Johnson, Aidan V.Piedade, M. Fátima M.Esteves, Catarina V.2024-03-282024-03-282023-07-052073-4352PURE: 85955515PURE UUID: 7dea930b-cf0f-4904-a911-d5c711e5f021Scopus: 85166212549WOS: 001035081700001http://hdl.handle.net/10362/165591Funding Information: This research was funded by Fundação para a Ciência e a Tecnologia (FCT), Portugal (projects PTDC/QUIOUT/28401/2017, LISBOA-01-0145-FEDER-028401, UIDB/00100/2020, UIDP/00100/2020, and LA/P/0056/2020). Publisher Copyright: © 2023 by the authors.2-, 4-, 5-, and 6-hydroxynicotinic acids were crystallized in a pH-dependent manner using only water as the preferred solvent. The crystallization outcome was quite diverse: individual crystals of different sizes and shapes, microcrystalline powders, crystalline aggregates, and almost amorphous solids. Such a variety of solid forms demonstrates the relevance of pH control during crystallization processes.96081594eng2-, 4-, 5-, and 6-hydroxynicotinic acidscrystallizationpH controlGeneral Chemical EngineeringGeneral Materials ScienceCondensed Matter PhysicsInorganic Chemistryjournal article10.3390/cryst13071062https://www.scopus.com/pages/publications/85166212549