Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 12Citation - Scopus: 12Supercritical Fluid Reactive Deposition: a Process Intensification Technique for Synthesis of Nanostructured Materials(Elsevier, 2022) Yousefzadeh, Hamed; Akgün, Işık Sena; Barım, Şansım Bengisu; Sarı, Tarık Bercan; Eriş, Gamze; Uzunlar, Erdal; Bozbağ, Selmi Erim; Erkey, CanSupercritical fluid reactive deposition (SFRD) is a promising process intensification technique for synthesis of a wide variety of nanostructured materials. The enhanced mass transfer characteristics of supercritical fluids (SCFs) coupled with high solubilities of reducing gases in SCFs provide many advantages related to equipment size and time minimization over conventional techniques. Among SCFs, the emphasis has been placed on supercritical CO2 (scCO2) which is non-toxic, cheap and leaves no residue on the treated medium. Moreover, in SFRD, multiple processes such as dissolution, adsorption, reaction, and purification are combined in a single piece of equipment which is an excellent example of process integration for process intensification. In this review, the fundamental thermodynamic and kinetic aspects of the technology are described in detail. The studies in the literature on synthesis of a wide variety of nanostructured materials including supported nanoparticles, films, and ion-exchanged zeolites by SFRD are reviewed and summarized. The applications of these materials as catalysts and sensors are described. The review hopes to lead to further studies on further development of this technology for a wide variety of applications.Article Citation - WoS: 16Citation - Scopus: 17Porous Nanocomposites Prepared From Layered Clay and Pmma [poly(methyl Methacrylate)](Elsevier Ltd., 2007) Tanoğlu, Metin; Ergün, YeldaThe aim of the present work is the preparation of PMMA based porous nanocomposites that contain clay (montmorillonite, MMT) platelets as reinforcements within the cell walls of the porous structure. To render the clay layers organophilic, MMT was surface treated by an ion exchange reaction between interlayer cations of the clay and ammonium ions of a surfactant. Clay/PMMA based porous nanocomposites were prepared by polymerization of water-in-oil emulsions with and without clay addition. The microstructure and compressive mechanical behavior of the nanocomposites were investigated. The results of mechanical tests showed that the porous systems with the addition of 1 wt.% of organoclay (OMMT) exhibited a 90% and 50% increase of collapse stress and elastic modulus values, respectively, as compared to neat porous PMMA.Article Citation - WoS: 74Citation - Scopus: 77Full Bulk Spin Polarization and Intrinsic Tunnel Barriers at the Surface of Layered Manganites(Nature Publishing Group, 2005) Freeland, John W.; Gray, Kenneth E.; Özyüzer, Lütfi; Berghuis, Peter; Badica, E.; Kavich, Jerald J.; Zheng, Hong; Mitchell, John F.The affect of full bulk spin polarization and intrinsic tunnel barriers on the surface of layered manganites were studied using a combination of surface-sensitive x-ray and tunnelling process. The surface bilayer of air-cleaved layered manganites forms an antiferromagnetic insulating nanoskin composed of a single bilayer unit. It was shown that for the quasi-two-dimensional bilayer manganites the outermost Mn-O bilayer is affected while the next bilayer displays the full spin polarization of the bulk. The results show that the outermost bilayer act as an intrinsic barrier between the fully spin-polarized bilayer beneath and a subsequently deposited ferromagnetic counterelectrode.Article Citation - WoS: 185Pmma/Zinc Oxide Nanocomposites Prepared by In-Situ Bulk Polymerization(John Wiley and Sons Inc., 2006) Demir, Mustafa Muammer; Memesa, Mine; Castignolles, Patrice; Wegner, GerhardDispersing surface-modified zinc oxide nano-particles (ZnO) in methyl methacrylate (MMA) improves the free radical bulk polymerization process as well as the thermal stability of the formed polymer. Hydroxy groups available on the ZnO surface may induce a degenerative transfer. This suppresses the gel effect, which leads to a better control of the heat evolution during the late stages of polymerization. The formation of chains having vinylidene end groups and head-to-head links is suppressed, which shifts the onset of thermal decomposition to the regime where decomposition occurs by random chain scission.