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Water-soluble sulfolignin (SL) was grafted onto hydroxyapatite (Hap) by using epichlorohydrin. SLgHap was then entrapped in cross-linked polyacrylamide by in situ polymerizations of acrylamide and N, N′ -methylenebisacrylamide to obtain the composite of PSLgHap. The composite was characterized by FT-IR, BET- porosity, XRD, EDXRF, SEM-EDX, TGA-DTG, PZC, CEC, and swelling tests. The adsorptive features of PSLgHAP were investigated for Th4+ and BSA in view of its dependence on pH, ionic intensity, concentration, temperature, and time. The results of characterization tests confirmed the formation of PSLgHap. The grafting efficiency concerning sulfur contents of PSLgHap was 96% by EDXRF. The isotherms were best represented by the Sips model, Langmuir adsorption capacities were 369 and 390 mg gSLgHap����� 1 for BSA and Th4+. The enthalpy and entropy changes were positive whilst Gibbs energy was negative by entropy controlled. The adsorption kinetics of both species was obeyed to pseudo second-order model, whereas it was first-order for BSA and hybrid-order for Th4+ of Langmuir model.

Binary (AC, AG), ternary (ACG, ACP, AGP), quaternary (ACGP) composite beads of alginate (A), carrageenan (C), gelatin (G), and poly (lactic-co-glycolic acid) (P) were prepared. The dried beads had a 700 μm average diameter. The microspheres with and without P were characterized by FT-IR, TGA/DTA, SEM, and PZC analysis. The results proved that the features of the composites were completely different from their bare components. Density Functional Theory (DFT) calculations were performed at the B3LYP/6-311++G** level to enlighten the elementary physical and chemical properties of A, C, P, and G compounds. The vibrational modes obtained by calculations were compared with those observed in the FT-IR spectra. The Frontier Molecular Orbital (FMO) analyses showed that the component G was the softer and had smaller energy gap than the other components and vice versa for component P. NBO (Natural Bond Orbital) analyses implied that the n → П* (resonance) interactions for components A, G, and P contributed to the lowering of the molecular stabilization, whereas that the n → σ* (anomeric) interactions were responsible for decreasing of the stabilization of the component. From the obtained results, these kinds of components can be hoped the promising materials for usage in the many scientific fields, especially in medicine and in drug design.

Bu çalışma, SARS-CoV-2 enfeksiyonunun tedavisi ve önlenmesi için güncel durumda uygulanan ilaç tedavilerinin yanı sıra bağışıklık sisteminde önemli işlevleri olduğu bilinen bazı vitamin ve minerallerin etkilerini inceleyen örnek makalelerin derlemesidir. Diğer derlemelerden en önemli farkı, bir Biyokimya Bölümü Lisans öğrencisinin bilimsel makalelere olan bakışını içermesidir. Çalışmada COVID-19 salgını, vitamin ve mineraller ile ilgili genel bilgiler de mevcuttur. Ayrıca, çalışma Kasım 2021’e kadar yayınlanan makaleleri içeren en kapsamlı Türkçe derlemedir. Derlemede, önce COVID-19 enfeksiyonu ile ilgili genel bilgilerden, daha sonra vitaminlerin ve minerallerin (Zn, Fe, Se) viral enfeksiyonlar üzerindeki etkilerinden bahsedilecektir. Her bölümün içinde ilgili vitamin ve mineralin COVID-19 üzerine etkilerini içeren güncel makaleler ve sonuçların yer aldığı tablolar bulunmaktadır.

Water-soluble sulfolignin (SL) was grafted onto hydroxyapatite (Hap) by using epichlorohydrin. SLgHap was then entrapped in cross-linked polyacrylamide by in situ polymerizations of acrylamide and N, N′-methylenebisacrylamide to obtain the composite of PSLgHap. The composite was characterized by FT-IR, BET- porosity, XRD, EDXRF, SEM-EDX, TGA-DTG, PZC, CEC, and swelling tests. The adsorptive features of PSLgHAP were investigated for Th4+ and BSA in view of its dependence on pH, ionic intensity, concentration, temperature, and time. The results of characterization tests confirmed the formation of PSLgHap. The grafting efficiency concerning sulfur contents of PSLgHap was 96% by EDXRF. The isotherms were best represented by the Sips model, Langmuir adsorption capacities were 369 and 390 mg gSLgHap−1 for BSA and Th4+. The enthalpy and entropy changes were positive whilst Gibbs energy was negative by entropy controlled. The adsorption kinetics of both species was obeyed to pseudo second-order model, whereas it was first-order for BSA and hybrid-order for Th4+ of Langmuir model.

Water-soluble sulfolignin (SL) was grafted onto hydroxyapatite (Hap) by using epichlorohydrin. SLgHap was then entrapped in cross-linked polyacrylamide by in situ polymerizations of acrylamide and N, N'-methylenebisacrylamide to obtain the composite of PSLgHap. The composite was characterized by FT-IR, BET- porosity, XRD, EDXRF, SEM-EDX, TGA-DTG, PZC, CEC, and swelling tests. The adsorptive features of PSLgHAP were investigated for Th

