Polimer Mikrokirleticilerin Su Ortamında 3B Nanoskopik Karakterizasyonları ve Yapay Kirlenmiş Suların Farklı Benzetim Teknikleri ile Tasarımı

Abstract

Micro and nano plastics pose a significant pollution problem in natural water resources. This issue not only threatens public health but also requires urgent preventive measures. In response to this challenge, several projects have been initiated to evaluate, develop, and implement alternative scientific approaches aimed at addressing this problem. This thesis outlines SAXS and WAXS analyses that will be conducted as part of the approved TUBITAK project (ÇAYDAG 121Y201), which includes interdisciplinary studies titled "Evaluation of Photocatalytic Ozonation Treatment Efficiency, Nanocomposite Recovery and Reuse with GO-TiO2-Fe3O4 and Sepiolite-WO3-Fe3O4 Nanocomposites for the Mineralization of Nanoplastics". First of all, nanoscopic characterizations of polluting plastics, which are common in existing polluted waters, were made and their morphology, size and distribution in the aquatic environment were followed. Polluted water and clean water will be used for these processes, and the focus is on Polystyrene (PS), Polypropylene (PP), Nylon66, Polyvinyl Chloride (PVC), Polyurethane (PU) and Polyethylene Terephthalate (PET) as polluting polymer materials. The structures of plastic waste collected from the seaside of Antalya-Manavgat Çavuşköy Mevkii were determined, and the differences between the structures of these plastic materials without pollutants were examined using FTIR and WAXS analyzes at the molecular level, SAXS analyzes at the nanoscopic scale. This thesis focuses on the characterization of nanoplastics (NPs) (<100 nm) that are formed by the fragmentation of large plastic residues. These materials are of particular concern as they are resistant to physical and chemical degradation, can diffuse into the cells of living organisms, and pose a direct threat to healthy life. Through this thesis, the NPs have been characterized, and it has been made possible to track their nanoscale structures in aqueous environments. This research provides valuable insights into the physicochemical properties of NPs, which can aid in the development of effective mitigation strategies. Based on the obtained results, it has been observed that PP, PVC, Nylon66, PS, and PET materials are commonly found in the form of NPs with radii ranging from 10.4 to 20.1 nm, as a result of their degradation in aqueous environments. The maximum particle widths of these polymer materials varied between 300 – 550 nm. Shrinkage was observed in PP, PVC, Nylon66, and PET materials, while an increase in radius was recorded in the case of PS material. Fractal morphologies have been found to be applicable to the nanostructures of most polymer materials. During the aging process, morphological changes were observed in many cases; however, only PVC exhibited preserved stability in its structure, maintaining a fractal morphology. This demonstrates the remarkable structural stability of PVC in pollution investigations. Nanoscopic analyses were conducted on water samples entering and leaving the water treatment facility, and the characterized NP morphologies were traced. Surprisingly, nanoscale PVC particles were detected even in the purified water environment. The effective radius of the identified PVC polymer material in the purified water was determined to be 13.2 nm, with maximum diameters reaching 450 nm. These measurements provide evidence suggesting that the utilization of PVC (polyvinyl chloride) in the construction of water pipes can potentially result in nanoscale water pollution, as indicated by the detection of PVC particles in the purified water samples. In order to examine the effect of artificial aging, a factory-produced polyurethane (PU) material was exposed to UV radiation for a period of 8 days. In addition, a natural PU polymer material with an unknown aging time was also analyzed. Two different forms of each of the natural and artificial PU polymer materials were investigated. After aging process, the radius of the artificial PU polymer increased from 15 nm to 16 nm, while the radius of the natural PU polymer material increased more significantly, from 17 nm to 23.6 nm. To investigate the effects of artificial aging, a factory-produced polyurethane (PU) material was directly subjected to UV radiation for a continuous period of 8 days. Additionally, a sample of PU polymer material obtained from nature, with an undetermined aging duration, was also analyzed. Samples from both the naturally occurring and artificially aged PU polymer materials were taken, considering areas directly exposed to UV radiation and regions within the material where the radiation penetrated. These distinct samples, representing external surface and internal portions, were examined. The analysis revealed that, as a result of aging, the artificially aged PU polymer exhibited an increase in nanoparticle radius from 15 nm to 16 nm, while the naturally obtained aged PU polymer material displayed a more pronounced change in radius, increasing from 17 nm to 23.6 nm. Consequently, it was determined that the natural aging process, as well as artificial aging induced by UV radiation, led to an increase in nano particle dimensions. At the molecular scale, the natural physicochemical aging effects on each material were thoroughly investigated using FT-IR analysis, taking into account the atomic and molecular components. The findings obtained from these analyses revealed that natural aging had the most pronounced effect in terms of molecular structural changes in PVC, while the least aging effect was observed at the molecular level in Nylon66. In the case of PU material, the most significant molecular change during the aging process was observed in the range of 2800-3000 cm-1 (corresponding to the alteration in the symmetric and asymmetric stretching of the C-H bond). As a result, the characterization of molecular and nanoscale pollutants has been conducted, enabling their tracking in aqueous environments. The aging effects under natural conditions have been examined, and nano solutions contaminated with polymer pollutants have been designed in aqueous environments. Furthermore, the identification of polymer nanoparticles present in naturally polluted waters has been achieved. Keywords: Nanoplastics, Micropollutants, Nanoscopic Analysis, SAXS, WAXS, FT-IR.