Controlled Release Systems Based on Intercalated Paraquat onto Montmorillonite and Clinoptilolite Clays Encapsulated with Sodium Alginate

Abstract

As a model herbicide, paraquat (PQ) was intercalated into montmorillonite (MMT) and clinoptilolite (CL) clays at different concentrations. FT-IR, XRD, and SEM techniques were used to characterize the structures of the prepared formulations. The prepared PQ/clay samples were further encapsulated with alginate (Alg) polymer. After characterization, the potential application was verified through release of PQ from PQ/clay and PQ/clay/Alg formulations. According to the results, the release of PQ from PQ/MMT was slower than the release from the PQ/CL system. The presence of the alginate polymer in PQ/clay/Alg capsule beads caused the system to liberate PQ in a more controlled release manner than PQ/clay samples. Furthermore, the release data were fitted to empirical equations to estimate the kinetic parameters. The results suggested the feasibility of the use of clay/Alg formulations for controlled release of herbicides in agricultural applications. C 2015 Wiley Periodicals, Inc. Adv Polym Technol 2015, 0, 21597; View this article online at wileyonlinelibrary.com.

Paraquat Degradation From Contaminated Environments: Current Achievements and Perspectives

“…Depending upon the texture and composition, soil particles immediately adsorb paraquat (Singh and Singh, 2016). Rashidzadeh et al (2017) described better paraquat adsorption in montmorillonite as compared to clinoptilolite clay and adsorption in clay is stronger than sandy soil (Amondham et al, 2006). Microorganisms can only utilize and degrade less than 1% of paraquat in soil particles (Figure 1) (Roberts et al, 2002), and its half-life can be up to 3∼6.6 years (Hance et al, 1980; Pateiro-Moure et al, 2009).…”

Microfluidisation trends in the development of nanodelivery systems: characterisation and release study of resveratrol‐loaded nanostructured lipid carrier prepared with high‐pressure microfluidisation

“…Therefore, the parameters (coefficient of determination) acquired in the release profile by using all the mathematical models are compiled in Table 1. The goodness of fit was appraised applying the R 2 values [36]. Concerning the R 2 values, the zero‐order and Higuchi models are not apposite for ascertaining the release kinetics of the Res from the nanocarrier structure.…”

Lauric Acid-ModifiedNitrariaSeed Meal Composite as Green Carrier Material for Pesticide Controlled Release

“…In theory, most ester groups fixed on the structure of LA-NSM carriers could combine with hydrogen ions (H + ) in strong acidic media (3 < pH < 6) to form hydrophilic carboxyl groups (-COOH) [56], decreasing the oleophilic and hydrophobic action. us, the attraction between the LA-NSM and DEL molecules would be weakened [15], strongly facilitating the DEL molecules to quickly diffuse into the surrounding medium. When the pH was higher (pH > 6), the carboxyl groups were deprotonated under alkaline conditions and a limited amount of DEL molecules was released from the LA-NSM composites.…”

“…Up to date, various materials including clay minerals [10], montmorillonites [11], and starch [12][13][14] have been suggested to act as the scaffold for the controlled release of pesticides. In contrast, using alternative biomaterials as a vehicle has sparked another particular interest owing to their stable raw-material supply and low cost, renewable nature, nontoxicity, and biodegradable advantages [12,15].…”