Bu arastirmanin konusu amidoksimlestirilmis yari-icice gecmis ag yapili polimerik adsorbanin (y-IPN a ) sulu cozeltiden Pb 2+ uzaklastirmada kullanimidir. Y-IPN a , Poli (etilen glikol)’un akrilonitrildeki cozeltisinin 60 Co γ-kaynagiyla 14 kGy dozda isinlanmasiyla hazirlanan yari-ic ice gecmis ag yapidaki (y-IPN) –CN uclarinin amidoksimlestirilmesiyle hazirlanmistir. y-IPN ve y-IPN a yapilari, FT-IR, TGA ve SEM analizleri ile karakterize edilmistir. y-IPN a ’nin adsorban ozellikleri Pb 2+ adsorpsiyonun pH, derisim, kutle, zaman ve sicaklik ile degisimi arastirmalariyla degerlendirilmistir. 25-2000 ppm baslangic derisimi araliginda adsorpsiyon izotermleri elde edilmis, 500-2000 ppm araliginda %60’a ulasan adsorpsiyon gozlenmistir. Langmuir adsorpsiyon izoterminden elde edilen maksimum adsorpsiyon kapasitesi X L =678 mg g -1 ’dir. Adsorpsiyon kinetiginin yalanci ikinci derece tepkime kinetigine uydugu gozlenmis ve yari omur 176 dk olarak hesaplanmistir. Adsorpsiyonun sicaklikla degisiminden elde edilen termodinamik veriler (ΔH=59.3 kJ mol -1 , ΔS=246.1 J mol -1 K -1 , ΔG=-14.0 kJ mol -1 ) adsorpsiyonun endotermik ve kendiliginden oldugunu gostermistir. Es molar Al 3+ iyonu varliginda Pb 2+ adsorpsiyonunun ≈%60 oldugu gozlendi. Bu sonuc y-IPN a ’nin 2+ degerlikli metallere karsi secici oldugu ile ilgili bir kanit olabilir.

Thesubject of this investigation is the use of amidoximized semi-interpenetratingpolymer network polymeric adsorbent (s-IPNa) for removal of Pb2+from aqueous medium. S-IPNa was prepared from the amidoximation of–CN terminals of the s-IPN obtained by irradiation of Poly (ethylene glycol) inacrylonitrile solution under a dose of 14 kGy with a 60Co gammasource. Semi-interpenetrating polymer networks (s-IPN) and modified s-IPNastructures were characterized by FT-IR, TGA and SEM analysis. The adsorbent propertiesof s-IPNa were evaluated by investigating the change of Pb2+adsorption with pH, concentration, mass, time and temperature. Adsorptionisotherms were obtained for 25-2000 ppm concentration range, the adsorptionreached up to 60% in 500-2000 ppm interval. The maximum adsorption capacityobtained from the Langmuir adsorption isotherm is XL = 678 mg g-1.The adsorption obeyed to pseudo-second order reaction kinetics and half-lifewas calculated as 176 minutes. Thermodynamics data obtained from the change inadsorption by temperature (ΔH=59.3 kJ mol-1, ΔS=246.1 J mol-1K-1, ΔG=-14.0 kJ mol-1) demonstrated that adsorption isendothermic and spontaneous. The adsorption of Pb2+ in presence ofequimolar Al3+ was ≈%60. This result might be considered as a proof forthe selectivityof s-IPNa for divalent cations., Bu araştırmanınkonusu amidoksimleştirilmiş yarı-içiçe geçmiş ağ yapılı polimerik adsorbanın (y-IPNa)sulu çözeltiden Pb2+ uzaklaştırmada kullanımıdır. Y-IPNa,Poli (etilen glikol)’ün akrilonitrildeki çözeltisinin 60Coγ-kaynağıyla 14 kGy dozda ışınlanmasıyla hazırlanan yarı-iç içe geçmiş ağ yapıdaki(y-IPN) –CN uçlarınınamidoksimleştirilmesiyle hazırlanmıştır. y-IPN ve y-IPNa yapıları,FT-IR, TGA ve SEM analizleri ile karakterize edilmiştir. y-IPNa’nınadsorban özellikleri Pb2+ adsorpsiyonun pH, derişim, kütle, zaman vesıcaklık ile değişimi araştırmalarıyla değerlendirilmiştir. 25-2000 ppmbaşlangıç derişimi aralığında adsorpsiyon izotermleri elde edilmiş, 500-2000ppm aralığında %60’a ulaşan adsorpsiyon gözlenmiştir. Langmuir adsorpsiyonizoterminden elde edilen maksimum adsorpsiyon kapasitesi XL=678 mg g-1’dir.Adsorpsiyon kinetiğinin yalancı ikinci derece tepkime kinetiğine uyduğugözlenmiş ve yarı ömür 176 dk olarak hesaplanmıştır. Adsorpsiyonun sıcaklıkladeğişiminden elde edilen termodinamik veriler (ΔH=59.3 kJ mol-1,ΔS=246.1 J mol-1 K-1, ΔG=-14.0 kJ mol-1) adsorpsiyonunendotermik ve kendiliğinden olduğunu göstermiştir. Eş molar Al3+iyonu varlığında Pb2+ adsorpsiyonunun ≈%60 olduğu gözlendi. Bu sonuçy-IPNa’nın 2+ değerlikli metallere karşı seçici olduğu ile ilgilibir kanıt olabilir.

WOS: 000329299200039, This study investigated a new adsorbent prepared from lignin modified organoclay for the removal of Pb2+ and UO2 (2+) from aqueous solutions. The characterization of new adsorbent was performed by FT-IR and XRD. Adsorption of Pb2+ and UO2 (2+) species in aqueous solution as a function of ion concentration, pH, temperature and time of adsorption was investigated in detail. The adsorption data were analyzed by using the Langmuir, Freundlich and Dubinin-Radushkevich models. The monolayer adsorption capacities of organoclay-lignin were 0.12 mol kg(-1) and 0.42 mol kg(-1) for Pb2+ and UO2 (2+), respectively. The experimental kinetic data were analyzed by using pseudo-second-order kinetic and intra-particle diffusion models. The proposed adsorption mechanism follows a pseudo-second-order kinetic and endothermic because of increasing disorderliness at adsorbate/adsorbent interface., Cumhuriyet University, This work was partly supported by The Research Fund of Cumhuriyet University to which the authors are grateful.

