Title :

Identification of an amorphous-amorphous two-step transformation in indomethacin embedded within mesoporous silica

Author(s) :

Malfait, Benjamin [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Paccou, Laurent [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
T. Correia, Natália [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Guinet, Yannick [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Unité Matériaux et Transformations - UMR 8207 [UMET]
Hedoux, Alain [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Unité Matériaux et Transformations - UMR 8207 [UMET]

Journal title :

Microporous and Mesoporous Materials

Volume number :

328

Pages :

111502

Publisher :

Science direct

Publication date :

2021-10-16

ISSN :

1387-1811

English keyword(s) :

Geometrical confinement
Nanocrystals stability
Specific area
Raman spectroscopy
Pharmaceuticals

HAL domain(s) :

Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Physique [physics]/Matière Condensée [cond-mat]/Matière Molle [cond-mat.soft]
Physique [physics]/Matière Condensée [cond-mat]/Systèmes désordonnés et réseaux de neurones [cond-mat.dis-nn]

English abstract : [en]

A very unusual amorphous-amorphous two-step transformation was observed in indomethacin confined within MCM-41 mesoporous silica, via isothermal and non-isothermal routes. Isothermally, at room temperature, the first step ...
Show more >A very unusual amorphous-amorphous two-step transformation was observed in indomethacin confined within MCM-41 mesoporous silica, via isothermal and non-isothermal routes. Isothermally, at room temperature, the first step corresponds to the 1-dimensional growth of γ-nanocrystals along the mesoporous channels from pre existing incipient nuclei. In the second step nanocrystals slowly transform into an undercooled liquid state structurally different from the original liquid and characterized by a higher molecular mobility. The instability of nanocrystals detected in the continuation of the isothermal growth was explained as resulting from a very high specific area of nanocrystals imposed by the geometrical confinement when the size of nanocrystals along the channels achieves a dimension much larger than the channel diameter. The mechanism of the slow dissolution of nanocrystals was identified as similar to a digestive ripening process, inverse to the Ostwald ripening, by which larger clusters dissolve to the detriment of smaller ones. This two-step transformation was also observed upon heating. In this case, the growth of nanocrystals is followed by a melting far below the melting point of γ-crystals, according to Gibbs-Thomson effects. This study shows that the original amorphous form of indomethacin transforms into a second amorphous form via the transient growth of nanocrystals which become unstable via two different mechanisms induced by the geometrical confinement.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
CNRS
INRA
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Matériaux Moléculaires et Thérapeutiques

Submission date :

2022-01-28T08:12:08Z
2022-01-31T11:13:46Z
2023-01-23T10:06:42Z