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ÖZET Bu doktora tezi dört bölümden oluşmaktadır. İlk bölümde, makroçaprazbağlayıcılar (MCR) sentezlenmiş ve sürenin polimerizasyonunda kullanılarak, çapraz bağlı polimerik mikroküreler sentezlenmiştir. Çapraz bağlayıcı olarak kullanılan MCR'lerin mol kütlelerine bağlı olarak polimer dönüşüm oram, çapraz bağlanma dereceleri ve denge şişme oranlan belirlenmiştir. İyon değiştirici reçinelerin sentezlenmesi için, dumanlı sülfürik asit (oleum) kullanılarak, çapraz bağlı polimerik mikrokürelere sülfo grupları takılmıştır. Polimerik ürünlerin karakterizasyonunda FTIR, NMR ve elementel analiz yöntemleri kullanılmıştır. İkinci bölümde, N-Vinil imidazol (N-VİM) ve çapraz bağlayıcı olarak etilenglikol dimetakrilat (EGDMA) kullanılarak, süspansiyon polimerizasyon yöntemiyle çapraz bağlı poli (etilenglikol dimetakrilat-N-vinil imidazol) [poli(EGDMA-N-VİM)] kopolimer mikroküreler sentezlenmiştir. Bu polimerin karakterizasyonunda FTIR, elementel analiz ve SEM yöntemlerinden yararlanılmıştır. Üçüncü bölümde, sentezlenen iyon değiştiricilerin Cr(III), Cu(II), Zn(II) ve K(I) metal iyonlarına karşı seçimlilikleri incelenmiş, seçimlilik sırasının Cr(III) > Cu(II) > Zn(II) > K(I) şeklinde olduğu belirlenmiştir. Dördüncü bölümde, poli(EGDMA-N-VİM) çapraz bağlı kopolimer mikrokürelerin Cr(III), Cu(II), Zn(II) ve K(I) metal iyonlarına karşı seçimlilikleri incelenmiş ve seçimliliğin Cu(II) > Zn(II) > Cr(III) > K(I) sırasında olduğu belirlenmiştir. Bu sonuçlar, reçinelerin iyon değişimi (toplam adsorpsiyon) özellikleri ile karşılaşünlmıştir. ANAHTAR KELİMELER: Adsorpsiyon, İyon değişimi, Metal uzaklaştırma, Şelat küreler, Makroçaprazbağlayıcılar, Krom(III), Bakır(II), Çinko(II), Potasyum(I), N-Vinil imidazol. ABSTRACT In this Ph.D. thesis, there are four main parts. Firstly, macrocrosslinkers (MCR) were prepared and crosslinked polymeric microbeads was obtained by using these MCRs in polymerization of styrene. Equilibrium swelling ratios, crosslinking degree and ratio of polymer transformation were determined depending on molecular mass of the MCRs used as crosslinkers. In order to synthesis of ion-exchange resins, sulpho groups were attached by using oleum. FTIR, NMR, elemental analysis methods were used for the charactherization of polymeric products. In the second part, crosslinked poly(EGDMA-VIM) [poly(ethylenglycole dimethacrylate-N-vinyl imidazole)] copolymer microbeads was prepared with suspension polymerization method which was the ethylenglycole dimethacrylate (EGDMA) used as a crosslinker. The characterization of this copolymer was made by using FTIR, elemental analysis and SEM methods. Thirdly, affinity of synthesized ion-exchangers to Cr(III), Cu(II), Zn(II) ve K(I) metal ions was investigated and the order of affinity was found as Cr(III) > Cu(II) > Zn(II) > K(I), respectively. Finally, affinity of crosslinked poly(EGDMA-VIM) copolymer microbeads to Cr(III), Cu(II), Zn(II) ve K(I) metal ions was investigated and the order of affinity was found as Cu(II) > Zn(II) > Cr(III) > K(I), respectively. These results were compared with ion- exchange (total adsorption) properties of resins. KEY WORDS: Adsorption, ion-exchange, Metal removal, Chelate beads, Macrocrosslinkers, Crom(III), Copper(II), Zinc(II), Potasium(I), N- Vinyl imidazole. 240

Aspirinin etken maddesi asetilsalisilik asit’tir ve steroid olmayan ağrı kesiciler grubuna ait bir ilaçtır. Ağrı kesici, ateş düşürücü ve kan sulandırıcı özellikleri vardır. Aspirinin ham maddesi olan salisilik asit ve türevleri söğüt gibi bazı bitkilerin yaprak ve kabuklarında bulunur. Salisilik asit antiseptiktir ve bazı gıdalara koruyucu olarak ta katılır. Bu çalışmada, süspansiyon polimerizasyon tekniği ile manyetik polimerik mikropartiküller sentezlenmiştir. Polimerizasyonda kullanılan manyetik malzeme, süperparamanyetik ve biyouyumlu özelliklerinden dolayı demir (II, III) oksit (Fe3O4) olarak seçilmiştir. Bu polimerizasyon yöntemi iki fazda gerçekleşti. Dispersiyon fazı stabilizörün saf suda çözünmesiyle hazırlanıp, organik fazda gözenek oluşturucu özelliği nedeniyle toluen tercih edilmiştir. Bu fazda başlatıcı, çapraz bağlayıcı ve monomer karıştırılarak homojen bir karışım elde edilmiştir. İki faz da kapalı bir polimerizasyon reaktöründe manyetik karıştırıcı kullanılarak karıştırılacak ve polimerizasyon reaksiyonu gerçekleştirildi. Salisilik asit, adsorpsiyon yöntemi ile sentezlenmiş manyetik polimerik partiküllere yüklendi. Salisilik asit adsorpsiyonu üzerine, konsantrasyon, sıcaklık ve zaman parametrelerinin etkileri araştırıldı. Taramalı Elektron Mikroskobu (SEM), gözlemleri parçacıkların partikül olduğunu gösterdi. Bu partiküller üzerine salisik asit adsorpsiyonu başarılı bir şekilde gerçekleştirilmiştir. Geliştirilmiş manyetik polimerik partiküller, ilaç salınımı için potansiyel bir aday olup, inflamasyonun bulunduğu bölgeye ilaç salınımı için salisilik asit taşıyıcısı olarak kullanılabilir. The active ingredient of aspirin is acetylsalicylic acid, and it is a drug belonging to the group of non-steroidal pain relievers. It has analgesic, antipyretic and blood thinning properties. Salicylic acid, which is the raw material of aspirin, and its derivatives are found in the leaves and bark of some plants such as willow. Salicylic acid is an antiseptic and is added to some foods as a preservative. In this study, magnetic polymeric microparticles were synthesized by suspension polymerization technique. The magnetic material used in the polymerization was chosen as iron (II, III) oxide (Fe3O4) due to its superparamagnetic and biocompatible properties. This polymerization method took place in two phases. The dispersion phase is prepared by dissolving the stabilizer in pure water, and toluene is preferred because of its pore-forming feature in the organic phase. In this phase, a homogeneous mixture was obtained by mixing the initiator, crosslinker and monomer. The two phases will be mixed using a magnetic stirrer in a closed polymerization reactor and the polymerization reaction is carried out. Salicylic acid was loaded onto magnetic polymeric particles synthesized by adsorption method. The effects of concentration, temperature and time parameters on salicylic acid adsorption were investigated. Scanning Electron Microscopy (SEM),observations showed that the particles were particles. Salicylic acid adsorption on these particles was successfully performed. Developed magnetic polymeric particles are a potential candidate for drug delivery and can be used as a salicylic acid carrier for drug delivery to the site of inflammation.

