Materials Science and Engineering / Malzeme Bilimi ve Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4719

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End date: 2019Publisher: search.filters.publisher.Trans Tech Publications

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Now showing 1 - 6 of 6
  • Article
    Citation - WoS: 18
    Citation - Scopus: 17
    Cnt Incorporated Polyacrilonitrile/Polypyrrole Nanofibers as Keratinocytes Scaffold
    (Trans Tech Publications, 2019) İnce Yardımcı, Atike; Aypek, Hande; Öztürk, Özgür; Yılmaz, Selahattin; Özçivici, Engin; Meşe, Gülistan; Selamet, Yusuf
    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.
  • Conference Object
    Citation - Scopus: 1
    Spontaneous Adhesion of Dopa and Tryptophan Functionalized Peg To Polystyrene Nanobeads: an Epr Study
    (Trans Tech Publications, 2018) Göksel, Yaman; Kırpat, İklima; Akdoğan, Yaşar
    Wet adhesion is achieved by mussels so naturally. Their adhesion mechanism has inspired scientists to obtain wet adhesives for a long time. The amino acid 3,4-dihydroxyphenylalanine (DOPA) produced by mussels adheres to different types of surfaces and also contributes to cohesive interactions. Here, we showed the spontaneous adhesion of DOPA functionalized four armed poly(ethylene glycol) (PEG) polymer to spin labeled polystyrene (SL-PS) nanosurfaces by electron paramagnetic resonance (EPR) spectroscopy. In addition to DOPA, adhesion property of another amino acid of tryptophan (Trp) was studied. Trp attached four armed PEG polymers did not adhere to the surface of SL-PS in the force free condition. However, two armed DOPA and two armed Trp functionalized PEG adhere to the PS.
  • Conference Object
    Citation - Scopus: 3
    Investigation of Lithium Sorption Efficiency Using Swcnt Functionalized Electrospun Fiber Mats From the Hypersaline Geothermal Brine
    (Trans Tech Publications, 2018) Çelik, Aslı; Topçu, Gökhan; Isık, Tuğba; Baba, Alper; Horzum, Nesrin; Demir, Mustafa Muammer
    Geothermal mining from brines becomes increasingly important with the increasing demand for rare earth elements in various engineering applications. Geothermal fluids contain valuable minerals and metals such as silica, zinc, lithium, and other materials that can be processed to recover these products. Solution mining by nature is challenging because of variable composition as well as the concentration of the interfering ions, particularly calcium and magnesium, and the presence of interfering ions increases the recovery costs requiring additional steps. The aim of this study is the fabrication of single-walled carbon nanotube functionalized electrospun chitosan, poly(methyl methacrylate) (PMMA), and polyacrylonitrile (PAN) fiber mats. Effect of polymer type, dilution factor, and surface modification on the sorption of lithium (Li+) ions was investigated. The maximum sorption performance was obtained with SWCNT functionalized PAN (15 wt%) fiber mats and they have sorption percentage as 55% at diluted (1/100) brine samples.
  • Conference Object
    The Shape and Size Effect of the Diatom Frustule Addition on the Compression Behavior of an Epoxy
    (Trans Tech Publications, 2018) Zeren, Doğuş; Kesici, Kutsal; Sukatar, Atakan; Güden, Mustafa
    The effects of the Achnanthes Taeniata and the diatomaceous earth (diatomite) frustules addition on the compressive strength of an epoxy matrix were investigated experimentally. The Achnanthes Taeniata frustules having relatively high length/diameter aspect ratio (2-4) were isolated and cultured in laboratory. While the as-received commercial natural diatomite frustules were non-homogenous in shape and size. The filling epoxy matrix with ~6 wt% of commercial natural diatomite increased the compressive strength from 60 MPa to 67 MPa, while the Achnanthes Taeniata frustules addition increased to 79 MPa. The increased compressive strength and modulus of the the Achnanthes Taeniata frustules filled epoxy was attributed to the higher aspect ratio and relatively strong bonding with the epoxy matrix. The more effective load transfer from the matrix to the Achnanthes Taeniata frustules associated with the enhanced interface bonding was also proved microscopically. The frustules were observed to pull-out on the fracture surface of the Achnanthes Taeniata frustules filled epoxy.
  • Conference Object
    Citation - Scopus: 2
    Fabrication of Polymer Nanofiber-Conducting Polymer Fabric and Noncontact Motion Sensing Platform
    (Trans Tech Publications, 2018) Mutlu, Mustafa Umut; Akın, Osman; Demir, Mustafa Muammer; Yıldız, Ümit Hakan
    Conductive polymer-electrospun polymer nanofiber network was combined to host iron oxide nanoparticles providing micrometer thick sensing interface. The sensor has fabricated as freestanding fabric exhibiting 10 to 100 KOhm base resistivity upon bias applied. The moving object has been sensed through the electrostatic interactions between fibers and object. The sensing range has been found to be 1-5 cm above the surface of fabric. By the controlled combination of conductive polymers electrospun polymer nanofibers effective device miniaturization has been provided without loss of performance. The noncontact motion sensor platform has unique flexibility and light weight holding a potential for wearable sensor technology.
  • Conference Object
    Microstructure-Performance Relation in Pmma-Based Open-Cell Porous Materials for High Pressure Ceramic Sanitaryware Casting
    (Trans Tech Publications, 2004) Ergün, Yelda; Dirier, C.; Yılmaz, M.; Tokman, C.; Tanoğlu, Metin
    The ceramic whiteware/sanitaryware industry is rapidly undergoing to implement high-pressure casting techniques for ceramic article production. In these techniques, materials with open pore microstructure that allows drainage of water under applied pressure are needed. The polymethyl methacrylate (PMMA) based polymeric porous materials have become the most suitable type of materials for this purpose because of their short casting periods and high service lives. However, the superior service life and performance of these materials are closely related to the microstructure. In the present study, the porous materials with various compositions of the constituents in the emulsion were produced to effect the microstructure of PMMA-based materials. The variations on the pore microstructure were interrelated to the performance of the material for high-pressure sanitaryware casting. The pore morphology and water permeability of the samples was measured using optical and SEM microscopy and permeability measurement techniques, respectively. The compressive collapse stress and modulus values were determined by performing compression testing. The results showed a significant interrelation between microstructure and the performance of the PMMA-based ceramic mould materials.