eprintid: 1540142 rev_number: 25 eprint_status: archive userid: 608 dir: disk0/01/54/01/42 datestamp: 2017-02-15 12:53:38 lastmod: 2021-09-28 22:13:59 status_changed: 2017-02-15 12:53:38 type: article metadata_visibility: show creators_name: Buanz, ABM creators_name: Gaisford, S title: Formation of Highly Metastable β Glycine by Confinement in Inkjet Printed Droplets ispublished: pub divisions: UCL divisions: B02 divisions: C08 divisions: D10 divisions: G08 note: This document is the Accepted Manuscript version of a Published Work that appeared in final form in Crystal Growth & Design, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: http://dx.doi.org/10.1021/acs.cgd.6b01633. abstract: Inkjet printing was used to deposit picoliter droplets of aqueous glycine solution onto glass or aluminum substrates and it was found that the volume constraint on crystal growth resulted in formation of the highly metastable β form. When the droplet volume increased to 0.1 μL or greater, a mixture of the α and β forms was seen in a coffee-ring formation. When the droplet volume increased to 10 μL, needle-like β crystals formed in the bulk of the ring and bipyramidal α crystals on the outer edge at the air–water interface. The β form was stable under ambient conditions for at least 6 weeks. The observations suggest that glycine nucleates to, and remains stable as, the β form when constrained in small volumes, because on the nanometer scale the β form is thermodynamically stable. As the droplet volume increases, and constraint on crystal growth is reduced, the α form becomes thermodynamically stable, and so phase transformation occurs, probably facilitated by a solvent-mediated mechanism. Inkjet printing picoliter droplets may offer a new route to isolation of metastable polymorphs. date: 2017-01-11 date_type: published official_url: http://dx.doi.org/10.1021/acs.cgd.6b01633 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1207356 doi: 10.1021/acs.cgd.6b01633 lyricists_name: Buanz, Asma lyricists_name: Gaisford, Simon lyricists_id: ABMBU27 lyricists_id: SGAIS88 actors_name: Gaisford, Simon actors_id: SGAIS88 actors_role: owner full_text_status: public publication: Crystal Growth & Design volume: 17 number: 3 pagerange: 1245-1250 issn: 1528-7505 citation: Buanz, ABM; Gaisford, S; (2017) Formation of Highly Metastable β Glycine by Confinement in Inkjet Printed Droplets. Crystal Growth & Design , 17 (3) pp. 1245-1250. 10.1021/acs.cgd.6b01633 <https://doi.org/10.1021/acs.cgd.6b01633>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1540142/1/Glycine%20CGD%20.pdf