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In the present study, the surface of non-woven polypropylene (NW-PP) fabric was modified to form CN layers using a modified DC-pulsed (frequency: 60 kHz, pulse shape: square) sputtering with a roll-to-roll system. After plasma modification, structural damage in the NW-PP fabric was not observed, and the C–C/C–H bonds on the surface of the NW-PP fabric converted into C–C/C–H, C–N(CN), and C=O bonds. The CN-formed NW-PP fabrics showed strong hydrophobicity for H2O (polar liquid) and full-wetting characteristics for CH2I2 (non-polar liquid). In addition, the CN-formed NW-PP exhibited an enhanced antibacterial characteristic compared to NW-PP fabric. The reduction rate of the CN-formed NW-PP fabric was 89.0% and 91.6% for Staphylococcus aureus (ATCC 6538, Gram-positive) and Klebsiella pneumoniae (ATCC4352, Gram-negative), respectively. It was confirmed that the CN layer showed antibacterial characteristics against both Gram-positive and Gram-negative bacteria. The reason for the antibacterial effect of CN-formed NW-PP fabrics can be explained as the strong hydrophobicity due to the CH3 bond of the fabric, enhanced wetting property due to CN bonds, and antibacterial activity due to C=O bonds. Our study presents a one-step, damage-free, mass-productive, and eco-friendly method that can be applied to most weak substrates, allowing the mass production of antibacterial fabrics. [ABSTRACT FROM AUTHOR]

We investigated the carbonization process of polymer sheets such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyimide (PI) using an UV diode laser in N2 atmospheric condition, and proposed the carbonization mechanism. After the laser treatment, oxygen and nitrogen-related products in polymer sheets remarkably decreased, and carbon phase appeared in the sheets. This implied that the laser treatment using UV diode laser was an effective technique for polymer carbonization. Thus, it was concluded that the laser-treated process was expected to modify and control the properties of polymer sheet for various applications. [ABSTRACT FROM AUTHOR]

Transparent polymer sheets (PET, PEN, PI) were treated in a vacuum condition by a laser-diode (wavelength: 408 nm). The polymers were decomposed thermally with an endothermic reaction by the laser heating, and carbonization, due to the evolution of gaseous products including CO and CO2, occurred on the surface. The heating mechanism of the polymers was summarized as the formation of carbonized layer on polymer sheets and the thermal conduction due to the heating of carbonized layer by the laser-diode. Thus, it is concluded that the choice of an appropriate wavelength for the laser-diode can facilitate modification processes for various transparent polymers. [ABSTRACT FROM AUTHOR]

TiC films were formed by low-frequency (60 Hz) plasma-enhanced chemical vapor deposition (LFPECVD) using TiCl, CH, and H gas mixtures. The effects of the growth temperature and feasibility for the on-glass deposition of TiC films were investigated. The growth kinematics of TiC films was controlled mainly by surface-reactions below 450 ºC, and dominated by a mass-transfer process above 450 ºC. The films exhibited a face-centered cubic structure, and the preferred orientation of film growth was mainly the (200) plane. The [C]/[Ti] ratio was over-stoichiometric below 400 ºC, and became almost stoichiometric above 450 ºC. The optical properties of the films were characterized by high reflectance in near infrared (NIR) region and a steep edge in the visible region, and the reflectance in the NIR region increased gradually with increasing temperature. As a result, LF-PECVD is a useful technique to acquire Cl-free TiC films at relatively low temperatures. [ABSTRACT FROM AUTHOR]

In this study, the reduced graphene oxide (rGO) films were fabricated at room temperature using capacitively coupled CH4plasma treatment of the spin-coated graphene oxide (GO) films. The variations of the rGO films were evaluated according to the treatment positions (bulk plasma region (Rb) and sheath region (Rs)) and the treatment time. The reduction of the GO films began immediately after the CH4plasma was exposed to both regions. However, as the treatment time increased, the physical properties of rGO films became different. The reduction in the Rbwas effective to modify the rGO films for transparent conducting films. [ABSTRACT FROM AUTHOR]

Ga(S2CN(CH3)2)3(Ga(mDTC)3) nanoparticles (NPs) were prepared using ultrasonic spray method, and well mono-dispersed, with a mean particles size of 82 nm. Ga(mDTC)3NPs changed into Ga2S3at 300°C under N2environment, and the spin-coated films transformed into GaN films above 700°C under NH3environment. From these results, Ga(mDTC)3films were transformed into γ-Ga2S3films by thermal decomposition, and S elements were substituted simultaneously by N elements. In this stage, the pyrolytic GaN film underwent a recrystallization process, and a preferred direction of GaN films was mainly aligned to z-axis direction due to the lower energy surface of hexagonal structure. [ABSTRACT FROM AUTHOR]