidacloprid

“…The results also showed that the combination of bentonite (weight percentage of 50%) increased the release of imidacloprid from alginate beads. 12 A further study from our laboratory indicated that the release of imidacloprid from bentonite-alginate composite hydrogel could be reduced by a small quantity of bentonite, similar to the release of sodium diclofenac from the MMT-UPEO composite, 10 suggesting a possibility of structure regulation of the bentonite-alginate composite for controlled release. Unfortunately, the structure features of the bentonitealginate composite and its effects on the release properties remained unclear.…”

“…1,2 For bentonite, a strong absorption around 990 cm −1 was observed for Si−O stretching, along with the broad absorption of adsorbed water between 3600 and 3200 cm −1 and a weak absorption due to the stretching vibration of the structural −OH (Si−OH and Al−OH) at 3630 cm −1 . 1,2,12 The addition of bentonite had little influence on the peak position of the characteristic absorption of alginate. However, a decrease in the intensity of the stretching of carboxylate (1600 and 1430 cm −1 ) was observed, accompanying an increase in the intensity of −CH 2 bending around 1028 cm −1 , which was overlapped with Si−O stretching of bentonite.…”

Organosilane-functionalized halloysite for high performance halloysite/heterophasic ethylene–propylene copolymer nanocomposites

“…The surface modification of clays minerals with organic moieties has attracted attention because it produces versatile compounds with new potential application , such as in clay polymer nanocomposites (CPN) (de Paiva et al, 2008;Jain and Datta, 2015), drug delivery (Li et al, 2014;Tan et al, 2014) and environmental materials (Parolo et al, 2014;Jiang et al, 2015). There are different ways to modify surface clays minerals, i.e., adsorption (Guo et al, 2010), ion exchange with organic/inorganic cations and grafting with organic compounds (Albdiry and Yousif, 2014).…”