WOS: 000368558900006, Polyacrylamide-montmorillonite (PAAm-Mt) and polyacrylamide-clinoptilolite (PAAm-Z) composites were prepared by cross-linked polymerization of acrylamide in dispersions of Mt and Z. The composites were characterized by FT-IR, SEM, XRD, CEC, and PZC analysis. The adsorptive features of PAAm-Mt and PAAm-Z for methylene blue (MB) were investigated by their relevance to initial dye concentration, temperature, contact time, PZC, and pH. The monolayer adsorption capacities were 0.14 and 0.08 mol kg(-1) for PAAm-Z and PAAm-Mt, respectively. The changes in pH of MB solution had an insignificant influence on their adsorption capacities. The values of enthalpy and entropy changes were positive (Delta HPAAm-Mt = 7.6 and Delta HPAAm-Z = 17.6 kJ mol(-1), Delta SPAAm-Mt = 55.7, and Delta SPAAm-Z = 107.2 J mol(-1)K(-1)). The negative free enthalpy change was proof of the spontaneity of adsorption (Delta G(PAAm-Mt) = -9.0, Delta G(PAAm-Z) = -14.4 kJ mol(-1)). The adsorption kinetics obeyed a pseudo-second order model (k(PAAm-Mt) = 11.5 and k(PAAm-Z) = 1.18 mol(-1) kg min(-1), R-2 > 0.99). The adsorption mechanism was the combination of chemical and physical adsorption governed by Coulombic forces (liquid film diffusion) on which the contribution of intraparticle diffusion was not significant. This was consistent with a low value of the adsorption activation energy (E-a = 9.4 kJ mol(-1)). The composites had amphoteric features buffering the pH of the studied adsorption environment to approximately neutral levels., Research Fund of Cumhuriyet University (CUBAP), This work was supported by the Research Fund of Cumhuriyet University (CUBAP).

Polyacrylamide{montmorillonite (PAAm-Mt) and polyacrylamide{clinoptilolite (PAAm-Z) composites wereprepared by cross-linked polymerization of acrylamide in dispersions of Mt and Z. The composites were characterizedby FT-IR, SEM, XRD, CEC, and PZC analysis. The adsorptive features of PAAm-Mt and PAAm-Z for methylene blue(MB) were investigated by their relevance to initial dye concentration, temperature, contact time, PZC, and pH. Themonolayer adsorption capacities were 0.14 and 0.08 mol kg1for PAAm-Z and PAAm-Mt, respectively. The changesin pH of MB solution had an insigni cant in uence on their adsorption capacities. The values of enthalpy and entropychanges were positive (∆HP AAmMt= 7.6 and ∆HP AAmZ= 17.6 kJ mol1, ∆SP AAmMt= 55.7, and ∆SP AAmZ= 107.2 J mol1K1). The negative free enthalpy change was proof of the spontaneity of adsorption (∆GP AAmMt= {9.0, ∆GP AAmZ= {14.4 kJ mol1). The adsorption kinetics obeyed a pseudo-second order model (kP AAmMt= 11.5 and kP AAmZ= 1.18 mol1kg min1, R2>0.99). The adsorption mechanism was the combination ofchemical and physical adsorption governed by Coulombic forces (liquid lm diffusion) on which the contribution ofintraparticle diffusion was not signi cant. This was consistent with a low value of the adsorption activation energy (Ea= 9.4 kJ mol1). The composites had amphoteric features buffering the pH of the studied adsorption environment toapproximately neutral levels.

WOS: 000286955900020, The adsorption of Th4+ ions was studied on composites of polyacrylamide (PAAm) with montmorillonite (Mt), clinoptilolite (Z) and zeolite Y (ZY), and after phytic acid (Phy) modification. The monolayer adsorption capacity was 0.33 and 0.65 mol kg(-1) for PAAm-Mt and PAAm-Mt-Phy, 0.07, 0.21 and 0.60 mol kg(-1) for Z, PAAm-Z and PAAm-Z-Phy, and 0.74, 0.89 and 1.18 mol kg(-1) for ZY, PAAm-ZY and PAAm-ZY-Phy. The enthalpy and entropy changes were positive for all adsorbents. The adsorption kinetics followed the pseudo-second order model indicating that the rate controlling step was chemical adsorption by ion exchange. The reusability tests for five uses proved that the PAAm-Mt and PAAm-Z were reusable and complete recovery of the adsorbed ions was possible. ZY and the composites modified with Phy were not reusable. The presence of foreign metal cations did not influence the Th4+ adsorption. The adsorbed Th4+ onto the columns was effectively recovered with diluted HNO3. (C) 2010 Elsevier B.V. All rights reserved., Cumhuriyet University (CUBAP) [F-194], This work was supported by The Research Fund of Cumhuriyet University (CUBAP, Project no: F-194) to which the authors are grateful.

In this study, hexadecyltrimethylammonium (HDTMA) bentonite was synthesized by placing alkylammonium cation onto bentonite. Adsorption of some textile dyes such as Everdirect Supra Yellow PG, Everdirect Supra Orange 26 CG, Everdirect Supra Rubine BL, Everdirect Supra Blue 4BL and Everdirect Supra Red BWS on Na-bentonite and HDTMA-bentonite was investigated. While the Na-bentonite had no affinity for the dyes, the HDTMA-bentonite showed significant adsorption from aqueous solution. The Langmuir and Dubinin-Rasdushkevich (D-R) isotherm equations were applied to the data and values of parameters of these isotherm equations were evaluated. The mean energy of adsorption, E, was also calculated from the adsorption energy constant K' values determined from the D-R isotherm equation.

