Effect of interface modification on PMMA/graphene nanocomposites

J of Applied Polymer Sci

Kenelak

Chand

et al. 2020

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Advanced functional composites have attracted a great attention for fabricating flexible devices. In this article, the GnP/epoxy composite film was prepared by mixing graphene platelets (GnPs) with epoxy through sonication process. The morphology, mechanical properties, and electrical conductivity of the prepared composites were investigated. As the GnP contents increased from 2.5 to 7.5 vol%, the composites showed an increase in strain sensitivity with the rapid decrease in the strain gauge to 4.4. Additionally, when dynamic movement of the flexible film was performed, at bending and twist angle of 135° and 180°, respectively, steady increase in both resistance changes were detected and compared. The electrical resistance of the flexible was measured over a temperature range of 20–95°C, an increase in temperature lead to a linearly equivalent increase in resistance. The composites can also detect slight pressure changes at 2 kPa compression force with rapid decrease of resistance. Additionally, fatigue test was performed with stable, sensitive, and no distinguishable reading under 2,000 stretching cycles. The composite film exhibits an excellent self‐sensing responds when fracture occurred. Thus, the obtained highly flexible, conductive, and mechanical robust composite sensor can be applied as advanced composites sensors for health monitoring.

Section: Introductionmentioning

confidence: 75%

A highly flexible, electrically conductive, and mechanically robust graphene/epoxy composite film for its self‐damage detection

J of Applied Polymer Sci

Kenelak

Chand

et al. 2020

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“…Alternatively, a cost‐effective derivative is derived; graphene platelets (GnPs). GnPs are few layer of graphene (3–5 layers) and proved its effectiveness in reinforcing elastomers and ploymer‐based composites Nonetheless, preventing GnPs from staking in the host polymer is a tentative process and demands preprocessing procedures to accomplish uniform dispersion such as chemical modification and/or longtime sonication …”

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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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.

“…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.