Kriyojellerin sentezi, karakterizasyonu ve bazı uygulamaları
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Tarih
2014
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Çanakkale Onsekiz Mart Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu tez çalışması kapsamında kriyopolimerizasyon yöntemine göre sentezlenen süpergözenekli p(AMPS), p(VI), p(AAm) ve p(HEMA) kriyojelleri bazı katalitik çevre ve enerji uygulamalarında katalizör destek maddeleri olarak kullanılmışlardır. Bazik ve nötral fonksiyonelliğe sahip kriyojellere çeşitli modifikasyon yöntemleri uygulanarak metal iyonlarını tutma özelliği kazandırılmıştır. Süpergözenekli kriyojel ağ yapıları içerisinde güçlü indirgeyici ajan sodyum bor hidrür (NaBH4) kullanılarak kobalt (Co), nikel (Ni) ve bakır (Cu) gibi çeşitli metal nanopartiküller sentezlenmiştir. Kriyojeller ve metal kompozitleri, şişme çalışmaları, optik mikroskop, SEM ve TEM görüntüleri, FT-IR, AAS ve TGA analizleri gibi çeşitli yöntemlerle karakterize edilmiştir. Sentezlenen kriyojel-metal kompozit malzemeler NaBH4 ve amonyum boren (NH3BH3) gibi kimyasal hidrürlerin hidrolizinden hidrojen (H2) üretimi ve metilen mavisi (MB), eozin Y (EY) boyar maddeleri, 2- ve 4-nitrofenol (2- ve 4-NP) gibi toksik bileşiklerin indirgenme reaksiyonuyla giderimi çalışmalarında katalizör olarak kullanılmışlardır. Bor hidrür bileşiklerinin hidrolizinden H2 üretimi ve toksik bileşiklerin indirgenmesi reaksiyonlarına gözeneklilik, metal nanopartikül türü, metal nanopartikül miktarı, sıcaklık vb birçok parametrenin etkisi detaylı olarak incelenmiştir. Süpergözenekli kompozit malzemelerin bor bileşiklerinin hidrolizinden H2 üretimi ve toksik bileşiklerin giderimi reaksiyonlarına ait hidrojen üretimi hızı (HGR) ve toplam dönüşüm frekansı (TOF) gibi hız değerleri ve aktivasyon enerji (Ea), entalpi (?H) ve entropileri (?S) gibi aktivasyon parametreleri hesaplanmıştır. Süpergözenekli kriyojel destekli katalizörlerin literatürde yer alan benzer katalitik çalışmalarla kıyaslanabilen oldukça iyi katalitik performans değerlerine sahip oldukları bulunmuştur. Kriyojellerin yapı ve fonksiyonelliğine bağlı olarak kriyojel-Co metal kompozitlerin bor bileşiklerinin hidrolizinden H2 üretimi ve toksik bileşiklerin indirgenme reaksiyonlarına ait 15-40 kjmol-1 arasında değişen aktivasyon enerjisi (Ea) değerleri elde edilmiştir.
In the scope of this thesis, superporous p(AMPS), p(VI), p(AAm) and p(HEMA) cryogels were synthesized by cryopolymerization technique and used in the catalytic application for environment and energy as catalyst support materials. Metal ions absption property was provided to basic and neutral cryogels by applying various modification methods. Metal nanoparticles such as cobalt (Co), nickel (Ni) and copper (Cu) were synthesized within superporous cryogel networks by using strong reduction agent such as sodium borohydride (NaBH4). Cryogels and their metal composites were characterized with various methods such as swelling studies, optical microscope, SEM and TEM images, FT-IR, AAS and TGA analysis. The synthesized cryogel-metal composite materials were used as catalyst in hydrogen (H2) generation from hydrolysis of chemical hydrides such as NaBH4 and ammonia boren (NH3BH3), and in the reductive removal of toxic compounds such as methylene blue (MB), eosin Y (EY) dyes, 2- and 4-nitrophenol (2- and 4-NP). The effect of various parameters such as porosity, metal nanoparticle species, the amount of metal nanoparticle, temperatures etc on the H2 generation from hydrolysis of boron hydride compounds, and on the reduction reactions of toxic compounds were investigated in detail. Rate values such as hydrogen generation rate (HGR) and total turnover frequencies (TOF) and the activation parameters such as activation energy (Ea), enthalpy (?H) and entropies (?S) were calculated for the H2 generation from hydrolysis of boron compounds and for the reduction of toxic compounds reactions of superporous cryogel-metal composites. Superporous cryogel used as catalyst supports have found rather good catalytic performance in comparison to the similar catalytic studies in the literature. Activation energy values of 15-40 kjmol-1 were obtained for the H2 generation from hydrolysis of boron compoundsö and for the reduction of toxic compounds of cryogel-Co metal composites depending on the structure and the functionalility of the cryogels.
In the scope of this thesis, superporous p(AMPS), p(VI), p(AAm) and p(HEMA) cryogels were synthesized by cryopolymerization technique and used in the catalytic application for environment and energy as catalyst support materials. Metal ions absption property was provided to basic and neutral cryogels by applying various modification methods. Metal nanoparticles such as cobalt (Co), nickel (Ni) and copper (Cu) were synthesized within superporous cryogel networks by using strong reduction agent such as sodium borohydride (NaBH4). Cryogels and their metal composites were characterized with various methods such as swelling studies, optical microscope, SEM and TEM images, FT-IR, AAS and TGA analysis. The synthesized cryogel-metal composite materials were used as catalyst in hydrogen (H2) generation from hydrolysis of chemical hydrides such as NaBH4 and ammonia boren (NH3BH3), and in the reductive removal of toxic compounds such as methylene blue (MB), eosin Y (EY) dyes, 2- and 4-nitrophenol (2- and 4-NP). The effect of various parameters such as porosity, metal nanoparticle species, the amount of metal nanoparticle, temperatures etc on the H2 generation from hydrolysis of boron hydride compounds, and on the reduction reactions of toxic compounds were investigated in detail. Rate values such as hydrogen generation rate (HGR) and total turnover frequencies (TOF) and the activation parameters such as activation energy (Ea), enthalpy (?H) and entropies (?S) were calculated for the H2 generation from hydrolysis of boron compounds and for the reduction of toxic compounds reactions of superporous cryogel-metal composites. Superporous cryogel used as catalyst supports have found rather good catalytic performance in comparison to the similar catalytic studies in the literature. Activation energy values of 15-40 kjmol-1 were obtained for the H2 generation from hydrolysis of boron compoundsö and for the reduction of toxic compounds of cryogel-Co metal composites depending on the structure and the functionalility of the cryogels.
Açıklama
Fen Bilimleri Enstitüsü, Kimya Ana Bilim Dalı
Anahtar Kelimeler
Kimya, Chemistry