WOS: 000308896400001, The composite of synthetically produced hydroxyapatite (HAP) and polyacrylamide was prepared (PAAm-HAP) and characterized by BET, FT-IR, TGA, XRD, SEM and PZC analysis. The adsorptive features of HAP and PAAm-HAP were compared for UO22+ and Th4+. The entrapment of HAP into PAAm-HAP did not change the structure of HAP. Both structures had high affinity to the studied ions. The adsorption capacity of PAAm-HAP was than that of HAP. The adsorption dependence on pH and ionic intensity provided supportive evidences for the effect of complex formation on adsorption process. The adsorption kinetics was well compatible to pseudo second order model. The values of enthalpy and entropy changes were positive. Th4+ adsorption from the leachate obtained from a regional fluorite rock confirmed the selectivity of PAAm-HAP for this ion. In consequence, PAAm-HAP should be considered amongst favorite adsorbents for especially deposition of nuclear waste containing U and Th, and radionuclide at secular equilibrium with these elements. (C) 2012 Elsevier Inc. All rights reserved., Cumhuriyet University, This work was supported by The Research Fund of Cumhuriyet University to which the authors are grateful.

WOS: 000288630800028, PubMed ID: 21256673, The composites of natural (clinoptilolite) and synthetic zeolite (Z and YZ) with polyacrylamide (PAAm) were synthesized and characterized by FT-IR, TGA, XRD, SEM and PZC analysis. The adsorptive features of the minerals and its composites were investigated for Tb analogues to the rare earth elements (REs) by isotopic tracer method, Tb-160 was the radiotracer. The composites were the hybrid formations of PAAm and Z or YZ. Tb adsorption capacities of the composites were higher than those of bare Z and YZ. The compatibility of Tb adsorption kinetics to the second order and Weber-Morris models implied that the sorption process was chemical via ion exchange. The values of enthalpy and entropy changes were positive and the negative free enthalpy change was evidence for the spontaneity of adsorption. The reusability tests for the composites for five uses demonstrated that the adsorbents could be reused after complete recovery of the loaded ion. Unlike PAAm-YZ, PAAm-Z was resistant to acidic environment. The overall results eventually suggested that the composite of Z and PAAm was a potential cost effective adsorbent for Tb3+ and REs. (C) 2011 Elsevier B.V. All rights reserved., Cumhuriyet University (CUBAP), This work was supported by The Research Fund of Cumhuriyet University (CUBAP) to which the authors are grateful.

