Sürdürülebilir Kalkınma Amaçları
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- ArticleYalnız künye2016Flow injection potentiometric determination of silver(I) in photographic film developing solution samples by polyvinylchloride membrane silver(I) selective electrode
Topcu, Cihan; Coldur, Fatih; Andac, Muberra; Cubuk, Osman; Kanberoglu, Gulsah Saydan; Caglar, Bulent; Isildak, Ibrahim
A polyvinylchloride (PVC) membrane silver(I) selective electrode was developed for the determination of silver(I) ions in photographic film developing solutions. The electrode was embedded into a home-made flow cell and successfully used as a potentiometric detector in a flow injection potentiometric (FIP) system. Under the optimized flow injection conditions, the electrode exhibited a non-Nernstian slope of 67.20±0.80 mV in the linear range from 1.0×10-5 to 1.0×10-1 mol/L (R2=0.9961) and the lowest value for limit of detection (LOD) was calculated as 7.1×10-6 mol/L. The electrode displayed good sensitivity, selectivity, repeatable and rapid response towards silver(I) ions. Lifetime of the electrode was determined as at least two months in FIP system. The electrode was also successfully applied for the potentiometric determination of silver(I) ions in photographic film developing solution samples in FIP system. The results attained from FIP system were compared with the atomic absorption spectrophotometry (AAS) results by using student's t-test at 95 % confidence level and relative deviation (RD) between the two methods was < 8 %.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2016A Novel Flow-Injection Potentiometric Detector for Determination of Tamoxifen in Anticancer Drug Formulations
Kanberoglu, Gulsah Saydan; Coldur, Fatih; Cubuk, Osman; Topcu, Cihan; Caglar, Bulent
A flow-injection potentiometric detector was reported for the rapid determination of tamoxifen (TAM), by using a poly(vinyl chloride) (PVC) membrane electrode containing tamoxifen-phosphomolibdate (TAM-PM) ion-pair as electroactive component. The potentiometric quality of the electrode response was optimized. Under the optimized condition (carrier solution: 5.0×10-7 M TAM, injection volume: 20 °L, flow-rate: 2.0 mL min-1, tubing length: 10 cm), the calibration plot for TAM was linear over the concentration range of 1.0×10-4-1.0×10-2 M with a sub-Nernstian slope of 37.7 mV per decade of TAM activity and detection limit of 4.2×10-5 M. The interference effects of some common alkaline metal, alkaline earth metal, heavy metals, organic and pharmaceutical molecules on electrode response were investigated and selectivity coefficients were calculated. The relative standard deviation of the electrode response for thirteen replicate measurements of 5.0×10-4 M TAM was 1.81%. The flow-through detector system revealed sampling rates of approximately 90 injections per hour depending on the TAM concentration of the injected sample. The offered potentiometric flow-injection system was applied for the determination of TAM in pharmaceutical preparations and the obtained results were compared with High-Performance Liquid Chromatography (HPLC) results.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2016Characterization of a hybrid-smectite nanomaterial formed by immobilizing of N-pyridin-2-ylmethylsuccinamic acid onto (3- Aminopropyl)triethoxysilane modified smectite and its potentiometric sensor application
Topcu, Cihan; Caglar, Sema; Caglar, Bulent; Coldur, Fatih; Cubuk, Osman; Sarp, Gokhan; Gedik, Kubra; Cirak, Burcu Bozkurt; Tabak, Ahmet
A novel N-pyridin-2-ylmethylsuccinamic acid-functionalized smectite nanomaterial was synthesized by immobilizing of N-pyridin-2-ylmethylsuccinamic acid through chemical bonding onto (3- Aminopropyl)triethoxysilane modified smectite. The structural, thermal, morphological and surface properties of raw, silane-grafted and the N-pyridin-2-ylmethylsuccinamic acidfunctionalized smectites were investigated by various characterization techniques. The thermal analysis data showed the presence of peaks in the temperature range from 200 °C to 600 °C due to the presence of physically adsorbed silanes, intercalated silanes, surface grafted silanes and chemically grafted silane molecules between the smectite layers. The powder x-ray diffraction patterns clearly indicated that the aminopropyl molecules also intercalated into the smectite interlayers as bilayer