# Fileset

[SupportingInformation.pdf](https://mdr.nims.go.jp/filesets/f28617a5-7289-46bd-a7ba-11bdc74c2c2a/download)

## Creator

[Clement Lebastard](https://orcid.org/0000-0002-4302-3603), Yousra Hattali, Antoine Le Gendre, Stephane Cordier, Adèle Renaud, [Tohru Suzuki](https://orcid.org/0000-0001-9458-6863), [Tetsuo Uchikoshi](https://orcid.org/0000-0003-3847-4781), [Fabien Grasset](https://orcid.org/0000-0002-4911-0214)

## Rights

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Optical Materials, copyright © 2025 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acsaom.4c00446.[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[Facile and Rapid Fabrication of Opal Photonic Crystals by Electrophoretic Deposition](https://mdr.nims.go.jp/datasets/e2fffe4d-b791-462c-b8ad-0623052c4af3)

## Fulltext

Template for Electronic Submission to ACS Journals S1 Supporting Information: Facile and Rapid Fabrication of Opal Photonic Crystals by Electrophoretic Deposition Clement Lebastard1,2*†, Yousra Hattali1,2,3, Antoine Le Gendre3, Stephane Cordier,3 Adele Renaud3, Tohru Suzuki1,2, Tetsuo Uchikoshi1,2*, Fabien Grasset1,2 1CNRS-Saint Gobain-NIMS, IRL 3629, Laboratory for Innovative Key Materials and Structures (LINK), National Institute for Materials Science (NIMS), Tsukuba, 305-0044, Japan 2National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan 3Université de Rennes, CNRS, UMR6226, Institut des Sciences Chimiques de Rennes (ISCR), F-35000 Rennes, France *Corresponding authors: clement.lebastard@ensc-rennes.fr, uchikoshi.tetsuo@nims.go.jp †Université de Rennes, Ecole Nationale Supérieure de Chimie de Rennes CNRS, UMR6226, Institut des Sciences Chimiques de Rennes (ISCR), F-35000 Rennes, France   mailto:clement.lebastard@ensc-rennes.frmailto:uchikoshi.tetsuo@nims.go.jp S2   Stöber method. The hydrolysis of tetraethyl orthosilicate and the condensation of silanol groups steps are the keystone to obtain silica. They both involved nucleophilic substitution reaction and their rate can be accelerated by acidic or basic catalysis. Silica nanoparticles are obtained in basic conditions to control the condensation step rather than the hydrolysis one. In acidic condition, silanol monomers will prefer to do the nucleophilic substitution on less substitute Si (linear polymer), leading to film or gel. Whereas in basic condition, the siloxane bond will be favored on the most substituted Si atoms (branched polymers), forming nanoparticles (Figure S1).           Figure S1. Descriptive scheme of acid (a) and base (b) catalysis for the SiO2 sol-gel reaction.    S3  Figure S2. Optical photograph of the sedimentation process after 120 hours.    S4  Figure S3. Sedimentation rate of the whole series as a function of time. Solid lines represent the sedimentation rates based on the measured height of sedimentation (dots) and dashed lines represents the theoretical rates based on DLS particle size.  S5  Figure S4. SEM images (cross-section) of EPD PCs fabricated from an ethanol suspension containing 1 wt% of SiO2 particles (25 V – 2 min). Scale bars have been redrawn for greater readability.     S6  Figure S5. SEM images (cross-section) of EPD PCs fabricated on 2.5 × 1 cm rectangles ITO glass substrates, from an ethanol suspension containing 1 wt% of SiO2 particles at different voltage and during different period of time (conditions are described on every picture). Scale bars have been redrawn for greater readability.     S7  Figure S6. SEM images (cross-section) of EPD PCs fabricated on 2.5 × 1 cm rectangles ITO glass substrates (left) or 5 × 2.5 cm rectangles (right), from an ethanol suspension containing 1 wt% of SiO2 particles at different period of time (conditions are described on every picture). Scale bars have been redrawn for greater readability.