Person: ORHAN, MEHMET
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ORHAN
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MEHMET
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Publication Wrinkle recovery and performance properties of viscose surface treated with different crosslinking agents(Gazi Üniversitesi Mühendislik Mimarlık Fakültesi, 2021-01-01) Orhan, Mehmet; ORHAN, MEHMET; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Tekstil Mühendisliği; 0000-0001-8043-4148; AAG-8034-2021Cellulosic-based surfaces, such as viscose and linen, tend quickly to wrinkle, and this is an undesirable property during uses. In this study, it is aimed to investigate their effects on formaldehyde amount, color, tear and tear resistance, modulus of elasticity, softness, and wrinkle recovery angle of viscose surface after applying three different cross-linking chemicals. It has been observed that cross-linking agents had bound to viscose surface, and cross-links were formed between adjacent fibers. Although free formaldehyde values were positively below 75 ppm in all applications, it was seen that color difference and yellowing continued to be a problem. Considering the physical properties, which is one of the other negative results, the improvements in breaking and tearing strength were obtained compared to the untreated surface. While lower bending rigidity values were measured for all applications, surfaces had a softer handle after treatments. At the same time, the higher wrinkle angle values were achieved on the surfaces with an increase in concentration. It was determined that imidazoline gave the best wrinkle angle values among cross-linkers. The results showed that cross-linkers made a positive contribution to the wrinkle property of the viscose surface.Publication Investigation of poly(lactic acid) nanocapsules containing the plant extract via coaxial electrospraying method for functional nonwoven applications(Sage Publications Inc, 2021-01-25) İbili, Hatice; Daşdemir, Mehmet; Çankaya, I. Irem Tatlı; Orhan, Mehmet; Güneşoğlu, Cem; Anul, Serap Arabacı; ORHAN, MEHMET; Bursa Uludağ Üniversitesi/Tekstil Mühendisliği Bölümü; 0000-0001-8043-4148; AAG-8034-2021This study focuses on the development of functional nanocapsules via the coaxial electrohydrodynamic atomization (electrospraying) method. These nanocapsules can manipulate nonwoven surface functionality in terms of antibacterial characteristics for medical textile purposes. Electrosprayed nanocapsules were produced from Poly(lactic acid) (PLA) polymer and Plumbago europaea plant extract. Here, we employ optimized solution and process parameters (needle to collector distance, electrical field, application time, and needle dimension) for the coaxial electrospraying process. Different Plumbago europaea extract concentrations and co-fluids' flow rates were investigated as part of the study. Also, the effect of these parameters on capsule morphology and dimension were investigated. After the formation of PLA nanocapsules, morphological and dimensional characteristics were analyzed through SEM, FESEM, TEM images in addition to FTIR and nanosize measurements. According to our findings, a lower co-fluids' flow rate gives the smaller nanocapsules with narrow-sized distribution and desired spherical morphology. Antibacterial efficiency doesn't show any significant difference except the lowest plant extract concentrations. After characterizing the nanocapsules' structures, the core-sheath structure can be clearly identified. Consequently, the desired capsule morphology and size for nanocapsules were accomplished. The antibacterial efficiency of covered surfaces with nanocapsules is up to 80% for Staphylococcus aureus and about 31% for Escherichia coli, even with low pick-up ratios. Even for a very low amount of extract usage, good antibacterial efficiency can be achieved. The application has endless potential in terms of higher concentration and a wide range of chemical usage.Publication Supercritical carbon dioxide application using hydantoin acrylamide for biocidal functionalization of polyester(Elsevier, 2020-11-01) Orhan, Mehmet; Demirci, Fatma; Koçer, Hasan B.; Nierstrasz, Vincent; ORHAN, MEHMET; Bursa Uludağ Üniversitesi/Tekstil Mühendisliği Bölümü/Mühendislik Fakültesi; 0000-0001-8043-4148; AAG-8034-2021Biocidal functionalization in polyester fibers is a really tough challenge because of the lack of tethering groups. This study indicated supercritical carbon dioxide application using N-halamine would be an alternative solution for obtaining antibacterial function on the polyester surface. Firstly, N-(2-methyl 1-(4 methyl-2,5-dioxo-imidazolidin-4 yl)propan-2-yl)acrylamide was synthesized and applied to the polyester in supercritical carbon dioxide medium, at 120 degrees C, 30 MPa for different processing times. The addition of N-halamine on the surface significantly brought antibacterial activity against E. coli. The chlorine loadings showed that 6-h exposure time was critical to obtain sufficient antibacterial activity. This treatment caused a reasonable and tolerable loss in color and mechanical properties. But, the durability to abrasion, stability, and rechargeability of oxidative chlorine, and the durability of N-halamine on the surface were remarkably good. Conclusively, it can be available to work on polyester surfaces with resource-efficient and eco-friendly supercritical carbon dioxide technique for getting more functionalization and modification. (C) 2020 Elsevier B.V. All rights reserved.