Novel Industrially Scalable Approaches to Drying and Redispersing Silica Nanoparticles

OVERVIEW

Elkem, the Seeker for this Wazoku Crowd Challenge, is looking for an efficient, cost-effective, and environmentally friendly process of drying and redispersing silica nanoparticles (SNPs), while preserving their essential structural and functional characteristics.

Our silica particles are dispersed in a liquid phase, while our goal is to have a dry product, which is capable of being fully dispersed to the initial particle size in a water matrix.

This Challenge therefore is looking for an efficient, cost-effective, and environmentally friendly process of drying and redispersing SNPs. Due to the chemical nature of SNPs, they have a high tendency for aggregate formation. The proposed process should therefore preserve all essential characteristics of original SNPs (such as their spherical shape, size distribution, and specific surface area) and be easily scalable to industrial volumes.

Your IP Rights are protected in this Prize Challenge; Elkem must award you to obtain them.

The best solution has the opportunity to win the award of $25,000 for meeting all solution requirements. The Challenge requires a written proposal to be submitted and Awards will be contingent upon the theoretical evaluation and experimental validation of the proposal by Elkem against the Solution Requirements. To receive an Award, Solvers are required to grant non-exclusive rights to the Intellectual Property (IP) in their proposed solution. There is no assignment of IP Rights with this challenge. Solvers will retain all rights to any proposal not Awarded.

Submissions to this Challenge must be received by 11:59 PM (US Eastern Time) on October 28th, 2024.

- Login or register your interest to start solving!

ABOUT THE SEEKER & ELIGIBILITY

Elkem is one of the world’s leading providers of advanced silicon-based materials shaping a better and more sustainable future. The company develops silicones, silicon products and carbon solutions by combining natural raw materials, renewable energy and human ingenuity. Elkem helps its customers create and improve essential innovations like electric mobility, digital communications, health and personal care as well as smarter and more sustainable cities. With a strong track record since 1904, its global team of more than 7,300 people has a joint commitment to stakeholders: Delivering your potential.

Employees of Elkem are ineligible to receive an award for this Challenge.

Find out more about participation in Wazoku Crowd Challenges.

THE CHALLENGE

Background

Silica nanoparticles (SNPs) are tiny particles of silicon dioxide (SiO₂) with the diameter ranging from 50-300 nm. They can adopt different shapes—spherical, rod-shaped, virus-like, etc.—and some types of SNPs have pores of diameters in the 2-50 nm range. SNPs have silanol groups (Si-OH) on their surface, which strongly attract water molecules.

The size, shape of SNPs, and the size of their pores can be controlled during SNP manufacturing. All three parameters may affect SNPs’ properties, but regardless of a specific SNP type, all SNPs share the same important characteristics: they’re biocompatible, chemically stable, and easily modified.

These properties make SNPs useful in various applications, some of which are:

• Biomedicine: as drug delivery vehicles.
• Electronics: as insulating devices in computer chips.
• Cosmetics: as thickeners, exfoliants, and UV protectants.
• Water purification: as agents helping remove contaminants from water.

In our specific application, we use microsilica (silica fume) in refractory castables and in high-performance concrete to increase the particle packing. This results in less porosity, hence improved strength and durability of the refractory castables or high-performance concrete.

The microsilica we use are spherical amorphous SNPs with a D50 (median diameter) of 150-200 nm and a specific surface area in the range of 20-30 m²/g.

The microsilica also contains some additional elements (<1%), predominantly Al, Ca, Mg, Fe, K, Na, Cl and S. These elements will be partly soluble in an aqueous solution.

Our silica particles are dispersed in a liquid phase, at approximately 50% (v/w), while our goal is to have a dry product, which is capable of being fully dispersed to the initial particle size in the application described above.

The process of water removal is somewhat complicated, due to surface tension forces, SNPs tend to clump together, forming large aggregates. This aggregate formation during water removal makes SNPs unsuitable for the described end applications.

There exist several methods for dry dispersions of solid particles; however, all of them suffer from certain shortcomings, making them unsuitable for our purposes:

• Solvent exchange: replacing water with a more volatile organic solvent. The solvent is then evaporated at a low temperature to remove the water without aggregating the particles.

We tried this approach, but it’s difficult to scale up due to complexity of the process, environmental health and safety issues related to the use of organic solvents, and cost.

• Lyophilization: freezing the water in the SNP suspension and then removing it under vacuum at low pressure. The ice sublimates without going through a liquid phase, minimizing particle aggregation.

As with the Solvent exchange approach, this technology is difficult to scale up to industrial volumes.

• Spray Drying: creating a mist of the SNP suspension and drying it with hot air.

Unfortunately, spray drying does not prevent the nanoparticles from forming aggregates.

• Supercritical Drying: using supercritical CO₂, a fluid with properties of both a gas and a liquid, to extract water from the nanoparticles.