Bu araştırmanın amacı, bir hidrojel olan Poliakrilamitin (PAA) `konukçu', ilgilenilen adsorban minerallerin ise [Bentonit (B), Zeolit (Z) ve Y-Zeolit (YZ)] `konuk' olarak tanımlanabileceği kompozit adsorbanların hazırlanması, karakterizasyonu ve Th için adsorban özelliklerinin araştırılmasıdır. PAA-B ve PAA-Z'nin hazırlanması, karakterizasyonu ve Fe, Zn, Pb ve U için adsorban özellikleri daha önce yapılan bir yüksek lisans tezi kapsamında yer almıştır. Yalnızca FT-IR ile sınırlı olan önceki araştırmadaki karakterizasyon çalışması, bu çalışmada yapılan TGA, SEM, BET-Porozite ve sıfır yüzey yük noktası (SYN) analizleri ile detaylandırılmıştır. Th için adsorban özellikler, PAA-B ve PAA-Z'ye ek olarak PAA-YZ ve ticari bir katyon değiştirici (KDR) için de incelenerek ayrıntılı bir şekilde araştırılmış, kompozitlerin fitik asitle (FA) yüzey modifikasyonunun adsorpsiyona olan etkisi incelenmiştir.Biri tabakalı ve faz farklı nanokompozit (PAA-B) diğer ikisi ise faz farklı mikro kompozit (PAA-Z ve PAA-YZ) olarak sınıflandırılan bu kompozitler, ilgili mineralleri süspansiyon olarak içeren akrilamit çözeltisinde akrilamitin bir çapraz bağlayıcı eşliğinde doğrudan polimerleştirilmesiyle elde edilmiştir.Th ile ilgili adsorpsiyon özellikler; pH, derişim, zaman (kinetik), sıcaklık (termodinamik), iyonik şiddet ve farklı metal iyonları varlığında seçicilik açısından incelenmiş, adsorbanları karakterize eden ilgili parametreler türetilmiştir. Adsorbanların tekrar kullanılabilirlik (rejenerasyon) ve doğal örneklerden (florit ve kömür örnekler) elde edilen özüt çözeltilerde bulunan Th için adsorpsiyon özellikleri incelenmiş, doğal örnek özütleri için kolon kromotografisi uygulanabilirliği araştırılmıştır.Yalnızca Th içeren çözeltilerde Th derişim ölçümleri Arsenazo-III'ün komplekleştirici şelat olarak kullanıldığı spektrofotometrik yöntemin doğrudan, Th'ye eşlik eden ve girişime neden olan diğer metal iyonlarının varlığında ise ticari bir anyon değiştirici reçinenin (ADR) kullanıldığı saflaştırma işlemlerinden sonra uygulanmasıyla ölçülmüştür. Ölçümlerde gama-spektrometrik ölçme yöntemi de kullanılmış, bu yöntemin kullanımında hem spektrofotometrik yöntemi doğrulamak hem de Th ile sürekli dengedeki izotopların adsorplanabilirliklerini araştırmak amaçlanmıştır.Oluşturulan kompozit yapıların FT-IR, XRD, TGA, SEM, BET-porozite ve SYN analizleri kompozit oluşumu ile ilgili kesin kanıtlar sunmuş, yapıların polimer/mineral hibrit oluşumu değil faz farklı karışımlar olduğunu kanıtlamıştır. Fitik asit (FA) ile modifikasyonların mineral-FA bağlanması ile gerçekleştiği gözlenmiştir.Adsorpsiyonun pH ile değişimi araştırması, tüm adsorbanlar için adsorplanan miktarın artan pH ile arttığını göstermiş, bulunan adsorpsiyon miktarları ilgilenilen minerallerin PAA ile kompozit olarak kullanımının adsorpsiyon kapasitelerini anlamlı bir şekilde artırdığını kanıtlamıştır. Yapıların FA ile modifikasyonu ise bu artışı daha da yükseltmiştir.Adsorpsiyonun derişimle değişimi incelenmesi sonucu elde edilen izotermlerin tümünün Giles sınıflandırmasındaki L veya H tipte olduğu görülmüştür. Bu sonuçlar, kullanılan kompozitlerin Th'a olan yüksek adsorpsiyon ilgisi olarak nitelendirilmiştir. Deneysel izotermlerin Langmuir, Freundlich ve Dubinin-Radushkevich modellerine uyumundan türetilen parametreler bu ilgiyi kanıtlamıştır. PAA-Z ve Z için bulunan değerlerin kıyaslanmasından PAA-Z'ye ait artışın oldukça çarpıcı olduğu gözlenmiştir.Adsorpsiyon kinetiği ile ilgili araştırma sonuçları adsorpsiyonun sözde (pseudo) ikinci derece modelle açıklanabileceğini göstermiştir. İkinci derece hız denklemine uyum ve Weber-Morris modelinden iki doğrusal bileşen elde edilmesi; adsorpsiyonun derişime bağlı, kimyasal olduğunu ve hız belirleyen basamağın iyon değişimi/kompleks oluşumu olduğunu kanıtlamıştır.Adsorpsiyon entalpi değişim değerleri, araştırması yapılan tüm adsorbanlar için Th adsorpsiyonunun ısı alan, ?H>0 (endotermik) olduğunu kanıtlamış, kompozit ve modifiye yapılara Th4+ adsorpsiyonu için gerekli ısı, saf minerallerden daha düşük bulunmuştur. Bu durum kompozit yapısındaki PAA'nın adsorpsiyon sürecine katalizör etkisi olarak değerlendirilmiştir. Adsorpsiyon sürecinin beklenildiği gibi kendiliğinden olduğunu gösteren serbest entalpi (?G0 olduğunu göstermiştir. DR modelinden türetilen serbest enerji (EDR) değerlerinin 8 kJ mol-1 değerinden büyük bulunması adsorpsiyonunun serbest enerji açısından da tüm adsorbanlar için kimyasal olduğunu göstermiştir.Kompozitlerin yeniden kullanılabilirlikleri ilgili sonuçlar; PAA-B ve PAA-Z'nin rejenere edilerek tekrar kullanılabilir olduğunu, FA modifiye yapılar ve YZ içeren kompozitlerin ise kimyasal kararsızlık nedenli olarak etkin kullanılamayacaklarını göstermiştir.Adsorbanlara Th adsorpsiyonunun CaCl2 derişimine bağlı iyonik şiddetle değişiminin incelemesi, artan ortam iyon şiddetinin PAA-B dışındaki tüm yapılar için Th adsorpsiyonunu azaltıcı yönde etkilediğini kanıtlamıştır.Adsorbanların diğer metal iyonlarından (Al3+, Cu2+, Zn2+, Cr3+, Mn2+, Fe3+, Ni2+, Co2+, Pb2+, UO22+ ve Tb3+) birinin bulunduğu ortamdan Th seçiciliği araştırması, bu araştırmanın ilgisini oluşturan tüm adsorbanların Th için olan yüksek adsorpsiyon kapasitesini koruduğunu göstermiştir.Adsorbanların kolon (kromatografi) uygulaması sonuçları, kullanılan kompozit adsorbanların tümünün polimer temelli KDR ile karşılaştırılabilir derecede yüksek miktarda Th adsorpladığını göstermiştir. Kolon uygulamasında, Th ile sürekli dengedeki izotoplardan 212Pb, 212Bi ve 208Tl'nin adsorpsiyon davranışları incelenmiş, Th ve bu radyoaktif türlerin farklı sıyırma (eluent) çözeltileri ile geri kazanım davranışlarından Th saflaştırma ile ilgili dikkat çekici sonuçlar bulunmuştur.Anahtar Sözcükler: Adsorpsiyon, kompozit, bentonit, zeolit, Na-Y-zeolit, toryum, fitik asit, Arsenazo-III, alüminosilikat The concerns of this investigation are that the preparation of composites adsorbents containing Polyacrylamide (PAA) as the host and the minerals [Bentonite (B), Zeolite (Z) and Y-Zeolite (YZ)] as the guests, the characterization and the investigation of the adsorptive features for Th. PAA-B and PAA-Z were of the subject of an MSc studied previously in which the preparation and characterization together with adsorptive features for Fe, Zn, Pb and U were of interests. The characterization limited with FT-IR therein was expanded and detailed by TGA, SEM, BET-Porosity and Point of Zero Charge (PZC) analysis. The adsorptive features for Th was also investigated in details for PAA-YZ and a commercial cation exchange resin (CER) as well as for PAA-B and PAA-Z, and the effects of surface modification of these composites by phytic acid (Phy) on the adsorptive features were of the intents.These composites, which could be classified in layered and phase separated nano-composite (PAA-B), and phase separated micro-composites (PAA-Z nad PAA-YZ) were prepared direct polymerization of AA solutions containing mineral suspensions by accompaniment of a cross linking agent.Adsorptive features for Th were investigated in view of its dependency on pH, concentration, time (kinetics), temperature (thermodynamics), ionic strength and selectivity in the presence of any other competitive metal ions, from which the associated parameters characterizing the adsorbents were obtained. Reusability (regeneration) of the composites and their Th sorption properties from extracts obtained from natural samples (florite and coal ashes) were studied, and applicability of the composites in column chromatography for these natural extracts was investigated.The measurement of Th in solution containing Th alone was performed by the spectrophotometric method, where Arsenazo-III was used as complexing agent. A Th purification procedure involving anion exchange resin (AER) was applied for solutions containing Th and accompaniment ions that were potential interferences, after which the spectrophotometric method was employed. Gamma-spectrometric method was also used in the determinations so that to confirm the accuracy of measurements by the spectrophotmetry and also to investigate absorbability of the radio-isotopes in secular equilibrium with Th.The analysis of the synthesized composites by FT-IR, XRD, TGA, SEM, BET-porosity and PZC introduced certain evidences for the formation of composites, they proved that the formations were not hybrids but were phase separated mixtures.Results of the investigation associated with adsorption dependence to pH showed that the adsorbed amounts increased with increasing pH, the use of minerals in their composites significantly improved Th adsorption capacities in comparison to their uses in their bare forms. The Phy modification was further improved the capacities.All the isotherms obtained from the adsorption dependency on concentration were of L and H type of Giles classification which qualified that the high adsorption affinity of Th to the composites. The parameters obtained from Langmuir, Freundlch and Dubinin-Radsushkevich models were proved the quality of this affinity. The difference in parameters found for Z and PAA-Z in favor of PAA-Z was worthy noting.The results of investigations related to the adsorption kinetics indicated that the sorption process could be explained by the second order kinetic model. The fitness to the second order model and the provision of linear lines with two components from Weber-Morris model proved the facts that the adsorption process was concentration dependent, chemical and the rate defining step was ion exchange/complex formation.The values of enthalpy changes proved that the Th adsorption was endothermic, ?H>0 for all studied composites, the values found for the composites and their Phy modifications were lower than those found for bare minerals. This was attributed to the catalytic effect of PAA to the sorption process. Free adsorption energy were with negative signs, as it was expected, also indicated that the sorption onto the composites were more spontaneous than its occurrence for the bare minerals. The values of entropy changes showed that the processes overall were with entropy increased. The findings for the free adsorption energy higher than 8 kJ mol-1 were also evidence for the chemical characteristics of sorption process in view of the free energy.The results associated with the reusability of the composites implied that the composites were reusable after regeneration, but the Phy modified composites and PAA-YZ, because of their chemical instabilities, suggesting that these were not efficiently usable.The investigations for the effect of ionic strength controlled by CaCl2 concentration on Th sorption proved that the increasing strength decreased the sorption capacities of all composites except PAA-B.The studies related to Th selectivity of adsorbents from medium containing Th together with one of the metal ions (Al3+, Cu2+, Zn2+, Cr3+, Mn2+, Fe3+, Ni2+, Co2+, Pb2+, UO22+ ve Tb3+) showed that all the adsorbents of interest had selective to Th so that they kept their sorption capacities.The applications of the composites for column chromatography showed that all composites had comparably high sorption capacities with the polymer based commercial KDR. The results for the adsorptive features for the radio-isotopes of 212Pb, 212Bi and 208Tl were interestingly revealed that Th could be purified from these metal ions as depending on the used eluent solutions.Key words: Adsorption, kompozite, bentonite, zeolite, Y-zeolite, thorium, phytic acid, Arsenazo-III, Aluminosilicate 166

