What is the biggest challenge associated with incorporating nanoparticles into products?
The biggest challenge is achieving compatibility between the nanoparticle and the product or system – this is critical for obtaining optimal performance. Compatibility is the key to preserving material integrity when exposed to downstream processing conditions, maintaining stability in final product formulations, and avoiding the need for reformulation to accommodate the nanoparticle.
The process of co-optimizing a system with a nanoparticle is often an iterative process that requires input from the nanomaterial provider and product integrator to scope out possible options for the system. This is widely known as the most straightforward path to success because the nanoparticle design attributes that are essential for compatibility can be identified early on, thereby ensuring proper integration without adversely affecting other beneficial properties in the system.
Alternatively, product integrators can explore working with catalog or off-the-shelf nanomaterials – the challenge here is that there are limited material choices and the choices that do exist may have attributes (such as non-optimal solvents, dispersants, etc.) that interfere with the chemistry in their system.
Why do catalog or unoptimized nanomaterials often not work for product developers?
From a chemistry perspective, this is very similar to the previous question regarding compatibility. Catalog nanomaterials will most often not be compatible with the chemistries present in a specific product or system – think pH, solvent choice, additives, size requirements, and so on.
For example, if a product developer or researcher needs a haze-free stable suspension, an off-the-shelf powder is unlikely to work because there are considerable difficulties in perfectly redispersing a material that has been dried to a powder. The slightest amount of larger hard aggregates can cause considerable haze in a colloidal solution.
That said, catalog nanomaterials oftentimes will play an important role in the very early stages of product development when testing hypotheses and establishing basic proof of concept.
Another consideration is the question of scalability and cost-effectiveness of off-the-shelf materials. If the goal is to use this nanomaterial in a commercialized product, there needs to be confidence in the catalog provider’s ability to supply the volume required in the long term and at a price that aligns with budget goals – this is not always a guarantee.
Cerion is transparent from the beginning when evaluating a prospective customers’ requirements and we give our honest feedback about feasibility, end cost, scalability, and material availability so the best and most informed decision about the development of your product can be made.
What methods ensure nanomaterials can easily integrate into products or systems, while also being compatible with downstream processing conditions?
The first step is to always start with understanding what your requirements are. You should be able to answer technical and commercialization questions like – What are my performance goals? What is my budget and target volume? What are my processing conditions?
The next steps can be carried out in-house if you have established the proper infrastructure and expertise for nanomaterial design, characterization, scale-up, and manufacturing internally. If not, a reputable nanomaterial service provider can take your nanomaterial to the next stage in development. The provider should listen to what your requirements are and what issues you have been experiencing so that a compatible nanomaterial formulation can be designed. The more that is understood about your specific system, the more likely a successful and compatible nanoparticle can be created. Another important consideration is to complete an NDA early on so that all parties are assured that the technology remains confidential throughout the entire process.
Regarding how Cerion successfully provides nanomaterials that integrate into customers’ products, we use an iterative and phased approach. We listen to the customer and the information they can share on their product and processing conditions and develop a Phase 1 material for them to try. They then provide feedback including aspects that could offer improvement and we refine our material accordingly. Typical refinements we have been asked to make include modifying particle size and/or dispersity, particle concentration, capping agent selection, and solvent system. Additionally, if a customer is willing to share system information, compatibility can also be tested at Cerion to accelerate the design process.
How can nanoparticles remain monodisperse and stable in a dispersion? And why is this important for product integration?
Every system is different – when working with nanomaterials, in most cases a custom approach is the fastest and, many times, most affordable route. The main focus should be on avoiding incompatible chemistries and matching the solvent system – whether it’s aqueous, organic, polymeric, or a proprietary solvent. Sometimes it’s a fairly straightforward path to achieve the optimal properties directly in the desired solvent and avoid using dispersants. Other times this is not possible. In these cases, other techniques will need to be used, like solvent shifting, or testing dispersants and other stabilizers.
For products like optical coatings requiring well-dispersed nanoparticles, Cerion designs nanoparticles often including capping agents to prevent agglomeration. Capping agents and solvent choices are discussed with customers (or suggested by customers) to ensure compatibility with other system components. For some systems, capping agents may be designed to be removable downstream (chemically or thermally for example) for customers who want particle dispersity, but the presence of capping agents causes issues.
Why is the surface chemistry of nanoparticles important for successful integration in a product, and how can it be controlled?
The surface chemistry of nanoparticles is critical for ensuring there is compatibility with the desired solvent system. Cerion has used a variety of capping agents to control surface charge or functional groups. Examples of capping agents we’ve worked with before include silanes or thiols that can generally strongly bond to oxide or metallic particles and are often available with a variety of chemical functionalities – but this is all highly dependent on the nanoparticle we are working with and the product or system it will be incorporated into. With other materials and systems, a weaker ionic bond to the particle may be desired, so that the capping agent could be more easily removed later on.
In dispersion formulation, things like solvent choice, pH, ionic strength, capping agents, polarity, additives, and nanoparticle concentration can affect surface chemistry so they must be controlled to meet exact specifications. We control them by developing processes and formulations that are designed to ensure critical nanoparticle attributes are consistent with the customers’ exact requirements. Once the optimal formulation is identified, the process of integrating nanoparticle dispersions in customer systems is generally straightforward.
How can nanoparticle composition be controlled to achieve precise properties that are needed for a specific application?
Many times, a specific material composition or phase will be needed to obtain a property of interest. In these cases, a synthetic process needs to be designed that is consistent with obtaining the necessary composition or phase, ideally in high yield.
This is something Cerion has done routinely for customers. In certain cases, we will dope materials to enhance or change specific properties. For example, nitrogen doping of titanium dioxide can introduce absorbance in the visible light range in addition to UV, which can be advantageous in certain use cases.
How does particle size affect performance and how can it be precisely controlled?
Cerion works with our customers to understand what particle size is best for their application. What is very important here is that we make sure we are on the same page regarding sizing details to understand whether crystallite size, agglomerate size, or grain size is the value of most importance.
We ask what analytical sizing method has been used to determine the preferred particle size so we can use the same method when evaluating our candidate materials. Cerion then designs a synthetic process to prepare appropriately sized particles, which may include chemistries to control crystallite growth and agglomeration and a washing step designed not to compromise particle size. For many of the materials we make, changing factors like nucleation/growth won’t offer significant control to move particle size up or down – so we typically will use a different process to make different particle sizes. Oftentimes in our synthetic processes, we will adjust reaction time, temperature, and capping agents to fine-tune and find the most optimal size.
Specific size can be important for haze for example (smaller is better in this case), or if particles need to embed within a system (where larger size may be better). Many times, this will involve a more delicate balance. In displays, for example, if a particle is too large, transparency is negatively impacted. Additionally, if it’s too small, it may limit the increase in refractive index. Because of this, it’s essential that you harness the exact right nanoparticle size so you can achieve the performance that you need.
How do I know if my candidate material will integrate with my product or system?
Ideally, once a successful candidate material is produced at lab-scale, it will enter the development and scale-up phase where the customized material will be produced in a pilot production environment. During this phase, you are looking to replicate the behaviors achieved in applied research at a larger volume and optimize the formulation.
Due to the resource-intensive nature of the scale-up and manufacturing phases, it is good to explore a myriad of options to find the best fit. Cerion CEO, Landon Mertz, outlined several options for bringing nanomaterials to market in this Specialty Chemicals Magazine publication: Strategies for Using Nanomaterials in Product Development.
If you are ready to move forward and are looking for the support of a nanomaterial service provider let’s connect. Please visit our Contact Us page.