Green synthesis of copper oxide nanoparticles and its efficiency in degradation of rifampicin antibiotic.

In recent ages, green nanotechnology has gained attraction in the synthesis of metallic nanoparticles due to their cost-effectiveness, simple preparation steps, and environmentally-friendly. In the present study, copper oxide nanoparticles (CuO NPs) were prepared using Parthenium hysterophorus whole plant aqueous extract as a reducing, stabilizing, and capping agent. The CuO NPs were characterized via UV-Vis Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), powder X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Dynamic Light Scattering (DLS). The UV-Vis spectra of CuO NPs showed a surface plasmonic resonance band to occur at 340 nm. FTIR analysis revealed the presence of secondary metabolites on the surface of CuO NPs, with a characteristic Cu-O stretching band being identified at 522 cm-1. Scanning electron micrographs and transmission electron micrographs showed that CuO NPs were nearly spherical, with an average particle of 59.99 nm obtained from the SEM micrograph. The monoclinic crystalline structure of CuO NPs was confirmed using XRD, and crystallite size calculated using the Scherrer-Debye equation was found to be 31.58 nm. DLS showed the presence of nanoparticle agglomeration, which revealed uniformity of the CuO NPs. Furthermore, the degradation ability of biosynthesized nanoparticles was investigated against rifampicin antibiotic. The results showed that the optimum degradation efficiency of rifampicin at 98.43% was obtained at 65℃ temperature, 50 mg dosage of CuO NPs, 10 mg/L concentration of rifampicin solution, and rifampicin solution at pH 2 in 8 min. From this study, it can be concluded that CuO NPs synthesized from Parthenium hysterophorus aqueous extract are promising in the remediation of environmental pollution from antibiotics. In this light, the study reports that Parthenium hysterophorus-mediated green synthesis of CuO NPs can effectively address environmental pollution in cost-effective, eco-friendly, and sustainable ways.

Stimuli-Responsive and Antibacterial Cellulose-Chitosan Hydrogels Containing Polydiacetylene Nanosheets.

Herein, we report a stimuli-responsive hydrogel with inhibitory activity against Escherichia coli prepared by chemical crosslinking of carboxymethyl chitosan (CMCs) and hydroxyethyl cellulose (HEC). The hydrogels were prepared by esterification of chitosan (Cs) with monochloroacetic acid to produce CMCs which were then chemically crosslinked to HEC using citric acid as the crosslinking agent. To impart a stimuli responsiveness property to the hydrogels, polydiacetylene-zinc oxide (PDA-ZnO) nanosheets were synthesized in situ during the crosslinking reaction followed by photopolymerization of the resultant composite. To achieve this, ZnO was anchored on carboxylic groups in 10,12-pentacosadiynoic acid (PCDA) layers to restrict the movement of the alkyl portion of PCDA during crosslinking CMCs and HEC hydrogels. This was followed by irradiating the composite with UV radiation to photopolymerize the PCDA to PDA within the hydrogel matrix so as to impart thermal and pH responsiveness to the hydrogel. From the results obtained, the prepared hydrogel had a pH-dependent swelling capacity as it absorbed more water in acidic media as compared to basic media. The incorporation of PDA-ZnO resulted in a thermochromic composite responsive to pH evidenced by a visible colour transition from pale purple to pale pink. Upon swelling, PDA-ZnO-CMCs-HEC hydrogels had significant inhibitory activity against E. coli attributed to the slow release of the ZnO nanoparticles as compared to CMCs-HEC hydrogels. In conclusion, the developed hydrogel was found to have stimuli-responsive properties and inhibitory activity against E. coli attributed to zinc nanoparticles.

Advances in green nanotechnology: Data for green synthesis and characterization of iron nanoparticles synthesized using Galinsoga parviflora, Conyza bonariensis and Bidens pilosa leaf extracts, and their application in degradation of methylene blue dye and rifampicin antibiotic.

This data article reports contents of the information derived from an efficient, environmentally friendly, and low-cost method of synthesis and recovery of iron nanoparticles using Galinsoga parviflora, Conyza bonariensis and Bidens pilosa aqueous leaf extracts as reducing, stabilizing, and capping agents, and applications of the nanoparticles in degradation of organic dyes and antibiotics. Various spectroscopic and microscopic techniques were used to collect the data. Data is displayed in the form of .raw files, graphs, images, Microsoft Excel sheets, .data point files, and PDF files, along with other formats. Data analysis and interpretation methods have also been presented. Researchers, research students, academicians, and industrialists can benefit greatly from the data in order to gain knowledge about the green synthesis of iron nanoparticles and related applications such as degradation organic pollutants. The data is deposited in the mendeley data repository as two independent datasets at https://data.mendeley.com/datasets/rxkv6j7hrx.

Cellulose nanofibrils and silver nanoparticles enhances the mechanical and antimicrobial properties of polyvinyl alcohol nanocomposite film.

Recent findings of microplastics in marine food such as fish, crabs and shrimps necessitate the need to develop biodegradable packaging materials. This study reports on the development of a biodegradable packing material from cellulose nanofibril-polyvinyl alcohol nanocomposite embedded with silver nanoparticles. Microcrystalline cellulose was isolated from sugarcane bagasse via the kraft process followed by conversion of cellulose I to cellulose II using NaOH/urea/water solution. The nanofibrils were then isolated using (2,2,6,6-Tetramethylpiperidin-1-yl) oxyl (TEMPO) and used as a reinforcing element in polyvinyl alcohol composite prepared through solvent casting. The tensile strength, water solubility, optical properties, water vapor permeability and wettability of the prepared films were then evaluated. The antimicrobial potency of the films was evaluated using the disc diffusion antimicrobial assay against selected microorganisms.