Functional Nanostructured Oligochitosan–Silica/Carboxymethyl Cellulose Hybrid Materials: Synthesis and Investigation of Their Antifungal Abilities

Abstract

Functional hybrid materials were successfully synthesized from low-cost waste products, such as oligochitosan (OCS) obtained from chitosan (one of the main components in crab shells) and nanosilica (nSiO2) obtained from rice husk, in a 1:1 ratio (w/w), and their dispersion in the presence of carboxymethyl cellulose at pH 7 was stable for over one month without aggregation. The molecular weights, chemical structures, morphologies, and crystallinities of the obtained materials were characterized by GPC, FTIR, TEM, and XRD, respectively. The antifungal effects of OCS, nSiO2, and the OCS/nSiO2 hybrid materials were investigated via a disk-diffusion method. The results showed that the nanohybrid materials had better resistance to Phytophthora infestans fungus than the individual components, and a concentration of the OCS2/nSiO2 hybrid material of 800 mg L−1 was the lowest concentration where the material completely inhibited Phytophthora infestans growth, as measured via an agar dilution method. This study not only creates a novel environmentally friendly material with unique synergistic effects that can replace current toxic agrochemicals but also can be considered a new platform for further research in green agricultural applications.

Highly Functional Materials Based on Nano-Lignin, Lignin, and Lignin/Silica Hybrid Capped Silver Nanoparticles with Antibacterial Activities

“…SiO 2 nanoparticles were synthesized according to a previously reported procedure. 19,20 Preparation of Lignin from the Rice Husk. RHs were rinsed with water to wash off dirt and other soluble impurities before getting dried at 60 °C.…”

The Engineering of Porous Silica and Hollow Silica Nanoparticles to Enhance Drug-loading Capacity

“…Figure 5 shows the XRD patterns of PNS (a) and HMSN (b). As shown, the broad XRD reflection peaks of PNS (2θ = 21.1 • ) and HMSN (2θ = 23.0 • ) both indicate the amorphous nature of silica nanoparticles [31]. In addition, apart from a small amorphous bump at 37 • in the PNS sample that could be attributed to trace CTAB left after calcination, no considerable difference was found between the two XRD patterns of PNS and HMSN, indicating that these nanoparticles likely have similar structures.…”

“…Having said that, further investigations on strategies to modify the surface of HMSN are still required to improve the controllability of this system, due to its similar nature to silica nanoparticles, whose availability for functionalization is abundant [4,34]. [31]. In addition, apart from a small amorphous bump at 37° in the PNS sample that could be attributed to trace CTAB left after calcination, no considerable difference was found between the two XRD patterns of PNS and HMSN, indicating that these nanoparticles likely have similar structures.…”

Nanohybrid Antifungals for Control of Plant Diseases: Current Status and Future Perspectives

“…The same team found that silica and hybrid material had good antifungal properties against P. infestans , the causal organism for late blight in tomato and potato, but the antifungal properties of hybrid materials, due to their synergistic effect, had better antifungal capacities than that of each individual component. Interestingly, the inhibition zone diameters of OCS/nSiO 2 were approximately 4–5 mm and 7–9 mm larger than those of OCS and nSiO 2 , respectively [ 87 ]. Bio-synthetized MgO nanoparticles are produced using the native bacterial strain like Bacillus sp.…”