Publication: İyonik sıvı destekli PVDF polielektrolitlerin kontrollü polimerizasyon ile hazırlanması ve karakterizasyonu
Abstract
İyonik sıvılar, büyük organik katyonlar ve zayıf koordine edici inorganik veya organik anyonlardan oluşan ve 100 °C'nin altında erime noktaları sergileyen tuzlardır. İyonik sıvıları elektrolit uygulamaları için çekici kılan özellikleri, anyon ve katyonların değiştirilerek yüksek iletkenlik, termal stabilite ve düşük yanıcılık gibi özellikleri aynı anda taşıyarak güvenli üretimine imkân sağlamasından kaynaklanmaktadır. Bu tez çalışmasında, iyonik sıvı destekli poli(viniliden florür-ko-heksafloropropilen) (PVDF-HFP) nanofiberlerin kontrollü polimerizasyon metodu kullanılarak hazırlanması ve karakterizasyonu hedeflenmiştir. Bu amaçla hem nanofiber yüzeyine modifikasyon hem de yüzeyden modifikasyon ile ilgili denemeler yapıldı. Bu tez çalışması iki bölümden oluşmaktadır. İlk bölümde, farklı konsantrasyonlarda hazırlanan PVDF-HFP çözeltileri ile belirli parametreler seçilerek optimizasyon işlemi gerçekleştirildi. Daha sonra seçilen optimum fiber üzerinden yüzeyde başlatılan atom transfer radikal polimerizasyonu (ATRP) ile hazırlanan poli(etilen glikol) diakrilat-İmidazol (PEGA-İm) monomerinin kontrollü polimerizasyonu gerçekleştirildi. Aynı zamanda glisidil metakrilat (GMA) monomeri ile hazırlanan makro PVDF-HFP başlatıcı ile ATRP çalışmaları da gerçekleştirildi. Çalışmanın ikinci bölümünde ise tiyol fonksiyonel PVDF-HFP ile iyi tanımlanmış allil fonksiyonel poli(glisidil metakrilat) polimerleri sentezlendi ve tiyol-en klik reaksiyonu ile reaktif elektrospinning tekniğini kullanılarak nanofiber hazırlanarak karakterizasyon çalışmaları gerçekleştirildi. Daha sonra elde edilen nanofiber yapılar üzerinde imidazol grupları bağlandı ve ultrasonikasyon işlemiyle halojenür grup içeren iyodoetan ile reaksiyona sokularak imidazol grupları kuaternize edildi. Aynı zamanda hazırlanan nanofiberler kuarternizasyon öncesi ve sonrasında morfolojik yapıları SEM ile karakterize edildi.
Ionic liquids are salts composed of large organic cations and poorly coordinating inorganic or organic anions and exhibit melting points below 100 °C. The features that make ionic liquids attractive for electrolyte applications are that they enable safe production by changing anions and cations, while simultaneously carrying properties such as high conductivity, thermal stability and low flammability. In this thesis, it was aimed to prepare and characterize ionic liquid supported poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibers using the controlled polymerization method. For this purpose, experiments were carried out on both nanofiber modification to surface and from surface. This thesis work consists of two parts. In the first part, the optimization process was carried out by selecting certain parameters with PVDF-HFP solutions prepared at different concentrations. Then, controlled polymerization of poly(ethylene glycol) diacrylate-Imidazole (PEGA-Im) monomer prepared by surface initiated atom transfer radical polymerization (ATRP) over the selected optimum fiber was performed. At the same time, ATRP studies were performed with the macro PVDF-HFP initiator prepared with glycidyl methacrylate (GMA) monomer. In the second part of the study, well-defined allyl functional poly(glycidyl methacrylate) polymers were synthesized with thiol functional PVDF-HFP and characterization studies were carried out by preparing nanofibers using the reactive electrospinning technique with thiol-en click reaction. Then, imidazole groups were attached on the obtained nanofiber structures and imidazole groups were quaternized by reacting with iodoethane containing halide groups by ultrasonication. At the same time, the morphological structures of the prepared nanofibers were characterized by SEM before and after quaternization.
Ionic liquids are salts composed of large organic cations and poorly coordinating inorganic or organic anions and exhibit melting points below 100 °C. The features that make ionic liquids attractive for electrolyte applications are that they enable safe production by changing anions and cations, while simultaneously carrying properties such as high conductivity, thermal stability and low flammability. In this thesis, it was aimed to prepare and characterize ionic liquid supported poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibers using the controlled polymerization method. For this purpose, experiments were carried out on both nanofiber modification to surface and from surface. This thesis work consists of two parts. In the first part, the optimization process was carried out by selecting certain parameters with PVDF-HFP solutions prepared at different concentrations. Then, controlled polymerization of poly(ethylene glycol) diacrylate-Imidazole (PEGA-Im) monomer prepared by surface initiated atom transfer radical polymerization (ATRP) over the selected optimum fiber was performed. At the same time, ATRP studies were performed with the macro PVDF-HFP initiator prepared with glycidyl methacrylate (GMA) monomer. In the second part of the study, well-defined allyl functional poly(glycidyl methacrylate) polymers were synthesized with thiol functional PVDF-HFP and characterization studies were carried out by preparing nanofibers using the reactive electrospinning technique with thiol-en click reaction. Then, imidazole groups were attached on the obtained nanofiber structures and imidazole groups were quaternized by reacting with iodoethane containing halide groups by ultrasonication. At the same time, the morphological structures of the prepared nanofibers were characterized by SEM before and after quaternization.