In this study; adsorption of uranium and thorium series elements CU, Ac, Pb,Bi and Tl) from the solution of a radioactive rock sample provided from fluorite areaat the north-west of Kuluncak-Malatya-TURKEY and also adsorption of uraniurnand lead from the aqueous media by a new polymeric adsorbent was investigated.The adsorbent is prepared by amidoximation (lPNa) of Interpenetrating PolyrnerNetworks (IPNs) synthesized by garnma irradiation of polyethylene glycolacrylonitrilesolution.The effects of adsorbent mass, particle shape and size, pH and solutionconcentration to the adsorption of these elements were determined by UV -visiblespectrofotometric and garnma spectrometric methods.The optimum particle size were determined 0.6-1.0 mm for all experiments.The optimum mass of the adsorbent were determined as 25 mg for the rock and leadsolution and 10 mg for the uranyl solution. The optimum concentrations and pH value s were determined for the rock, lead and uranyl solutions as 1.0-200 fgIL, 2.5-3; 14 mg Pb2+ IL, 4-5 and 10 g UO;+ IL, 3 respectively.The maximum adsorption value s of each elements obtained from theadsorption isotherms (L, or H type according to Giles) were found as 75%, 43%,95%, 38% for Ac, Pb, Bi and Tl for the adsorption from the radioactive rocksolution; ~804 mg U/g IPNa for uranium from aqueous uranyl nitrate solution; ~450mg U/g IPNa for uranium from uranium added radioactive rock solution; ~ 7 mg Pb/gIPNa for Icad from aqueous lead nitrat e solution. The adsorption sequence of theelements was found as Ac>Pb>Bi>TI from the radioactive rock solution.lt was concluded that the polymeric adsorbent could be effectively used forU, Ac, Pb, Bi and Tl adsorption from radioactive rock solution and also for theuranium and lead adsorption from aqueous salt solutions. 100

