Mechanical strength

US-based Avadain has developed a novel graphene type, which it brands as Large, Thin, Defect-Free (LTDF) graphene, which is meant to position graphene around high value applications, including three strategic use cases: reducing dependence on foreign-sourced critical minerals, strengthening rare-earth-free iron nitride (Fe₂₁₆N₂) permanent magnets, and improving heat dissipation in high-power electronics.

LTDF graphene, SEM image

Why LTDF graphene's physics are different

Avadain says that graphene's performance ceiling is set by three parameters acting together: flake size, layer count and defect density. Most commercial graphene falls short on at least one of these, which is why products marketed as "graphene" often behave more like graphite or amorphous carbon in practice.

Large Surface Area: Every flake boundary acts as a scattering point for electrons, phonons and mechanical load, so larger, continuous flakes translate into fewer interruptions and performance closer to graphene's intrinsic limits. Graphene nanoparticles sit at the opposite end of that spectrum: Avadain says its LTDF flakes run in the 25-100+ µm² range, roughly five orders of magnitude larger than the sub-micron nanoparticles sold by many graphene producers, which tend to clump and form discontinuous conductive pathways.

Researchers at Soochow University, University of Science and Technology of China, Peking University, ShanghaiTech University, Beijing Graphene Institute and additional collaborators have developed a copper-based growth process that produces large-area trilayer graphene films with uniform thickness and improved mechanical strength.

Schematic representation illustrating the synchronous growth process catalyzed by the heterogeneous Cu–Cu2O substrate. Inset: schematic of the graphene edge–Cu–Cu2O three-phase interfaces. Image from: Nature Communications

The team stated that much of graphene's functional promise - especially in electronics and optoelectronics - relies not on the single-layer form that dominates laboratory work, but on precise multilayer structures. Adding layers enables electronic band structures to be tuned and improves properties such as stiffness and thermal transport. Despite this, the controlled synthesis of multilayer graphene films with consistent thickness across large areas has remained quite elusive.

Researchers from the University of Vienna and Technical University of Vienna have used a unique technique to significantly enhance the stretchability of graphene for the first time by creating an accordion-like ripple effect. This achievement could open up new possibilities for applications that require specific levels of stretchability, such as wearable electronics. 

Graphene is notable for its high electrical conductivity but tends to be extremely stiff, as its atoms are arranged in a honeycomb pattern that contributes to this stiffness. It makes sense that removing some atoms from the material along with their bonds would result in reduced stiffness. Scientific research, however, has documented both a modest decline and a notable rise. Scientists have now resolved these contradictions with new measurements. Modern devices were used in the experiments and housed in the same ultra-clean, airless environment. As a result, samples can be moved between the various devices without contacting outside air.

GrapheneUP®, an industry vanguard in manufacturing verified few-layer graphene and a diverse array of graphene-centric intermediary products, announces the debut of MASTERGUP® — an innovative line of thermoplastic masterbatches. This breakthrough harnesses the transformative potential of graphene, setting a new benchmark for sustainability and recyclability within multiple sectors.

Graphene, distinguished by its exceptional strength and conductivity, imparts enhanced thermoplastic properties, including mechanical robustness, thermal stability, and gas barrier properties. These advancements extend the lifespan of products and significantly reduce waste, thereby contributing to more excellent environmental stewardship. Moreover, incorporating the graphene GUP® into thermoplastic matrices elevates processability, streamlining the molding, reshaping, and recycling processes. GUP®-fortified thermoplastics demonstrate remarkable endurance through repeated recycling, mitigating material degradation — a commendable achievement in material sustainability.

Researchers at Australia's RMIT University and University of Melbourne have investigated the effectiveness of graphene oxide (GO) sheets in enhancing the compressive strength of 3D-printed cementitious mortar. 

They added graphene oxide to the cement used as a binder in 3D-printed concrete. After experimenting with different amounts, it was found that when graphene oxide was added at a dosage of 0.015% the weight of the cement, the resulting concrete exhibited better inter-layer bonding. This boost produced a 10% increase in overall strength.

Researchers at the Korea Advanced Institute of Science and Technology (KAIST) and Pusan National University in South Korea recently developed a graphene-enhanced  actuator for robotics applications, that is inspired by mammalian skeletal and muscle structures. The new actuator is based on soft fibers with strong contractive actuation properties.

The team explained that they based their work on liquid crystal elastomer (LCE) actuators, promising soft actuator materials with unusually large reversible dimensional change (shrink/relaxation) upon actuation, which is rarely observed in other kinds of actuator materials but highly significant to ideally mimic natural skeletal muscle behavior. Many actuators developed in the past are based on LCE materials, a class of polymers that can rapidly change shape in response to environmental stimuli. Despite their shape-morphing advantages, LCE polymers are known to be associated with the relatively poor mechanical properties and weak actuation behavior. To overcome this limitation, the researchers incorporated graphene fillers within the LCE actuators. In addition to enhancing their mechanical properties, the team expected the graphene fillers to enable light-driven, rapid and remotely controllable actuation, owing to the photothermal conversion capability of graphene.

Researchers from China's Xiamen University and Hangzhou Dianzi University, working with Wageningen University & Research in the Netherlands, have developed graphene-based woven filter membrane with excellent strength and efficiency for water desalination. 

Their development resulted in an efficient water filtering method using these graphene-based woven filter membrane (GWFM), leading to an improvement of water permeation and mechanical properties by the optimization of GWFM membrane and providing a new way to utilize nano-woven membranes for desalination.

Building on the Memorandum of Understanding (MOU) signed with Viritech in September 2021, Haydale, has announced the next phase with the cleantech engineering company to develop nano-enhanced epoxy resins for hydrogen storage vessels.

The £97,750 Storage of Hydrogen and Nanomaterial Enhancement ('SHYNE') project will run for an initial period of seven months, starting in March.

A research team led by the University of Basel has found that the electronic properties of graphene can be specifically modified by stretching the material evenly.

The researchers, led by Professor Christian Schönenberger at the Swiss Nanoscience Institute and the Department of Physics at the University of Basel, have studied how the material’s electronic properties can be manipulated by mechanical stretching. In order to do this, they developed a kind of rack by which they stretch the atomically thin graphene layer in a controlled manner, while measuring its electronic properties.

Northwestern University researchers have added graphene nanoplatelets to cement, resulting in smarter, more durable and highly functional cement.

With cement being the most widely consumed material globally and the cement industry accounting for 8% of human-caused greenhouse gas emissions, civil and environmental engineering professor Ange-Therese Akono turned to nanoreinforced cement to look for a solution. Akono, the lead author on the study and an assistant professor in the McCormick School of Engineering, said nanomaterials reduce the carbon footprint of cement composites, but until now, little was known about its impact on fracture behavior.