Loading...

Synthesis of Graphene Structures by Chemical Vapor Deposition Method and Evaluation of their Electrical and Biological Properties

Kiani Shahvandi, Fatemeh | 2015

704 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 48058 (07)
  4. University: Sharif University of Technology
  5. Department: Materials Science and Engineering
  6. Advisor(s): Simchi, Abdolreza
  7. Abstract:
  8. Graphene is a newly developed nanomaterial that has resived considerable attention in recent years. Graphene – based structures having remarkable properties, e.g. high specific surface area, ultrahigh electrical conductivity and good biocompability, are ideal choices for nanomedical applications such as biosensors and cell culture scaffolds. So, in this project 2D graphene and 3D graphene foam structures were synthesized by chemical vapor deposition (CVD) method and their electrical and biological properties were evaluated. First step of this project was to design and make a CVD system suitable for the synthesis of high quality graphene structures, i.e. single layer graphene and 3D graphene foams, was resulted by chenging experimental parameters and studing their effect on the quality of the resulted graphene. After synthesizing single layer graphene, transferring process to Si/SiO2(300 nm) substrate was done in order to characterize the products. Optical microscope, Scaning Electrical Microscope (SEM), Atomic Force Microscope (AFM) and Raman spectroscopy method were used for microstructural studies and evaluating the quality of products. Results of the characterization methods showed the products are continuous single layer graphene having good quality and 0.6 nm thicknese. Moreover, results of characterization methods on 3D graphene foams, also showed that relatively high quality and pure graphene foams with micropores (~200 µm) are resulted from a combination of single layer to multilayer graphene sheets. Evaluations of electrical propertis of graphene was done by making a Graphene – based field effect transistor (FET) and mesurment of its electrical properties. Transfer characteristic of graphene FET showed an evident field field effect and transconductance of 2×10-7 S for 2D graphene layer. Also, the Dirac point of 25 V was resulted at bias voltage of 0.05 V, showing that the graphene is of P – type. Biological properties of graphene foams were evaluated by invitro cell culture assay with Human bone marrow-derived mesenchymal stem cells (hMSCs). So, MTT test and scanning electron microscopy were used for evaluate of biocompability and cell attachment on the surface of graphene foam samples, respectively. Results showed that the hMSCs have good adhesion to surface of graphene scaffolds and cell viability percent of 110.5% results after 48 hours of cell culture on the samples, showing that graphene foam substrates not only doesn’t have any toxicity for hMSCs but also couse to stimulate their growth and proliferation
  9. Keywords:
  10. Chemical Vapor Deposition (CVD) ; Field Effect Transistors ; Biocompatibility ; Three Dimentional Graphene Foam ; In-Vitro Biological Assays ; Two Dimentional Graphene

 Digital Object List

 Bookmark

No TOC