Epoxy/Glass Fiber Nanostructured p- and n-Type Thermoelectric Enabled Model Composite Interphases

Abstract

This experimental study is associated with the modification of glass fibers with efficient, organic, functional, thermoelectrically enabled coatings. The thermoelectric (TE) behavior of the coated glass fiber tows with either inherent p semiconductor type single wall carbon nanotubes (SWCNTs) or the n-type molecular doped SWCNTs were examined within epoxy resin matrix in detail. The corresponding morphological, thermogravimetric, spectroscopic, and thermoelectric measurements were assessed in order to characterize the produced functional interphases. For the p-type model composites, the Seebeck coefficient was +16.2 μV/K which corresponds to a power factor of 0.02 μW/m∙K2 and for the n-type −28.4 μV/K which corresponds to power factor of 0.12 μW/m∙K2. The p–n junction between the model composites allowed for the fabrication of a single pair thermoelectric element generator (TEG) demonstrator. Furthermore, the stress transfer at the interphase of the coated glass fibers was studied by tow pull-out tests. The reference glass fiber tows presented the highest interfacial shear stress (IFSS) of 42.8 MPa in comparison to the p- and n-type SWCNT coated GF model composites that exhibited reduced IFSS values by 10.1% and 28.1%, respectively.

An Approach toward the Realization of a Through-Thickness Glass Fiber/Epoxy Thermoelectric Generator

“…Scientific works related to bulk or structural TEGs targeting different application areas have also been published [ 26 , 27 , 28 ]. Special interest has been concentrated on polymer nanocomposites [ 29 , 30 , 31 ], and fiber-reinforced polymer (FRP) composites [ 32 , 33 ] since such materials are widely used in aerospace, automotive, renewable energy, etc. applications.…”

Healing Efficiency of CNTs-Modified-UF Microcapsules That Provide Higher Electrical Conductivity and EMI Shielding Properties

“…The 0.5% nanomodified capsules were chosen as they exhibited a combination of satisfactory healing efficiency and increased initial mechanical properties, together with electrical percolation. The capsule and catalyst percentages were chosen as they have been reported to impart the optimal properties to the self-healing matrix [ 4 ]. Finally, UD (unidirectional) glass fiber reinforced laminates were manufactured by hand lay-up.…”

“…Multifunctional composites represent a state-of-the-art technology, since they are capable of simultaneously performing two or more functions [ 1 ]. Among their functionalities, such as energy harvesting [ 2 , 3 , 4 ] and structural health monitoring (SHM) [ 5 , 6 , 7 , 8 ], self-healing is being vigorously studied [ 9 , 10 ]. Self-healing can be intrinsic [ 11 , 12 , 13 , 14 ] or extrinsic, with the incorporation of vascules [ 15 ] or capsules [ 16 ] inside the material.…”

Decoration of SiO2 and Fe3O4 Nanoparticles onto the Surface of MWCNT-Grafted Glass Fibers: A Simple Approach for the Creation of Binary Nanoparticle Hierarchical and Multifunctional Composite Interphases

“…Specifically, wet chemical techniques such as (i) electrophoretic deposition [ 22 ], and (ii) sizing mixtures containing CNTs [ 23 ] and (iii) conventional dip-coating [ 24 ], as well as (iv) chemical vapor deposition (CVD) [ 25 ] are the main methods that have been reported to grow CNTs as coatings onto micro-scale fiber reinforcements. Namely, glass [ 26 , 27 , 28 ], carbon [ 29 , 30 ], ceramic [ 31 ] and natural fibres [ 32 , 33 , 34 ] have been utilised as the reinforcement support materials for the CNT coating. Single fiber pull-out and single fiber fragmentation micromechanical tests have demonstrated a positive effect of the hierarchical reinforcements on the interfacial properties, i.e., a significant increase of the composite interfacial adhesion strength studied [ 29 , 35 , 36 ].…”

“…Furthermore, it is worth mentioning that some new multi-functional properties are endowed to the final bulk composites, specifically arising from the interfacial regions. To that end, different functionalities such as thermal energy harvesting [ 26 , 27 , 28 ], temperature sensing [ 38 ], UV-/cure-sensing [ 26 ] and strain sensing for possible structural health monitoring (SHM) purposes [ 39 ] have already been reported. In our previous study, highly electrically conductive glass fibers (GFs) grafted with multi-walled carbon nanotubes (MWCNTs) have been prepared by a fully controlled dip coating deposition process [ 8 ].…”