Showing papers by "Kin-tak Lau published in 2020"
TL;DR: In this article, a hierarchical ternary carbon aerogel structure is designed by integrating graphene (Gr), carbon nanofibers (CNFs), and carbon nanotubes (CNTs).
138 citations
TL;DR: Development of clear standards for the assessment of graphene material properties, improvement of existing materials and scalable manufacturing technologies, and specific regulations concerning human health and environmental safety are key factors to accelerate the successful commercialized gFRPs.
Abstract: Graphene has become an important research focus in many current fields of science including composite manufacturing. Developmental work in the field of graphene-enhanced composites has revealed several functional and structural characteristics that promise great benefits for their use in a broad range of applications. There has been much interest in the production of multiscale high-performance, lightweight, yet robust, multifunctional graphene-enhanced fiber-reinforced polymer (gFRP) composites. Although there are many reports that document performance enhancement in materials through the inclusion of graphene nanomaterials into a matrix, or its integration onto the reinforcing fiber component, only a few graphene-based products have actually made the transition to the marketplace. The primary focus of this work concerns the structural gFRPs and discussion on the corresponding manufacturing methodologies for the effective incorporation of graphene into these systems. Another important aspect of this work is to present recent results and highlight the excellent functional and structural properties of the resulting gFRP materials with a view to their future applications. Development of clear standards for the assessment of graphene material properties, improvement of existing materials and scalable manufacturing technologies, and specific regulations concerning human health and environmental safety are key factors to accelerate the successful commercialization of gFRPs.
61 citations
TL;DR: Epoxy resins are widely used in various applications including electronic materials, automobiles, adhesives and coatings, and fiber-reinforced composites because of their unique properties.
Abstract: Epoxy resins are widely used in various applications including electronic materials, automobiles, adhesives and coatings, and fiber-reinforced composites because of their unique properties. Additiv...
35 citations
TL;DR: In this paper, the feasibility of using carbon fiber reinforced polymer (CFRP) laminates for the dual functions on aircraft as high loadbearing structural materials as well as for the harvesting and storage of static electricity during flight which can be used to power navigation lights and other electrical systems.
Abstract: In this paper, we demonstrate the feasibility of using carbon fibre reinforced polymer (CFRP) laminates for the dual functions on aircraft as high load-bearing structural materials as well as for the harvesting and storage of static electricity during flight which can be used to power navigation lights and other electrical systems. CFRP laminate was fabricated into a structural dielectric capacitor (SDC) composite by sandwiching graphene oxide (GO) film between two electrically-conductive carbon fabric layers. To meet the high requirements of aviation applications, the mechanical properties of the GO-based SDC composite were increased using a polymer cross-linking agent in the GO film. This work opens a new concept and possibility of converting the safety threatening static charges into useful electrical energy, which not only reduces the safety hazard, but also improves the energy efficiency of aircraft without compromising the mechanical performance.
23 citations
TL;DR: In this paper, the effects of chemical treatments on hemp fibres and the resulted polyester matrix composite were analyzed through impact testing of the composite samples, and the results showed that composites failed under lower impact resistance compared to the NaOH treated samples.
Abstract: Plant based hemp fibre properties were found to be highly influenced by changes in the amounts of cellulose, hemicellulose and lignin constituents within the fibre. These fibre constituents play a major role for effective interfacial adhesion between the fibre and the matrix. Chemical treatments such as alkali (NaOH), acetyl (acetic acid & acetic anhydride) and silane (siloxane) treatments have the potential to react with constituent contents by varying their amounts. In this study, hemp fibre was treated with alkali (0–10 % NaOH), acetyl and silane chemicals. Treated fibres were mixed with polyester matrix to produce composites. The effects of chemical treatments on hemp fibres and the resulted polyester matrix composite were analysed through impact testing of the composite samples. Alkali treatments on hemp fibres enhanced the impact resistance properties (around 43 % lower absorbed energy and 40 % higher rebounded energy) of its composites compared to the untreated cases. Lower absorption energy and higher rebounded energy indicates strong interfacial bonding between the fibre and matrix. Improvements are governed by the removal of hemicellulose and lignin from the fibre, which provides a platform for better chemical reactions between fibres and matrix. On the other hand, acetyl treatments on the higher concentrations of NaOH pre-treated fibres reduced the fibres’ ability to support impact loadings (22 % higher rebounded energy compared to the untreated cases). In the two treatment conditions, fibre lessen their strength due to excessive removal of hemicellulose and lignin constituents, and composites exhibited lower impact properties compared to the NaOH treated samples. Similar impact properties were also recorded for alkali pre-treated silanised composites. As alkali pre-treatment removed the hydroxyl groups from the fibre, further silane treatment could not develop silanols to create strong interface bonding. As a result, composites failed under lower impact resistance compared to the NaOH treated samples.
9 citations
TL;DR: Graphene and its associated compounds have been identified as extraordinary structural nano-fillers that can tailor the properties of new polymer-based composites with specific functionalities.
Abstract: Graphene and its associated compounds have been identified as extraordinary structural nano-fillers that can tailor the properties of new polymer-based composites with specific functionalities. Gra...
6 citations