Manyetik poli(etilen glikol dimetakrilat-N-izopropil akrilamid) [m-poli(EGDMA-N-IPAAm)] partiküllerinin sentezi, manyetik özelliğin kazandırılabilmesi amacıyla Fe3O4 nanopartikülleri kullanılarak süspansiyon polimerizasyonu metoduyla gerçekleştirildi. Elde edilen partiküllerin karakterizasyonu için elemental analiz, taramalı elektron mikroskopisi, Fourier dönüşümlü kızılötesi spektroskopisi, Brunauer-Emmett-Teller analizi ve elektron spin rezonans spektroskopisi teknikleri çalışıldı. m-poli(EGDMA-N-IPAAm) partiküllerinin yapısında %3,30 oranında azot tespit edildi. Partiküllerin spesifik yüzey alanı 64,57 m2/g, g faktörü 1,75 olarak belirlendi. Karakterizasyon sonuçları, elde edilen polimerik partiküllerin manyetik özelliğe sahip olduğunu göstermektedir. m-poli(EGDMA-N-IPAAm) partiküllerinin potansiyel bir ilaç taşıyıcısı olarak uygunluğu araştırıldı. Bunun için model ilaç olarak sitikolin seçildi. İlacın partiküllere yüklenmesi adsorpsiyon yöntemiyle gerçekleştirildi ve adsorpsiyona etki eden sıcaklık, zaman ve başlangıç konsantrasyonu parametreleri incelendi. Sıcaklık etkisinin değerlendirilmesinde, adsorpsiyon kapasitesinin en yüksek olduğu sıcaklığın 25 ºC olduğu ve sıcaklık artışının adsorpsiyon kapasitesini düşürdüğü gözlemlendi. Elde edilen adsorpsiyon verilerine Langmuir ve Freundlich izoterm modelleri uygulandı ve m-poli(EGDMA-N-IPAAm) partiküllerinin sitikolin adsorpsiyonunun Langmuir izotermine uyduğu belirlendi. Adsorpsiyon kinetiğinin incelenmesi için yalancı birinci dereceden, yalancı ikinci dereceden ve partikül içi difüzyon kinetik modelleri kullanıldı ve adsorpsiyon sürecinin yalancı birinci dereceden kinetik modeline uyduğu görüldü. The synthesis of magnetic poly(ethylene glycol dimethacrylate-N-isopropylacrylamide) [m-poly(EGDMA-N-IPAAm)] particles was carried out by suspension polymerization method, using Fe3O4 nanoparticles to obtain particles that exhibit magnetic properties. Elemental analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmet-Teller analysis, and electron spin resonance spectroscopy studies were performed for the characterization of the obtained particles. The nitrogen ratio in the structure of m-poly(EGDMA-N-IPAAm) particles was detected as 3.30%. The specific surface area and g factor of the particles was determined as 64,57 m2/g and 1,75, respectively. Results of the characterization studies indicated that the obtained polymeric particles have magnetic properties. The availability of m-poly(EGDMA-N-IPAAm) particles as a potential drug carrier was investigated. For this purpose, citicoline was used as the model drug. Drug loading onto particles was performed by the adsorption method. Temperature, time, and initial concentration parameters that affect the adsorption process were investigated. Evaluation of the temperature effects showed that the maximum adsorption capacity was found to be at 25 ºC and increasing the temperature results in decreased adsorption capacity. Langmuir and Freundlich isotherm models were tested and the Langmuir isotherm model was found to be adequate for the process of citicoline adsorption onto m-poly(EGDMA-N-IPAAm) particles. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were also tested to investigate the adsorption kinetics and the adsorption process was determined to fit the pseudo-first-order kinetic model

Atık sudaki renk tekstil terbiye endüstrisinin ilgilendiği sorunlardan birisidir. Bu konuda yasal sınırlamalar mevcuttur. Manyetik polimerler ise güçlü adsorpsiyona sahip olması, dış manyetik alan yardımıyla kolaylıkla ayrılabilmesi özelliği sayesinde iyi adsorpsiyon gösterir. Manyetik polimerler güçlü adsorpsiyon/indirgeme aktivitesine sahiptir. İyi kütle aktarımı ve yüzey özellikleri seçici ayırma ve uzaklaştırma için idealdir. Kimyasal yapıları sayesinde atık sulardan kirlilik uzaklaştırmada yüksek verimlilik sağlar. Bu çalışmada, reaktif bir boya olan, Reaktif Siyah 5 ve Reaktif Turuncu 16'nın sulu çözeltilerden uzaklaştırılmasının adsorpsiyon üzerine pH etkileri, poli (divinilbenzen-1-vinilimidazol) [poli (DVB-VIM)] ve manyetik poli (divinilbenzen-1-vinilimidazol) [m-poli (DVB-VIM)] ile incelenmiştir. Poli (DVB-VIM) ve manyetik poli (DVB-VIM) mikro boncuklar sentezlendi ve karakterize edildi; lineer regresyon analizinde pH etkilerinin adsorbana etkisi olarak kullanımı araştırıldı. Poli (DVB-VIM) mikro boncuklar, divinilbenzenin (DVB) 1-vinilimidazol (VIM) ile kopolimerleştirilmesiyle hazırlandı. Poli (DVB-VIM) ve manyetik poli (DVB-VIM) mikroboncuklar taramalı elektron mikroskobu (SEM), fourier-transform kızılötesi spektroskopi (FTIR) çalışmaları ve şişme çalışmaları ile karakterize edildi. Bu çalışmada, adsorpsiyon üzerine pH etkilerinin lineer regresyon analizi [pH: 2 ile pH: 12 arasında] detaylı olarak incelenmiştir. The color in the waste is one of the problems that the textile finishing industry is interested in. There are legal limitations. Magnetic polymers have good adsorption and good adsorption due to their ability to be easily separated by external magnetic field. Magnetic polymers have strong adsorption. The good mass transfer and surface properties are ideal for selective separation and removal. Thanks to its chemical structures, it provides high efficiency in removing pollution from waste water. In this study, pH effects of removal a reactive dye, Reactive Black 5 and Reactive Orange 16, from aqueous solutions were studied by adsorption on poly(divinylbenzene-1-vinylimidazole) [poly(DVB-VIM)] and magnetic poly (divinilbenzen-1-vinilimidazol) [m-poly (DVB-VIM)]. The poly(DVB-VIM) microbeads were synthesized and characterized; their use as adsorbent of pH effects in linear regression analysis were investigated. The poly(DVB-VIM) microbeads were prepared by copolymerizing of divinylbenzene (DVB) with 1-vinylimidazole (VIM). The poly(DVB-VIM) and magnetic poly (DVB-VIM) microbeads were characterized by scanning electron microscope (SEM), fourier-transform infrared spectroscopy (FTIR) studies and swelling studies. In this study, linear regression analysis of pH effects on adsorption has been examined in details [between pH:2 and pH:12]. 158

Boyarmaddelerin sulu çözeltiden giderilmesi amacıyla fotokatalitik özelliğe sahip, manyetik poli(etilenglikoldimetakrilat-vinil fosfonik asit) [m-poli(EGDMA-VPA)]-TiO2 çapraz bağlı mikroküreler, Fe3O4/TiO2 nanopartikülleri varlığında süspansiyon polimerizasyon yöntemiyle sentezlendi. [m-poli(EGDMA-VPA)]-TiO2 mikrokürelerin karekterizasyonları taramalı elektron mikroskobu (SEM), diferansiyel termal analiz (TG-DTA), Fourier Transform Infrared spektroskopisi (FT-IR), yüzey alanı ve gözeneklilik ölçümü Brunauer, Emmet ve Teller (BET), faz bilgisi X- Işığı Kırınımı (XRD), elementel analizi X-ışını fotoelektron spektroskopisi (XPS), manyetik özelliği Elektron Spin Rezonans (ESR) ve yüzey yükünün belirlenmesi Zeta potansiyeli ölçüm yöntemleriyle karakterize edildi. [m-poli(EGDMA-VPA)]-TiO2 mikrokürelerinin spesifik yüzey alanı 195,0 m2/g, şişme oranı, % 40.19. m-poli(EGDMA-VPA)]-TiO2 mikroküreleri için g faktörü 1,94 olması sentezlenen polimer kompozitin manyetik özellik kazandığını göstermektedir. Sentezlenen mikrokürelerin, sulu ortamdan Reaktif mavi 221 (RB 221) boyarmaddesi gideriminde kullanılabilirliği incelendi. Polimer mikrokürelerin adsorpsiyon, desorpsiyon ve fotokatalitik etki üzerine pH, başlangıç boyarmadde konsantrasyonu, sıcaklık, adsorban miktarı, zaman, gün ışığı, UV ışığı parametreleri incelendi. Maksimum adsorpsiyon pH 3,0’te; maksimum desorpsiyon 0,01M NaOH çözeltisinde olduğu gözlemlendi. Fotokatalitik dekolorizasyon için maksimum giderim pH 3’te olduğu belirlendi. Fotokatalitik dekolorizasyon için 298K’de %96 oranında giderim sağlandığı belirlendi. Adsorpsiyon prosesinin Langmuir ve Freundlich modellerine uygulanabilirlikleri araştırıldı ve Langmuir izotermine uygun olduğu belirlendi. Adsorpsiyon ve fotokatalitik dekolorizasyon kinetiği incelendiğinde yalancı 1. derece, yalancı 2. derece ve partikül içi difüzyon modelleri kullanıldı. Adsorpsiyon ve fotokatalitik dekolorizasyon için tepkime hız sabiti hesaplandı. Magnetic photocatalytic poly (ethyleneglycoldimethacrylate-vinyl phosphonic acid) [m-poly (EGDMA-VPA)]-TiO2 crosslinked microspheres were synthesized by suspension polymerization in the presence of Fe3O4 / TiO2 nanoparticles to remove reactive blue 221 dye from aqueous solution. [m-poly (EGDMA-VPA)] - Characterization of TiO2 the microspheres scanning electron microscopy (SEM), differential thermal analysis (TG-DTA), Fourier Transform Infrared spectroscopy (FT-IR), surface area and porosity measurement Brunauer, Emmet and Teller (BET), phase information X-Ray Diffraction (XRD), elemental analysis X-ray photoelectron spectroscopy (XPS), magnetic property Electron Spin Resonance (ESR) and surface charge determination were characterized by Zeta potential measurement methods. [m-poly (EGDMA-VPA)] - Specific surface area of TiO2 microspheres 195.0 m2/g, swelling rate, 40.19%. m-poly (EGDMA-VPA)] - For TiO2 microspheres, the g factor is 1.94, indicating that the synthesized polymer composite gains magnetic property. The usability of synthesized microspheres for the removal of Reactive blue 221 (RB 221) from aqueous medium was examined. PH, initial dye concentration, temperature, adsorbent amount, time, daylight, UV light parameters on adsorption, desorption and photocatalytic effect of polymer microspheres were examined. Maximum adsorption at pH 3.0; maximum desorption was observed in 0.01M NaOH solution. The maximum removal for photocatalytic decolorization was determined at pH 3. It was determined that 96% removal was achieved at 298 K for photocatalytic decolorization. The applicability of adsorption process to Langmuir and Freundlich models was investigated and determined to be suitable for Langmuir isotherm. Adsorption and photocatalytic decolorization kinetics of the system were investigated. For this purpose, Pseudo first degree, false second degree and intraparticle diffusion models were used. Reaction rate constant was calculated for adsorption and photocatalytic decolorization.

