Water‐soluble polypyrrole‐polybis (4‐oxy benzene sulfonic acid) phosphazene composites and investigation of their performance as cathode binder in Li‐ion batteries

Current electric storage systems eagerly focus on high‐power and energy‐dense Lithium‐ion batteries to cope with increasing energy storage demands. Since cathode materials are one of the bottlenecks of these batteries, there is much interest in layered lithium‐rich manganese oxide‐based (LLMO) cathodes which can develop this technology. However, Initial Coulombic Efficiency (ICE) loss, poor rate performance and cycling instability issues are still persistent as problems to be solved for these materials. Recent research shows that water‐soluble binders are effective in improving the performance of LLMO materials. Herein, we describe the synthesis, characterisation, and application of a series of water‐soluble composites as a binder for LLMO cathodes. The PPy is introduced as part of the binder to improve the electronic conductivity and two different oxidants and various PPy to PSAP ratios were used to optimise the final properties. The electrochemical performance and morphology of the cathodes before and after cycling were investigated and compared with the conventional PVDF binder. The LLMO−2c electrode showed excellent charge‐discharge performance, especially at 5 C and 10 C rates, and high cycling stability at 0.2 C whilst maintaining a final capacity of 184 mAh/g after 200 cycles, which is equal to 89.3 % capacity retention

The Synthesıs Of 3-Amıno-1-Hetarylfluorene/Fluorenone And Derıvatıves, Spectroscopıc Determınatıon Of Photophysıcal Propertıes And Interactıon Mechanısms For Double Helıx/G4-Dna

Önemli fotofiziksel özelliklere sahip floren/florenon temelli bileşiklerin çift sarmal ve G4- DNA’ya karşı ilgilerinin olduğu bilinmektedir. Bundan dolayı son yıllarda floren/florenon ana iskeletini içeren yeni bileşiklerin sentezi fonksiyonel boyar madde konusunda çalışan organik kimyacıların ilgisini çekmektedir. Bu doğrultuda tez kapsamında, 3-Amino-1- hetaril-2,6-disiyano temelli bileşiklerin desiyanizasyonu sonucu 4 adet 3-Amino-1- hetarilfloren ve alkillenmiş türevlerinin sentezi literatüre kazandırılmıştır. Desiyanizasyon tepkimesi sonucunda hedef ürünlerin yanında elde edilen alkillenmiş ürünler çeşitli çözücü karışımları kullanılarak kolon kromotografisi yöntemiyle birbirlerinden ve hedef ürünlerden ayırılmış ve yapıları FT-IR (ATR), 1H-NMR, 13C-NMR, HR-MS ve X-ışını kristallografisi yöntemleriyle karakterize edilmiştir. Seçilen bazı bileşiklerin fotofiziksel özellikleri farklı polariteye sahip çözücüler (ACN, MeOH, DCM ve PhMe) içerisinde incelenmiş, kuantum verimleri, molar absorpsiyon katsayıları ve Stokes kaymaları belirlenmiştir. Ayrıca, 3- Amino-1-(2-, 3-, 4-piridil)floren ve florenon bileşiklerinin katyonik ve amit türevlerinin çift sarmal DNA ve G4-DNA ile kovalent olmayan etkileşim mekanizmalarının ve ilgilerinin belirlenmesi çalışmaları için Ultraviyole-Görünür Bölge (UV-GB), floresan spektroskopisi (FL), termal bozunma ve guanince zengin dizilimler ile etkileşim çalışmaları için Floresans Rezonans Enerji Transferi (FRET) deneyleri yapılmıştır. Bileşiklerin her iki DNA çeşidiyle etkileşim çalışmaları sonuçlarından yararlanılarak bağlanma sabiti, seçiciciliği, bağlanma türü ve bağlanma ilgisi belirlenmeye çalışılmıştır. Katyonik amit türevi floren bileşiğinin guanince zengin F21T ve 22AG kodlu oligonükleotidler ile etkileştiği görülmüş ve Tm değerinde kayda değer bir artışa (6,2 oC) sebep olmuştur.It is known that fluorene/fluorenone-based compounds with important photophysical properties have double helix and G4-DNA affinity. Therefore, in recent years, the synthesis of new compounds containing the main skeleton of fluorene/fluorenone has attracted the attention of organic chemists working on functional dyestuffs. In this context, the synthesis of 4 piece of 3-Amino-1-hetarylfluorene and alkylated derivatives was acquired in the literature as a result of the decyanation of 3-Amino-1-hetaryl-2,6-dicyano based compounds within the scope of the thesis. The alkylated products obtained by the decyanation reaction as well as main products were separated from each other and the main products using various solvent mixtures and their structures were characterized by from each other by column chromatography using various solvent mixtures and characterized by FT-IR (ATR), 1HNMR, 13C-NMR, HR-MS and X-ray crystallography methods. The photophysical properties of some selected compounds were investigated in solvents with different polarity (ACN, MeOH, DCM and PhMe), quantum yields, molar absorption coefficients and Stokes shifts were determined. Furthermore, in order to determine the interaction mechanisms and interests of the cationic and amide derivatives of 3-amino-1-(2-, 3-, 4-pyridyl) compounds with double helix DNA and G4-DNA, Fluorescence Resonance Energy Transfer (FRET) experiments were conducted for interaction studies with Ultraviolet-visible region (UVGB), fluorescence spectroscopy (FL), thermal degradation and guanine-rich sequences. Binding constant, selectivity, binding type and binding affinity were determined by using the results of interaction studies of the compounds with both DNA types. The cationic amide derivatives have been observed to interact with guanine-rich F21T and 22AG coded oligonucleotides and have resulted in a significant increase in TM value (6.2 oC)