Modeling the Competition between Polymorphic Phases: Highlights on the Effect of Ostwald Ripening

Tahri, Yousra; Kožíšek, Z.; Gagnière, Émilie; Chabanon, Élodie; Bounahmidi, Tijani; Mangin, Denis

doi:10.1021/acs.cgd.6b00640

Cited by 16 publications

(38 citation statements)

References 36 publications

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“…Our nanospectroscopy showed that, although the crystallinity index and vibrational exciton delocalization were overall correlated as could be expected, crystallite domain size remained small until the crystallinity index was very high, and significant short-range disorder remained, even with a high degree of long-range order. The observed aggregate ripening, increase in crystallinity, and increasing crystalline domain size are likely associated with Ostwald stages of growth, in which an amorphous phase is favored at early times to be replaced by an increasing fraction of a crystalline phase at longer annealing times (43)(44)(45)(46)(47). As illustrated in Fig.…”

Section: Discussionmentioning

confidence: 87%

Vibrational exciton nanoimaging of phases and domains in porphyrin nanocrystals

Muller

Gray

Zhou

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

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Much of the electronic transport, photophysical, or biological functions of molecular materials emerge from intermolecular interactions and associated nanoscale structure and morphology. However, competing phases, defects, and disorder give rise to confinement and many-body localization of the associated wavefunction, disturbing the performance of the material. Here, we employ vibrational excitons as a sensitive local probe of intermolecular coupling in hyperspectral infrared scattering scanning near-field optical microscopy (IR s-SNOM) with complementary small-angle X-ray scattering to map multiscale structure from molecular coupling to long-range order. In the model organic electronic material octaethyl porphyrin ruthenium(II) carbonyl (RuOEP), we observe the evolution of competing ordered and disordered phases, in nucleation, growth, and ripening of porphyrin nanocrystals. From measurement of vibrational exciton delocalization, we identify coexistence of ordered and disordered phases in RuOEP that extend down to the molecular scale. Even when reaching a high degree of macroscopic crystallinity, identify significant local disorder with correlation lengths of only a few nanometers. This minimally invasive approach of vibrational exciton nanospectroscopy and -imaging is generally applicable to provide the molecular-level insight into photoresponse and energy transport in organic photovoltaics, electronics, or proteins. infrared spectroscopy | molecular vibrations | scattering-scanning near-field optical microscopy (s-SNOM) | vibrational exciton | molecular energy transport

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Section: Discussionmentioning

confidence: 87%

Vibrational exciton nanoimaging of phases and domains in porphyrin nanocrystals

Muller

Gray

Zhou

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

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“…Therefore, to explain the Ostwald rule of stages using the dissolution resulting from the Gibbs Thomson effect, we present in this section the result of simulations done at low temperature. The parameters of the model, as well as the boundary conditions, were given in a previous work 20 . It is worth noting that supersaturation depletion was taken into account.…”

Section: Modeling Resultsmentioning

confidence: 99%

“…Others were calculated using nucleation data 25 . The interfacial energy values for α and β deduced from a comparative study 20 and used in the simulations are: = 0.013 ( . −2 ) and = 0.014 ( .…”

Section: Modelmentioning

confidence: 99%

Multiscale Experimental Study and Modeling of l-Glutamic acid Crystallization: Emphasis on a Kinetic Explanation of the Ostwald Rule of Stages

Tahri

Gagnière

Chabanon

et al. 2019

Crystal Growth & Design

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This work presents an experimental and a numerical study to highlight a kinetic explanation of the Ostwald rule of stages (ORS). To demonstrate this explanation, L-glutamic acid (LGlu) (a monotropic system with two polymorphs) was crystallized in three different scales: liter scale in a 2 L stirred crystallizer, milliliter scale in a 4 mL stagnant cell, and microliter scale in microfluidic channels. Cooling crystallization experiments were performed in water at different temperatures and supersaturation conditions. The LGlu polymorphic system was found to follow the ORS at low temperature (between 5 and 30 °C). However, in similar operating conditions, the stable polymorph crystallized preferentially or exclusively in the stagnant cell and in microfluidics. To explain the ORS in the stirred crystallizer at low temperature, a model based on the kinetic equation was used. By taking into account the Gibbs−Thomson effect (solubility variation with size), the simulations at the nanoscopic scale showed the dissolution of the slow-growing stable phase nuclei in favor of the fast-growing metastable phase nuclei. Consequently, the numerical results showed that the Gibbs−Thomson effect is a key factor in polymorph competition and that considering this effect, in certain kinetic and equilibrium conditions, could allow explaining and simulating the ORS.

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“…Unfortunately, our understanding of these stages remains insufficient [26]. Because of the molecular-scale involved, numerous specifics of nucleation remain largely unknown.…”

Section: Discussionmentioning

confidence: 99%

Phenomenological Consideration of Protein Crystal Nucleation; the Physics and Biochemistry behind the Phenomenon

Nanev

2017

Crystals

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Physical and biochemical aspects of protein crystal nucleation can be distinguished in an appropriately designed experimental setting. From a physical perspective, the diminishing number of nucleation-active particles (and/or centers), and the appearance of nucleation exclusion zones, are two factors that act simultaneously and retard the initially fast heterogeneous nucleation, thus leading to a logistic time dependence of nuclei number density. Experimental data for protein crystal (and small-molecule droplet) nucleation are interpreted on this basis. Homogeneous nucleation considered from the same physical perspective reveals a difference-the nucleation exclusion zones lose significance as a nucleation decelerating factor when their overlapping starts. From that point on, a drop of overall system supersaturation becomes the sole decelerating factor. Despite the different scenarios of both heterogeneous and homogeneous nucleation, S-shaped time dependences of nuclei number densities are practically indistinguishable due to the exponential functions involved. The biochemically conditioned constraints imposed on the protein crystal nucleation are elucidated as well. They arise because of the highly inhomogeneous (patchy) protein molecule surface, which makes bond selection a requisite for protein crystal nucleation (and growth). Relatively simple experiments confirm this assumption.

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Modeling the Competition between Polymorphic Phases: Highlights on the Effect of Ostwald Ripening

Abstract: This is the supporting information for the paper: "Modeling the competition between polymorphic phases: highlights on the effect of Ostwald Ripening". Appendix A is the derivation of equation ( 18). Appendix B explains the demonstration of equation ( 23) from equation ( 22).

Cited by 16 publications

References 36 publications

Vibrational exciton nanoimaging of phases and domains in porphyrin nanocrystals

Vibrational exciton nanoimaging of phases and domains in porphyrin nanocrystals

Multiscale Experimental Study and Modeling of l-Glutamic acid Crystallization: Emphasis on a Kinetic Explanation of the Ostwald Rule of Stages

Phenomenological Consideration of Protein Crystal Nucleation; the Physics and Biochemistry behind the Phenomenon

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