arrangement whereas N-pyridin-2-ylmethylsuccinamic acid molecules were only attached to 3- Aminopropyltriethoxysilane molecules on the external surface and edges of clay and they did not intercalate. Fourier transform infrared spectroscopy confirms N-pyridin-2- ylmethylsuccinamic acid molecules bonding through the amide bond between the amine group of aminopropyltriethoxysilane molecules and a carboxylic acid functional group of N-pyridin-2- ylmethylsuccinamic acid molecules. The guest molecules functionalized onto the smectite caused significant alterations in the textural and morphological parameters of the raw smectite. The anchoring of N-pyridin-2-ylmethylsuccinamic acid molecules led to positive electrophoretic mobility values when compared to starting materials. N-pyridin-2-ylmethylsuccinamic acidfunctionalized smectite was employed as an electroactive ingredient in the structure of potentiometric PVC-membrane sensor. The sensor exhibited more selective potentiometric response towards chlorate ions compared to the other common anionic species.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2016New metal complexes with diclofenac containing 2-pyridineethanol or 2-pyridinepropanol: synthesis, structural, spectroscopic, thermal properties, catechol oxidase and carbonic anhydrase activities
Caglar, Sema; Dilek, Esra; Caglar, Bulent; Adiguzel, Ekrem; Temel, Ersin; Buyukgungor, Orhan; Tabak, Ahmet
Four new neutral diclofenac-based complexes, [Co(dicl)2(2-pyet)2] 1, [Ni(dicl)2(2-pyet)2] 2, [Cu2(dicl)2(2-pyet)2] 3, and [Cu2(dicl)2(2-pypr)2] 4 have been synthesized and characterized by elemental analysis, FT-IR, thermal analysis. Complexes 1, 3, and 4 have also been characterized by X-ray single-crystal structural analysis. The compounds of Co(II) and Ni(II) have octahedral geometry with two diclofenac and two 2-pyridineethanol ligands in the coordination sphere. The compounds of Cu(II) have square-pyramidal geometry and Cu(II) ions are linked via oxygens to the bridging 2-pyridineethanol or 2-pyridinepropanol ligands. The Δν values acquired by FT-IR are in agreement with the single XRD data. Studies on the thermal properties are reported and the complexes are stable to 196, 216, 215, and 201 °C in air, respectively. Two dinuclear Cu(II) complexes have demonstrated catalytic activity on oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone showing saturation kinetics at high substrate concentrations. The diclofenac complexes are investigated as inhibitors of the human cytosolic isoforms hCA I and II. The complexes are good as hCA I inhibitors (Kis of 1.52–55.06 μM) but only moderately efficient as hCA II inhibitors (Kis of 0.23–5.61 μM).
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2016New copper(II) complexes including pyridine-2,5-dicarboxylic acid: synthesis, spectroscopic, thermal properties, crystal structure and how these complexes interact with purified PON 1 enzyme
Caglar, Sema; Dilek, Esra; Hamamci Alisir, Sevim; Caglar, Bulent
We report the synthesis of two square-pyramidal copper(II) complexes, [Cu(2,5-pydc)(2-aepy)(H2O)]·H2O, 1, and [Cu(2,5-pydc)(2-ampy)(H2O)]·H2O, 2 (2-aepy = 2-(aminoethyl)pyridine, 2-ampy = 2-(aminomethyl)pyridine, 2,5-pydc = pyridine-2,5-dicarboxylic acid or isocinchomeronic acid). The synthesized complexes have been characterized by X-ray diffraction, FT-IR, elemental, and thermal analysis techniques. The crystal structure of 1 was established by X-ray analysis. Powder X-ray diffraction analysis showed that the complexes are pure. The inhibition of human serum paraoxonase 1 (PON 1, EC 3.1.8.1) enzyme with these complexes were investigated. We used diethyl 4-nitrophenyl phosphate as a substrate to measure the paraoxonase activity of PON 1 enzyme spectrophotometrically. Complexes 1 and 2 decreased the in vitro PON 1 activity with different inhibition mechanisms. Complexes 1 and 2 inhibited paraoxonase activity of this enzyme as competitively and noncompetitively, respectively.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2015Characterization of AlFe-pillared Unye bentonite: A study of the surface acidity and catalytic property
Caglar, Bulent; Cubuk, Osman; Demir, Ersin; Coldur, Fatih; Catir, Mustafa; Topcu, Cihan; Tabak, Ahmet
