Compressible Graphene Research Articles

Highly compressible anisotropic graphene aerogels fabricated by directional freezing for efficient absorption of organic liquids

Highly compressible three-dimensional graphene aerogels with anisotropic porous structure are fabricated by directional freezing of graphene hydrogel using anisotropically grown ice crystals as templates followed by freeze–drying. The directional freezing approach endows the graphene aerogel with a high compressive strength in the axial direction and good compressibility in both axial and radial directions. The anisotropic graphene aerogel also exhibits ultralow density, excellent flexibility in liquids, satisfactory fire-resistance, and strain-sensitive electrical conductivity. After absorbing organic liquids, the aerogel can be well recycled by burning, distilling, or squeezing, which makes it promising for oil absorption with a good recyclability.

Toward highly compressible graphene aerogels of enhanced mechanical performance with polymer

The highly compressive durable graphene aerogels with enhanced strength was prepared by combining the freeze-casting process with the binding effect of polymer.

Broadband and tunable high-performance microwave absorption of an ultralight and highly compressible graphene foam.

The broadband and tunable high-performance microwave absorption properties of an ultralight and highly compressible graphene foam (GF) are investigated. Simply via physical compression, the microwave absorption performance can be tuned. The qualified bandwidth coverage of 93.8% (60.5 GHz/64.5 GHz) is achieved for the GF under 90% compressive strain (1.0 mm thickness). This mainly because of the 3D conductive network.

Energy Storage: Reversibly Compressible, Highly Elastic, and Durable Graphene Aerogels for Energy Storage Devices under Limiting Conditions (Adv. Funct. Mater. 7/2015)

Energy Storage: Reversibly Compressible, Highly Elastic, and Durable Graphene Aerogels for Energy Storage Devices under Limiting Conditions (Adv. Funct. Mater. 7/2015)

Compressible graphene aerogel supported CoO nanostructures as a binder-free electrode for high-performance lithium-ion batteries

Binder-free electrodes have been synthesized by coupling compressible graphene aerogels with CoO nanostructures, which exhibit superior electrochemical performance to conventional electrodes made of powders and binders in lithium-ion batteries.

Reversibly Compressible, Highly Elastic, and Durable Graphene Aerogels for Energy Storage Devices under Limiting Conditions

High porosity combined with mechanical durability in conductive materials is in high demand for special applications in energy storage under limiting conditions, and it is fundamentally important for establishing a relationship between the structure/chemistry of these materials and their properties. Herein, polymer‐assisted self‐assembly and cross‐linking are combined for reduced graphene oxide (rGO)‐based aerogels with reversible compressibility, high elasticity, and extreme durability. The strong interplay of cross‐linked rGO (x‐rGO) aerogels results in high porosity and low density due to the re‐stacking inhibition and steric hinderance of the polymer chains, yet it makes mechanical durability and structural bicontinuity possible even under compressive strains because of the coupling of directional x‐rGO networks with polymer viscoelasticity. The x‐rGO aerogels retain >140% and >1400% increases in the gravimetric and volumetric capacitances, respectively, at 90% compressive strain, showing reversible change and stability of the volumetric capacitance under both static and dynamic compressions; this makes them applicable to energy storage devices whose volume and mass must be limited.

Polymer/Graphene Hybrid Aerogel with High Compressibility, Conductivity, and “Sticky” Superhydrophobicity

The idea of extending functions of graphene aerogels and achieving specific applications has aroused wide attention recently. A solution to this challenge is the formation of a hybrid structure where the graphene aerogels are decorated with other functional nanostructures. An infiltration-evaporation-curing strategy has been proposed by the formation of hybrid structure containing poly(dimethylsiloxane) (PDMS) and compressible graphene aerogel (CGA), where the cellular walls of the CGA are coated uniformly with an integrated polymer layer. The resulting composite shows enhanced compressive strength and a stable Young's modulus that are superior to those of pure CGAs. This unique structure combines the advantages of both components, giving rise to an excellent electromechanical performance, where the bulk resistance repeatedly shows a synchronous and linear response to variation of the volume during compression at a wide range of compressed rates. Furthermore, the foamlike structure delivers a water droplet with "sticky" superhydrophobicity and a size as large as 32 μL that remains tightly pinned to the composite, even when it is turned upside-down. This is the first demonstration of superhydrophobicity with strong adhesion on a foamlike structure. These outstanding properties qualify the PDMS/CGA composites developed here as promising candidates for a wide range of applications such as in sensors, actuators, and materials used for biochemical separation and tissue engineering.

Recyclable catalyst for catalytic hydrogenation of phenylacetylene by coupling Pd nanoparticles with highly compressible graphene aerogels

Highly compressible graphene aerogels were made by chemical reduction of graphene oxide with HI, which act as recyclable catalyst to exhibit excellent catalytic performance towards selective semi-hydrogenation reaction after loading Pd nanoparticles.

Ultra-light, compressible and fire-resistant graphene aerogel as a highly efficient and recyclable absorbent for organic liquids

Compressive graphene aerogels were obtained by the one-step reduction and self-assembly of graphene oxide with ethylenediamine and then freeze-drying. The aerogels hold good compressibility, variable electrical resistance and fire-resistance. The high porosity with a hydrophobic nature, allows the aerogels to absorb different organic liquids, and the absorption–squeezing process has been demonstrated for oil collection.

Ultralight and Highly Compressible Graphene Aerogels

Chemically converted graphene aerogels with ultralight density and high compressibility are prepared by diamine-mediated functionalization and assembly, followed by microwave irradiation. The resulting graphene aerogels with density as low as 3 mg cm(-3) show excellent resilience and can completely recover after more than 90% compression. The ultralight graphene aerogels possessing high elasticity are promising as compliant and energy-absorbing materials.