N-halamin esaslı klor depolayabilen kriyojellerin sentezi ve karakterizasyonu
Yükleniyor...
Dosyalar
Tarih
2019
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Bursa Teknik Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Kriyojeller, matris boyunca heterojen şekilde dağıtılmış bir polimerik zincir ağı oluşturmak için, düşük sıcaklıklarda monomerik veya polimerik prekürsörlerin çapraz bağlanması, polimerizasyonu veya fiziksel dolanması veya jelleşmesi ile oluşur. Donmuş çözücü, çözüldükten sonra, gazların, sıvı ve mikron altı parçacıkların çok fazla zorlanmadan serbestçe hareket etmesine izin veren yüksek gözenekli ara bağlantıya sahip, yüksek derecede makro gözenekli bir yapı ortaya çıkar. Kriyojellerin en dikkat çekici özelliği sahip oldukları birbiri ile bağlantılı makro gözenekleri sayesinde absorpladıkları suyu bir kuvvet altında çok hızlı desorpsiyon etmeleridir. Bu sebepten biyoteknolojik ve biyomedikal alanlarda kullanımları oldukça yaygındır. Kullanım alanları gereği antibakteriyel özellik göstermeleri ise kriyojelleri daha efektif malzemeler haline getirebilmektedir. Bu amaca yönelik olarak bu çalışmada en etkili antibakteriyel biyositlerden olan N-halamin bileşikleri tercih edilmiştir. Yapılarında bulundurdukları azot-klor veya azot-brom bağları ile N-halamin bileşikleri halojen stabilizatörleri olarak da ifade edilmektedir. Bu bağ mikroorganizmalar ile temas sonucunda kırılır ve oksidatif klor veya brom atomu mikroorganizmanın hücre zarına transfer olur. Hücre zarındaki proteinlerin okside edilmesiyle çok kısa süre içinde mikroorganizma inaktivasyonu gerçekleşir. N-halaminler, yüksek stabilite, düşük toksisite ve yeniden şarj edilebilir gibi üstün özelliklere sahiptirler. Çalışma kapsamında, antibakteriyel potansiyele sahip klor depolayabilen kriyojeller N,N'-metilen bis akrilamid çapraz bağlayıcısı varlığında N-halamine prekürsörleri olan 2-akrilamido-2-metil-1-propan sülfonik asit sodyum tuzu, akrilamid ve N-[3-(Dimetilamino)propil] metakrilamid monomerlerinin kopolimerizasyonu ile elde edilmiştir. Sentezlenen kriyojeller seyreltik sodyum hipoklorit çözeltisi ile muamele edilerek klor yüklenmiştir. Aynı zamanda klorlama işlemi için klorlama süresi ve pH parametreleri optimize edilmiştir. Kriyojellerin su absorplama miktarına, absorpsiyon ve desorpsiyon hızına klor yüklemesinin etkisi incelenmiştir. Elde edilen kriyojel örneklerindeki fonksiyonel gruplar FT-IR ile tanımlanmıştır. N-Halamin yapının kararlılığı ısı ve UV ışığına oldukça duyarlı olduğundan kiyojellerin TGA analizi ile termal davranışı ve UV ışığına maruz bırakılarak klor tutma kabiliyetinin değişimi gözlemlenmişitir. Mekanik test cihazı ile şişmiş haldeki kriyojellerin mekanik özellikleri tespit edilmiştir. SEM görüntüleme tekniği ile kriyojellerdeki gözenek yapısında meydana gelen değişim ve EDS analizi ile yapıya klor atomunun bağlanma durumu ortaya konulmuştur. Sonuç olarak, oldukça hızlı ve yüksek oranda su absorplayabilen ve klor depolayabilen kriyojeller üretilmiştir. Geliştirilen küre formdaki kriyojeller özellikle biyomedikal ve biyoteknolojik endüstrisinin çeşitli alanlarında kullanılmak için büyük bir potansiyele sahiptir.