Aluminium-iron-pillared bentonite has been prepared by incorporation of the iron mixed aluminium-polyoxocation into bentonite layers and characterized by the powder X-ray diffraction, Fourier transform infrared, thermal analysis and surface area measurement techniques. The characteristic d001 basal spacing of raw bentonite increased with the pillaring process and reached to 18.05 Å. The siloxane layers of bentonite were perturbed and the positions of Si-O stretching vibrations were altered by pillaring process. However, these pillars in the interlayer gallery spacing enhanced the thermal stability of bentonite. The new micropores were formed by the pillaring process and the specific surface area of raw bentonite increased by ca. 2-fold for aluminium-iron-pillared bentonite. FTIR spectra and thermal analysis curves of pyridine adsorbed samples clearly show that the surface Lewis acidity of aluminium-iron-pillared bentonite is greater than that of raw bentonite. Raw and aluminium-iron-pillared bentonites have been utilized as solid catalysts for benzoylation of benzene with benzoyl chloride. The aluminium-iron-pillared bentonite catalyst showed promising catalytic activity whereas raw bentonite showed no catalytic activity in benzoylation of benzene with benzoyl chloride.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2015Adsorption of lysozyme from aqueous solutions by a novel bentonite-tyrptophane (Bent-Trp) microcomposite affinity sorbent
Kalburcu, Tulden; Tabak, Ahmet; Ozturk, Nevra; Tuzmen, Nalan; Akgol, Sinan; Caglar, Bulent; Denizli, Adil
This study deals with developing bentonite-tryptophan (Bent-Trp) microcomposite affinity sorbent (38-105 μm) for lysozyme adsorption from aqueous solutions. The structural analysis results of Bent-Trp microcomposites obtained from X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), thermal (TG-DTG/DTA) and elemental analysis techniques clearly pointed out that the pseudo-biospecific affinity ligand L-Tryptophan was penetrated into interlayer space of the bentonite by diplacing water molecules and an elemental analysis of immobilized L-Tryptophan for nitrogen was 541.3 μmol g-1 bentonite. The effects of initial concentration, pH, and temperature on the adsorption efficiency of this sorbent were also studied in a batch system. The maximum amount of lysozyme adsorption from aqueous solution was determined as 365.16 mg/g at pH 10.0 and 1.25 mg/mL initial concentration of lysozyme, while the non-specific adsorption of lysozyme was very low (4.21 mg g-1 sorbent). We concluded that Bent-Trp microcomposite affinity sorbents could be repeatedly applied for lysozyme adsorption without significant losses in the adsorption capacity.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2015Structural characterization of hexadecyltrimethylammonium-smectite composites and their potentiometric electrode applications
Cubuk, Osman; Caglar, Bulent; Topcu, Cihan; Coldur, Fatih; Sarp, Gokhan; Tabak, Ahmet; Sahin, Erdal
Organosmectites were prepared by the intercalation of hexadecyltrimethylammonium cations at various ratios into interlayer of Unye smectite. Structural, thermal, morphological and textural properties of the synthesized organosmectites were characterized. Afterwards, a novel potentiometric PVC-membrane thiocyanate selective electrode was prepared based on the obtained hexadecyltrimethylammonium modified smectites as electroactive material. The basal spacing values of organosmectites were observed in the range of 15.61 and 35.50 Å. Powder X-ray diffraction data show that the surfactant cations penetrated into the smectite layers with different molecular arrangements. Modification of smectite with hexadecyltrimethylammonium led to appreciable decreases in the intensities of the FTIR bands at 3402 and 1635 cm -1 and the new characteristic vibrational bands at 2927, 2850, 1472 and 722 cm -1 originating from the surfactant molecules appeared. The thermal analysis data showed that the decomposition of surfactant species occurred in the temperature range of 170-720 °C and the amount of dehydrated water gradually decreased with the increase in surfactant amount. The intercalation of surfactant species within the gallery spacing led gradually to smaller surface areas. In addition, the electrophoretic mobility values indicate that excess surfactant loadings also generate positive charges on the organosmectite surfaces. The most convenient membrane composition resulting in the best potentiometric performance was investigated. The optimum membrane composition was determined to have 20.0% (w/w) 2.5CEC.HDTMA-smectite, 26.0% (w/w) PVC, 54.0% (w/w) DBP The fabricated electrode exhibited a linear response over the thiocyanate concentration range of 1.0 × 10 -4 -1.0 × 10 -1 M (R 2 = 0.9996) with a slope of -48.6 mV/decade. The detection limit, response time and pH working range were determined as 4.3 × 10 -5 M, ∼10 s and 4-8, respectively. The proposed electrode exhibited selective potentiometric response to thiocyanate comparable to most of the common anions.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2013Covalent grafting of pyridine-2-methanol into kaolinite layers