This study is aimed at the synthesis and characterization of the mesoporous magnetic-poly(divinylbenzene-1-vinylimidazole)[m-poly(DVB-VIM))microbeads(average diameter = 53-212 mu m); their application as adsorbent in the removal of Cu(II) ions from aqueous solutions was investigated. The mesoporous m-poly(DVB-VIM) microbeads were prepared by copolymerizing of divinylbenzene (DVB) with 1-vinylimidazole (VIM). The mesoporous m-poly(DVB-VIM) microbeads were characterized by N-2 adsorption/desorption isotherms, ESR, elemental analysis, scanning electron microscope (SEM), and swelling studies. At fixed solid/solution ratio the various factors affecting adsorption of Cu(II) ions from aqueous solutions such as pH, initial concentration, amount of mesoporousm-poly(DVB-VIM)) microbeads, contact time, and temperature were analyzed. Langmuir, Freundlich, and Dubinin-Radushkvich isotherms were used the model adsorption equilibrium data. The Langmuir isotherm model was the most adequate. The pseudo first-order, pseudo-second-order, Ritch-second-order, and intraparticle diffusion models were used to describe the adsorption kinetics. The experimental data fitted to pseudo second-order kinetic. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy, and entropy changes. Morever, after the use in adsorption, the mesoporous m-poly(DVB-VIM) microbeads with paramagnetic property was separated via the applied magnetic force. These features make the mesoporous m-poly(DVB-VIM) microbeads a potential candidate for support of Cu(II) ions removal under magnetic field.

The adsorption of poly(1-vinylimidazole) (PVI) onto sepiolite from aqueous solutions was investigated as a function of some parameters such as pH, ionic strength, and temperature. The adsorption of PVI was increased with increasing pH and with decreasing ionic strength and temperature. The Langmuir isotherm model fitted the isotherm data better than the Freundlich model. The electrophorotic mobility of sepiolite dispersions was measured at different PVI concentrations and pH. The thermodynamic parameters Gibbs free energy, enthalpy, and entropy were evaluated. The dimensionless separation factor (R-L.) revealed that sepiolite can be used for adsorption of PVI from aqueous solutions. The second-order kinetics equation best fitted the experimental data. Dielectric properties of sepiolite coated with PVI have been also investigated. The sample with adsorbed PVI at 25 degrees C has the maximum the AC conductivity and the charge carriers can move easily in comparison with other samples. The real permittivities of the PVI-adsorbed samples are quite high in comparison with those of the pure polymer as a result of interface interactions. Kocaeli Üniversitesi -2007/071 Balıkesir Üniversitesi Uygulamalı Bilimler Araştırma Merkezi (BURCAS)

The magnetic-poly(divinylbenzene-4-vinylpyridine) [m-poly(DVB-4VP)] microbeads (average diameter: 180–212 μm) were synthesized by copolymerizing of divinylbenzene (DVB) with 4-vinylpyridine (4VP) and by mixing this copolymer with Fe 3 O 4 nanoparticles. The resultant material was characterized by N 2 adsorption/desorption, ESR, elemental analysis, scanning electron microscope (SEM) and swelling studies. After functionalized with sulfonic acid, m-poly(DVB-4VP-SO 3 H) was characterized by FT-IR and TGA analysis. The results showed that both of Fe 3 O 4 and –SO 3 H are bonded to the polymer successfully. N 2 adsorption/desorption isotherms of synthesized samples had the hysteresis behaviour associated with mesoporous materials (pore diameter: 3.73 nm). Sulfonic acid functionalized mesoporous m-poly(DVB-4VP-SO 3 H) has been demonstrated to have higher reactivity than commercially available solid acid catalysts for the conversion of propionic acid to methyl ester. The apparent activation energy was found to be 38.5 kJ mol −1 for m-poly(DVB-4VP-20%SO 3 H). The catalyst showed negligible loss of activity after four repetitive cycles.

A modified two-step seeded polymerization was used for the preparation of porous mono-sized microspheres of poly(ethylene glycol dimethacrylate-co-1-vinylimidazole) [poly(EGDMA-co-VIM)] of 7 mu m in size. The specific surface area and the EGDMA/VIM molar ratio of the microspheres were determined as 64.5 m(2)/g and 1.5:1.0 mol/mol, respectively. The adsorption of Pb(II) ions from aqueous solution onto the porous mono-sized poly(EGDMA-co-VIM) microspheres was examined. The maximum adsorption capacities of the microspheres towards Pb(II) ions were determined as 21.74, 30.52, 49.23 and 56.48 mg/g at 293 K, 303 K, 318 K and 338 K, respectively. The dynamic and equilibrium adsorption behaviours of the system were adequately described by the pseudo-second-order kinetic model and the Langmuir isotherm, respectively. The apparent activation energy was determined as 6.212 kJ/mol, which is characteristic of a chemically controlled reaction. The values of E-fe obtained from the Dubinin-Radushkevich equation in the non-linear form were 9.153 kJ/mol at 293 K, 10.34 kJ/mol at 303 K, 10.18 kJ/mol at 318 K and 10.91 kJ/mol at 333 K, thereby indicating that the adsorption of Pb(II) ions onto the porous mono-sized poly(EGDMA-co-VIM) microspheres occurred via a chemical process at all the temperatures studied. Various thermodynamic parameters, such as the Gibbs' free energy change (Delta G(0)), the standard enthalpy change (Delta H-0) and the standard entropy change (Delta S-0) were also determined. The thermodynamic parameters obtained indicated that the adsorption process was endothermic in nature. These results demonstrate that the material studied could be used as a purifier for the removal of Pb(II) ions from water and wastewater.

The synthesis of single wall nanotubes (SWNT)/poly(vinyl)triazole (PVTri) composites by in situ emulsion polymerization method and its chemical and physical properties were investigated throughout this work. The surface modification of the SWNT by nitric acid treatment and air oxidation has improved the dispersion of the SWNT in the PVTri matrix. The SWNT/PVTri composite is obtained by covalent bonding of the carboxyl terminated SWNTs to PVTri. The effect of covalent bond formation between PVTri and SWNT on the thermal and electrical properties of the composite is also studied. The spectroscopic, thermal, and microscopic analysis has confirmed the structure, homogeneity, and the morphology of surface functionalized SWNT and SWNT/PVTri composites. SWNT/PVTri composites showed enhanced chemical stability in many common solvents and high electrical conductivity.

Poly(ethylene glycol dimethacrylate-1-vinyl-1,2,4-triazole) [poly(EGDMA-VTAZ)] beads (average diameter = 150–200 μm) were prepared by copolymerizing ethylene glycol dimethacrylate (EGDMA) with 1-vinyl-1,2,4-triazole (VTAZ). Poly(EGDMA-VTAZ) beads were characterized by swelling studies and scanning electron microscope (SEM). The adsorption of Cr(VI) from solutions was carried at different contact times, Cr(VI) concentrations, pH, and temperatures. High adsorption rates were achieved in about 240 min. The amount of Cr(VI) adsorbed increased with increasing concentration and decreasing pH and temperature. The intraparticle diffusion rate constants at various temperatures were calculated. Adsorption isotherms of Cr(VI) onto poly(EGDMA-VTAZ) have been determined and correlated with common isotherm equations such as Langmuir and Freundlich isotherm models. The Langmuir isotherm model appeared to fit the isotherm data better than the Freundlich isotherm model. The pseudo first-order kinetic model was used to describe the kinetic data. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy, and entropy changes. The dimensionless separation factor (RL) showed that the adsorption of metal ions onto poly(EGDMA-VTAZ) was favorable. It was seen that values of distribution coefficient (KD) decreasing with Cr(VI) concentration in solution at equilibrium (Ce) indicated that the occupation of activate surface sites of adsorbent increased with Cr(VI). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The aim of this study is to prepare magnetic beads which can be used for the removal of heavy metal ions from synthetic solutions. Magnetic poly(ethylene glycol dimethacrylate-vinyl imidazole) [m-poly(EGDMA-VIM)] beads were produced by suspension polymerization in the presence of magnetite Fe3O4 nano-powder. The specific surface area of the m-poly(EGDMA-VIM) beads was found to be 63.1 m(2)/g with a size range of 150-200 m in diameter and the swelling ratio was 85%. The average Fe3O4 content of the resulting m-poly(EGDMA-VIM) beads was 12.4%. The maximum binding capacities of the m-poly(EGDMA-VIM) beads were 32.4 mg/g for Cu2+, 45.8mg/g for Zn2+, 84.2 mg/g for Cd2+ and 134.5 mg/g for Pb2+. The affinity order on mass basis is Pb2+ > Cd2+ > Zn2+ > Cu2+. Equilibrium data agreed well with the Langmuir model. pH significantly affected the binding capacity of the magnetic beads. Binding of heavy metal ions from synthetic wastewater was also studied. The binding capacities were 26.2 mg/g for Cu2+, 33.7 mg/g for Zn2+, 54.7 mg/g for Cd2+ and 108.4 mg/g for Pb2+. The magnetic beads could be regenerated up to about 97% by treating with 0.1 M HNO3. These features make m-poly(EGDMA-VIM) beads a potential candidate for support of heavy metal removal under magnetic field.

