DSM’s unique MP Coat AR (Same sun. More power.TM) is the best-performing anti-reflective coating technology for solar cover glass on the market today. It maximizes light transmission by minimizing reflection, which leads to a gain in solar module output up to 4%. MP Coat AR combines high durability with easy clean ability. Light is reflected at the boundary of two media with different refractive indices (n1 and n2). In standard glass, 8% of the incident light is reflected (∠i = 90°). A sol-gel based coating, with a layer thickness of about 1/4l for destructive interference of reflected light and a lower refractive index than glass (ca 1.3), can be a one-layer solution to reduce the reflection. Together with high durability and clean ability requirements this calls for a closed surface, and meso-porosity with closed pore structure within the sol-gel coating. Inspired by Stephen Armes’ work who created core-shell nanoparticles (2007), by controlled silica-deposition onto polymer micelles, we investigated cationic block-copolymer micelles based on quaternary ammonium groups. We soon ran into fundamental questions like: are the ammonium groups catalysts for the sol-gel reaction or merely acting like scaffolds? Are the solica nanoparticles nucleating inside the micelle shells or templated on it? Are these core-shell structures suitable for encapsulation? Working with Eindhoven University of Technology, we established the mechanism for nucleation and growth of silica nanoparticles, using cryo-TEM, and bridging the Monomer Growth model with the Aggregation Growth model. In this presentation we will show the answers to the above fundamental questions, and how we have broadened our toolbox based on these insights, moving from micelles to cationic polymer dispersions and from polymer dispersions to solvent emulsion droplet templation, enabling for example the application of antireflective coatings even on polymer foils.

Controlled silica templation technologies for antireflective coatings

254th National Meeting (2017)

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