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Publication Metadata only A Vibrational Spectroscopic Study of the Adsorption of 4 4 Bipyridiyl by Smectite Group Clay Minerals From Anatolia Turkey(Kluwer Academic Publishers, 1993-06) Davies, J. Eric D.; AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; 1012The adsorption of 4,4′-bipyridyl by natural sepiolite and smectite group clay minerals (bentonite, hectorite and saponite) from Anatolia (Turkey) has been studied using vibrational spectroscopy. Investigation of Fourier-transform infrared and Fourier-transform Raman spectra of adsorbed 4,4′-bipyridyl indicate the presence of chemisorbed species. However, any evidence for the generation of anionic species on the surface of the phyllosilicates has not been detected. It is proposed that the adsorbed bipyridyl molecules on sepiolite are centrosymmetric and H-bonded to the surface hydroxyls through both the nitrogen lone pairs as bidentate ligands. The adsorbed bipyridyl molecules on the smectite group clays are coordinated to exchangeable cations both directly and also indirectly through water as monodentate ligands. XRD patterns of the clays studied are also recorded.Publication Metadata only Influence of Raw Rice Husk Addition on Structure and Properties of Concrete(Elsevier Sci Ltd, The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1Gb, Oxon, England, 2013-07) Biricik, Hasan; Yüzer, Nabi; Çınar, Zekiye; Aköz, Zekiye; Yalçın Gürkan, Yelda; Kabay, Nihat; Kızılkanat, Ahmet Beşer; 58815; 1338; 6305; 111437; 47928; 185408; 173987When concrete is exposed to high temperatures, vapor pressure increases and the concrete may spall. In order to prevent this, polypropylene fibers are added to concrete. However, it is known that these fibers produce harmful gases at high temperatures that affect health. In this study, instead of polypropylene fibers, the usability of raw rice husk which is a by-product of paddy-rice dehusking was tested in normal strength concrete. Four concrete series were produced with a constant water/cement ratio and slump and exposed to high temperatures. Compressive strength, density, ultrasonic pulse velocity, thermal conductivity and water vapor diffusion resistance factor were investigated experimentally. FT-IR, SEM, XRD and BET analyses were also performed. Although the use of rice husk reduces mechanical strength, it provides benefits in other properties. Rice husk reduces vapor pressure within the concrete thus prevents spalling and releases less harmful gases than polypropylene fibers. (C) 2013 Elsevier Ltd. All rights reserved.Publication Metadata only FT-IR spectroscopic investigation of adsorption of pyrimidine on sepiolite and montmorillonite from Anatolia(Springer, Van Godewijckstraat 30, 3311 Gz Dordrecht, Netherlands, 2003-06) AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; 10127The adsorption of pyrimidine ( PM) on natural montmorillonite and sepiolite from Turkey was investigated by FT-IR spectroscopy. The intercalation of PM within montmorillonite has been shown by X-ray diffraction to increase the interlayer spacing. The spectroscopic results indicate that PM molecules adsorbed on sepiolite are coordinated to Lewis acidic centers or surface hydroxyls by H-bonding interaction through one of the pyrimidine ring nitrogen lone pairs. Moreover, some of the adsorbed PM molecules may enter the interior channels of the sepiolite structure and replace zeolitic water. The intercalated PM molecules within montmorillonite are coordinated to exchangeable cations directly or indirectly through water bridges.Publication Metadata only FT-IR spectroscopic investigations adsorption of pyrazinamide and 4-aminopyrimidine by clays(SPRINGER, VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS, 2004-02) AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANILThe adsorption of pyrazinamide (PZA) and 4-aminopyrimidine (4APM) on natural sepiolite, loughlinite (Na-sepiolite), natural and ion-exchanged montmorillonite (Co- or Cu-montmorillonite) has been investigated using FT-IR spectroscopy. The intercalation of pyrazinamide and 4-aminopyrimidine within natural and ion-exchanged montmorillonites has been shown by X-ray diffraction to increase the interlayer spacing. PZA and 4APM interacted with montmorillonites by direct or indirect coordination ( through water molecules) to the exchangeable cations. The spectroscopic results indicate that PZA or 4APM molecules adsorbed on sepiolite and loughlinite are coordinated to Lewis acidic centers or surface hydroxyls by H-bonding interaction through either one of the pyrimidine ring nitrogen lone pairs ( in the case of 4APM) or carbonyl group ( in the case of PZA).Publication Metadata only Adsorption of 2 2 Bipyridyl onto Sepiolite Attapulgite and Smectite Group Clay Minerals from Anatolia FT IR and FT Raman Spectra of Surface and Intercalated Species(Kluwer Academic Publishers, 1994-06) Davies, J. Eric D.; AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; 10127The adsorption of 2,2′-bipyridyl by natural sepiolite, attapulgite, hectorite, saponite and natural and ion exchanged (Mn, Fe, Co, Ni, Cu, Zn or Sn) bentonites has been investigated by FT-IR and FT-Raman spectroscopy. Spectroscopic