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: 53Citation - Scopus: 60Properties of N-Eicosane Silk Fibroin-Chitosan Microcapsules(John Wiley and Sons Inc., 2011) Başal, Güldemet; Şirin Deveci, Senem; Yalçın, Dilek; Bayraktar, OğuzPCM microcapsules containing n-eicosane were prepared by complex coacervation of silk fibroin (SF) and chitosan (CHI). Chemical characterization of microcapsules was carried out using Fourier-transform infrared (FT-IR) spectroscopy. Thermal properties and thermal stability of microencapsulated n-eicosane were determined by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). FTIR spectra confirmed the encapsulation of n-eicosane within the microcapsules. Results from thermal analyses showed that microcapsules consisted of an average of 45.7 wt % n-eicosane, and had a thermal energy storage and release capacity of about 93.04 J/g and 89.68 J/g, respectively.Article Citation - WoS: 22Citation - Scopus: 21A Novel Silk Fibroin-Supported Iron Catalyst for Hydroxylation of Phenol(John Wiley and Sons Inc., 2006) Pekşen, Bahar Başak; Üzelakçil, Caner; Güneş, Alev; Malay, Özge; Bayraktar, OğuzThe aim of this study was to explore the potential use of silk fibroin (SF) as a catalyst support material for phenol hydroxylation reactions. Iron-substituted silk fibroin fibers were prepared using formic acid at room temperature and characterized using inductively coupled plasma atomic-emission spectrometry, scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) and optical microscopy. Measurement of an FTIR spectrum showed that the secondary structure was β-structure before and after iron substitution. To evaluate the catalytic properties of prepared catalyst, phenol hydroxylation reaction was carried out using aqueous hydrogen peroxide as an oxidant. An excellent transformation of phenol into dihydroxybenzenes (catechol and hydroquinone) was achieved. Phenol conversions of 3.3%, 61.2%, and 80.3% were obtained at room temperature, 40°C and 60°C respectively. It was found that no further phenol conversion proceeded because catalysts became separated from the reaction system during the reaction. No significant leaching of the iron was detected. Catalyst could be reused several times without a significant change in activity. Parent silk fibroin fibers without iron were inactive.