Nylon | EPFL Graph Search

Nylon is a generic designation for a family of synthetic polymers composed of polyamides (repeating units linked by amide links). Nylon is a silk-like thermoplastic, generally made from petroleum, that can be melt-processed into fibers, films, or shapes. Nylon polymers can be mixed with a wide variety of additives to achieve many property variations. Nylon polymers have found significant commercial applications in fabric and fibers (apparel, flooring and rubber reinforcement), in shapes (molded parts for cars, electrical equipment, etc.), and in films (mostly for food packaging). History DuPont and the invention of nylon Researchers at DuPont began developing cellulose-based fibers, culminating in the synthetic fiber rayon. DuPont's experience with rayon was an important precursor to its development and marketing of nylon. DuPont's invention of nylon spanned an eleven-year period, ranging from the initial research program in polymers in

Innovative UVC Light (185 nm) and Radio-Frequency-Plasma Pretreatment of Nylon Surfaces at Atmospheric Pressure and Their Implications in Photocatalytic Processes

Juan Kiwi, César Pulgarin

Innovative pretreatment by UVC light (185 nm) and by radio-frequency (RF) plasma at atmospheric pressure to functionalize the Nylon surface, increasing its bondability toward TiO2, is reported in this study In the case of UVC light pretreatment in air, the molar absorption coefficient of O-2/N-2 at 185 nm is very low and the air in the chamber absorbs very little light from the UVC source before reaching the Nylon sample Nylon fabrics under RF plasma were also functionalized at atmospheric pressure because of the marked heating effect introduced in the Nylon by the RF plasma This effect leads to intermolecular bond breaking and oxygenated surface groups in the topmost Nylon layers. Both pretreatments enhanced significantly the photocatalytic discoloration of the red-wine stain in Nylon-TiO2 compared with samples without pretreatment. The UVC and RF methods in the absence of vacuum imply a considerable cost reduction to functionalize textile surfaces, suggesting a potential industrial application Red-wine-stain discoloration under simulated sunlight was monitored quantitatively by diffuse-reflectance spectroscopy and by CO2 evolution X-ray photoelectron spectroscopy (XPS) was used to monitor the changes of the C, N, and S species on the Nylon topmost layers during the discoloration process Significant changes in the XPS spectra of Ti 2p peaks were observed during discoloration of the wine spots Wine stains attenuated the signal of the Ti 2p (458.4 eV) peak in the Nylon-TiO2-stained wine sample at time zero (from now on, the time before (he discoloration process) Furthermore. a decrease of the wine-related O 1s signal at 529 7 eV and N 1s signal at 399 5 eV was observed during the discoloration process. indicating an efficient catalytic decomposition of the wine pigment on Nylon-TiO2, X-ray diffraction detected the formation of anatase on the Nylon fibers High-resolution transmission electron microscopy shows the formation of anatase particles with sizes between 8 and 20 nm

2009

Photocatalytic evaluation of TiO2/nylon systems prepared at different impregnation times

Juan Kiwi, César Pulgarin

TiO2/nylon fabrics were investigated for methanol degradation under UV light irradiation. TiO2 Degussa P-25 was supported on nylon by immersing the nylon in sol-gel TiO2 and silicone. The TiO2 layers on the nylon were explored as a function of the time of immersion, impregnation agent and the type of nylon fabric used. The energy diffuse spectroscopy (EDS) and infrared spectroscopy (ATR-FTIR) confirmed the presence of TiO2 bonded to the nylon fabrics. Optical microscopy (OM) and scanning electron microscopy (SEM) show a more uniform distribution of TiO2 on nylon fabrics prepared by immersion in sol-gel as compared to the silicone method. The most suitable photodegradation of gaseous methanol by TiO2/nylon samples was obtained by sol-gel samples prepared by 24 h immersion time. (C) 2010 Elsevier B.V. All rights reserved.

Elsevier2011

Innovative UVC Light (185 nm) and Radio-Frequency-Plasma Pretreatment of Nylon Surfaces at Atmospheric Pressure and Their Implications in Photocatalytic Processes

Juan Kiwi, César Pulgarin

2009