Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Book Part The Role of Polyurethane Foam Indoors in the Fate of Flame Retardants and Other Semivolatile Organic Compounds(American Chemical Society, 2021) Sofuoğlu, Aysun; Sofuoğlu, Sait Cemil; Sofuoğlu, Aysun; Genişoğlu, Mesut; Sofuoğlu, Sait Cemil; 03.02. Department of Chemical Engineering; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyFlame retardant chemicals are added to polyurethane foams (PUFs) during production. These chemicals are released to the environment during the use of PUF containing furniture or building materials. In contrast, organic pollutants such as polychlorinated biphenyls, polycyclic aromatic hydrocarbons, synthetic musk compounds, and volatile organic compounds could be sorbed by PUF depending on the concentration gradient, ambient temperature, and the physicochemical properties. Most of these substances tend to accumulate by adhering to organic matter in dust, particles, and surfaces, as they do not degrade for long periods of time. Sorption-emission cycles of PUF-associated organic compounds prolong their presence in indoor environments, which could increase human exposure. Since these organic compounds might have carcinogenic or chronic-toxic health effects on living organisms, it is important to understand the role of PUF in exposure to these substances in indoor environments. This chapter reviews the literature on the relationship of organic substances with PUF in indoor environments.Article Citation - WoS: 39Citation - Scopus: 44Polyurethane Foam (puf) Disk Passive Samplers Derived Polychlorinated Biphenyls (pcbs) Concentrations in the Ambient Air of Bursa-Turkey: Spatial and Temporal Variations and Health Risk Assessment(Elsevier Ltd., 2017) Birgül, Aşkın; Kurt Karakuş, Perihan Binnur; Alegria, Henry; Güngörmüş, Elif; Çelik, Halil; Çiçek, Tuğba; Güven, Emine Can; 01. Izmir Institute of TechnologyPolyurethane foam (PUF) passive samplers were employed to assess air concentrations of polychlorinated biphenyls (PCBs) in background, agricultural, semi-urban, urban and industrial sites in Bursa, Turkey. Samplers were deployed for approximately 2-month periods from February to December 2014 in five sampling campaign. Results showed a clear rural-agricultural-semi-urban-urban-industrial PCBs concentration gradient. Considering all sampling periods, ambient air concentrations of Σ43PCBs ranged from 9.6 to 1240 pg/m3at all sites with an average of 24.1 ± 8.2, 43.8 ± 24.4, 140 ± 190, 42.8 ± 24.6, 160 ± 280, 84.1 ± 105, 170 ± 150 and 280 ± 540 pg/m3for Mount Uludag, Uludag University Campus, Camlica, Bursa Technical University Osmangazi Campus, Hamitler, Agakoy, Kestel Organised Industrial District and Demirtas Organised Industrial District sampling sites, respectively. The ambient air PCB concentrations increased along a gradient from background to industrial areas by a factor of 1.7–11.4. 4-Cl PCBs (31.50–81.60%) was the most dominant homologue group at all sampling sites followed by 3-Cl, 7-Cl, 6-Cl and 5-Cl homologue groups. Sampling locations and potential sources grouped in principal component analysis. Results of PCA plots highlighted a large variability of the PCB mixture in air, hence possible related sources, in Bursa area. Calculated inhalation risk levels in this study indicated no serious adverse health effects. This study is one of few efforts to characterize PCB composition in ambient air seasonally and spatially for urban and industrial areas of Turkey by using passive samplers as an alternative sampling method for concurrent monitoring at multiple sites.Article Citation - WoS: 62Citation - Scopus: 67Thermal Stability of Carbonic Anhydrase Immobilized Within Polyurethane Foam(John Wiley and Sons Inc., 2010) Kanbar, Bora; Özdemir, Ekrem; Özdemir, Ekrem; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThermal stability of carbonic anhydrase (CA) immobilized within polyurethane (PU) foam was investigated. The catalytic activity of the enzyme was estimated by using p-nitrophenyl acetate (p-NPA) as the substrate in tris buffer containing 10% acetonitrile. The immobilized CA was stable during the repeatable washings and stability tests over 45 days stored in tris buffer at ambient conditions indicating that the CA was covalently attached to the polyurethane (PU) foam by crosslinking. The immobilized CA was found to be 98% stable below 50°C, whereas a drastic decrease was seen at temperatures between 50 and 60°C. The optimum temperature for the immobilized CA was found to be 45°C and it lost its activity completely at 60°C. Thermal deactivation energies for the free and immobilized CA were estimated to be 29 and 86 kcal/mol, respectively. The association of unfolded CA with the polymeric backbone chains of the PU foam was also addressed. It was concluded that the immobilized CA was highly stable at temperatures less than 50°C and could be used in biomimetic CO sequestration processes. © 2010 American Institute of Chemical Engineers