We investigated the antiviral activity of nanosized copper(I) iodide (CuI) particles having an average size of 160 nm. CuI particles showed aqueous stability and generated hydroxyl radicals, which were probably derived from monovalent copper (Cu ؉ ). We confirmed that CuI particles showed antiviral activity against an influenza A virus of swine origin (pandemic [H1N1] 2009) by plaque titration assay. The virus titer decreased in a dose-dependent manner upon incubation with CuI particles, with the 50% effective concentration being approximately 17 g/ml after exposure for 60 min. SDS-PAGE analysis confirmed the inactivation of the virus due to the degradation of viral proteins such as hemagglutinin and neuraminidase by CuI. Electron spin resonance (ESR) spectroscopy revealed that CuI generates hydroxyl radicals in aqueous solution, and radical production was found to be blocked by the radical scavenger N-acetylcysteine. Taken together, these findings indicate that CuI particles exert antiviral activity by generating hydroxyl radicals. Thus, CuI may be a useful material for protecting against viral attacks and may be suitable for applications such as filters, face masks, protective clothing, and kitchen cloths.

No abstract

Carbon fibers were prepared from silk fibers after an iodine treatment and the carbon yield, fiber morphology, structure and mechanical properties were investigated.A single or multi step carbonization process was used for the preparation. In the single step process, silk fibroin (SF) fibers were heated from 25 to 800 °C with a heating rate of 5 °C min-1 under Ar atmosphere. However, the carbon fiber obtained was partially melted and was too fragile to handle. For better performance, SF fibers were treated with iodine vapor at 100 °C for 12 h and untreated and iodinated SF fibers were heated from 25 to 800 °C by a multi step carbonization process, which was defined based on the optimum thermal degradation rate of silk. In this multi step process, the carbon fibers obtained from iodinated SF were structurally intact and stable in appearance, and the carbon yield achieved was ca. 36 wt%, much higher than the value for untreated SF.X-ray diffraction, Raman spectroscopy and transmission electron microscopic observation revealed that the obtained carbon fibers from both untreated and iodinated SF were a basically amorphous structure. The strength of carbon fibers prepared from 1 iodinated SF using the multi step carbonization was considerably increased compared to that of untreated SF. According to viscoelastic measurement, by heating above 280 °C the iodine introduced intermolecular cross-linking of the SF, and its melt flow was inhibited which produced a higher yield and better performance of the carbon fiber.

ABSTRACT:Nylon 6 doped with Ag nanoparticles (nylon 6/Ag) was prepared by immersion of nylon 6 in aqueous AgNO 3 solution followed by reductive treatment by heating under H 2 gas or immersing in an aqueous NaBH 4 solution. As a result of either reductions, Ag nanoparticles below 10 nm in diameter were successfully dispersed within the nylon 6 matrix. The Ag content and the dispersion state of the Ag nanoparticles can be varied by the concentration of the AgNO 3 solutions and the reduction methods, respectively. From the results of the absorbed Ag + content in nylon 6via immersion in AgNO 3 solution, nylon 6 was found to have some affinity for silver ion. Nylon 6 doped with Ag 2 S nanoparticles (nylon 6/Ag 2 S) was also prepared by immersion in AgNO 3 aqueous solution and the following immersion of Na 2 S aqueous solution. Ag 2 S particles having several nanometers in diameter were dispersed in nylon 6. The nylon 6/Ag 2 S film showed strong photoluminescence in the near infrared region. KEY WORDS Nylon 6 / Ag / Ag 2 S / Nanocomposite / Nanoparticle / Organic/inorganic composite materials consisting of polymers doped with metal or semiconductor nanoparticles, which possess characteristic optical properties, such as non-linear optical and laser amplification properties, have attracted increasing interest for potential application as novel photonics devices. [1][2][3][4] In contrast to inorganic matrices such as glasses or ceramics, the use of organic polymers as a matrix has the advantages of processability and ease of handling of the composite materials. 2 Specifically, the polymer matrices can be molded at lower temperatures, are generally flexible, and show higher toughness than inorganic matrices. Furthermore, various inorganic compounds for doping components can be readily introduced in the polymer matrices using in-situ reactions under mild conditions. 2

We propose a copper iodide (CuI)-doped nylon mesh prepared using polyiodide ions as a precursor toward anti-biofouling polymer textile. The CuI-doped nylon mesh was subjected to the prevention of biofouling in marine environments. The attachment of the marine organisms was markedly inhibited on the CuI-doped nylon mesh surface until 249 days. Scanning electron microscopy-energy dispersive X-ray analysis indicated that copper compounds were maintained in the nylon mesh after the field experiment, although copper content in the nylon mesh was reduced. Therefore, the copper ions slowly dissolved from nylon mesh will contribute to the long-term prevention of biofouling. Furthermore, electron spin resonance analysis revealed the generation of reactive oxygen species (ROS) from CuI-doped nylon mesh after the field experiment. One of the possibilities for toxic action of copper ions will be the direct effect of Cu+ -induced ROS on biofilm forming on nylon mesh surface. The proposed polymer textile can be applied to fishing and aquafarming nets, mooring rope for ship, or silt fence to restrict polluted water in marine environments.