Introduction
Graphene is widely regarded as a “wonder material” for the 21st century, with the potential to transform industries ranging from energy storage and construction materials to coatings, composites, and electronics. Yet, despite more than a decade of global research, not all application areas have reached commercialization. It is well known that graphene performance is dependent upon crystallinity and thickness of the graphene platelets. One critical factor that is often overlooked is the availability of optimal graphene platelet size for each application. The lateral dimensions and thickness of graphene platelets are not only technical details for scientists to consider, they are central to determining performance in practical applications. To achieve commercial success, it is essential to be able to manufacture a broad range of platelet sizes and to tailor those sizes to meet the requirements of specific markets.
Why platelet size matters
The performance of graphene materials is strongly dependent on platelet dimensions. Small platelets typically disperse more easily in polymer systems, paints, and inks, providing uniform distribution and enhanced processability. At the other end of the spectrum, large platelets overlap to form more effective barriers, producing films and coatings with superior impermeability to gases and liquids. Between these extremes, medium-sized platelets offer the best balance for stress transfer in composites, ensuring mechanical reinforcement without sacrificing dispersion. Larger platelets also form more effective percolation networks for electrons and phonons, which reduces junction resistances and allows for significantly higher levels of electrical and thermal conductivity.
The consequence is that no single platelet size can be regarded as universally optimal. Each size offers its own distinctive attributes and enhancements in target applications, meaning there is a place in the graphene landscape for a variety of products. However, this also means that companies restricted to narrow platelet size ranges are limited to a handful of applications. Their prospects for commercialization are ultimately constrained by the fact that most industries require specific performance outcomes that cannot be achieved by one platelet size alone.
Documented evidence of size-performance relationships
This principle is well documented in the scientific literature. For example, Jiang et al (2019) demonstrated that graphene oxides with higher aspect ratio exhibited the potential to better protect against corrosion. These large graphene oxide sheets with high aspect ratios provide a more tortuous path for corrosive chemicals compared to smaller counterparts. Li et al (2021) predicted that platelets with higher aspect ratio improve the thermal conductivity more than low aspect ratio platelets. Their results show 21 µm platelets improved thermal properties more than 7 or 13 µm platelets at the same loading level. Ravindran et al (2018) proved that the electrical conductivity of epoxy could be improved by increasing the lateral size of graphene platelets. Electrical conductivity increased consistently by changing platelet size from 5 to 25 µm. Each of these examples reinforces the point that platelet size is not incidental but rather decisive in determining whether a graphene product achieves its intended performance.
Manufacturing constraints and opportunities
There remain two general routes to manufacture of graphene platelets: top-down exfoliation of graphite raw materials or bottom-up synthesis from gaseous carbon feedstocks.
Top-down exfoliation has the advantage of starting with highly structured graphite layers and produces a distribution of platelet sizes and thicknesses. The graphene platelet product often has high levels of 1-layer and few-layer platelets and can have lateral sizes into 10’s of microns. Electrochemical exfoliation of graphite in particular has been shown to produce high-aspect ratio (large lateral size with low thickness), defect free graphene platelets that can be manufactured at tonnage scales.
Thin film chemical vapour deposition is typically used to deposit few layer graphene films that have high value in electronic devices and sensors. Thin film deposition has high per kg costs and is unsuitable for bulk manufacturing. Gas phase synthesis is used to manufacture bulk materials; the challenge here is often building the defect free graphitic layers. These can be enhanced by synthetic processes based upon catalysis; plasma or detonation technologies but it remains challenging to elevate the layer integrity up to that of graphite ores. Platelet sizes achieved through gas phase synthesis are typically smaller than those attained through top-down exfoliation.
Graphene customers demand high performing (high aspect ratio, low-defect) graphene products in a range of lateral sizes tailored to meet their application needs. They also quite rightly demand graphene products that meet their quality and supply robustness requirements. Electrochemical exfoliation is a manufacturing approach that can meet these requirements.
Strategic imperative: range enables reach
For the graphene industry to achieve its full potential, companies must provide a complete suite of platelet sizes rather than a single product. Commercial opportunities are too diverse for one size to fit all. Smaller platelets are necessary for dispersible additives in inks, paints, and polymer blends. Mid-sized platelets are essential for enhancing strength in structural composites and elastomers. Large platelets are indispensable for creating high-performance conductive networks and barrier layers. The need for such breadth of supply is so fundamental that it could ultimately drive consolidation across the industry, as companies unable to offer more than one platelet size range may be forced to merge or align with others that can. In other words, long-term success in the graphene industry depends not just on producing graphene, but on offering the right form of graphene for each application.
First Graphene’s positioning
First Graphene has already established itself as a leader in the production of high-performing, high-quality graphene. A key part of this leadership stems from the company’s ability to provide a broad range of platelet sizes to the market. This capability allows First Graphene to address the diverse requirements of industries from construction and energy storage to transport and coatings. Moreover, with continuous process innovation, particularly in electrochemical exfoliation, the company is actively expanding its ability to deliver tailored products for emerging applications.
This breadth of supply is not simply a competitive advantage; it is the foundation for industry leadership. By offering a diverse portfolio of platelet sizes, First Graphene ensures that customers across many industries can access graphene that is truly fit for purpose, accelerating the path from laboratory research to real-world adoption.
Conclusion
The promise of graphene lies in its ability to be engineered to deliver specific performance benefits. Control of platelet dimensions is the fundamental lever that will allow graphene to transition from a laboratory material to a commercial enabler. Every platelet size has a place in the wider graphene ecosystem, but companies with only a narrow range are limited to a small number of applications, making it difficult to scale and to achieve widespread commercialization. By contrast, those that can provide a full suite of platelet sizes will have the flexibility to serve multiple industries and capture the full commercial opportunity.
First Graphene, with its wide portfolio of high-quality graphene products with controlled platelet sizes and an ongoing investment in scalable and tunable production methods, is uniquely positioned to lead in this space. As the global graphene industry matures, the ability to tailor platelet size will become the cornerstone of success, and it is here that First Graphene has already built a clear and sustainable advantage.
References
Li, C. et al, “A dual-role theory of the aspect ratio of the nanofillers for the thermal conductivity of graphene-polymer nanocomposites”, International Journal of Engineering Science 2021.
Jiang, F. et al, “Anti-corrosion behaviours of epoxy composite coatings enhanced via graphene oxide with different aspect ratios”, Progress in Organic Coatings, 2019.
Ravindran, A. et al “Effects of Graphene Nanoplatelet Size and Surface Area on the AC Electrical Conductivity and Dielectric Constant of Epoxy Nanocomposites”, Polymers, 2018