Magnetic vinylphenyl boronic acid microparticles, poly(ethylene glycol dimethacrylate(EG)-vinylphenyl boronic acid(VPBA)) [m-poly(EG-VPBA)], produced by suspension polymerization and characterized, was found to be an efficient solid polymer for Cr(VI) adsorption. The m-poly(EG-VPBA) microparticles were prepared by copolymerizing of ethylene glycol dimethylacrylate (EG) with 4-vinyl phenyl boronic acid (VPBA). The m-poly(EG-VPBA) microparticles were characterized by N-2 adsorption/desorption isotherms, electron spin resonance (ESR), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), elemental analysis, scanning electron microscope (SEM) and swelling studies. The m-poly(EG-VPBA) microparticles were used at adsorbent/Cr(VI) ion ratios. The influence of pH, Cr(VI) initial concentration, temperature of the removal process was investigated. The maximum removal of Cr(VI) was observed at pH 2. Langmuir isotherm and Dubinin-Radushkvich isotherm were found to better fit the experiment data rather than Fruendlich isotherm. The kinetics of the adsorption process of Cr(VI) on the m-poly(EG-VPBA) microparticles were investigated using the pseudo first-order, pseudo-second-order, Ritch-second-order and intraparticle diffusion models, results showed that the pseudo-second order equation model provided the best correlation with the experimental results. The thermodynamic parameters (free energy change, Delta G(0) enthalpy change, Delta H-0; and entropy change, Delta S-0) for the adsorption have been evaluated.

Adsorption, electrokinetic properties and the interactions between polymer and clay minerals have recently received much attention, owing to the physicochemical properties of these materials. In this study, surface properties of poly(vinylimidazole)-adsorbed expanded perlite such as adsorption, adsorption kinetics and electrokinetic properties have been investigated as a function of temperature, ionic strength and pH. The zeta potential measurements have been performed to determine the isoelectric point (iep) and potential determining ions (pdi). Although pH strongly altered the zeta potential of expanded perlite sample, expanded perlite does not yield any isoelectric point in the pH ranges of 2–11, poly(vinylimidazole) (PVI) changes the interface charge from negative to positive for expanded perlite when adsorbed on its surface. Adsorbed amounts ( q e ) showed a great dependence on pH. The adsorption of PVI increases with increasing pH, ionic strength and temperature. The pH values where the maximum adsorbed mass occurred might be considered as the conditions where electrostatic attraction is the most favourable. Experimental adsorption data were investigated using Langmuir and Freundlich isotherm models and found that Langmuir isotherm model gave the best representation of the adsorption equilibrium. In order to investigate the mechanism of adsorption and potential rate controlling step, pseudo-first- and second-order kinetic equations, and intraparticle diffusion model have been used to test the experimental data. The rate constants and the related correlation coefficients were determined in order to assess which model provides the best-fit predicted data with experimental results. Pseudo-first-order kinetic equation provided the best fit to experimental data.

Poly(ethylene glycol dimethacrylate- n -vinyl imidazole) [poly(EGDMA-VIM)] hydrogel (average diameter 150–200 μm) was prepared by copolymerizing ethylene glycol dimethacrylate (EGDMA) with n -vinyl imidazole (VIM). The copolymer hydrogel bead composition was characterized by elemental analysis and found to contain 5 EGDMA monomer units each VIM monomer unit. Poly(EGDMA-VIM) beads had a specific surface area of 59.8 m 2 /g. Poly(EGDMA-VIM) beads were characterized by swelling studies and SEM. Cu 2+ ions were chelated on the poly(EGDMA-VIM) beads, then these beads were used in the adsorption of α-amylase from Aspergillus Oryzae in batch system. The maximum α-amylase adsorption capacity of the poly(EGDMA-VIM)–Cu 2+ beads was observed as 38.9 mg/g at pH 4.0. The K m values for immobilized α-amylase (poly(EGDMA-VIM)–Cu 2+ ) (22.5 mM) was higher than that of free enzyme (15.8 mM). Storage stability was found to increase with immobilization. It was observed that enzyme could be repeatedly adsorbed and desorbed without significant loss in adsorption capacity or enzyme activity.

Ağır metallerin giderilmesi amacıyla manyetik poli(etilenglikoldimetakrilat-n-vinil-2-pirolidon) [m-poli(EG-VPO)] mikroküreleri Fe3O4 nanopartikül varlığında süspansiyon polimerizasyonu yöntemiyle sentezlendi. m-poli(EG-VPO) mikroküreleri elementel analiz, N2 adsorpsiyon-desorpsiyon izoterm testi, şişme testi, taramalı elektron mikroskobu (SEM) ve manyetizma ölçümleri ile karakterize edildi. m-poli(EG-VPO) mikrokürelerinin spesifik yüzey alanı 140,7 m2/g, şişme oranı, %40.19, sıfırlayıcı alan, Hc=0,0118 T, elementel analiz sonuçlarında azot oranı %N = 3.77 olarak belirlendi. Bu durum, m-poli(EG-VPO) mikrokürelerinin yumuşak manyetik malzeme olduğunu ve n-vinil-2-pirolidon ligantının polimerik yapıya girdiğini göstermektedir.Elde edilen mikrokürelerin ağır metal iyonları uzaklaştırılmasında kullanılabilirliğini araştırmak amacıyla Hg(II), Cu(II) ve Cr(VI) iyonları incelendi. Mikrokürelerin adsorpsiyon kapasitesi üzerinde etkili parametrelerden pH, başlangıç ağır metal iyonu derişimi, sıcaklık, zaman etkisi incelendi. Maksimum uzaklaştırma Cr(VI) iyonları için pH 2,0?de; Cu(II) iyonları için pH 5,0?te; Hg(II) iyonları için pH 6,5?te gözlendi. Sıcaklığın adsorpsiyona etkisi incelenmesi sonucunda, sıcaklığın 4oC?den 65oC?ye çıkarılmasıyla ağır metal iyonları adsorpsiyonunun arttığı gözlendi.m-poli(EG-VPO) mikrokürelerinin maksimum adsorpsiyon kapasitesi Hg(II), Cu(II) ve Cr(VI) iyonları için sırasıyla 400,0 mg/g, 270,3 mg/g ve 109,9 mg/g olarak belirlendi. Bu durum sulu çözeltilerden ağır metal iyonlarını uzaklaştırılmasında m-poli(EG-VPO) mikrokürelerinin etkili olduğunu göstermektedir. Kütle bazında ilgi sırası Cu(II) > Cr(VI) > Hg(II) şeklindedir. Adsorpsiyon kinetikleri incelenerek mevcut sistem için 4, 25, 45 ve 65oC?de Langmuir ve Freundlich adsorpsiyon izotermlerine uygulanabilirlik test edildi ve Langmuir modeline uygun bulundu. Ayrıca yalancı 1. derece, yalancı 2. derece ve partikül içi difüzyon modelleri de adsorpsiyon kinetiğinin incelenmesinde kullanıldı. Gibbs serbest enerji, entalpi ve entropi değişimi gibi termodinamik parametreler hesaplanarak sıcaklık etkisi belirlenmesi sonucunda adsorpsiyon sürecinin endotermik olduğu ve kendiliğinden gerçekleştiği belirlendi.Anahtar Kelimeler: Adsorpsiyon, ağır metal iyonları, manyetik polimerler, etilenglikoldimetakrilat, n-vinil-2-pirolidon Magnetic poly(ethyleneglycoldimethacrylate-n-vinyl-2-pyrrolidone) [m-poly(EG-VPO)] microbeads were synthesized by suspension polymerization technique in the presence of magnetite Fe3O4 nano-powder with the aim of heavy metal removal. M-poly(EG-VPO) microbeads were characterized by elemental analysis, N2 adsorption-desorption isotherm tests, swelling studies, scanning electron microscope (SEM) and magnetism measurements. The specific surface area of the m-poly(EG-VPO) beads was found to be 140,7 m2/g and the swelling ratio was 40,19%, coercive field was 0,00118, nitrogen ratio was %3,77. It was determined that m-poly(EG-VPO) microbeads were soft magnetic materials and the ligand N-vinyl-2-pyrrolidone was inserted into the polymer structure. In order to investigate usability of m-poly(EG-VPO) microbeads for heavy metal removal, Hg(II), Cu(II) and Cr(VI) ions were studied . Effects of pH, initial heavy metal ions concentration, temperature, contact time were investigated as the effective parameters on the adsorption capacities of the microspheres. Maximum uptake was obtained for Cr(VI) ions at pH 2,0; Cu(II) ions at pH 5,0; Hg(II) ions at pH 6,0. The result of the effect of temperature on the adsorption was that the adsorption of heavy metal ions was increased with the rise in temperature from 4 to 65oC. The maximum adsorption capacities of the m-poly(EG-VPO) beads for Hg(II), Cu(II), Cr(VI) were found 400,0 mg/g, 270,3 mg/g, 45,01 mg/g and109,9 mg/g respectively. In other words m-poly(EG-VPO) beads are efficient to remove heavy metal ions from aqueous solutions. The affinity order on mass basis is Cu(II) > Cr(VI) > Hg(II). Adsorption kinetics have been tested and the applicability of the Langmuir and Freudlich adsorption isotherms for the present system have been tested at 4, 25, 45 and 65oC and the Langmuir model was adequate. Also pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to describe the adsorption kinetics. In consequence of the study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes, adsorption process was endothermic in nature and spontaneous.Key Words: Adsorption, heavy metal ions, magnetic polymers, ethyleneglycoldimethacrylate, n-vinyl-2-pyrrolidone 103

