resumo
Producing crystals of the desired form (polymorph) is currently a challenge as nucleation is yet to be fully understood. Templated crystallization is an efficient approach to achieve polymorph selectivity; however, it is still unclear how to design the template to achieve selective crystallization of specific polymorphs. More insights into the nanoscale interactions happening during nucleation are needed. In this work, we investigate crystallization of glycine using graphene, with different surface chemistry, as a template. We show that graphene induces the preferential crystallization of the metastable alpha-polymorph compared to the unstable beta-form at the contact region of an evaporating droplet. Computer modeling indicates the presence of a small amount of oxidized moieties on graphene to be responsible for the increased stabilization of the alpha-form. In conclusion, our work shows that graphene could become an attractive material for polymorph selectivity and screening by exploiting its tunable surface chemistry.
palavras-chave
THERMODYNAMIC ASPECTS; CRYSTAL NUCLEATION; GLYCINE CRYSTALS; 1ST PRINCIPLES; EXFOLIATION; FUNCTIONALIZATION; SOLUBILITY; GRAPHITE; GROWTH
categoria
Chemistry; Science & Technology - Other Topics; Materials Science
autores
Boyes, M; Alieva, A; Tong, JC; Nagyte, V; Melle-Franco, M; Vetter, T; Casiraghi, C
Grupos
agradecimentos
This work is supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 648417. V.N. acknowledges funding from the National Physical Lab in London and the EPSRC in the framework of the CDT Graphene NOWNANO. M.M.F. acknowledges support from the Portuguese Foundation for Science and Technology (FCT), under the projects PTDC/FIS-NAN/4662/2014, IF/00894/2015, and FCT ref. UID/CTM/50011/2019 for CICECO-Aveiro Institute of Materials. T.V. thanks the Royal Academy of Engineering for the support through an Engineering for Development research fellowship (Grant No. RF1516/15/22). The authors thank Aurora J. Cruz-Cabeza and Kostya Novoselov for useful discussions.