Due to the unique behaviors of nanomaterials, the design has a significant impact on a candidate material’s ability to scale-up and integrate with your product.
Simply put, nanomaterials are not a ‘one-size-fits-all’ solution for the many industries and companies looking to incorporate them into their products. When properly leveraged, the unique behaviors of these materials can substantially improve existing products, or be the basis to introduce new, highly differentiated products to the marketplace. The remarkable behaviors demonstrated by nanomaterials are a result of their much smaller scale and is what separates them from their larger, bulk counterparts — and that just scratches the surface as to why design matters …
Big Impact with Small Changes
Nanomaterials are generally defined as any material that is 1–100 nanometers (nm) in at least one of its dimensions. At these small sizes, the material’s surface area increases exponentially in comparison to bulk materials and its surface layer becomes a significant fraction of its overall volume. Depending on the type of nanomaterial, this can express new thermal, mechanical, optical, electrical and magnetic properties that could never been achieved using sub-micron or micron scale materials. Additionally, further tuning of the nanoparticle’s design can express, inhibit or modify these properties in interesting ways.
A nanoparticle’s design comprises several variables, including:
- Particle size
- Particle size distribution
- Morphology – its form, shape and structure
- Surface charge
- Surface functionalization
By way of illustration, look at how particle size affects the properties of one of the most abundant metals in the periodic table — aluminum. We interact daily with aluminum at bulk scale, and it is generally inert. However, when brought to nanoscale, it becomes highly reactive and pyrophoric, leading researchers to explore its use as a next generation solid-state propellant for rocket engines. Modifications of the design of aluminum nanoparticles broaden its uses into transport, healthcare and energy applications, amongst others.
What if we were to alter the composition of an aluminum nanoparticle? When tin is alloyed into the microstructure of an aluminum particle, the material can be made to off-gas significant quantities of hydrogen in the presence of water. Paired with a fuel cell, this allows for on-demand electricity generation, where 1 kg of nanomaterial has the same energy density as 13 kg of disposable batteries.
Now consider surface stability. When the surface of aluminum is properly stabilized, it can be used as a cost-effective means to increase thermal conductivity in heat transfer fluids for products such as refrigerators, air conditioners and heat pumps.
Aluminum is just one example of the many materials that can be made to express a wide variety of commercially useful behaviors. The key to unlocking these behaviors is precise control over the nanomaterial’s design. When strategically developed nanomaterials can be fine-tuned to tackle many diverse challenges, easily integrated into products and systems, and assure fitness of use, even when manufactured at volume.
As a leader in designing, scaling and manufacturing metal, metal oxide and ceramic nanomaterials, Cerion frequently sees companies begin to work with a material, only to conclude that it has limited utility in their product. More often than not, this is because they were attempting to incorporate an off-the-shelf material into their product or system — one where the nanomaterial attributes have not been precisely engineered and tailored. An often-overlooked aspect of nanomaterials is that small changes to their design can have a measurable — even immense — impact on their performance. Further, design can impact their compatibility upstream with the product it is intended to be incorporated into.
Here’s an illustration of that: A customer asked Cerion to create a 2.5 nm particle to validate their theory that a particular rare earth element at nanoscale would catalyze a proprietary chemical reaction. For this application, high oxygen storage capacity and rate of oxygen release were critical performance attributes. The client’s theory was largely proven to be true. Particle reduction to the nanoscale alone being a significant contributor to its performance.
While a strong validation of the theory, the resulting performance was insufficient for the intended application. With a small amount of exploration, Cerion’s scientific team was able to establish that creating an alloy of the rare earth element with a small amount of a low-cost metal yielded a significant — and highly desirable — transformation in behavior. Oxygen storage capacity increased by an impressive 1,100% over baseline, while the rate of oxygen release improved by 55%. For the comparison between the alloy and the 2.5 nm rare earth alone, see Table 1.
Table 1: measured performance for oxygen storage and oxygen release of rare earth nanoparticles of varying sizes and compositions.
In another example, this time for a life sciences application, a nanomaterial was explored as a remediator of free radicals — significant contributors to diseases such as multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). Developed as an injectable compound, particle size played a critical role in the therapeutic efficacy of the material. With a mean particle size of 2.4 nm, the material was able to pass through the blood-brain barrier and into the brain, where it could deliver its therapeutic effect, an achievement of which fewer than 2% of neurological drugs are capable. Stabilization of the nanomaterial was just as important as particle size to ensure biocompatibility in vivo without inhibiting its mechanism of action. After testing a small number of options, a suitable ratio of two stabilizers was identified (Figure 1).
Figure 1: Fine tuning of the biocompatible stabilizer ratio (A:B) to achieve tolerability & efficacy in vivo
Animal testing showed that by simply varying the ratio of each stabilizer, the results ranged from very negative to very positive. These small changes resulted in findings as variable as premature death, to high tolerability with marginally improved clinical scores, and finally clinically significant performance with high tolerability.
The use of nanomaterials to create improved or disruptive products holds a great deal of potential. Today, many companies in industry and life sciences are using nanomaterials for commercial applications that improve the products that we use every day. For example, help in the delivery of medicines and diagnosis of disease to improve human health, and even in applications like building materials and coatings to help the environment for our future cities. Companies aiming to differentiate their products by using nanotechnology will be best served in considering customization as the way to achieve the unique behaviors necessary to enable optimal product performance and to ensure success in the crucial integration processes required for commercialization and transition to the marketplace.