Publications by authors named "Dilek Akcakayiran"

Ionic liquids confined in porous materials are important solvents which allow a simple heterogenization of homogenous liquids. The perdeuterated ionic liquid N-ethylpyridinium-bis(trifluoromethanesulfonyl)amide ([C(2)Py][BTA]-d(10)) was prepared and its bulk phase behavior was studied by differential scanning calorimetry (DSC) and temperature-resolved (2)H and (19)F solid-state NMR spectroscopy. Its bulk properties were compared to [C(2)Py][BTA]-d(10) confined in a mesoporous silica support material as model material usable in SILP catalysts.

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In nanosized pores, liquid water can be thermodynamically stable down to temperatures well below the limit of homogeneous nucleation of bulk water ( approximately 235 K). Studies of water in such pores therefore offer an opportunity to reveal the anomalous behavior of deeply supercooled water. Herein we focus on recent studies of the limits of freezing and melting of water in the cylindrical pores of ordered mesoporous silicas with pore diameters in the range of 2-10 nm, based on vapor sorption measurements, calorimetric studies, NMR spectroscopy and cryoporometry, and neutron diffraction studies.

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Article Synopsis
  • The study investigates the structural characteristics of MCM-41 and SBA-15 silicas using (29)Si and (15)N NMR techniques, aiming to establish standard parameters for their atomic-scale models.
  • MCM-41 features ideal uniform pores and thin walls, while SBA-15 has thicker walls with structural defects, with silanol and silicate groups being quantitatively analyzed.
  • The findings suggest that surface interactions and the arrangement of silanol groups can be influenced by post-synthesis treatments, affecting the overall surface chemistry and reactivity of these materials.
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It is shown that intrinsically stiff chain aggregates of a metallosupramolecular coordination polyelectrolyte (MEPE) can form in the cylindrical nanopores of MCM-41 and SBA-15 silica by self-assembly of its constituents (metal ions and organic ligand). The UV/vis spectra of the resulting MEPE-silica composites exhibit the characteristic metal-to-ligand charge transfer band of the MEPE complex in solution. For the MEPE-silica composite in SBA-15 an iron content of 1.

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