It's a relatively new and complex technology that requires sophisticated equipment that isn’t available in many industrial settings. At this stage of development, it appears to be prohibitively expensive and difficult to scale.

It’s therefore important to identify new and improved technologies for drying microsilica so that it is readily re-dispersible in the end applications.

We envision that a process of drying the microsilica dispersions will be developed allowing removal of the adsorbed water from 50% to less than 0.2% (v/w).

Importantly, the proposed process should allow the recovered SNPs to retain their original size distribution, preventing them from forming aggregates.

Equally importantly, we envision that the proposed process can be easily scaled up to a few thousand tons SNPs/year. We also anticipate that the proposed process will be safe to operate and environmentally friendly. For example, if using a solvent is proposed, water will be the optimal choice.

Finally, the proposed process should be fast (taking no more than 1 h to process one ton of SNPs) and cost-effective, meaning that the total production cost per ton of processed microsilica would not exceed $1,200/ton.

SOLUTION REQUIREMENTS

We’re open to any innovative solution for as long as this solution meets the following Solution Requirements:

1. The proposed process should be able to remove water from microsilica NSPs from 50% to less than 0.2% (v/w).
2. The proposed process should be able to retain the size distribution of the original SNPs with D50 in the 150-200 nm diameter range in the end application.
3. The proposed process should be able to retain the specific surface area of 20-30 m²/g of the original SNPs.
4. The proposed process should be potentially scalable to a few thousand tons of SNPs/year.
5. The proposed process should take no more than 1 h to dry and re-disperse one (1) ton of SNPs.
6. The proposed process should be safe to operate and environmentally friendly. Ideally, water will be the choice of a solvent, if the proposed process involves one.
7. The anticipated cost of the process, when fully scaled up, shouldn’t exceed $1,200/ton of SNPs.

Important: We’re not discouraging Solvers from considering the four existing technologies listed above. However, should a solution be based on one (or a combination of a few) of them, dramatic improvement in performance is expected, and Solvers are required to provide solid arguments in favor of their choice.

At the same time, we’re not going to accept solutions that:

• Are based on early-stage, unproven, technologies that will take years to develop and implement.
• Use highly specialized and expensive equipment not easily available in on-the-ground settings.

Solutions with Technology Readiness Levels (TRLs) 2-5 are invited.

This Prize Challenge has the following features:

1. Your IP Rights are protected; Elkem must award you to obtain them. Solvers retain all rights to any proposal not awarded.
2. The best solution has the opportunity to win the award of $25,000 for meeting all solution requirements, as solely determined by Elkem.
3. This Prize Challenge requires a written proposal to be submitted and awards will be contingent upon the theoretical evaluation and experimental validation of some selected proposals by Elkem against the Solution Requirements.
4. To receive an award for this Prize Challenge, Solvers are required to grant non-exclusive rights to the Intellectual Property (IP) in their proposed solution.
5. Elkem may also issue “Honourable Mention” recognitions for notable submissions that are not selected for monetary awards.
6. Elkem may wish to partner with the Solver at the conclusion of the Challenge. Please indicate your interest in partnering.
    

YOUR SUBMISSION

Please login and register your interest, to complete the submission form.

The submitted proposals must be written in English and can include:

1. Participation type – you will first be asked to inform us how you are participating in this challenge, as a Solver (Individual) or Solver (Organization).
2. Solution Level - the Technology Readiness Level (TRL) of your solution.
3. Partnering - there may be an opportunity to partner at the conclusion of this Challenge. Please indicate if partnering is of interest to you.
4. Problem & Opportunity - highlight the innovation in your approach to the Problem, its point of difference, and the specific advantages/benefits this brings (up to 500 words).
5. Solution Overview - detail the features of your solution and how they address the SOLUTION REQUIREMENTS (500 words, there is space to add more in the summary field, and attach supporting data, diagrams, etc.).
6. Solution Feasibility – Supporting Information and Rationale, such as references and precedents, that will help Elkem evaluate and experimentally validate the feasibility of the solution (up to 500 words).
7. Experience - Expertise, use cases and skills you or your organization have in relation to your proposed solution (up to 500 words).
8. Solution Risks - any risks you see with your solution and how you would plan for this (up to 500 words).
9. Timeline, capability, and costs - describe what you think is required to deliver the solution, estimated time and cost (up to 500 words).
10. Online References - provide links to any publications, articles or press releases of relevance (up to 500 words).

Wazoku encourages the use by Solvers of AI approaches to help develop their submissions, though any produced solely with generative AI are not of interest.

Find out more about participation in Wazoku Crowd Challenges.

Submissions to this Challenge must be received by 11:59 PM (US Eastern Time) on October 28th, 2024.

Late submissions will not be considered.

Your submission will be evaluated by the evaluation team first reviewing the information and content you have submitted at the submission form, with attachments used as additional context to your form submission. Submissions relying solely on attachments will receive less attention from the evaluation team.

After the Challenge submission due date, Elkem will complete the review process and make a decision with regards to the winning solution(s).