Caglar, Bulent; Çirak, Çaǧri; Tabak, Ahmet; Afsin, Beytullah; Eren, Erdal
A novel hybrid organic-clay material was prepared by grafting of pyridine-2-methanol in the interlayer space of kaolinite by using a kaolinite/methanol compound as an intermediate. A kaolinite/methanol compound was obtained by guest displacement process of a kaolinite/N-methylformamide pre-intercalation complex with methanol. The structural, morphological and thermal properties of the hybrid material and intermediate species were examined by using X-ray powder diffraction, Fourier transform infrared, thermal analysis, scanning electron microscopy and surface area measurement techniques. The X-ray powder diffraction patterns showed that the penetration of pyridine-2-methanol between the kaolinite/methanol layers caused the emergence of a new peak at 6.51(2θ) with the distance of 13.57 Å. The pyridine-2-methanol species present in the kaolinite interlayers led to appreciable decreases in the intensities of the peaks at 3696, 3667, 3650 and 938 cm-1 which originate from inner-surface hydroxyl groups of pure kaolinite and the new vibrational peaks belonging to the guest molecule were appeared. The thermal analysis data confirmed that the removal of intercalated species occurred in the temperature range 100-180 °C, whereas the grafted pyridine-2-methanol molecules remained stable up to 350 °C which may be explained by grafting of the pyridine-2-methanol molecules onto the inner-surface hydroxyls on the interlayer surfaces of kaolinite through Al-O-C covalent bond formations. The organic molecules located in the interlayer spaces caused significant alterations in the morphology of the pure kaolinite. The specific surface areas of the kaolinite-methanol and kaolinite-N-methylformamide compounds increased whereas that of kaolinite/pyridine-2-methanol hybrid material decreased with respect to that of pure kaolinite.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2013Four copper(II) diclofenac complexes with pyridine derivatives: Synthesis, crystal structures, spectroscopic properties, thermal analysis and catechol oxidase activities
Caglar, Sema; Aydemir, Ismihan E.; Adigüzel, Ekrem; Caglar, Bulent; Demir, Serkan; Buyukgungor, Orhan
Four novel mononuclear copper(II) complexes [Cu(dicl)2(2-pic) 2] 1, [Cu(dicl)2(3-pic)2] 2, [Cu(dicl) 2(4-pic)2] 3 and [Cu(dicl)2(2-ampy) 2] 4 have been synthesized. The crystal structures of the complexes 2 and 3 have been determined by X-ray crystallography. X-ray structure analysis has shown that copper(II) ions have distorted octahedral geometry in 2 and 3 and diclofenac coordinates to Cu(II) ion as a deprotonated ligand through carboxylato oxygens. Four complexes have been characterized by elemental analysis and IR spectroscopy. Their thermal stabilities have been determined by TG/DTA/DTG techniques. Four mononuclear complexes have shown catalytic activity on the oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone exhibiting saturation kinetics at high substrate concentrations.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2013Synthesis, crystal structure, spectroscopic, thermal, catechol oxidase and catalase-like studies: New copper(II) complexes of 2-benzoylbenzoate and 2-pyridilpropanol ligands
Caglar, Sema; Adigüzel, Ekrem; Caglar, Bulent; Saykal, Tuba; Sahin, Ertan; Büyükgüngör, Orhan
