Epoxy-based composites and coatings: improvement of multifunctional properties

Download
2019
Çaldıklıoğlu, Almira
The purposes of this study are to improve mechanical properties, thermal stability, resistance to flammability, electrical conductivity and hydrophobicity of epoxy (E) by incorporation of expanded graphite (EG) and titanium dioxide (T) particles. In this study, sonication with the use of solvent method was primarily determined for the epoxy-based binary composite and coating preparation. By this method, the epoxy composites and coatings were produced by changing EG concentration as 0.05, 0.1, 0.25, 0.5, 0.75 and 1 wt.% and changing TiO2 concentration as 0.5, 1, 2 and 5 wt.%. On the other hand, sonication with the use of solvent method was modified for fabrication of the epoxy-based hybrid composites and coatings, and their optimum formulations were determined based on the mechanical properties of the E/EG and E/T binary composites. The epoxy-based composites were characterized by tensile and impact tests, Shore D hardness test, SEM analysis, thermal analyses, LOI analysis and electrical resistivity test while water contact angle measurement and surface energy analysis were performed on their coatings. The tensile strength, elastic modulus and impact strength of the neat epoxy were increased by 24%, 25% and 40% over the neat epoxy at 0.1 wt.% EG loading while the electrical resistivity was reduced from 1014 to 109 ohm.cm at this concentration. The LOI value of the neat epoxy was increased to 26% by 5 wt.% TiO2 addition. The E/0.05EG/0.5T hybrid composite provided higher enhancement in tensile and impact properties compared to its binary composites.

Suggestions

Nano patterning of AISI 316L stainless steel with Nonlinear Laser Lithography: Sliding under dry and oil-lubricated conditions
Gnilitskyi, Iaroslav; Rotundo, Fabio; Martini, Carla; Pavlov, Ihor; Ilday, Serim; Vovk, Evgeny; Ilday, Fatih Omer; Orazi, Leonardo (2016-07-01)
Femtosecond laser-based Nonlinear Laser Lithography (NLL) was applied to AISI 316L stainless steel, which requires surface modification to achieve satisfactory tribological behaviour. NLL advances over the well-known Laser Induced Periodic Surface Structures (LIPSS) in terms of uniformity and long-range order of high speeds, over large areas. A galvanometric scanner head was used for an high production rate. Dry and lubricated sliding tests, considering different orientations of the nanotexture showed that ...
Indium tin oxide nanoparticles as anode for light-emitting diodes
Çırpan, Ali (Wiley, 2006-02-15)
Thin films of indium tin oxide (ITO) nanoparticles have been investigated as anode materials for polymer light-emitting diodes. A luminance efficiency (0.13 cd/ A), higher than that (0.09 cd/A) obtained in a control devices fabricated on conventional commercial ITO anodes were found. The thin films were made by spin coating of a suspension followed by annealing. The ITO nartoparticle films have a stable sheet resistance of 200 ohm/sq, and an optical transmittance greater than 86% over the range of 400-1000 ...
Nanomaterial-Enhanced All-Solid Flexible Zinc-Carbon Batteries
Hiralal, Pritesh; Imaizumi, Shinji; Ünalan, Hüsnü Emrah; Matsumoto, Hidetoshi; Minagawa, Mie; Rouvala, Markku; Tanioka, Akihiko; Amaratunga, Gehan A. J. (2010-05-01)
Solid-state and flexible zinc carbon (or Leclanche) batteries are fabricated using a combination of functional nanostructured materials for optimum performance. Flexible carbon nanofiber mats obtained by electrospinning are used as a current collector and cathode support for the batteries. The cathode layer consists of manganese oxide particles combined with single-walled carbon nanotubes for improved conductivity. A polyethylene oxide layer containing titanium oxide nanoparticles forms the electrolyte laye...
Epoxidation of Ethylene by Silver Oxide (Ag2O) Cluster: A Density Functional Theory Study
Fellah, Mehmet Ferdi; van Santen, Rutger A.; Önal, Işık (2011-06-01)
Density functional theory (DFT) calculations were employed to study epoxidation of ethylene on a [Ag14O9] cluster model representing silver oxide (001) surface. Theoretical results obtained in this study showed that formation paths of acetaldehyde and vinyl alcohol have higher activation barriers than that of ethylene oxide formation path on silver oxide (35 and 35 vs. 20 kcal/mol). Formation of the ethylene oxometallocycle intermediate is found to have a low probability on Ag2O(001) surface. The essential ...
Surfactant-modified multiscale composites for improved tensile fatigue and impact damage sensing
Yesil, Sertan; Winkelrnann, Charles; Bayram, Göknur; La Saponara, Valeria (Elsevier BV, 2010-10-25)
This paper documents the mechanical and electrical performance of self-sensing conductive polymer composites prepared with a low-cost technique and small hardware, able to considerably improve the dispersion and the surface adhesion of multi-walled carbon nanotubes (CNTs) in epoxy resin with respect to amine-modified CNTs and as-received CNTs. Surface treatment of the CNTs is performed using hexamethylene diamine, or a mix of sulfuric and nitric acid, and one of two surfactants (for the diamine treatment on...
Citation Formats
A. Çaldıklıoğlu, “Epoxy-based composites and coatings: improvement of multifunctional properties,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Chemical Engineering., Middle East Technical University, 2019.