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: 2Dimensions of Polystyrene Particles Deposited on Mica From Dilute Cyclohexane Solution at Different Temperatures(American Chemical Society, 2002) Demir, Mustafa Muammer; Erman, BurakUsing atomic force microscopy, the height, diameter, and volume of polystyrene particles deposited on mica from dilute cyclohexane solution at different temperatures are determined. Dimensions exhibit a strong temperature dependence. The heights of the deposited particles are only a few atomic diameters, the major dimension being parallel to the mica surface. The number of single polystyrene molecules in a deposited particle cannot be determined directly by atomic force microscopy. However, the maximum number of molecules that may be present in a particle may be estimated. Below 35 °C, the particles possibly consist of single collapsed molecules. This number increases with temperature and becomes as large as about 30 molecules per particle at 80 °C. The volume occupied by a single chain in solvent is calculated as a function of temperature and compared with observed volumes of dry particles on mica. A linear relationship is observed between single chain volumes in solvent and corresponding particle volumes on mica. On the average, the volume of a single chain in solution is 10 times the volume of a dry particle at the corresponding temperature. Fluctuations of chain volumes that are dominant in solution are also present in the volumes of particles deposited and dried on mica.Article Citation - WoS: 12Probing Nanoscale Domains of J-Aggregates Deposited on a Mica Surface(American Chemical Society, 2004) Demir, Mustafa Muammer; Özçelik, Serdar; Birkan, BurakJ-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.