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: 31
    Citation - Scopus: 36
    Integration of Triboluminescent Eud4tea Crystals To Transparent Polymers: Impact Sensor Application
    (American Chemical Society, 2017) İncel, Anıl; Eanes, Mehtap; McMillen, Colin D.; Demir, Mustafa Muammer
    Lanthanide-based organometallic materials are well-known candidate triboluminescent (TL) materials that can show bright emission when a mechanical force is applied. These materials are usually in the form of crystalline powders, and it is often useful to integrate these samples into a polymer matrix in order to achieve processability, enabling coating from a solution/molten state or fabrication as a complex-shaped matrix. In this work, micrometer-sized europium tetrakis (dibenzoylmethide) triethylammonium (EuD4TEA) crystals were synthesized and integrated with various transparent polymers (PMMA, PS, PVDF, and PU) using two approaches: (i) blending and (ii) surface impregnation. In the former method, the crystalline particles were molecularly dissolved; therefore, a TL response cannot be achieved. More than 10 wt % TL crystals in the composite is needed to obtain TL signals. However, TL signal was achieved at 2.5 wt % when a composite was prepared by the latter approach. TL intensity shows exponential decay with consecutive mechanical action. The TL emission of PU-based surface impregnated composite expires with long-lived emission, and maximum TL response with respect to applied force was measured between 2.45 and 42.0 N.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 5
    Hydrothermal Synthesis and Characterization of a New Layered Compound Li2vgeo5
    (Elsevier Ltd., 2004) Eanes, Mehtap; Kolis, Joseph W.
    The new compound Li2VGeO5 with a layered structure has been synthesized at 580°C via the hydrothermal method. The compound crystallizes in the space group P4/n of the tetragonal system with two formula units in a cell of dimensions a=6.5187(9)Å, c=4.5092(9)Å (T=298K), V=191.61(5)Å3. The structure is composed of layers made of repeating [(VO5)(GeO4)]1- units. Li+ ions reside between the layers. The magnetic susceptibility data show an antiferromagnetic coupling below 5K with C=0.47emuKmol-1, and θ=-13K with μeff=1.89μB for each Li 2VGeO5 unit.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 12
    Hydrothermal Synthesis, Characterization and Magnetic Properties of Navge2o6 and Livge2o6
    (Elsevier Ltd., 2004) Eanes, Mehtap; Kolis, Joseph W.
    Supercritical fluids are shown to be an excellent reaction media for the synthesis of novel solid state phases at intermediate temperatures. LiVGe 2O6 and NaVGe2O6 have the common pyroxene structure composed of VO6 linear chains. NaVGe 2O6 crystallizes in the monoclinic space group C2/c with four formula units having cell dimensions a = 9.960(4)Å, b = 8.853(10)Å, c = 5.4861(10)Å, β = 106.403(3)°. The structure was refined until R = 0.0290 and Rw = 0.0370. For LiVGe 2O6 in space group P21/c: a = 9.8508(7)Å, b = 8.754(3)Å, c = 5.3948(13)Å, β = 108(3)°, R = 0.0240 and Rw = 0.0250. The compounds contain edge-shared VO6 octahedral chains and corner-shared GeO4 tetrahedral chains. The presence of these VO6 chains results in spin-Peierls distortion. Structural and physical characterization of the compounds are reported.