Photoacid‐mediated controllable gelation in a chemical reaction cycle Lopez‐Acosta, Alvaro Valera, Jorge S. Klajn, Rafal Hermans, Thomas M. ddc:540 We explore the use of a photoacid in a chemical reaction cycle, which allows for the controlled sol‐to‐gel transition of a saccharide aldehyde‐based self‐assembling system. The modulation of the pH with light enables to generate chemical fuels in situ, thus triggering monomer activation and gelation. Our efforts represent a promising step toward dissipative self‐assembled systems with a higher degree of spatiotemporal control. Wiley 2026 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_2df8fbb1 https://research-explorer.ista.ac.at/record/21838 https://research-explorer.ista.ac.at/download/21838/21887 Lopez‐Acosta A, Valera JS, Klajn R, Hermans TM. Photoacid‐mediated controllable gelation in a chemical reaction cycle. <i>ChemSystemsChem</i>. 2026;8(3). doi:<a href="https://doi.org/10.1002/syst.70037">10.1002/syst.70037</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1002/syst.70037 info:eu-repo/semantics/altIdentifier/e-issn/2570-4206 https://creativecommons.org/licenses/by-nc/4.0/ info:eu-repo/semantics/openAccess