The magnetic-poly(divinylbenzene-1-vinylimidazole) [m-poly(DVB-VIM)] microbeads (average diameter 53-212 mu m) were synthesized and characterized; their use as adsorbent in removal of Cr(VI) ions from aqueous solutions was investigated. The m-poly(DVB-VIM) microbeads were prepared by copolymerizing of divinylbenzene (DVB) with 1-vinylimidazole (VIM). The m-poly(DVB-VIM) microbeads were characterized by N-2 adsorption/desorption isotherms, ESR, elemental analysis, scanning electron microscope (SEM) and swelling studies. At fixed solid/solution ratio the various factors affecting adsorption of Cr(VI) ions from aqueous solutions such as pH, initial concentration, contact time and temperature were analyzed. Langmuir, Freundlich and Dubinin-Radushkvich isotherms were used as the model adsorption equilibrium data. Langmuir isotherm model was the most adequate. The pseudo-first-order, pseudo-second-order, Ritch-second-order and intraparticle diffusion models were used to describe the adsorption kinetics. The apparent activation energy was found to be 5.024 kJ mol(-1), which is characteristic of a chemically controlled reaction. The experimental data fitted to pseudo-second-order kinetic. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes. The thermodynamic parameters obtained indicated the endothermic nature of adsorption of Cr(VI) ions. Morever, after the use in adsorption, the m-poly(DVB-VIM) microbeads with paramagnetic property were separeted via the applied magnetic force. The magnetic beads could be desorbed up to about 97% by treating with 1.0 M NaOH. These features make the m-poly(DVB-VIM) microbeads a potential candidate for support of Cr(VI) ions removal under magnetic field.

Sulfonic acid functionalized poly(ethylene glycol dimethacrylate-1-vinyl-1,2,4-triazole), poly(EGDMA-VTAZ-SO 3 H), is evaluated in the esterification of lactic acid with methanol. From nitrogen physisorption data, high surface area (220 m 2 /g) and type IV isotherm are obtained. Conversion measurements indicate a stronger interaction of poly(EGDMA-VTAZ-20%SO 3 H) with water molecules than that occurring in poly(EGDMA-VTAZ-10%SO 3 H). Hence, the higher catalytic activity of poly(EGDMA-VTAZ-10%SO 3 H) is related to the more hydrophobic microenvironment of –SO 3 H sites, which reduces the acid site deactivation associated with adsorption of water generated during the reaction. Moreover, apparent activation energy is found to be 48.02 kJ mol −1 , which can be comparable with the literature values.

Köçkar, Hakan (Balikesir Author), In this paper we report the electrical characteristics of the Schottky diodes formed by surface polymerization of the Poly(ethylene glycol dimethanylate-n-vinyl imidazole)/Single Walled Carbon Nanotubes on n-Si The Single Walled Carbon Nanotubes were synthesized by CVD method. The main electrical properties of the Poly(ethylene glycol dimethanylate-n-vinyl imidazole)/Single Walled Carbon Nanotubes/n-Si have been investigated through the barrier heights, the ideality factors and the impurity density distribution, by using current-voltage and reverse bias capacitance voltage characteristics. Electrical measurements were carried out at room temperature. Poly(ethylene glycol dimethacrylate-n-vinyl imidazole)/Single Walled Carbon Nanotubes/n-Si Schottky diode current-voltage characteristics display low reverse-bias leakage currents and average barrier heights of 0.61 +/- 0.02 eV and 0.72 +/- 0.02 eV obtained from both current-voltage and capacitance-voltage measurements at room temperature, respectively.

Designing an immobilised metal ion affinity process on large-scale demands that a thorough understanding be developed regarding the adsorption behaviour of proteins on metal-loaded gels and the characteristic adsorption parameters to be evaluated. In view of this requirement, interaction of alpha-amylase as a model protein with newly synthesised magnetic-poly(divinylbenzene-1-vinylimidazole) [m-poly(DVB-VIM)] microbeads (average diameter, 53-212 mu m) was investigated. The m-poly(DVB-VIM) microbeads were prepared by copolymerising of divinylbenzene (DVB) with 1-vinylimidazole (VIM). The m-poly(DVB-VIM) microbeads were characterised by N-2 adsorption/desorption isotherms, electron spin resonance, elemental analysis, scanning electron microscope and swelling studies. Cu2+ ions were chelated on the m-poly(DVB-VIM) beads and used in adsorption of alpha-amylase in a batch system. The maximum alpha-amylase adsorption capacity of the m-poly(DVB-VIM)-Cu2+ beads was determined as 10.84 mg/g at pH 6.0, 25 A degrees C. The adsorption data were analyzed using three isotherm models, which are the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The pseudo-first-order, pseudo-second-order, modified Ritchie's-second-order and intraparticle diffusion models were used to test dynamic experimental data. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes.

The barium hexaferrite (BaFe 12 O 19 ) containing magnetic poly(ethylene glycol dimethacrylate–vinyl pyridine), (mag-poly(EGDMA–VP)) beads (average diameter = 53–212 μm) were synthesized and characterized. Their use as an adsorbent in the removal of diethyl phthalate (DEP) from an aqueous solution was investigated. The mag-poly(EGDMA–VP) beads were prepared by copolymerizing of 4-vinyl pyridine (VP) with ethylene glycol dimethacrylate (EGDMA). The mag-poly(EGDMA–VP) beads were characterized by N 2 adsorption/desorption isotherms (BET), vibrating sample magnetometer (VSM), X-ray powder diffraction (XRD), elemental analysis, scanning electron microscope (SEM) and swelling studies. At a fixed solid/solution ratio, the various factors affecting the adsorption of DEP from aqueous solutions such as pH, initial concentration, contact time and temperature were analyzed. The maximum DEP adsorption capacity of the mag-poly(EGDMA–VP) beads was determined as 98.9 mg/g at pH 3.0, 25 °C. All the isotherm data can be fitted with both the Langmuir and the Dubinin-Radushkevich isotherm models. The pseudo first-order, pseudo-second-order, Ritch-second-order and intraparticle diffusion models were used to describe the adsorption kinetics. The thermodynamic parameters obtained indicated the exothermic nature of the adsorption. The DEP adsorption capacity did not change after 10 batch successive reactions, demonstrating the usefulness of the magnetic beads in applications.

