Controlled Release Formulations of 2,4-Dichlorophenoxyacetic Acid with Ecofriendly Matrices for Agricultural and Environmental Sustainability

Starch-chitosan blends: A comprehensive review on the preparation, physicochemical properties and applications

Starch and chitosan, polysaccharides derived from natural sources, have significant potential across various domains. Starch is extracted from starch-bearing plants, such as potatoes, whereas chitosan is obtained from the exoskeletons of marine animals, fungi and insects. However, the original forms of starch and chitosan have several limitations, such as low solubility and weak mechanical strength. Interestingly, the combined effects of starch and chitosan resulted in the development of starch-chitosan blends with markedly improved functional properties. These blends demonstrated high tensile strength, improved hydrophilicity and increased adsorption capacity. Furthermore, modification of starch-chitosan blends by techniques such as crosslinking and incorporation of other functional materials contributes to diverse characteristics and functionalities. This review addresses a crucial gap in the literature by providing an overview and up-to-date analysis of starch-chitosan blends. The preparation methods and functional properties of these blends in various forms, such as films, beads and hydrogels, have been extensively discussed. Emphasis is placed on the versatile applications of these blends in research, development and industries such as pharmaceuticals, wastewater treatment, agriculture and food technology. This review aims to provide an insightful overview of starch-chitosan blends and stimulate broader interdisciplinary research interests. By providing concluding insights and prospects, this review highlights the potential for further exploration of the impact of starch-chitosan blends on consumers and the environment.

Comparative adsorptive behaviour of cow dung ash and starch as potential eco-friendly matrices for controlled organophosphorus pesticides delivery

The work reported herein explores the viability of cow dung ash (CDA) as a matrix for controlled pesticide delivery, by comparing its adsorptive characteristics towards two organophosphorus pesticides with those of starch, conventionally utilized in designing controlled pesticide delivery systems. CDA was characterized by Fourier transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD). Data for pesticide adsorption on the surfaces correlate well with Langmuir and Freundlich isotherms, with the former isotherm giving a slightly better fit (R² ≥ 0.90) than the latter (R² ≥ 0.81). Values of the adsorption parameters K_L and R_L indicate favourable pesticide adsorption on both surfaces. Desorption is the microscopic reverse of adsorption; both processes obey pseudo-second-order kinetics. The implication of this kinetic form is a mechanism in which adsorbate diffusion to the polymer surface and its transport into the polymer interior are important events. The isothermal and kinetic ratios, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{{K_{L}^{CDA} }}{{K_{L}^{Starch} }} = 3.8$$\end{document}KLCDAKLStarch=3.8 and 4.0, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{{k_{2}^{CDA} }}{{k_{2}^{Starch} }} = 1.3$$\end{document}k2CDAk2Starch=1.3 and 0.6, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\frac{{k_{ - 2}^{CDA} }}{{k_{ - 2}^{Starch} }} = 5.2$$\end{document}k-2CDAk-2Starch=5.2 and 1.0 at pH 7.0 and 27 °C, compare the adsorptive behaviour of diazinon and dichlorvos, respectively, on CDA and starch. These parameters are of the same order of magnitude, signalling that CDA is as potentially viable as starch for use as a matrix for pesticide-controlled delivery.