Benefits of Graphene Dispersion Technology

April 7, 2021

By:

Kris Eisemon – Global Industry Manager, Thermoset Plastics

Paul Rettinger – Director Technology Thermoset – Americas

Santosh Yadav – Product Development Scientist, Thermoset

Introduction

It has been said that true innovation requires thirty (30) years to go from inception to full commercial use. A familiar example is that of the computer mouse, introduced by Douglas Engelbart in 1964, adopted commercially in 1984 when the Macintosh operating system was launched by Apple, and finally gaining widespread use in the early 1990s. Graphene and graphene-enhanced materials appear to be tracking a similar course, with the composites industry leading the way.

History of Graphene

Discovered in 2004, graphene is already finding its way into a variety of applications.  There are demonstrated benefits of incorporating graphene in composites, while other benefits continue to be uncovered.  In composites, graphene has been used to enhance various properties, such as improved mechanical properties, greater strength-to-weight ratio, electrical conductivity and thermal conductivity.  The automotive, aerospace, and sporting goods market have capitalized on some of these benefits and introduced graphene-enhanced products in the market.  In automotive, graphene has been used to enhanced composites to improve mechanical properties, reduce noise, reduce weight, and improve thermal tolerance in vehicles already on the market.  In sporting goods, graphene has been used to improve toughness, reduce weight, and/or provide vibration dampening for equipment such as skis, bikes, tennis rackets, kayaks, fishing rods, and a host of others.

The Market For Graphene

The market potential for graphene is substantial.  The Graphene Council estimates the graphene market size to more than double in the next six (6) years, reaching a value of $300 million by 2027.  The composites industry is among the earliest to commercialize graphene enhanced products and represents a large market for graphene today.  With all the benefits graphene technology can bring to composites, it is probably the most significant growth opportunity near term.  We are seventeen years into the innovation cycle, moving from early commercial adoption to widespread use, so the next thirteen years promise to be exciting for our industry.

Manufacturing Challenges

With much promise comes many challenges to achieving benefits from graphene in a composite application. Worldwide, there are more than two thousand small companies producing material that is claimed to constitute graphene. Consequently, there can be quite a bit of difference between grades of graphene that are produced and sold in commercial industry.  One dilemma is that each company has its own process for manufacturing, and each process results in a somewhat different grade of material.  For example, a “top-down” approach starts with graphite and uses chemical and/or mechanical processes to exfoliate layers of graphite until particles containing (typically) between five (5) and twenty (20) atomic layers of carbon are achieved.  At the other extreme, a “bottom-up” approach involves carbon vapor deposition of pyrolyzed carbon onto a sheet (e.g., copper) from which particles containing one (1) to ten (10) atomic layers of carbon can be removed.  The significance of these different processes is that not all grades of graphene are created equal.  Some may be better for one application or property, while a different grade of graphene may provide a completely different set of properties.

One common issue is lot-to-lot variation of a given grade.  Many of the companies producing graphene are relatively new (in fact, many of them are start-ups), and consequently, not everyone’s processes and quality control methods are fully developed.   It can be frustrating to achieve one set of properties using one batch of graphene, and a different set of properties using the next.

A third problem in achieving benefits lies in the method of incorporation.  Many companies are not comfortable handling nano-sized airborne particulates in their processes.  There are handling and EHS concerns that need to be addressed.  In addition, the simple mixing of dry powder into a polymer matrix is not the best route to homogeneous distribution of the graphene throughout the matrix, which is key to achieving target mechanical and electrical and thermal properties.  Graphene can be extraordinarily difficult to properly disperse into a given polymer matrix.  For this reason, composite manufacturers often rely upon dispersion experts, and occasionally, the graphene manufacturers themselves, to identify the best route for functionalizing and incorporating graphene into their polymer matrixes.  It is important to understand that process and order of addition are extremely important:  From the start of the process of manufacturing graphene, to the point at which the final part is molded, a single misstep in the process is likely to result in a failure to achieve said benefits.

The benefits of graphene, once achieved, can be meaningful.  In our work, via dynamic mechanical analysis (DMA) we have seen as much as a 10% increase in storage modulus of a given material from as little as 0.01% (w/w) graphene incorporated into the polymer matrix. As compared to the use of conductive carbon black, a properly developed graphene dispersion can provide electrostatic dissipative conductivity in a composite application at the fraction of the loading and with little impact to viscosity.  But why use Chromaflo?

Our Expertise

Chromaflo is uniquely positioned to deliver the value of graphene to the composites industry through its expertise in dispersion technology.  Our customers expect to achieve the same properties and results in their materials without concern for lot-to-lot variation, and we deliver that. Our experience and expertise in nanoparticles enable us to help material compounders and molders achieve their desired objectives.  Our long history with dispersion technology enables us to ensure that graphene is properly and homogenously incorporated into polymer matrixes.  Where an off-the-shelf solution does not apply, we are able to diagnose failure modes, and develop a custom solution that will fit with your objectives.  Last but not least, the use of graphene dispersions eliminates hazards associated with airborne nanoparticulates, and allows ease of incorporation into a wide variety of processes.

Our continued commitment to innovation helps Chromaflo Technologies and its customers build composites Together.

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