Chemistry / Kimya

Permanent URI for this collectionhttps://hdl.handle.net/11147/4072

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  • Article
    Citation - WoS: 69
    Citation - Scopus: 77
    Morphosynthesis of Caco3 at Different Reaction Temperatures and the Effects of Pdda, Ctab, and Edta on the Particle Morphology and Polymorph Stability
    (Elsevier Ltd., 2007) Altay, E.; Shahwan, Talal; Tanoğlu, Metin
    Facile precipitation of CaCO3 was performed using aqueous solutions of CaCl2 with Na2CO3 over a wide range of mixing and aging temperatures. The precipitation process was then repeated in the presence of PDDA, CTAB, and EDTA at the mixing temperatures of 30 °C, 50 °C, 70 °C, and 90 °C. The presence of these additives was seen to greatly suppress the formation of aragonite. Among these additives, EDTA was the one that showed the most prominent effects on particle morphology of CaCO3. The sequence of pH adjustment appeared to be a critical factor for the additive functionality.
  • Article
    Citation - WoS: 12
    Probing Nanoscale Domains of J-Aggregates Deposited on a Mica Surface
    (American Chemical Society, 2004) Demir, Mustafa Muammer; Özçelik, Serdar; Birkan, Burak
    J-aggregates of 1,1′,3,3′-tetraethyl-5,5′,6,6′- tetrachlorobenzimidazolocarbocyanine (TTBC) were deposited on a mica surface and probed by atomic force microscopy operated at tapping mode in air. Optical spectra showed that J-aggregates were formed in aqueous solutions. Atomic force microscopy images revealed that J-aggregates deposited on mica surfaces mainly present single domains with a mean height of 2.00 ± 0.25 nm and an average diameter of 100 ± 20 nm. Quantitative analysis of the morphology of images indicated that the single domain of J-aggregates exhibits very uniform height and diameter distributions with polydispersity indices of 1.02 and 1.04, respectively. Based on the results, we propose a two-dimensional nanostructure in which TTBC J-aggregates could be arranged in a monolayer.