ABSTRACT
Novel and sustainable chitosan (CS)/activated charcoal (AC) composites were prepared by cross-linking with epichlorohydrin (ECH) to form a porous structure. Different titanium dioxide nanoparticle (TiO2 NPs) concentrations (0, 0.2, 0.4, and 0.8% w/w) were added to enhance the photocatalytic, antibacterial, larvicidal, and pupicidal activities' efficiency toward Rose Bengal (RB) dye and the Culex pipiens. The composites were characterized by FT-IR, XRD, XPS, BET and SEM. The SEM images revealed the porous structure of CS/AC and TiO2 nanoparticles were uniformly distributed in the CS/AC matrix. The degradation of RB dye was used to test the photocatalytic behavior of the composites. Supporting TiO2 on a CS/AC matrix resulted in a significant increase in photocatalytic performance. The antibacterial activities supported by CS/AC/TiO2 NPs were evaluated by bacterial growth inhibition against B. subtilis, S. aureus, E. coli, and P. aeruginosa. The results showed that CS/AC/TiO2 NPs composite has an inhibitory effect and therefore considered antibacterial agents. CS/AC/0.4%TiO2 NPs showed maximum efficacy against larvicidal activity and pupicidal of mosquito vector which recorded 99.00 ± 1.14, 95.00 ± 1.43, and 92.20 ± 2.64 for the first, second, and third larval instars and 66.00 ± 2.39 for pupal mortality, while the repellent activity reported high protection at 82.95 ± 2.99 with 3.24 mg/cm2 dose compared to control DEET.
Subject(s)
Chitosan , Nanoparticles , Animals , Catalysis , Charcoal/pharmacology , Chitosan/chemistry , Escherichia coli , Spectroscopy, Fourier Transform Infrared , Staphylococcus aureus , Titanium/chemistry , Titanium/pharmacologyABSTRACT
Cellulose nanocrystal (CNC) and ZnO/CuO nanostructure were successfully synthesized by acid hydrolysis and sol-chemical methods, respectively. For the first time, CNC was used as a host polymer for synthesis of CNC/ZnO/CuO through In-situ solution casting technique. Morphological and structural of CNC, ZnO/CuO and hybrid CNC/ZnO/CuO were investigated by TEM, SEM-EDX, FT-IR, XRD and XPS analyses. The analysis revealed that, poly-dispersed, smooth and rod like CNC with an average length of â¼ 85.4â¯nm, average diameter of â¼13.9â¯nm and surface charge of 0.01â¯mmol/gm. As well, irregular shapes as hexagonal, spherical and cluster or star like of ZnO/CuO were formed. EDX and XRD spectra exhibited highly purified CNC/ZnO/CuO and pointed to cellulose II crystallite form with a monoclinic structure. The results demonstrated that, 91.3 % and 99.7 % dye degradation was achieved after 40â¯min of irradiation due to ZnO/CuO and CNC/ZnO/CuO treatment. Moreover, the inhibition zones formed due to 100â¯ppm ZnO/CuO were duplicated after integrating CNC (from 7.7:10.3â¯mm to 14.3:20.3â¯mm). The hybrid nanostructure exhibit larvicidal activity against Anopheles stephensi better than CNC and ZnO/CuO nanostructures.