THE UTILIZATION OF POLYDOPAMINE INTERLAYER TO ADD SILVER NANOPARTICLES (AGNPS) TO PET FABRICS

Silver nanoparticles are structures used in many areas such as antibacterial materials, increasing conductivity, and wastewater treatment, etc. In recent years, demand for their use in textile products has been increasing. Starting from this point, this study aimed to produce silver nanoparticles on the surface of PET fabric in order to meet the different properties expected from silver. For this purpose, polydopamine coating was applied on PET fabric by in situ polymerization. Then, fabric structures containing polydopamine and silver nanoparticles were obtained with a reduction reaction of three different molarity silver nitrate salts. The after washing condition of the fabric with the highest produced amount of silver nanoparticles was examined. Spectrophotometric color measurement, FT-IR, SEM and EDX techniques were performed. The best results were obtained on the fabric where silver nitrate was applied at 50 mM. The amount of silver nanoparticles in this fabric was measured as 1.35% after washing.

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Polydopamine nanocoating to use surface functionalization of polypropylene fabrics with a closed structure

In this study, an experimental investigation was conducted to explore polydopamine (PDA) nano coating to use surface functionalization of polypropylene (PP) fabrics with a closed structure. Nano coatings were made on polypropylene nonwoven fabric with the oxygen-induced polymerization method of dopamine (DA) in six different times. Uncoated control samples, coated samples and washed samples after coating were compared. A change in the solution towards dark brown-black color was observed during the experimental as the reaction time increased. Based on this finding, spectrophotometric measurements of samples were made. The lowest lightness and highest color strength values were observed in fabric coated for 32 hours. In before and after washing SEM images, the formed nano coating could be easily seen on this fabric (32 h). The nitrogen ratio indicating the presence of polydopamine was detected as 17.05%. After washing, it was observed that this high percentage decreased up to 1.35% but the nitrogen element was distributed homogeneously on the fabric surfaces from EDX mapping. FTIR analysis results confirmed that the PDA coating formed a bond with the polypropylene fabric and that these bonds continued after washing. Differently from uncoated fabric, extra bands and signals were observed in two different regions on the FTIR graph due to polydopamine. The results presented here may facilitate improvements in the surface activation of PP fabrics, which have a more closed structure for functionalization.

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Investigation of the oxidative self polymerization of dopamine under alkaline conditions on wool fabrics

Most studies about polydopamine in the textile field have been related to cotton fibers. There are not many studies about the use of polydopamine on wool fibers. A limited number of studies have focused on the coloring of wool, whereas wool is the fiber with the highest variety of intermolecular attraction forces among all natural and man-made fibers. 

Polydopamine contains high amounts of catechol and amine functional groups due to its structure. In this study, different from the literature, oxidative self polymerization of dopamine was achieved on wool fabric for different periods of time, and the coated fabrics were examined with characterization tests and spectrophotometrically. 

In this study, lower values were obtained than lightness (L*) values reported for other fibers in previous studies, and it was concluded that the wool-PDA interaction is superior to other fibers. Scanning electron microscopy and energy dispersive X-ray spectroscopy results showed that the polymerization and nano-coating formed successfully and continued to remain on the surface after washing. 

The lowest lightness value was obtained in the 32 h coating. However, the lowest color change after washing was in the 16 h coating (0.44%). This result showed that the coating was completed within 16–32 hours and there was only accumulation on the surface in the later times.

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The use of mussel‑inspired polydopamine interlayer for high‑efficiency surface functionalization of PET fabrics

The surface modifications of polymer materials are carried out to improve surface properties, add new functionalities and thus enlarge their application areas. Polyethylene terephthalate (PET) is a commonly used textile fabric to achieve functional properties via surface modification techniques. However, its inert and non-reactive nature necessitates an activation process before the surface modification to create functional surfaces. Plasma treatment and chemical methods are commonly used for this aim. However, these techniques can easily damage the surface of the PET fabric and result in decreased mechanical properties. In this study, we proposed a new method to activate the surface of PET using polydopamine (PDA) interlayer, known as substrate-independent coating material, to form a better and more homogenous polyaniline (PAni) coating via an in-situ polymerization technique. The surface appearance of the samples was investigated using scanning electron microscopy, and the distribution of elements was analyzed using an energy-dispersive (EDS) detector. Thermal properties of the samples were explored using thermogravimetric analyses and Fourier-transform infrared spectroscopy was used to compare the chemical structures of the coated and uncoated samples. It was found that the PDA interlayer between PAni and PET significantly reduced the sheet resistance by providing more homogenous and chemically stable PAni coatings. Moreover, the effect of the PDA and PAni coating on the optical properties was investigated, and it was found that the PDA + PAni coated fabric exhibited a maximum of 10% reflectance in the range of 400 and 700 nm while uncoated fabric showed over 90%.

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