Poly(ethylene glycol dimethacrylate–1-vinyl-1,2,4-triazole) [poly(EGDMA–VTAZ)] beads with an average diameter of 100–200 μm were obtained by the copolymerization of ethylene glycol dimethacrylate (EGDMA) with 1-vinyl-1,2,4-triazole (VTAZ). The copolymer hydrogel bead composition was determined by elemental analysis and was found to contain 5 EGDMA monomer units for each VTAZ monomer unit. The poly(EGDMA–VTAZ) beads were characterized by swelling studies and scanning electron microscopy (SEM). The specific surface area of the poly(EGDMA–VTAZ) beads was found 65.8 m2/g. Cu2+ ions were chelated on the poly(EGDMA–VTAZ) beads. The Cu2+ loading was 82.6 μmol/g of support. Cu2+-chelated poly(EGDMA–VTAZ) beads with a swelling ratio of 84% were used in the immobilization of Aspergillus niger glucoamylase in a batch system. The maximum glucoamylase adsorption capacity of the poly(EGDMA–VTAZ)–Cu2+ beads was 104 mg/g at pH 6.5. The adsorption isotherm of the poly(EGDMA–VTAZ)–Cu2+ beads fitted well with the Langmuir model. Adsorption kinetics data were tested with pseudo-first- and second-order models. The kinetic studies showed that the adsorption followed a pseudo-second-order reaction model. The Michaelis constant value for the immobilized glucoamylase (1.15 mg/mL) was higher than that for free glucoamylase (1.00 mg/mL). The maximum initial rate of the reaction values were 42.9 U/mg for the free enzyme and 33.3 U/mg for the immobilized enzyme. The optimum temperature for the immobilized preparation of poly(EGDMA–VTAZ)–Cu2+–glucoamylase was 65°C; this was 5°C higher than that of the free enzyme at 60°C. The glucoamylase adsorption capacity and adsorbed enzyme activity slightly decreased after 10 batch successive reactions; this demonstrated the usefulness of the enzyme-loaded beads in biocatalytic applications. The storage stability was found to increase with immobilization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Sunulan çalışmada; manyetik poli(divinil benzen-N-vinil imidazol) [m-poli(DVB-VIM)] mikroküreleri Fe3O4 nanopartikül varlığında süspansiyon polimerizasyonu yöntemiyle sentezlenerek ağır metal iyonlarının uzaklaştırılmasında kullanıldı. m-poli(DVB-VIM) mikroküreleri elementel analiz, N2 adsorpsiyon-desorpsiyon izoterm testi, şişme testi, yoğunluk ölçümleri, taramalı elektron mikroskobu (SEM) ve manyetizma ölçümleri ile karakterize edildi. m-poli(DVB-VIM) mikrokürelerinin spesifik yüzey alanı 29.47 m2/g, boyut dağılımı 53-212 µm, şişme oranı %44 ve ortalama Fe3O4 içeriği %10,2 olarak belirlendi. Mikrokürelerin yapısındaki VIM miktarı 3,021 mmol/g polimer olarak bulundu. Bu durum m-poli(DVB-VIM) mikrokürelerinin manyetik olduğunu ve N-vinil imidazol ligantının polimerik yapıya girdiğini göstermektedir.Elde edilen mikrokürelerin ağır metal iyonları uzaklaştırılmasında kullanılabilirliğini araştırmak için; Cr(VI), Ni(II), Zn(II), Pb(II) ve Cu(II) iyonları örnek iyon olarak kullanıldı. Mikrokürelerin adsorpsiyon kapasitesi üzerinde etkili parametrelerden pH, başlangıç ağır metal iyonu konsantrasyonu, sıcaklık, zaman ve adsorban miktarı etkisi incelendi. Maksimum uzaklaştırma Cr(VI) iyonları için pH 2,0'de; Cu(II) iyonları için pH 5,0'te; Zn(II), Ni(II) ve Pb(II) iyonları için pH 6,0'da gözlendi. Sıcaklığın adsorpsiyona etkisi incelendi ve sıcaklığın 4oC'den 65oC'ye çıkarılmasıyla ağır metal iyonları adsorpsiyonunun arttığı gözlendi.m-poli(DVB-VIM) mikrokürelerinin 100 ppm konsantrasyonda ve 65oC'deki adsorpsiyon kapasitesi Cu(II), Cr(VI), Pb(II), Ni(II) ve Zn(II) iyonları için sırasıyla 52,90 mg/g, 46,85 mg/g, 45,01 mg/g, 23,07 mg/g ve 22,39 mg/g olarak belirlendi. Bu durum sulu çözeltilerden ağır metal iyonlarını uzaklaştırılmasında m-poli(DVB-VIM) mikrokürelerinin etkili olduğunu göstermektedir. Kütle bazında ilgi sırası Cu(II) > Cr(VI) > Pb(II) > Ni(II) > Zn(II) şeklindedir. Adsorpsiyon kinetikleri incelenerek mevcut sistem için 4, 25, 45 ve 65oC'de Langmuir ve Freundlich adsorpsiyon izotermlerine uygulanabilirlik test edildi. Denge verileri Langmuir modeline uygun bulundu. Ayrıca yalancı (pseudo) 1. derece, yalancı (pseudo) 2. derece ve partikül içi difüzyon modelleri de adsorpsiyon kinetiğinin incelenmesinde kullanıldı. Gibbs serbest enerji, entalpi ve entropi değişimi gibi termodinamik parametreler hesaplanarak sıcaklık etkisi belirlendi. Bu çalışmada adsorpsiyon sürecinin endotermik olduğu ve kendiliğinden gerçekleştiği belirlendi. Manyetik mikrokürelerin rejenerasyonu Cu(II), Pb(II), Ni(II) ve Zn(II) için 0,1 M HNO3; Cr(VI) için 1 M NaOH kullanılarak gerçekleştirildi. Aynı manyetik mikroküreler kullanılarak adsorpsiyon-desorpsiyon döngüsü 10 kez tekrarlandı ve ağır metal iyon kapasitesinde önemli bir değişim gözlenmedi. In present study, magnetic poly(divinyl benzene-N-vinyl imidazole) [m-poly(DVB-VIM)] microbeads were synthesized by suspension polymerization technique in the presence of magnetite Fe3O4 nano-powder and used for heavy metal ions removal studies. m-poly(DVB-VIM) microbeads were characterized by elemental analysis, N2 adsorption-desorption isotherm tests, swelling studies, density measurements, scanning electron microscope (SEM) and magnetism measurements. The specific surface area of the m-poly(DVB-VIM) beads was found to be 29.47 m2/g with a size range of 53-212 µm in diameter and the swelling ratio was 44%. The average Fe3O4 content of the resulting m-poly(DVB-VIM) microbeads was 10,2%. The incorporation of the VIM was found 3,021 mmol/g polymer. It was determined that m-poly(DVB-VIM) microbeads are magnetic and the ligand N-vinyl imidazole was inserted into the polymer structure.Cr(VI), Ni(II), Zn(II), Pb(II) and Cu(II) ions were used as model species to investigate the usability of the obtained microspheres in heavy metal removal. Effects of pH, initial heavy metal ions concentration, temperature, contact time and adsorbent dosage were investigated as the effective parameters on the adsorption capacities of the microspheres. Maximum uptake was obtained for Cr(VI) ions at pH 2,0; Cu(II) ions at pH 5,0; Zn(II), Ni(II) and Pb(II) ions at pH 6,0. The effect of temperature on the adsorption was studied and the adsorption of heavy metal ions was increased with the rise in temperature from 4 to 65oC.The adsorption capacities of the m-poly(DVB-VIM) beads for Cu(II), Cr(VI), Pb(II), Ni(II) and Zn(II) were found 52,90 mg/g, 46,85 mg/g, 45,01 mg/g, 23,07 mg/g and 22,39 mg/g, respectively at 100 ppm and 65oC. In other words m-poly(DVB-VIM) beads were found to efficiently remove heavy metal ions from aqueous solutions. The affinity order on mass basis is Cu(II) > Cr(VI) > Pb(II) > Ni(II) > Zn(II). Adsorption kinetics have been tested and the applicability of the Langmuir and Freudlich adsorption isotherms for the present system have been tested at 4, 25, 45 and 65oC. Equilibrium data agreed well with the Langmuir model. Also pseudo-first-order, pseudo-second order and intraparticle diffusion models were used to describe the adsorption kinetics. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes. In this study, adsorption process was endothermic in nature and spontaneous. Regeneration of the magnetic microbeads was easily performed with 0,1 M HNO3 for Cu(II), Pb(II), Ni(II) and Zn(II); 1 M NaOH for Cr(VI). Adsorption-desorption cycles were be performed ten-times by using same magnetic microbeads and any noticeable loss was not determined. 138

