Fabrication Of Copper Nanoparticles Research Articles

Novel fabrication of gelatin-encapsulated copper nanoparticles using Aspergillus versicolor and their application in controlling of rotting plant pathogens.

The fabrication of copper nanoparticles (CuNPs) with smallest size and more stability, with potential effects in plant disease management, may need a modified protocol for green synthesis. In this study, we could biosynthesize stable CuNPs extracellularly by an eco-friendly route using A. versicolor. The biosynthesis of nanoparticles was confirmed by UV-visible spectroscopy, Fourier transform infrared (FTIR), transmission electron microscope (TEM) and dynamic light scattering (DLS) techniques. CuNPs have a size range of 23-82nm with round to polygonal shape. Antifungal study showed that CuNPs have potential antifungal activity against rotting plant pathogens, where 3.2 and 2.8µgml-1 of nanoparticle solution totally inhibited the growth of both Fusarium oxysporum and Phytophthora parasitica, respectively. Damaged hyphae with limited deformed spores were detected through scanning electron microscope (SEM) analysis after the treatment of both pathogens with CuNPs. Between all tested polymers, gelatin-encapsulated nanoparticles were characterized 'by their smallest size, 7-33nm, and regular spherical shape at all experimental conditions. After 6months of storage, gelatin-CuNPs maintained full nanoscale and antifungal properties compared with uncoated particles which lost these properties after only 1month. It is concluded that CuNPs can be biosynthesized by an eco-friendly cheap method using A. versicolor and can be preserved stably for a long time with the smallest size and full antifungal activity by their encapsulation with gelatin as a natural polymer. These nanoparticles can be used safely in the management of plant rotting fungi.

Direct deposition of copper nanoparticles on poly(glycidyl methacrylate) beads

Fabrication of Copper nanoparticles (CuNPs) on the Poly(glycidyl methacrylate) (PGMA) to prepare Poly(glycidyl methacrylate) core/copper nanoparticle shell nanocomposite (PGMA/Cu nanohybrid) by deposition method. The deposition method consists of two simple steps (i) The synthesis of PGMA beads by suspension polymerization followed by (ii) direct deposition of CuNPs on activated PGMA beads. The PGMA beads were used as a soft template to host the CuNPs without surface modification of it. Two different concentrations of copper salts (1% and 5%) were employed to know the effect of concentration on the shape and size of nanoparticles. The catalytic activity of PGMA/Cu nanohybrids were tested for the reduction of 4‐nitrophenol (4NP) to 4‐aminophenol (4AP) with an excess amount of sodium borohydride (NaBH4). The results showed that, the diverse sizes and shapes of CuNPs were deposited on the PGMA matrix. The X‐ray diffraction study revealed that the CuNPs were present on the surface of the PGMA matrix. The scanning electron microscopic images show that the fabrication of CuNPs on the PGMA matrix changes the morphology and nature of PGMA beads significantly. The catalytic studies have demonstrated that the PGMA/Cu nanohybrid 1% exhibit better catalytic activity than 5%. POLYM. COMPOS., 39:1913–1921, 2018. © 2016 Society of Plastics Engineers

Synthesis, characterization and fabrication of copper nanoparticles in N-isopropylacrylamide based co-polymer microgels for degradation of p-nitrophenol

Abstract Poly(N-isopropylacrylamide-co-acrylic acid) [P(NIPAM-co-AAc)] microgels were synthesized by precipitation polymerization. Copper nanoparticles were successfully fabricated inside the microgels by in-situ reduction of copper ions in an aqueous medium. The microgels were characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and Dynamic Light Scattering (DLS). Hydrodynamic radius of P(NIPAM-co-AAc) microgel particles increased with an increase in pH in aqueous medium at 25 °C. Copper-poly(N-isopropylacrylamide-co-acrylic acid) [Cu-P(NIPAM-co-AAc)] hybrid microgels were used as a catalyst for the reduction of 4-nitrophenol (4-NP). Effect of temperature, concentration of sodium borohydride (NaBH4) and catalyst dosage on the value of apparent rate constant (kapp) for catalytic reduction of 4-NP in the presence of Cu-P(NIPAM-co-AAc) hybrid microgels were investigated by UV-Vis spectrophotometry. It was found that the value of kapp for catalytic reduction of 4-NP in the presence of Cu-P(NIPAM-co-AAc) hybrid microgel catalyst increased with an increase in catalyst dosage, temperature and concentration of NaBH4 in aqueous medium. The results were discussed in terms of diffusion of reactants towards catalyst surface and swelling-deswelling of hybrid microgels.

Fabrication of Copper Nanoparticles in a Thick Polyimide Film Cured by Rapid Thermal Annealing

We investigated the imidization of a polyimide (PI) and the formation of Cu nanoparticles in a PI film by curinga precursor of PI (polyamic acid (PAA) dissolved in n-methyl-2-pyrrolidinone) in a reducing atmosphere in the rapid thermal annealing (RTA) system. A Cu film was deposited onto the SiO2/Si substrate, and the PAA was spin-coated onto the Cu film. After the PAA reacted with the Cu film, soft-baking was performed to evaporate the solvent. Finally, the PAA was imidized to PI at 450 degrees C by curing in a reducing atmosphere with the RTA. Fourier transform infrared spectroscopy showed that the PAA was successfully imidized by the RTA. X-ray diffraction patterns revealed that Cu nanoparticles formed by RTA curing at 450 degrees C for 5 minutes in a reducing atmosphere, and transmission electron microscopy showed that Cu nanoparticles about 6.5 nm in size were uniformly dispersed in the PI film. Curing by RTA is an attractive method because it takes only a few minutes.