Thermal, microstructural, and spectroscopic analysis of Ca2+ alginate/clay nanocomposite hydrogel beads

Abstract

Polymeric hydrogels are important biomaterials with potential for various applications including the controlled release of drugs. Clay and zeolite nanostructures can enhance the absorption and release properties of hydrogels. In our previous work, a procedure was optimized for making hydrogel beads. The objectives of this study were to use the optimized bead forming procedure to prepare clay and zeolite nanocomposite hydrogel beads and characterize their microstructure, thermal and chemical properties. The hydrogels were prepared by dripping solutions of either sodium alginate or sodium alginate/nanostructure (clay and/or zeolite) into beakers containing different concentrations of CaCl 2 at 25°C. Fourier transform infrared spectroscopy (FTIR) analysis detected the presence of functional groups associated with alginate, clay and zeolite. The microstructure of the alginate beads was somewhat rough with small protrusions. Flakes were visible in micrographs of beads containing nanoclay. The elemental composition of the hydrogels was investigated by energy dispersive X-ray spectrometry (EDX). EDX spectra revealed magnesium, sodium, aluminum, silicon and increased the levels of oxygen in the nanoclay compositions. The incorporation of nanoclays decreased the percentage of organic matter lost as detected by thermogravimetric analysis (TG). TG was also able to detect the incorporation of nanoclay in hydrogels. The nanoclays proved to be more effective than zeolites in producing alginate hydrogels with satisfactory swelling characteristics.

Gellan Gum/Laponite Beads for the Modified Release of Drugs: Experimental and Modeling Study of Gastrointestinal Release

“…Among the smectite family, laponite Na 0.7 [(Si 8 Mg 5.5 Li 0.3 )O 20 (OH) 4 ] 0.7 is a synthetic clay composed of a layered structure (30–25 nm diameter, 1 nm thickness) that has been used to synthesize a wide range of nano-composite hydrogels [21,22,23]. Specifically, laponite (LAPO) nanoparticles can be uniformly dispersed within the polymeric matrix where they self-arrange and act as both filler and cross-linker during gel formation [24,25].…”

A Critical Review on the Synthesis of Natural Sodium Alginate Based Composite Materials: An Innovative Biological Polymer for Biomedical Delivery Applications

“…[63] Na-Alg/clay FTIR, SEM, TGA applications in the medical field such as in controlled-release medications could be further expanded. [64] Na-Alg/N-Hydroxy succinimide/MTT FTRI, TEM, CFM, Zeta Potential promising candidates for anti-viral drug delivery system for HIV/AIDS therapy. [65] Na-Alg/Fe 3 O 4 /Chitosan TEM, NMR, CLSM useful as therapeutic agents to treat MDR gastric cancer by reversing chemosensitization [66] Na-Alg/g-Poly(Nisopropylacrylamide)/Doxorubicin SEM, CLSM, 1 H-NMR useful means for the development of various delivery vehicles suitable for cancer therapy.…”

“…Via the German geologist Abraham Gottlob Werner, the term apatite was coined in 1786; apatite is from the Greek word "apatao," which means "to mislead." Aouada et al, 2018 [64] synthesized the clay-based Na-Alg magnetic nanoparticles. The cross-linker base Na-Alg has a versatile interaction with the clay, and this interaction is hydrophobic.…”

Environmentally Friendly Polyvinyl alcohol−alginate/bentonite Nanocomposite Hydrogel Beads as Efficient Adsorbents for Removal of Toxic Methylene Blue from Aqueous Solution

“…The presence of Bent nanoparticles homogeneously distributed in the hydrogel matrix was further confirmed by EDX elemental analysis as shown in Figure 4. EDX spectrum of Bent clay (Figure 5a) confirmed the presence of its main constituents such as O (51.70%), Si (21.89%), Al (9.81%), Fe (6.88%), and C (4.61%) [50,56]. The main characteristic peaks attributed to C (40.95 %) and O (52.19 %) elements are detected in the EDX spectrum of control hydrogel (Figure 4b), which are due to the contribution of PVA and Alg component.…”