Bu çalışmanın amacı; biyobozunur bir polimer olan poli(laktik-ko-glikolik asit) (P), yüksek mol kütleli polisakkaritlerden olan aljinat (A), karragenan (C) ve/veya jelatin (G) proteini ile oluşturulan ikili (A-C, A-G), üçlü (A-C-G, A-C-P, A-G-P) ve dörtlü (A-C-G-P) kompozit boncukların sentezlenmesi, bu kompozit boncukların yapısal karakterizasyonu ve bir antibiyotik etken maddesi olan Sefaklor'un salımında kullanılmasıdır. Çalışma kapsamında yukarıda belirtilen kompozit mikroküreler, iyonik jelasyon veya diğer bir ifadeyle süspansiyon çapraz bağlama yöntemi ile hazırlanmıştır. Yöntemde, PLGA'sız boncuklar, A, C, G bileşenlerinin suda çözünmesiyle oluşan jellerin, CaCl2 ve KCl içeren çöktürücü çözeltiye, şırınga yardımıyla damlatılmasıyla elde edilmiştir. PLGA'lı jellerin sentezinde ise, A, C, G içeren jellere, PLGA'nın asetondaki çözeltisi eklenmiştir. Homojen hale gelene kadar karıştırılan ve asetonu buharlaştırılan jel yapılar, CaCl2, KCl tuzları ve polivinil alkol (PVA) içeren çözeltiye şırınga ile damlatılmış ve küresel yapılar elde edilmiştir. PLGA'sız (A-C, A-G ve A-C-G) ve PLGA'lı (A-C-P, A-G-P ve A-C-G-P) boncukların karakterizasyonu; FTIR ve ısıl analizlerle (TGA ve DTA), SEM fotoğraflarıyla, sıfır yük noktası (SYN), şişme ve kararlılık deneyleriyle yapılmıştır. FTIR, ısıl analizler ve SEM fotoğrafları, boncukların kompozit yapılar olduğunu göstermiştir. SYN analizlerinden, kompozitlerin yüzey yüklerinin sıfır olduğu pH değerlerinin 6.3-7.0 aralığında olduğu belirlenmiştir. Kompozit boncukların sudaki en yüksek şişme değerleri %157-641 aralığında değişmektedir. Bu yüksek şişme miktarına sahip kompozit boncuklar hidrojel olarak adlandırılabilir. Kompozitlerin mide (pH=1.2, HCl) ve bağırsak (pH=7.4, fosfat tamponu) pH'sındaki kararlılıkları incelenmiş, asidik pH'da 14. gün sonunda kütle kayıplarının % 9-76 aralığında değiştiği, tampon ortamında ise 3. günün sonunda yapıların tümüyle dağıldığı belirlenmiştir. Salım çalışmaları için beta laktam antibakteriyeller sınıfına dahil, ikinci kuşak bir sefalosporin antibiyotik olan sefaklor tercih edilmiştir. Salım çalışmalarından önce etkenle ilgili kararlılık testleri yapılmıştır. Etkenin asitte kararlı, bağırsak pH'sında kararsız olduğu, saklama koşulları için en uygun sıcaklığın +4 oC olduğu bilgisi teyit edilmiştir. Sefaklorun UV bölgedeki (264 nm) belirgin, kararlı ve kompozit bileşenleri ile örtüşmeyen piki, UV-Vis spektrofotometrik derişim tayinlerinde kolaylık sağlamıştır. Sefaklor içeren kompozitler, birlikte sentez veya doğrudan ilaç yükleme yöntemi ile sentezlenmiştir. Boncuklarda etkenin tutuklanma verimi %93'lere kadar ulaşmıştır. Tutunma yüzdesi bilinen kompozitler için farklı pH aralıklarına sahip çözeltilerde salım kinetiği çalışmaları uygulanmıştır. Etken maddenin asidik ortamda kararlı olması, düşük pH değerinin (mide pH'sı) uzun süreli salım için uygun olmasına neden olmuştur. Salım deneylerinde kompozitlerden etken maddenin salımı kompozit içeriğine göre farklılık göstermekle birlikte maksimum salım süresinin 4 saate kadar ulaştığı ve salım yüzdesinin %90'a ulaştığı belirlenmiştir. Salım kinetiği verilerinin, Birinci dereceden salım kinetiği, Korsmeyer Peppas ve Higuchi salım kinetiği modellerine uyduğu belirlenmiş ve bu modellere ait sabitler türetilmiştir. The objective of this study that to synthesize bio-degradable composite beads composing of a polymer 'poly(lactic-co-glycolic) acid' (PLGA), a polysaccharide with high molecular weight 'alginate' (A), 'carregeenan' (C) and/or 'gelatin' (G) in combinations of binary (A-C, A-G), triple (A-C-G, A-C-P and A-G-P) and quadruple (A-C-G-P) forms and its use in the release of cefaclor as an antibiotic co-factor. Within the study context, above mentioned microsphere composites were prepared via ionic gelation, i.e., cross linking in suspension techniques. The beads not containing PLGA were prepared by dropwise addition of the gels formed in the dissolution of A, C and G in water in a syringe to the precipitant solution containing CaCl2 and KCl. The gels with PLGA were synthesized by addition of PLGA in acetone over the formed gels in water. The gels obtained by stirring for homogeneity and evaporation off its acetone content were dropped with a syringe in a solution of CaCl2, KCl and polyvinyl alcohol (PVA) and the spherical formations were obtained. The obtained beads with PLGA (A-C-P, A-G-P and A-C-G-P) and without PLGA (A-C, A-G and A-C-G) were characterized by FT-IR for chemical compositions, TGA and DTA for thermal features, SEM for the morphology, by determination of point of zero charge (PZC) for surface charge, and by swelling and stability tests. FTIR, thermal tests and SEM views proved the formation of composites. PZC values were in between 6.3-7.0. The ratio of swelling in water was in the range of 157641%. The materials having such welling ratio could be considered as hydrogels.The stability of hydrogels were inspected at stomach pH (1.2 in HCl) and gut pH (7.4 in phosphate buffer) by which it was found that the losses were 9-76% in acidic medium at the end of 14th day whereas the formations were completely disintegrated in the buffer solution at the end of third day. Cefaclor as a second generation cephalosporins antibiotics classified under beta lactam antibacterials was preferred for the release investigations. Preliminary tests for the stability of Cefaclor showed that it was stable in acidic medium unlike its instability at the gut pH and that confirmed that the best storage condition was 4+ 0C. Cefaclor was determined by its adsorption of UV lights at 264 nm, the clear peak without any interference with composite components was an advantage for its determination by Uv-Vis spectrophotometric technique. The composite containing Cefaclor was prepared via co-synthesis or direct drugloading method. The retention yield of factor on beads was reached about 93%. The release kinetics at different pHs were inspected for the composed containing known amounts of the factor. The stability of Cefaclor at acidic medium, the low pH (stomach pH) prolonged release. Although the releasing times showed variations amongst composites, the maximum time and ratio were reached up to 4 h and 90%. The results of the releasing kinetics obeyed first order kinetics, Korsmeyer Peppas and Higuchi models from which the relevant constants were calculated. 148