Sunulan çalışmada; manyetik poli(divinil benzen-N-vinil imidazol) [m-poli(DVB-VIM)] mikroküreleri Fe3O4 nanopartikül varlığında süspansiyon polimerizasyonu yöntemiyle sentezlenerek ağır metal iyonlarının uzaklaştırılmasında kullanıldı. m-poli(DVB-VIM) mikroküreleri elementel analiz, N2 adsorpsiyon-desorpsiyon izoterm testi, şişme testi, yoğunluk ölçümleri, taramalı elektron mikroskobu (SEM) ve manyetizma ölçümleri ile karakterize edildi. m-poli(DVB-VIM) mikrokürelerinin spesifik yüzey alanı 29.47 m2/g, boyut dağılımı 53-212 µm, şişme oranı %44 ve ortalama Fe3O4 içeriği %10,2 olarak belirlendi. Mikrokürelerin yapısındaki VIM miktarı 3,021 mmol/g polimer olarak bulundu. Bu durum m-poli(DVB-VIM) mikrokürelerinin manyetik olduğunu ve N-vinil imidazol ligantının polimerik yapıya girdiğini göstermektedir.Elde edilen mikrokürelerin ağır metal iyonları uzaklaştırılmasında kullanılabilirliğini araştırmak için; Cr(VI), Ni(II), Zn(II), Pb(II) ve Cu(II) iyonları örnek iyon olarak kullanıldı. Mikrokürelerin adsorpsiyon kapasitesi üzerinde etkili parametrelerden pH, başlangıç ağır metal iyonu konsantrasyonu, sıcaklık, zaman ve adsorban miktarı etkisi incelendi. Maksimum uzaklaştırma Cr(VI) iyonları için pH 2,0'de; Cu(II) iyonları için pH 5,0'te; Zn(II), Ni(II) ve Pb(II) iyonları için pH 6,0'da gözlendi. Sıcaklığın adsorpsiyona etkisi incelendi ve sıcaklığın 4oC'den 65oC'ye çıkarılmasıyla ağır metal iyonları adsorpsiyonunun arttığı gözlendi.m-poli(DVB-VIM) mikrokürelerinin 100 ppm konsantrasyonda ve 65oC'deki adsorpsiyon kapasitesi Cu(II), Cr(VI), Pb(II), Ni(II) ve Zn(II) iyonları için sırasıyla 52,90 mg/g, 46,85 mg/g, 45,01 mg/g, 23,07 mg/g ve 22,39 mg/g olarak belirlendi. Bu durum sulu çözeltilerden ağır metal iyonlarını uzaklaştırılmasında m-poli(DVB-VIM) mikrokürelerinin etkili olduğunu göstermektedir. Kütle bazında ilgi sırası Cu(II) > Cr(VI) > Pb(II) > Ni(II) > Zn(II) şeklindedir. Adsorpsiyon kinetikleri incelenerek mevcut sistem için 4, 25, 45 ve 65oC'de Langmuir ve Freundlich adsorpsiyon izotermlerine uygulanabilirlik test edildi. Denge verileri Langmuir modeline uygun bulundu. Ayrıca yalancı (pseudo) 1. derece, yalancı (pseudo) 2. derece ve partikül içi difüzyon modelleri de adsorpsiyon kinetiğinin incelenmesinde kullanıldı. Gibbs serbest enerji, entalpi ve entropi değişimi gibi termodinamik parametreler hesaplanarak sıcaklık etkisi belirlendi. Bu çalışmada adsorpsiyon sürecinin endotermik olduğu ve kendiliğinden gerçekleştiği belirlendi. Manyetik mikrokürelerin rejenerasyonu Cu(II), Pb(II), Ni(II) ve Zn(II) için 0,1 M HNO3; Cr(VI) için 1 M NaOH kullanılarak gerçekleştirildi. Aynı manyetik mikroküreler kullanılarak adsorpsiyon-desorpsiyon döngüsü 10 kez tekrarlandı ve ağır metal iyon kapasitesinde önemli bir değişim gözlenmedi. In present study, magnetic poly(divinyl benzene-N-vinyl imidazole) [m-poly(DVB-VIM)] microbeads were synthesized by suspension polymerization technique in the presence of magnetite Fe3O4 nano-powder and used for heavy metal ions removal studies. m-poly(DVB-VIM) microbeads were characterized by elemental analysis, N2 adsorption-desorption isotherm tests, swelling studies, density measurements, scanning electron microscope (SEM) and magnetism measurements. The specific surface area of the m-poly(DVB-VIM) beads was found to be 29.47 m2/g with a size range of 53-212 µm in diameter and the swelling ratio was 44%. The average Fe3O4 content of the resulting m-poly(DVB-VIM) microbeads was 10,2%. The incorporation of the VIM was found 3,021 mmol/g polymer. It was determined that m-poly(DVB-VIM) microbeads are magnetic and the ligand N-vinyl imidazole was inserted into the polymer structure.Cr(VI), Ni(II), Zn(II), Pb(II) and Cu(II) ions were used as model species to investigate the usability of the obtained microspheres in heavy metal removal. Effects of pH, initial heavy metal ions concentration, temperature, contact time and adsorbent dosage were investigated as the effective parameters on the adsorption capacities of the microspheres. Maximum uptake was obtained for Cr(VI) ions at pH 2,0; Cu(II) ions at pH 5,0; Zn(II), Ni(II) and Pb(II) ions at pH 6,0. The effect of temperature on the adsorption was studied and the adsorption of heavy metal ions was increased with the rise in temperature from 4 to 65oC.The adsorption capacities of the m-poly(DVB-VIM) beads for Cu(II), Cr(VI), Pb(II), Ni(II) and Zn(II) were found 52,90 mg/g, 46,85 mg/g, 45,01 mg/g, 23,07 mg/g and 22,39 mg/g, respectively at 100 ppm and 65oC. In other words m-poly(DVB-VIM) beads were found to efficiently remove heavy metal ions from aqueous solutions. The affinity order on mass basis is Cu(II) > Cr(VI) > Pb(II) > Ni(II) > Zn(II). Adsorption kinetics have been tested and the applicability of the Langmuir and Freudlich adsorption isotherms for the present system have been tested at 4, 25, 45 and 65oC. Equilibrium data agreed well with the Langmuir model. Also pseudo-first-order, pseudo-second order and intraparticle diffusion models were used to describe the adsorption kinetics. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes. In this study, adsorption process was endothermic in nature and spontaneous. Regeneration of the magnetic microbeads was easily performed with 0,1 M HNO3 for Cu(II), Pb(II), Ni(II) and Zn(II); 1 M NaOH for Cr(VI). Adsorption-desorption cycles were be performed ten-times by using same magnetic microbeads and any noticeable loss was not determined.

The aim of this study was to prepare magnetic beads that could be used for the removal of heavy-metal ions from synthetic solutions. Magnetic poly(ethylene glycol dimethacrylate-1-vinyl-1,2,4-triazole) [m-poly (EGDMA-VTAZ)] beads were produced by suspension polymerization in the presence of a magnetite Fe3O4 nanopowder. The specific surface area of the m-poly(EGDMAVTAZ) beads was 74.8 m(2)/g with a diameter range of 150-200 mu m, and the swelling ratio was 84%. The average Fe3O4 content of the resulting m-poly(EGDMA-VTAZ) beads was 14.8%. The maximum binding capacities of the m-poly (EGDMA-VTAZ) beads from aquous solution were 284.3 mg/g for Hg2+, 193.8 mg/g for Pb2+, 151.5 mg/g for Cu2+, 128.1 mg/g for Cd2+, and 99.4 mg/g for Zn2+. The affinity order on a mass basis was Hg2+ > Pb2+ > Cu2+ > Cd2+> Zn2+. The binding capacities from synthetic waste water were 178.1 mg/g for Hg2+, 132.4 mg/g for Pb2+, 83.5 mg/g for Cu2+, 54.1 mg/g for Cd2+, and 32.4 mg/g for Zn2+. The magnetic beads could be regenerated (up to ca. 97%) by a treatment with 0.1 M HNO3. These features make m-poly(EGDMA-VTAZ) beads potential supports for heavy-metal removal under a magnetic field. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 2246-2253, 2009

We prepared poly(ethylene glycol dimethacrylate–1-vinyl-1,2,4-triazole) [poly(EGDMA–VTAZ)] beads (average diameter = 150–200 μm) by copolymerizing ethylene glycol dimethacrylate (EGDMA) with 1-vinyl-1,2,4-triazole (VTAZ). The copolymer composition was characterized by elemental analysis and found to contain five EGDMA monomer units for each VTAZ monomer unit. The poly(EGDMA–VTAZ) beads had a specific surface area of 65.8 m2/g. Poly(EGDMA–VTAZ) beads were characterized by Fourier transform infrared spectroscopy, elemental analysis, surface area measurements, swelling studies, and scanning electron microscopy. Poly(EGDMA–VTAZ) beads with a swelling ratio of 84% were used for the heavy-metal removal studies. The adsorption capacities of the beads for Cd(II), Hg(II), and Pb(II) were investigated in aqueous media containing different amounts of these ions (5–750 mg/L) and at different pH values (3.0–7.0). The maximum adsorption capacities of the poly(EGDMA–VTAZ) beads were 85.7 mg/g (0.76 mmol/g) for Cd(II), 134.9 mg/g (0.65 mmol/g) for Pb(II), and 186.5 mg/g (0.93 mmol/g) for Hg(II). The affinity order toward triazole groups on a molar basis was observed as follows: Hg(II) > Cd(II) > Pb(II). pH significantly affected the adsorption capacity of the VTAZ-incorporated beads. The equilibrium data were well fitted to the Redlich–Peterson isotherm. Consideration of the kinetic data suggested that chemisorption processes could have been the rate-limiting step in the adsorption process. Regeneration of the chelating-beads was easily performed with 0.1M HNO3. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4276–4283, 2006

