Bottom-up vs top-down synthesis: why it matters
The nanoparticle dispersion market is divided by manufacturing philosophy. Top-down synthesis — ball-milling bulk material into nano-sized particles — is the conventional approach used by most competitors. The result is a broad particle size distribution with irregular morphology, which scatters light and produces unacceptable haze in optical applications.
Kriya Materials synthesises nanoparticles bottom-up, building from atoms via proprietary chemistry. This produces narrow particle size distributions with controlled morphology, achieving haze below 0.3% after processing — compared to greater than 1.7% typical of milled competitors. For automotive glazing, display optics, and waveguide applications where optical clarity is non-negotiable, this difference is the threshold between qualification and rejection.
RI range: 1.50 to 2.00 in multiple systems
Kriya's nanoparticle dispersions cover the high end of the refractive index spectrum, complementing the company's low-RI coatings to create a complete platform from RI 1.16 to 2.00. The HRI dispersions are available in three formulation formats:
- Solvent-based sol-gel — for thermal cure at 200 to 700 degrees Celsius on glass and high-temperature substrates
- UV-curable hybrids — solvent-containing systems for gravure, slot-die, and spin coating on polymer substrates
- 100% solids UV-curable — solvent-free formulations for nanoimprint lithography and R2R processing
Custom RI values within the 1.50 to 2.00 range are formulated to specification. Viscosity, solids content, and solvent system are tailored to the customer's coating process and target thickness.
Haze performance: below 0.3% at automotive grade
Haze is the critical-to-quality parameter for optical nanoparticle dispersions. Kriya's bottom-up synthesis consistently delivers:
- Haze after lamination: below 0.3% (automotive grade)
- Competitor benchmark (milled ATO): greater than 1.7%
- Every batch filtered to 0.8 micrometres
- Up to 10 critical-to-quality parameters tested per batch
This performance level is maintained from R&D samples through production scale. The synthesis process is inherently scalable — it does not depend on grinding time or media wear, both of which introduce variability in top-down processes.
Dispersion stability and shelf life
Nanoparticle dispersions are only useful if they remain stable during storage and coating. Kriya guarantees a minimum 6-month shelf life (unopened) for all standard products. Key stability parameters:
- No sedimentation over shelf life at recommended storage temperature
- Consistent viscosity within specification window
- Filtration to 0.8 micrometres standard; tighter filtration available on request
- Packaging in 5, 10, 20, or 200 kg units, ADR/IATA/IMO compliant for global shipping
Integration into coatings
Kriya's nanoparticle dispersions are designed for direct integration into three coating cure pathways:
- Sol-gel — thermal cure produces dense oxide films with excellent mechanical and environmental durability. Ideal for glass substrates in automotive and solar applications.
- UV-cure — rapid cure at ambient temperature, compatible with polymer substrates. The 100% solids grades eliminate solvent handling and drying steps entirely.
- Thermal-cure hybrids — lower cure temperatures than pure sol-gel, suitable for polymer substrates that cannot tolerate high heat.
Applications enabled
HRI nanoparticle dispersions from Kriya serve four major application verticals:
- MicroLED light extraction — graded RI layers from 1.40 to 2.00 bridge the GaN-to-air interface, achieving 30 to 40% efficiency gains. Learn more.
- AR/VR waveguides — HRI core layers (n = 1.65 to 1.85) paired with Kriya LRI cladding create complete waveguide systems from a single supplier. Learn more.
- Metalenses and photonics — ultra-high RI (n = 1.95 to 2.00) NIL-compatible materials for master-mold metalens replication. Learn more.
- Automotive thermal management — ATO nanoparticles for solar heat control in automotive glazing, with 5 times the effectiveness of milled competitors. Learn more.
Ordering and custom formulation
Standard products ship from stock within one week. Custom formulations — tailored RI, viscosity, solvent system, or solids loading — are available with a minimum order quantity of 200 kg. Kriya's formulation team works directly with the customer's process engineers to optimise coating performance for specific substrates and application methods.
All products are REACH compliant (EC 1907/2006) and manufactured under ISO 9001:2015. A Certificate of Analysis accompanies every delivery.