Two novel copper(II) complexes, mononuclear [Cu(bba)2(pypr) 2] 1 and dinuclear [Cu2(bba)2(pypr) 2] 2, have been synthesized by reactions of 2-pyridilpropanol with CuSO4·5H2O or Cu(CH3COO) 2·2H2O metal salt in the presence of 2-benzoylbenzoic acid. The copper(II) ion has a distorted octahedral geometry in 1 and distorted square pyramidal geometry in 2. 1 crystallizes in space group P1̄, while 2 crystallizes in the monoclinic crystal system with the space group P21/n. 2-Benzoylbenzoate behaves as a monodentate in 1, bidentate in 2. 2-pyridilpropanol ligand acts as a bidentate in 1 and bridging in 2. Both complexes were characterized by elemental analysis, mass and IR spectroscopy. Their molecular structures were determined by X-ray crystal structure analysis and their thermal stabilities were confirmed by TG/DTA/DTG techniques. Dinuclear compound shows high catalytic activity regarding the oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone exhibiting saturation kinetics at high substrate concentrations. In addition, dinuclear compound demonstrates significantly catalase-like activity. But mononuclear complex shows neither catalase-like nor catechol oxidase activity.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2013Characterization of unye bentonite after treatment with sulfuric acid
Caglar, Bulent; Afsin, Beytullah; Koksal, Engin; Tabak, Ahmet; Eren, Erdal
Unye bentonite was found to consist predominantly of a dioctahedral smectite along with quartz, tridymite, cristobalite, and minor fractions of feldspar and anatase. A considerable amount of Al was retained as a constituent in acid-resistant impurities following the decomposition of the montmorillonite via acid treatment at an acid/clay ratio of 0.4. These impurities were mesoporous with a maximum surface area of 303.9±0.4 m2 g -1. A sharp decrease in the d001 lattice spacing of the montmorillonite to 15.33 Å reflected the reduction of the crystallinity in the activated products. In addition, the increase in the ease with which newly formed hydroxyl groups were lost paralleled the severity of the acid treatment.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2012Two new 2-benzoylbenzoate metal complexes with bapen: Synthesis, spectroscopic and crystal structures
Caglar, Sema; Caglar, Bulent; Buyukgungor, Orhan
Coordination compounds of compositions [Ni(bba) 2(bapen)] (1) and [Cu(bba) 2(bapen)]0.5H 2O (2), where bba = 2-benzoylbenzoate, bapen = N,N'-bis(3-aminopropyl)ethylenediamine, have been prepared. The crystal and molecular structure of (1) and (2) were determined by X-ray analysis. Nickel and copper atoms are six-coordinated by four N atoms of amine and O donor atoms of 2-benzoylbenzoate anions, whereas 0.5 water molecule is situated outside the coordination sphere in (2). The calculated A(OCO) values are consistent with presence of monodentate carboxylate. Thermal analysis show that the mass losses of 1 in the temperature ranges 240-343 °C correspond to the decomposition of bba ligands, while the mass losses of 2 in the temperature ranges 105-125 °C correspond to the decomposition of crystal lattice water molecule.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2012Structural characterization of kaolinite-nicotinamide intercalation composite
Caglar, Bulent
A novel kaolinite-nicotinamide composite was prepared utilizing a kaolinite/N-methylformamide intercalation compound as a precursor material and examined the structural properties of the intercalated species. The X-ray powder diffraction pattern illustrated that intercalation of nicotinamide molecules between the layers of kaolinite caused an emergence of new peaks at 6.87 and 13.63(2θ) with the distance of 12.86 and 6.49 Å, respectively, belonging to the d001 and d002 planes of kaolinite-nicotinamide. The expansion of the d001 basal spacing (5.68 Å) point out the existence of nicotinamide species in the layers of kaolinite which are located as a monolayer arrangement. The aromatic rings of the nicotinamide molecules are perpendicular to the aluminum layers of kaolinite and also both top hydrogen atom of pyridine ring and oxygen atom of carbonyl is keyed into the ditrigonal holes in the silicate layers. The appearance of the peaks at 3630, 3533, 1596 and 1441 cm-1 and decrease of intensity of the inner-surface hydroxyls peak at 3696 cm-1 prove that nicotinamide molecules intercalated into kaolinite layers through forming H-bonds via pyridine ring nitrogen with inner-surface hydroxyls of kaolinite. The thermal stability of intercalated NAM molecules is up to 238°C. The organic molecules located in the interlayer spacing led to an appreciable decrease of particle size and differences in the morphology. The specific and mesoporous surface areas of intercalated composites increased whereas the average pore width of these species decreased with respect to that of pure kaolinite.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2010Adsorption of Reactive Red 120 from aqueous solutions by cetylpyridinium-bentonite