We investigated a new adsorbent system, Reactive Red 120 attached poly(2-hydroxyethyl methacrylate ethylene dimethacrylate) [poly(HEMA–EDMA)] beads, for the removal of Ni2+ ions from aqueous solutions. Poly(HEMA–EDMA) beads were prepared by the modified suspension copolymerization of 2-hydroxyethyl methacrylate and ethylene dimethacrylate. Reactive Red 120 molecules were covalently attached to the beads. The beads (150–250 μm), having a swelling ratio of 55% and carrying 25.5 μmol of Reactive Red 120/g of polymer, were used in the removal of Ni2+ ions. The adsorption rate and capacity of the Reactive Red 120 attached poly(HEMA–EDMA) beads for Ni2+ ions was investigated in aqueous media containing different amounts of Ni2+ ions (5–35 mg/L) and having different pH values (2.0–7.0). Very high adsorption rates were observed at the beginning, and adsorption equilibria were then gradually achieved in about 60 min. The maximum adsorption of Ni2+ ions onto the Reactive Red 120 attached poly(HEMA–EDMA) beads was 2.83 mg/g at pH 6.0. The nonspecific adsorption of Ni2+ ions onto poly(HEMA–EDMA) beads was negligible (0.1 mg/g). The desorption of Ni2+ ions was studied with 0.1M HNO3. High desorption ratios (>90%) were achieved. The intraparticle diffusion rate constants at various temperatures were calculated as k20°C = 0.565 mg/g min0.5, k30°C = 0.560 mg/g min0.5, and k40°C = 0.385 mg/g min0.5. Adsorption–desorption cycles showed the feasibility of repeated use of this novel adsorbent system. The equilibrium data fitted very well both Langmuir and Freundlich adsorption models. The pseudo-first-order kinetic model was used to describe the kinetic data. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:5056–5065, 2006

N-methacryloyl-(L)-alanine (MALA) was synthesized by using methacryloyl chloride and alanine as a metal-complexing ligand or comonomer. Spherical beads with an average diameter of 150–200 μm were obtained by suspension polymerization of MALA and 2-hydroxyethyl methacrylate (HEMA) conducted in an aqueous dispersion medium. Poly(HEMA–MALA) beads were characterized by SEM, swelling studies, surface area measurement, and elemental analysis. Poly(HEMA–MALA) beads have a specific surface area of 68.5 m2/g. Poly(HEMA–MALA) beads with a swelling ratio of 63%, and containing 247 μmol MALA/g were used in the removal of Hg2+ from aqueous solutions. Adsorption equilibrium was achieved in about 60 min. The adsorption of Hg2+ ions onto PHEMA beads was negligible (0.3 mg/g). The MALA incorporation into the polymer structure significantly increased the mercury adsorption capacity (168 mg/g). Adsorption capacity of MALA containing beads increased significantly with pH. The adsorption of Hg2+ ions increased with increasing pH and reached a plateau value at around pH 5.0. Competitive heavy metal adsorption from aqueous solutions containing Cd2+, Cu2+, Pb2+, and Hg2+ was also investigated. The adsorption capacities are 44.5 mg/g for Hg2+, 6.4 mg/g for Cd2+, 2.9 mg/g for Pb2+, and 2.0 mg/g for Cu2+ ions. These results may be considered as an indication of higher specificity of the poly(HEMA–MALA) beads for the Hg2+ comparing to other ions. Consecutive adsorption and elution operations showed the feasibility of repeated use for poly(HEMA–MALA) chelating beads. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1222–1228, 2006

Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) [poly(EGDMA-VIM)] hydrogel (average diameter 150-200 mu m) was prepared copolymerizing ethylene glycol dimethacrylate (EGDMA) with n-vinyl imidazole (VIM). Poly(EGDMA-VIM) beads had a specific surface area of 59.8 M-2/g. Poly(EGDMA-VIM) beads were characterized by swelling studies and scanning electron microscope (SEM). Cu2+ ions were chelated on the poly(EGDMA-VIM) beads (452 mu mol Cu2+/g), then the metal-chelated beads were used in the adsorption of yeast invertase in a batch system. The maximum invertase adsorption capacity of the poly(EGDMA-VIM)-Cu2+ beads was observed as 35.2 mg/g at pH 4.5. The adsorption isotherm of the poly(EGDMA-VIM)-Cu2+ beads can be well fitted to the Langmuir model. Adsorption kinetics data were tested using pseudo-first- and -second-order models. Kinetic studies showed that the adsorption followed a pseudo- second-order reaction. The value of the Michaelis constant K-m of invertase was significantly larger upon adsorption, indicating decreased affinity by the enzyme for its substrate, whereas V-max was smaller for the adsorbed invertase. The optimum temperature for the adsorbed preparation of poly(EGDMA-VIM)-CU2+- invertase at 50 degrees C, 10 degrees C higher than that of the free enzyme at 40 degrees C. Storage stability was found to increase with adsorption. Adsorbed invertase retains an activity of 82% after 10 batch successive reactions, demonstrating the usefulness of the enzyme-loaded beads in biocatalytic applications.

The adsorption of polyvinylimidazole (PVI) onto kaolinite from aqueous solutions has been investigated systematically as a function of parameters such as calcination temperature of kaolinite, pH, ionic strength, and temperature. According to the experimental results, the adsorption of PVI increases with pH from 8.50 to 11.50, temperature from 25 to 55 degrees C, and ionic strength from 0 to 0.1 mol L(-1). The kaolinite sample calcined at 600 degrees C has a maximum adsorption capacity. Adsorption isotherms of PVI onto kaolinite have been determined and correlated with common isotherm equations such as Langmuir and Freundlich isotherm models. The Langmuir isotherm model appeared to fit the isotherm data better than the Freundlich isotherm model. The physical properties of this adsorbent are consistent with the parameters obtained from the isotherm equations. Furthermore, the zeta potentials of kaolinite suspensions have been measured in aqueous solutions of different PVI concentrations and pH. From the experimental results, (i) pH strongly alters the zeta potential of kaolinite; (ii) kaolinite has an isoelectric point at about pH 2.35 in water and about pH 8.75 in 249.9 ppm PVI concentration; (iii) PVI changes the interface charge from negative to positive for kaolinite. The study of temperature effect has been quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy, and entropy changes. The dimensionless separation factor (RL) has shown that kaolinite can be used for adsorption of PVI from aqueous solutions.

Reactive Green HE 4BD carrying polyamide hollow fibers were investigated as dye-affinity adsorbents for removal of chlorophenols (i.e., phenol. o-chlorophenol, p-chlorophenol and 2,4,6-trichlorophenol). Adsorption rates of chlorophenols were very high. Equilibrium was achieved in about 30 min. The applicability of two kinetic models including pseudo-first order and pseudo-second order model was estimated on the basis of comparative analysis of the corresponding rate parameters, equilibrium capacity and correlation coefficients. Results suggest that chemisorption process could be the rate-limiting step in the adsorption process. The maximum adsorption values of chlorophenols onto the Reactive Green HE 4BD carrying hollow fibers were 145.9 mu mol/g for phenol, 179.2 mu mol/g for 2,4,6-trichlorophenol, 194.5 mu mol/g for p-chlorophenol and 202.8 mu mol/g for o-chlorophenol. The affinity order was as follows: o-chlorophenol > p-chlorophenol > 2,4,6-trichlorophenol > phenol. The adsorption capacity of chlorophenols decreased with increasing pH. Desorption of chlorophenols was achieved using methanol solution (30%, v/v). The Reactive Green HE 4BD-carrying hollow fibers are suitable for repeated use for more than 10 cycles without noticeable loss of adsorption capacity. (c) 2006 Elsevier B.V. All rights reserved.

Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) [poly(EGDMA-VIM)] hydrogel (average diameter 150-200 mum) was prepared by copolymerizing ethylene glycol dimethacrylate (EGDMA) with n-vinyl imidazole (VIM). The copolymer hydrogel bead composition was characterized by elemental analysis and found to contain 5 EGDMA monomer units each VIM monomer unit. Poly(EGDMA-VIM) beads had a specific surface area of 59.8 m(2)/g. Poly(EGDMA-VIM) beads were characterized by swelling studies and scanning electron microscopy (SEM). These poly(EGDMA-VIM) beads with a swelling ratio of 78% were used for the heavy metal removal studies. Chelation capacity of the beads for the selected metal ions, i.e., Cd(II), Hg(II) and Pb(II) were investigated in aqueous media containing different amounts of these ions (10-750 mg/l) and at different pH values (3.0-7.0). Chelation rate was very fast. The maximum chelation capacities of the poly(EGDMA-VIM) beads were 69.4 mg/g for Cd(H), 114.8 mg/g for Pb(II) and 163.5 mg/g for Hg(II). The affinity order on molar basis was observed as follows: Hg(H) > Cd(II) > Pb(II). Chelation behavior of heavy metal ions could be modelled using both the Langmuir and Freundlich isotherms. pH significantly affected the chelation capacity of VIM incorporated beads. Chelation of heavy metal ions from synthetic wastewater was also studied. The chelation capacities are 45.6 mg/g for U(II), 74.2 mg/g for Hg(H) and 92.5 mg/g for Pb(II) at 0.5 mmol/l initial metal concentration. Regeneration of the chelating-beads was easily performed with 0.1 M HNO3. These features make poly(EGDMA-VIM) beads potential candidate adsorbent for heavy metal removal: (C) 2003 Elsevier B.V. All rights reserved.