results indicate that most of the adsorbed molecules are coordinated to either exchangeable cations (in the case of smectite group clays) or Lewis acidic centres (in the case of sepiolite and attapulgite) as bidentate ligands. The formation of monoanionic surface species has also been detected, to a relatively small extent. No physisorbed surface species has been observed. XRD patterns and UV-visible spectra of the samples are also recorded for additional information.Publication Metadata only FT-IR spectra of natural loughlinite (Na-sepiolite) and adsorption of pyrimidine on loughlinite(ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2004-11-01) AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANILFT-IR spectroscopy has been used to characterise natural loughlinite and the adsorption of pyrimidine. A comparison of the spectra of loughlinite and sepiolite are given. The adsorption of pyrimidine was on the loughlinite Lewis acid cites through the pyrimidine lone pairs. Moreover. some of the adsorbed pyrimidine molecules may coordinate to surface SiOH groups. (C) 2004 Elsevier B.V. All rights reserved.Publication Metadata only Adsorption and interaction of 2-aminopyridine with loughlinite (Na-sepiolite) from Anatolia(ASIAN JOURNAL OF CHEMISTRY, 11/100 RAJENDRA NAGAR, SECTOR 3,, SAHIBABAD 201 005, GHAZIABAD, INDIA, 2008-06) AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; TR10127; TR111424FT-IR spectroscopy has been used to characterize adsorption and interaction of 2-aminopyridine by loughlinite, which belongs to palygorskite-sepiolite group of phyllosilicates class of clay minerals. The spectroscopic results indicate generation of 2-aminopyridinium cations. Cationic and neutral surface species adsorbed on loughlinite are coordinated to Bronsted acidic sites and surface hydroxyls (by H-bonding interaction through pyridine ring nitrogen lone pairs), respectively. It must be noted that the adsorption of 2-aminopyridine affected the hydroxyl group vibrations of loughlinite.Publication Metadata only Adsorption Of 3-And 4-Aminopyridine On Loughlinite-An IR Spectroscopic Study(Elsevier Science Bv, Po Box 211, 1000 Ae Amsterdam, Netherlands, 2010-05-26) AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; TR10127; TR111424In this study adsorption of 3- and 4-aminopyridine on loughlinite (Na-sepiolite) have been investigated by FT-IR spectroscopy. Spectroscopic results indicate that sorbed aminopyridine molecules onto loughlinite are coordinated to Lewis acidic centers, zeolitic/bound water molecules, and surface silanol groups by hydrogen bonding interaction through pyridine ring nitrogen lone pairs. Some of the adsorbed molecules coordinate to Bronsted acidic centers and aminopyridinium cationic surface species are also generated. (C) 2010 Elsevier B.V. All rights reserved.Publication Metadata only The Modification Of Na-Montmorillonite By Salts Of Fatty Acids: An Easy İntercalation Process(Elsevier Science Bv, Po Box 211, 1000 Ae Amsterdam, Netherlands, 2010-11-20) Önder, Emel; Ersoy, Sabri; SARIER, NİHAL; TR114920; TR10598; TR11772The organic modification of Na-montmorillonite (Na-MMT) clay by a reaction with the sodium salts of octadecanoic acid (SOD) and dodecanoic acid (SDD) was studied for the production of effectively intercalated and organophilic clays. The results of X-ray diffractometer (XRD) analysis reveal that the interlayer spacing of Na-MMT increased from 1.38 nm to 3.37-1.4-4 nm, 3.56-1.45 nm, 3.61-1.44 nm and 3.56-1.44 nm in the organoclays containing 393 mM SOD, 787 mM of SOD, 540 mM SDD and 1080 mM SOD, respectively. In the Fourier transform infrared spectrometer (FTIR) analyses, the stretching and bending vibrations of the hydroxyl groups of Na-MMT at 3619,3407 and 1634 cm(-1) 15 as well as the Si-O and Al-O vibrations of silica-alumina layers at 1039-534 cm(-1) 16 respond to the structural changes from hydrophilic to hydrophobic character. Thermogravimetric (TG) analyses results also suggest that the intercalation of SOD and SDD were achieved in the organoclays samples and the samples had permanent structural modifications, although they retained their inorganic character. The TEM-EDS and SEM results show that the SOD and SDD were well dispersed and intercalated throughout the interlayer spaces or adsorbed onto the clay surface. The suggested organic modification of Na-MMT is an easily applicable process in which the chemically stable, low cost and widely available SOD and SDD are used as intercalating agents. (C) 2010 Elsevier B.V. All rights reserved.Publication Metadata only Vibrational Spectroscopic Investigation of 2,2 '-Bipyridine Adsorbed on Loughlinite from Aqueous Suspensions(Asian Journal Of Chemistry, 11/100 Rajendra Nagar, Sector 3,, Sahibabad 201 005, Ghaziabad, India, 2010-01) AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; TR111424; TR10127The adsorption of 2,2'-bipyridine onto loughlinite (Na-sepiolite) has been investigated by FT-IR and micro-Raman spectroscopy. Spectroscopic results indicate the formation of monoanionic surface species. Most of the adsorbed molecules are incorporated in the channels of the clay structure and coordinated to Lewis acidic centers directly or indirectly through water molecules.