Tabak, Ahmet; Baltas, Nimet; Afsin, Beytullah; Emirik, Mustafa; Caglar, Bulent; Eren, Erdal
BACKGROUND: The removal of Reactive Red 120 (RR 120) from aqueous solutions using cetylpyridinium modified Resadiye bentonite (CP-bentonite) prepared by ion exchange was investigated with particular reference to the effects of temperature, pH and ionic strength on adsorption. RESULTS: Fourier transform infrared (FTIR) and thermal analysis (TG-DTG/DTA) techniques revealed that the anionic dye (RR 120) molecules replaced partly cationic surfactant species on interacting with CP-bentonite. The positive surface charge originating from the cationic surfactant species located on the external surface of the modified bentonite sample increased at low pH values. The significant amount of dye removal by CP-bentonite at high pH values proved the importance of π and van der Waals interactions other than the electrostatic attraction in the duration of the adsorption process. The adsorption isotherms and the kinetic data were well described by the Langmuir and pseudo-second-order kinetic model, respectively. The Gibbs energy (ΔG), enthalpy (ΔH) and entropy (ΔS) changes in the temperature range 25-65 °C pointed out that the RR 120 uptake increased in parallel with the temperature. CONCLUSION: This study showed that the structural arrangement of cetylpyridinium ions in the CP-bentonite sample aswell as the pH, temperature and ionic strength of the bulk solution influenced the adsorption of RR 120 dye from aqueous solutions by CP-bentonite.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2010Equilibrium and kinetic studies on the removal of basic dye using raw and thermal-activated fatsa bentonite
Eren, Erdal; Caglar, Bulent; Eren, Bilge; Tabak, Ahmet
The adsorption behavior of crystal violet (CV+) from aqueous solution onto raw Fatsa (RFB) and thermalactivated Fatsa (TAFB) bentonite samples was investigated as a function of parameters, such as pH, temperature, initial CV+ concentration and contact time. X-ray diffraction (XRD) and differential thermal analysis (DTA) were used for structural and thermal characterization. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. The pseudo-first-order, pseudosecond-order kinetic and intra-particle diffusion models were used to describe the kinetic data.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2010The spectral, structral and thermal characterizations of dimethyl sulphoxide, pyridine, ethanolamine and N-methyl formamide intercalated kaolinites
Caglar, Bulent; Afsin, Beytullah; Eren, Erdal; Tabak, Ahmet; Cirak, Cagri; Cubuk, Osman
The intercalation of dimethyl sulphoxide (DMSO), pyridine (Py), ethanolamine (Ea), and Nmethyl formamide (NMF) molecules into the kaolinite interlayers led to an appreciable decrease of 3697 cm-1 of the hydroxyl band. The appearance of the peaks at 3662, 3541, and 3504 cm-1 proved that the DMSO species are intercalated between the kaolinite layers through forming H-bonds with internal-surface hydroxyl groups. The intensities of the 942 and 796 cm-1 bending peaks arising from inner-surface hydroxyls decreased and new vibrational features appeared due to the intercalation of the guest species. The d001 value of pure kaolinite was found at 7.18 Å, and the d001 values were seen at 11.26, 11.62, 10.77, and 10.67 Å for kaolinite-dimethyl sulphoxide (K-DMSO), kaolinite-pyridine (K-Py), kaolinite-ethanolamine (K-EA), and kaolinite-N-methyl formamide (K-NMF) composites, respectively. The endothermic differential thermal analysis (DTA) peaks at a temperature of 108 - 334°C reflected the changes in the physicochemical properties of the intercalated species. The thermal stability increase followed the order of K-Py<K-NMF<K-Ea<K-DMSO. Based on the thermal analysis data, the intercalation ratios of the composites above were determined as 80.0, 40.0, 81.6, and 82.0%, respectively. The specific surface areas are affected by the intercalation geometry of the composites within the gallery spacing. The surface areas of the K-DMSO, K-Py, and K-EA complexes increased whereas the surface area of K-NMF decreased with respect to that of untreated kaolinite.
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