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    Batık Ultrafiltrasyon Hıghly Actıve And Robust Palladıum Nanopartıcles Immobılızed On Bıodegradable Mıcrocapsules Contaınıng Chıtosan-Guar Gum Composıte For Synthesıs Of Bıaryl Compounds
    (Selçuk Üniversitesi Mühendislik Fakültesi, 2020) Baran, Talat
    In this study, highly stable biodegradable microcapsules, which are composed of chitosan-guar gum composite (CS-GG), were prepared as catalyst support. Then, palladium nanoparticles were successfully decorated on the designed support without using any toxic reducing agent (Pd NPs@CS-GG). Structural characterizations of CS-GG and Pd NPs@CS-GG were carried out by different analytical techniques and it was detected that the size of palladium nanoparticles changed in the range of 23-48 nm. Then, the catalytic activity of Pd NPs@CS-GG was evaluated in the fabrication of various biaryl compounds under solventless media using microwave heating. Pd NPs@CS-GG showed high catalytic performance in the conversion of various aryl halides to desired biaryl compounds with good reaction yields. Moreover, it was found that Pd NPs@CS-GG was a catalyst having long life time because of its reuse at least seven times.
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    Differentiations of Chitin Content and Surface Morphologies of Chitins Extracted from Male and Female Grasshopper Species
    (PUBLIC LIBRARY SCIENCE, 2015) Kaya, Murat; Lelesius, Evaldas; Nagrockaite, Radvile; Sargin, Idris; Arslan, Gulsin; Mol, Abbas; Baran, Talat
    In this study, we used Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), and scanning electron microscopy (SEM) to investigate chitin structure isolated from both sexes of four grasshopper species. FT-IR, EA, XRD, and TGA showed that the chitin was in the alpha form. With respect to gender, two main differences were observed. First, we observed that the quantity of chitin was greater in males than in females and the dry weight of chitin between species ranged from 4.71% to 11.84%. Second, using SEM, we observed that the male chitin surface structure contained 25 - 90nm wide nanofibers and 90 - 250 nm nanopores, while no pores or nanofibers were observed in the chitin surface structure of the majority of females (nanofibers were observed only in M. desertus females). In contrast, the elemental analysis, thermal properties, and crystalline index values for chitin were similar in males and females. Also, we carried out enzymatic digestion of the isolated chitins using commercial chitinase from Streptomyces griseus. We observed that there were no big differences in digestion rate of the chitins from both sexes and commercial chitin. The digestion rates were for grasshoppers' chitins; 88.45-95.48% and for commercial chitin; 94.95%.
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    Preparation and characterisation of biodegradable pollen-chitosan microcapsules and its application in heavy metal removal
    (ELSEVIER SCI LTD, 2015) Sargin, Idris; Kaya, Murat; Arslan, Gulsin; Baran, Talat; Ceter, Talip
    Biosorbents have been widely used in heavy metal removal. New resources should be exploited to develop more efficient biosorbents. This study reports the preparation of three novel chitosan microcapsules from pollens of three common, wind-pollinated plants (Acer negundo, Cupressus sempervirens and Populus nigra). The microcapsules were characterized (Fourier transform infrared spectroscopy, thermo-gravimetric analysis, scanning electron microscopy and elemental analysis) and used in removal of heavy metal ions: Cd(II), Cr(III), Cu(II), Ni(II) and Zn(II). Their sorption capacities were compared to those of cross-linked chitosan beads without pollen grains. C. sempervirens-chitosan microcapsules exhibited better performance (Cd(II): 65.98; Cu(II): 67.10 and Zn(II): 49.55 mg g (1)) than the other microcapsules and the cross-linked beads. A. negundo-chitosan microcapsules were more efficient in Cr(III) (70.40 mg g (1)) removal. P. nigra-chitosan microcapsules were found to be less efficient. Chitosan-pollen microcapsules (except P. nigra-chitosan microcapsules) can be used in heavy metal removal. (C) 2014 Elsevier Ltd. All rights reserved.