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Öğe Adsorption of AR114 onto humic acid-modified Fe3O4 nanoparticles(Inst. Nat. Cercetare-Dezvoltare Text. Pielarie, 2023) Kaykioğlu, Gül; Bayramol, Derman Vatansever; Yildiz, AylinIn this study, Fe3O4 and humic acid-modified Fe3O4 (Fe3O4@HA) magnetic nanoparticles were synthesized and used for the removal of Acid Red 114 (AR114) dyestuff from aqueous. The batch adsorption method was used for the experiments. The magnetic nanoparticles, synthesised by an inexpensive and environmentally friendly precipitation process, were characterised by FTIR, SEM-EDX, BET surface area, and XRD analyses. The optimum pH values determined for Fe3O4 and Fe3O4@HA were the original pH (6.4) and 4, respectively. The equilibrium state was reached after 60 minutes for both adsorbents. The values for Fe3O4 and Fe3O4@HA were determined as 3.4 mg/g and 3.1 mg/g, respectively, when 10 mg/l initial dyestuff concentration and 2 g adsorbent were used. The results obtained in the adsorption experiments performed for both adsorbents were compatible with the Freundlich isotherm and pseudo-second-order kinetic model. Fe3O4 was found to be more efficient than Fe3O4@HA in terms of reuse and Fe3O4 can be used 5 times without any significant loss of adsorption capacity. The results showed that Fe3O4 and Fe3O4@HA can be environmentally friendly alternative adsorbents for the removal of hazardous azo dyestuffs from water, and have regeneration possibilities. © 2023 Inst. Nat. Cercetare-Dezvoltare Text. Pielarie. All rights reserved.Öğe Colored Nanofiber Production: A Literature Review and Case Study(wiley, 2021) Bayramol, Derman Vatansever; Atav, Rıza; Ağırgan, Ahmet Özgür; Yıldız, AylinMost of the studies on colored nanofiber production focus on coloring nanofibers and/or nanostructures after electrospinning process. There are few review articles and chapters available on coloring already produced nanofibers but there is a very limited number of work focused on coloring nanofibers during or before the electrospinning process, that the material collected from the collector is a colored material. In this chapter, both solution electrospinning and melt electrospinning, and their historical backgrounds were given. Then, scientific works on colored nanofiber production were summarized and discussed. By doing this, colored nanofiber production both with natural dyes and synthetic dyes were covered. Finally, the results of a case study on silver cyclohexane mono carboxylate:?-cyclodextrine inclusion complex doped colored functional PVA nanoweb production and its characterization were represented. It was aimed to give two functionalities namely antibacterial and halochromic. For this aim, bromothymol blue was added to electrospinning solution containing PVA and Ag-CC:?-CD inclusion complex and a colored functional PVA nanoweb was obtained. Then its halochromic functionality was tested by treating nanowebs with solutions whose pH values were adjusted between 1-14. It was determined that produced nanowebs change color with the change in pH, especially over pH 9 and below pH 4. © 2021 Scrivener Publishing LLC.Öğe From industrial waste to carbon-containing nanocomposites to obtain multifunctional properties for industrial applications(Elsevier B.V., 2022) Yıldız, Aylin; Açıkbaş, Bekir; Atav, Rıza; Dalmış, İbrahim Savaş; Bayramol, Derman Vatansever; Buğdaycı, BurhanHelianthus annuus (sunflower) and Brassica napus (canola) are two important crops for vegetable oil industry, but their residues after harvesting cause agricultural waste. In this study, agricultural wastes of sunflower and canola were utilized as activated carbon (AC) after pyrolysing the wastes at 450 °C and activating with HNO3 at 90 °C. Obtained AC was then used to produce Fe3O4@AC nanocomposites and ?-cyclodextrin(CD):Fe3O4@AC complex structures. Structural, morphological, spectroscopic, and thermal characteristic properties of the obtained nanocomposites and complex structures were examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier transform infrared (FTIR) and Thermogravimetric Analysis (TGA), respectively. Produced nanocomposites and complex structures were coated onto cotton woven fabrics which were then tested for their UV protection, flame retardant and antibacterial activity. The test results of the coated fabrics and the control (uncoated cotton fabric) samples showed that Fe3O4@AC and CD:Fe3O4@AC coated fabrics showed significant UV protection, flame retardancy and antibacterial properties. Thus, the effects which would normally be obtained with 3 different finishing chemicals, each of which causes individual waste load, were achieved with a single chemical recycled from a waste. This work is critical in terms of waste management and providing a cleaner production alternative in the field of textile finishing. © 2022 Elsevier B.V.Öğe Inclusion complexes of ?-cyclodextrıne with Fe3O4@HA@Ag Part II: Their use in the production of PVP nanowebs(Inst Natl Cercetare-Dezvoltare Textile Pielarie-Bucuresti, 2023) Atav, Riza; Agirgan, Ahmet Ozgur; Yildiz, Aylin; Bayramol, Derman Vatansever; Erguenay, UgurHumic acid is a material formed as a result of the degradation of animal and plant wastes, it cleans heavy metals which are industrial wastes that threaten both the environment and human health. In part I of this study, the Fe3O4@HA@Ag compound was synthesized, its inclusion complex with beta-cyclodextrin was prepared by using the kneading technique and obtained inclusion complexes were characterized. In this study, part II, nanowebs were formed from the inclusion of complex-containing polymer solution via the electrospinning method. The electrospinning solution consisted of beta-CD:Fe3O4@HA@Ag inclusion complexes at the rate of 5%, 7.5% and 10% by weight and the polyvinylpyrrolidone (PVP) polymer as the carrier. The obtained nanoweb material was characterized by instrumental methods such as SEM, FTIR, XRD, and TGA. The results obtained from FTIR, XRD and TGA revealed that beta-CD:Fe3O4@HA@Ag inclusion complexes containing nanowebs were successfully produced. The uniform fibre formation was detected from SEM images. The average fibre diameter of 5%, 7.5% and 10% beta-CD:Fe3O4@HA@Ag inclusion complex containing nanowebs were measured to be 612.5 nm, 610.8 nm and 431.2 nm, respectively.Öğe Novel 3-D spacer all fibre piezoelectric textiles for energy harvesting applications(Royal Soc Chemistry, 2014) Soin, Navneet; Shah, Tahir H.; Anand, Subhash C.; Geng, Junfeng; Pornwannachai, Wiwat; Mandal, Pranab; Siores, Elias; Bayramol, Derman VatanseverThe piezoelectric effect in poly(vinylidene fluoride), PVDF, was discovered over four decades ago and since then, significant work has been carried out aiming at the production of high beta-phase fibres and their integration into fabric structures for energy harvesting. However, little work has been done in the area of production of true piezoelectric fabric structures based on flexible polymeric materials such as PVDF. In this work, we demonstrate 3D spacer technology based all-fibre piezoelectric fabrics as power generators and energy harvesters. The knitted single-structure piezoelectric generator consists of high beta-phase (similar to 80%) piezoelectric PVDF monofilaments as the spacer yarn interconnected between silver (Ag) coated polyamide multifilament yarn layers acting as the top and bottom electrodes. The novel and unique textile structure provides an output power density in the range of 1.10-5.10 mW cm(-2) at applied impact pressures in the range of 0.02-0.10 MPa, thus providing significantly higher power outputs and efficiencies over the existing 2D woven and nonwoven piezoelectric structures. The high energy efficiency, mechanical durability and comfort of the soft, flexible and all-fibre based power generator are highly attractive for a variety of potential applications such as wearable electronic systems and energy harvesters charged from the ambient environment or by human movement.
