Physics / Fizik

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Department: search.filters.department.İzmir Institute of Technology. Materials Science and EngineeringSubject: search.filters.subject.Carbon nanotubes

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  • Article
    Citation - Scopus: 1
    Oxidizer Gases Effects on the Diameter-Controlled Synthesis of Carbon Nanotubes
    (MIM Research Group, 2021) İnce Yardımcı, Atike; Öğütlü, Deniz; Öğütlü, Ahmet Sabri; Öğütlü, Deniz; 01. Izmir Institute of Technology
    In this study, the influence of the oxidizers on the synthesis of carbon nanotubes by C2H4 decomposition over Fe catalyst has been investigated. CO2, O2, and H2O have been used as oxidizers, and to control catalyst particle formation and their sizes in the pretreatment stage. The same oxidizers have also been used in the growth stage to maintain the catalyst particle size, remove amorphous carbon formation to keep catalyst particle active. The results of scanning electron microscopy indicated that the average diameters of nanotubes decreased from 13.4±1.2 nm to 6.2±0.5 nm and extremely dense nanotubes were obtained when we added a small amount of CO2. Adding O2 extremely decreased the areal carbon nanotube density while widens the diameter distribution. H2O addition resulted in larger average diameters and made the growth strongly pretreatment dependent. Within the parameters tried for catalyst pretreatment and CNT growth processes, CO2 seemed the best choice for a weak oxidizing assistant. The strong dependency of the average diameter on pretreatment conditions indicated that pretreatment is a very important step in deciding the final diameters and their distribution.
  • Article
    Citation - WoS: 18
    Citation - Scopus: 17
    Cnt Incorporated Polyacrilonitrile/Polypyrrole Nanofibers as Keratinocytes Scaffold
    (Trans Tech Publications, 2019) Meşe Özçivici, Gülistan; Selamet, Yusuf; Özçivici, Engin; Yılmaz, Selahattin; Özçivici, Engin; Meşe, Gülistan; Selamet, Yusuf; 03.01. Department of Bioengineering; 03.02. Department of Chemical Engineering; 04.03. Department of Molecular Biology and Genetics; 04.05. Department of Pyhsics; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of Technology
    Polypyrrole (PPy) is an attractive scaffold material for tissue engineering with its non-toxic and electrically conductive properties. There has not been enough information about PPy usage in skin tissue engineering. The aim of this study is to investigate biocompatibility of polyacrilonitrile (PAN)/PPy nanofibrous scaffold for human keratinocytes. PAN/PPy bicomponent nanofibers were prepared by electrospinning, in various PPy concentrations and with carbon nanotube (CNT) incorporation. The average diameter of electrospun nanofibers decreased with increasing PPy concentration. Further, agglomerated CNTs caused beads and disordered parts on the surface of nanofibers. Biocompatibility of these PAN/PPy and PAN/PPy/CNT scaffolds were analyzed in vitro. Both scaffolds provided adhesion and proliferation of keratinocytes. Nanofiber diameter did not significantly influence the morphology of cells. However, with increasing number of cells, cells stayed among nanofibers and this affected their shape and size. In this study, we demonstrated that PAN/PPy and PAN/PPy/CNT scaffolds enabled the growth of keratinocytes, showing their biocompatibility.