Adsorption and Release Kinetics, Equilibrium, and Thermodynamic Studies of Hymexazol onto Diatomite

Abstract

Pesticide sustained-release agents have advantages of low toxicity, high efficiency, and long duration. However, the sustained-release effects were not ideal, such as short release time and low release rate. The physical and chemical properties of diatomite are high stability, high porosity, and good sustainedrelease and controlled-release abilities. A series of diatomite-based pesticide sustained-release agents were prepared by adsorbing hymexazol onto diatomite. Kinetics, equilibrium, and thermodynamic studies for adsorption were carried out as well. It was found that the modified diatomite has a better adsorption effect for hymexazol, and the adsorption rate reached 16.64%. The equilibrium data followed with the Langmuir isotherm model, and the adsorption process was an endothermic process. Release results showed that the diatomite-based pesticide has a significant sustained-release effect. The sustained-release time reached more than 25 days, and the maximum release rate was above 70%. The experimental data was fitted into the Ritger−Peppas equation, and it was found that the release was controlled by the Fick diffusion mechanism. This confirmed the applicability of the modified diatomite as an efficient adsorption carrier for pesticide release.

pH-Responsive Semi-Interpenetrated Polymer Networks of pHEMA/PAA for the Capture of Copper Ions and Corrosion Removal

“…For instance, equilibrating the gels at pH 3 for a few hours results in the quantitative exchange of the complex solution with water, while the process occurs overnight at pH 6. This makes the new pHEMA/PAA SIPNs appealing to a wide range of application, even beyond Cultural Heritage preservation, where controlled uptake and/or release of molecules is needed (e.g., drug delivery, − wastewater treatment, agricultural industry, − and food chemistry) …”

Combined Application of Tacrolimus with Cyproconazole, Hymexazol and Novel {2-(3-R-1H-1,2,4-triazol-5-yl)phenyl}amines as Antifungals: In Vitro Growth Inhibition and In Silico Molecular Docking Analysis to Fungal Chitin Deacetylase

“…The control of drug release by nanosized carriers, e.g., microemulsions, vesicular carriers, nanosuspensions, and wet media milling technology, also has a great impact on minimizing systemic absorption and decreasing toxicity, as in medicine and agriculture [ 74 ]. Recently, Liu et al [ 75 ] reported that modified diatomite was a highly efficient and stable carrier of hymexazol to prepare pesticide sustained-release agents suitable for neutral and acidic soil environments. Finally, possibly deleterious effects on the environment by the extensive use of combinations of active agents should be ruled out by appropriate toxicity studies [ 26 ].…”

Distribution of Emamectin Benzoate Granules in Maize Plants by Broadcasting into Maize Leaf Whorls

“…In addition, the performance of granules can be affected by the filler. Attapulgite, kaolin, diatomite, and other inorganic minerals have a large specific surface area, strong adsorption, and good adhesion and have become important carriers in the pesticide industry. ,− With the development of nanocomposites, the release process can be controlled by the addition of nano-carriers, which can significantly increase pesticide coverage and effectively reduce rainwater erosion . In addition, nanoscale photothermal materials have been used to achieve physical contact with killing pests, effectively reducing the use of chemical pesticides .…”