Cryogels are formed by crosslinking, polymerizing or physical entanglement or gelling of monomeric or polymeric precursors at low temperatures to form a polymeric chain network heterogeneously distributed throughout the matrix. After dissolving of the frozen solvent, a highly macroporous structure is formed with a high porous interconnection that allows gases, liquid and submicron particles to move freely without too much strain. The most attractive feature of cryogels is that they release the absorbed water very quickly under a force by means of their interconnected macro pores. Therefore, they are widely used in biotechnological and biomedical fields. Because of their antibacterial properties due to their usage areas, cryogels can become more effective materials. For this purpose, N-halamine compounds which are among the most effective bacterial biocides were preferred in this study. Nitrogen-chlorine or nitrogen-bromine bonds and N-halamine compounds in their structures are also referred to as halogen stabilizers. This bond is broken by contact with microorganisms and the oxidative chlorine or bromine atom is transferred to the cell membrane of the microorganism. The oxidation of the proteins in the cell membrane causes inactivation of the microorganisms in a very short time. N-halamines have superior properties such as high stability, low toxicity and rechargeability. In the scope of the study, cryogels with antibacterial potential which can store chlorine were obtained by copolymerization of N-halamine precursors, which are 2-acrylamido-2-methyl-1-propane sulfonic acid sodium salt , acrylamide and N-[3-(Dimethylamino) propyl] methacrylamide monomers, in the presence of N, N'-methylene bis acrylamide as cross-linker. The synthesized cryogels were treated with dilute sodium hypochlorite solution and charged with chlorine. At the same time, chlorination time and pH parameters were optimized for chlorination process. The effect of chlorine loading on water absorption rate, absorption and desorption rate of cryogels were investigated. Functional groups in the obtained cryogel samples were identified by FT-IR. Since the stability of the N-Halamine structure is very sensitive to heat and UV light, the thermal behavior of the biogels by TGA analysis and the changing in chlorine retention ability by exposure to UV light were observed. The mechanical properties of chlorinated and non-chlorinated cryogels in the swollen state were determined by mechanical test device. The change in pore structure in cryogels by SEM imaging technique and the binding state of chlorine atom to the structure were determined by EDS analysis. As a result, cryogels were produced which were able to absorb water rapidly and store chlorine at a fast rate. The developed spherical cryogels have great potential for use in various fields of the biomedical and biotechnological industries.
Cryogels are formed by crosslinking, polymerizing or physical entanglement or gelling of monomeric or polymeric precursors at low temperatures to form a polymeric chain network heterogeneously distributed throughout the matrix. After dissolving of the frozen solvent, a highly macroporous structure is formed with a high porous interconnection that allows gases, liquid and submicron particles to move freely without too much strain. The most attractive feature of cryogels is that they release the absorbed water very quickly under a force by means of their interconnected macro pores. Therefore, they are widely used in biotechnological and biomedical fields. Because of their antibacterial properties due to their usage areas, cryogels can become more effective materials. For this purpose, N-halamine compounds which are among the most effective bacterial biocides were preferred in this study. Nitrogen-chlorine or nitrogen-bromine bonds and N-halamine compounds in their structures are also referred to as halogen stabilizers. This bond is broken by contact with microorganisms and the oxidative chlorine or bromine atom is transferred to the cell membrane of the microorganism. The oxidation of the proteins in the cell membrane causes inactivation of the microorganisms in a very short time. N-halamines have superior properties such as high stability, low toxicity and rechargeability. In the scope of the study, cryogels with antibacterial potential which can store chlorine were obtained by copolymerization of N-halamine precursors, which are 2-acrylamido-2-methyl-1-propane sulfonic acid sodium salt , acrylamide and N-[3-(Dimethylamino) propyl] methacrylamide monomers, in the presence of N, N'-methylene bis acrylamide as cross-linker. The synthesized cryogels were treated with dilute sodium hypochlorite solution and charged with chlorine. At the same time, chlorination time and pH parameters were optimized for chlorination process. The effect of chlorine loading on water absorption rate, absorption and desorption rate of cryogels were investigated. Functional groups in the obtained cryogel samples were identified by FT-IR. Since the stability of the N-Halamine structure is very sensitive to heat and UV light, the thermal behavior of the biogels by TGA analysis and the changing in chlorine retention ability by exposure to UV light were observed. The mechanical properties of chlorinated and non-chlorinated cryogels in the swollen state were determined by mechanical test device. The change in pore structure in cryogels by SEM imaging technique and the binding state of chlorine atom to the structure were determined by EDS analysis. As a result, cryogels were produced which were able to absorb water rapidly and store chlorine at a fast rate. The developed spherical cryogels have great potential for use in various fields of the biomedical and biotechnological industries.
Açıklama
Anahtar Kelimeler
Polimer Bilim ve Teknolojisi, Polymer Science and Technology