Bu çalışmanın amacı, bir hidrojel olan poliakrilamidin (PAAm) bentonit (B) minerali ve bir aminopolisakkarit olan kitosan (Ch) ile oluşturduğu PB (poliakrilamid-bentonit), PCh (poliakrilamid-kitosan) ve PChB (poliakrilamid-bentonit-kitosan) kompozit adsorbanların hazırlanması, karakterizasyonu ve üreaz immobilizasyonunda kullanımının araştırılmasıdır.PB ve PCh kompozitleri, B ve Ch'yi süspansiyon olarak içeren akrilamid çözeltisinde akrilamidin bir çapraz bağlayıcı eşliğinde doğrudan polimerleştirilmesiyle elde edilmiştir. PChB kompozitinin hazırlanmasında B süspansiyonu üzerine asetik asitte çözünmüş kitosan eklenmiş ve epiklorohidrin (ECH) ilave edilmiştir. Oluşan viskoz süspansiyon şırınga içerisine alınarak sodyum tripolifosfat (NaTTP) çözeltisi bulunan behere damlalar halinde eklenerek Ch-B boncukları oluşturulmuştur. Ardıl yıkamalarla saflaştırılan ChB'nin PAAm ile oluşturduğu PChB kompoziti PB hazırlanmasındaki yöntemle hazırlanmıştır. Oluşturulan kompozit yapıların FT-IR, XRD, TGA, DSC, SEM ve SYN analizleri kompozit oluşumunu kanıtlamıştır.Kompozit yapılara üreaz immobilizasyonun, derişim, zaman ve sıcaklıkla değişimi, iletkenlik yöntemi kullanılarak araştırılmıştır. PB, PCh ve PChB'nin tek tabaka adsorpsiyon kapasiteleri sırasıyla 93, 174, 95 mg g-1'dir. İmmobilizasyonun zamanla değişiminin (kinetik) daha çok sözde (pseudo) ikinci derece hız modeline uyduğuviiiregresyon değerleri (R2) ile kanıtlanmıştır. Sıcaklıkla değişimi araştırması tutunmanın sıcaklığa bağlı olmadığını göstermiştir.Kompozite immobilize edilmiş üreaz aktivitelerinin substrat derişimi, pH ve sıcaklıkla değişimi, serbest üreazın aktivite ölçümleri ile kıyaslanarak değerlendirilmiştir. Ölçümlerde Berthelot yöntemi kullanılmıştır. Michaelis-Menten grafiğinden türetilen Vmax ve Km değerleri sırasıyla, serbest enzim için 11 ünite mg-1 ve 128 mM, PB için 11 ünite mg-1 ve 243 mM, PCh için 20 ünite mg-1 ve 104 mM, PChB için 19 ünite mg-1 ve 102 mM bulunmuştur. Her üç kompozit ve serbest enzim için optimum pH ve sıcaklık deneyleri yapılmıştır. The objectives of this investigation is to prepare, to characterize and to investigate the usability of urease immobilization of the composite adsorbents in combination of polyacrylamide (PAAm) as an hydrogel and bentonite (B) mineral, and chitosan (Ch) as a polysaccharide; PB (polyacrylamide-bentonite), PCh (polyacrylamide-chitosan) and (polyacrylamide-chitosan-bentonite) PChB.The Pb and PCh composites were synthesized by the polymerization of acrylamide in suspension of B and Ch in presence of a cross linking agent. The ChB beads were formed by drop wise addition of this suspension in a sodium tripolyphosphate solution by the aid of a syringe. The composite of PAAm with ChB purified by sequential washes was then formed by the method used for PB formation. The formation of the composites was proved by their analysis with FT-IR, XRD, TGA, DSC, SEM and PZC.The effect of concentration, time and temperature on urease immobilization on to the composites was investigated by the use of conductometric technique. The monolayer adsorption capacities of PB, PCh and PChB were composites were 93, 174 and 95 mg g-1 in respective order. High compatibility of time dependence of ureaseximmobilization (kinetics) to pseudo second order model was confirmed with the values of coefficients of regression (R2). The research for temperature dependence showed that the immobilization was not temperature dependent.The activity dependence of urease immobilized on the composites on the substrate (urea) concentration, pH and temperature was evaluated with reference to the activity measured for free urease. Berthelot method was used for the measurements. The Vmax and Km values derived from Michaelis-Menten graphs were 11 unit mg-1 and 128 mM for the free enzyme, 11 unite mg-1 and 243 mM for PB, 20 unit mg-1 and 104 mM for PCh, and 19 unite mg-1 and 102 mM for PChB. The optimum pH and temperature tests were performed for all three composite and free enzymes. 97