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The undertaken study describes synthesis of air resistant copper nanoparticles (Cu NPs) in an aqueous phase using sodium borohydride as a reducing agent via chemical reduction method. The hydrosol has resistant to oxidation by atmospheric oxygen for several days. The air stability was induced by capping Cu NPs with anionic surfactant "sodium dodecyl sulfate (SDS)". Ascorbic acid was used as an antioxidant. These Cu NPs were characterized by ultraviolet-visible (UV-VIS) spectroscopy, which contributed towards the understanding of surface plasmon resonance (SPR) generation and optical behavior of Cu NPs. It was used as an optical tracer for size control and confirmation of Cu NPs and was found to be affected by various parameters like reaction time, pH, concentration of copper sulfate and the surfactant SDS. SPR peaks were found to shift from 597 to 569 nm, while apparent color changes from yellow to brick red. Further characterization studies were carried out by using fourier transform infrared (FT-IR) spectroscopy to investigate the co-ordination between Cu NPs and SDS. X-ray diffraction (XRD) was used for phase purity of Cu NPs. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used the size and morphological characterization. The average size of the Cu NPs was found to be 15 nm in diameter with an average height of 14 nm. The Cu NPs showed excellent catalytic activity in the reductive degradation of Eosin B (EB) dye in just 16 sec of reaction time and maintained their catalytic activity when reused multiple times. The degradation rate was found to follow first order reaction kinetics with the EB degradation. The Cu NPs enhanced the rate of EB degradation 30 times more than the control test. Copper was found an attractive catalyst in the nanosize regimes. The Cu NPs are more economical as compared to noble metals. The Cu NPs are expected to be suitable alternative and play an imperative role in the fields of catalysis and environmental remediation.

Herein we report a rapid method for deacetylation of cellulose acetate (CA) nanofibers in order to produce cellulose nanofibers using ultrasonic energy. The CA nanofibers were fabricated via electrospinning thereby treated with NaOH and NaOH/EtOH solutions at various pH levels for 30, 60 and 90min assisted by ultrasonic energy. The nanofiber webs were optimized by degree of deacetylation (DD%) and wicking behavior. The resultant nanofibers were further characterized by FTIR, SEM, WAXD, DSC analysis. The DD% and FTIR results confirmed a complete conversion of CA nanofibers to cellulose nanofibers within 1h with substantial increase of wicking height. Nanofibers morphology under SEM showed slightly swelling and no damage of nanofibers observed by use of ultrasonic energy. The results of ultrasonic-assisted deacetylation are comparable with the conventional deacetylation. Our rapid method offers substantially reduced deacetylation time from 30h to just 1h, thanks to the ultrasonic energy.

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