Mechanical and electrical properties of graphene and carbon nanotube reinforced epoxy adhesives: Experimental and numerical analysis

J of Applied Polymer Sci

Xiao³

et al. 2019

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In this study, synergy between graphene platelets (GnPs) and carbon nanotubes (CNTs) in improving lap shear strength and electrical conductivity of epoxy composite adhesives is demonstrated. Adding two-dimensional GnPs with one-dimensional CNTs into epoxy matrix helped to form global three-dimensional network of both GnPs and CNTs, which provide large contact surface area between the fillers and the matrix. This has been evidenced by comparing the mechanical properties and electrical conductivity of epoxy/GnP, epoxy/CNT, and epoxy/GnP-CNT composites. Scanning electron microscopic images of lap shear fracture surfaces of the composite adhesives showed that GnP-CNT hybrid nanofillers demonstrated better interaction to the epoxy matrix than individual GnP and CNT. The lap shear strength of epoxy/GnP-CNT composite adhesive was 89% higher than that of the neat epoxy adhesive, compared with only 44 and 30% increase in the case of epoxy/GnP and epoxy/CNT composite adhesives, respectively. Electrical percolation threshold of epoxy/GnP-CNT composite adhesive is recorded at 0.41 vol %, which is lower than epoxy/GnP composite adhesive (0.58 vol %) and epoxy/CNT composite adhesive (0.53 vol %), respectively.

Section: Introductionmentioning

confidence: 99%

Synergistic effect of graphene and carbon nanotube on lap shear strength and electrical conductivity of epoxy adhesives

Han

J of Applied Polymer Sci

Xiao³

et al. 2019

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“…Adding fillers into the epoxy matrix is an effective method to improve its mechanical performance as well as functional properties. The most commonly used nanofillers are metal, silica [5], rubber [6], and carbon-based material [4,7,8]. Metal nanoparticles have been widely used to reinforce epoxy adhesive due to their excellent electrical conductivity and stability [9].…”

Section: Introductionmentioning

confidence: 99%

Mechanically robust, electrically and thermally conductive graphene-based epoxy adhesives

Journal of Adhesion Science and Technology

Han

Araby

et al. 2019

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This study develops a facile approach to fabricate adhesives consists of epoxy and cost-effective graphene platelets (GnPs). Morphology, mechanical properties, electrical and thermal conductivity, and adhesive toughness of epoxy/GnP nanocomposite were investigated. Significant improvements in mechanical properties of epoxy/GnP nanocomposites were achieved at low GnP loading of merely 0.5 vol%; for example, Young's modulus, fracture toughness (K 1C) and energy release rate (G 1C) increased by 71%, 133% and 190%, respectively compared to neat epoxy. Percolation threshold of electrical conductivity is recorded at 0.58 vol% and thermal conductivity of 2.13 W m À1 K À1 at 6 vol% showing 4 folds enhancements. The lap shear strength of epoxy/ GnP nanocomposite adhesive improved from 10.7 MPa for neat epoxy to 13.57 MPa at 0.375 vol% GnPs. The concluded results are superior to other composites or adhesives at similar fractions of fillers such as single-walled carbon nanotubes, multi-walled carbon nanotubes or graphene oxide. The study promises that GnPs are ideal candidate to achieve multifunctional epoxy adhesives.

“…These properties may cause negative effect on the performance of strain sensors . Graphene platelets (GnPs) have been reported for fabrication of flexible sensors recently which have advantages, including large surface area for electron transfer, high electrical conductivity and cost effectiveness . Therefore, high electrically conductive and structurally integrate GnPs instead of commonly used graphene oxide (GO) and RGO were selected for fabricating highly sensitive flexible sensor, which has great potential to detect strain and pressure.…”

Section: Introductionmentioning

confidence: 99%

Non‐oxidized graphene/elastomer composite films for wearable strain and pressure sensors with ultra‐high flexibility and sensitivity

Polymers for Advanced Techs

Liu

Cai

et al. 2019

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It remains challenging to prepare wearable strain and pressure sensors with excellent mechanical properties, ultra‐high flexibility and sensitivity. Electrically conductive graphene platelets (GnPs) with high structural integrity are used in making a composite film fabricated using robust fabrication techniques. The gauge factor for the strain is up to 100 at 0%‐5% strain and 50 at 5%‐30% strain, and the sensitivity to pressure is 2.7×10‐2 kPa‐1 between 0 and 10 kPa and 1.5×10‐4 kPa‐1 between 300 and 1000 kPa. In addition, the flexible sensor demonstrates good repeatability and durability after 1000 cycles of tensile and compression tests. The flexible sensor has fast response ability and a wide operating temperature range, suggesting the excellent response to temperature. The flexible sensor is applied in monitoring several human motions as a wearable device with high accuracy. The ability to detect strain, pressure and temperature of the flexible sensor extends its applications to multifunctional wearable devices.