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Sironi L, Macetti G, Lo Presti L. Molecular dynamics investigation of benzoic acid in confined spaces. Phys Chem Chem Phys 2023; 25:28006-28019. [PMID: 37819704 DOI: 10.1039/d3cp02886k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Classical molecular dynamics simulations are carried out to investigate the aggregation of supercooled benzoic acid in confined spaces. Nanocavities, nanotubes and nanolayers are defined by restricting the periodicity of the simulation to zero, one or two dimensions, with boundaries set by adjustable, general, and computationally cheap van der Waals barriers. The effect of different confinement geometries is explored. It is found that the confinement impacts the liquid collective dynamics, strengthening the correlations that affect the motion of distant molecules. Overall, confinement determines up to a tenfold increase of the viscosity of the liquid and strongly slows down the rotational correlation times. Aggregation mediated by interactions with the walls and partial polarization of the liquid are observed. Additionally, transitions to high-density liquid states occur when stiffer barriers are used. In general, a reduced accessible amount of phase space fosters the struggle for a closer packing to relieve unfavorable atom-atom contacts, while maximizing the attractive ones. In benzoic acid, this implies that the hydrogen bond network is organized more efficiently in high density states.
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Affiliation(s)
- Luca Sironi
- Università degli Studi di Milano, Department of Chemistry, Via Golgi 19, 20133 Milano, Italy.
| | - Giovanni Macetti
- Università degli Studi di Milano, Department of Chemistry, Via Golgi 19, 20133 Milano, Italy.
| | - Leonardo Lo Presti
- Università degli Studi di Milano, Department of Chemistry, Via Golgi 19, 20133 Milano, Italy.
- Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Frascati, Frascati, Italy
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Dodero A, Djeghdi K, Bauernfeind V, Airoldi M, Wilts BD, Weder C, Steiner U, Gunkel I. Robust Full-Spectral Color Tuning of Photonic Colloids. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2205438. [PMID: 36464635 DOI: 10.1002/smll.202205438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/24/2022] [Indexed: 06/17/2023]
Abstract
Creation of color through photonic morphologies manufactured by molecular self-assembly is a promising approach, but the complexity and lack of robustness of the fabrication processes have limited their technical exploitation. Here, it is shown that photonic spheres with full-color tuning across the entire visible spectrum can be readily and reliably achieved by the emulsification of solutions containing a block copolymer (BCP) and two swelling additives. Solvent diffusion out of the emulsion droplets gives rise to 20-150 µm-sized spheres with an onion-like lamellar morphology. Controlling the lamellar thickness by differential swelling with the two additives enables color tuning of the Bragg interference-based reflection band across the entire visible spectrum. By studying five different systems, a set of important principles for manufacturing photonic colloids is established. Two swelling additives are required, one of which must exhibit strong interactions with one of the BCP blocks. The additives should be chosen to enhance the dielectric contrast, and the formation kinetics of the spheres must be sufficiently slow to enable the emergence of the photonic morphology. The proposed approach is versatile and robust and allows the scalable production of photonic pigments with possible future applications in inks for cosmetics and arts, coatings, and displays.
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Affiliation(s)
- Andrea Dodero
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg, 1700, Switzerland
| | - Kenza Djeghdi
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg, 1700, Switzerland
| | - Viola Bauernfeind
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg, 1700, Switzerland
| | - Martino Airoldi
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg, 1700, Switzerland
| | - Bodo D Wilts
- Department of Chemistry and Physics of Materials, University of Salzburg, Jakob-Haringer-Straße 2A, Salzburg, 5020, Austria
| | - Christoph Weder
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg, 1700, Switzerland
| | - Ullrich Steiner
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg, 1700, Switzerland
| | - Ilja Gunkel
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, Fribourg, 1700, Switzerland
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Relationship between Localization of PBSU in Interlamellar/Interfibrillar Regimes and Double Peaks in DSC/SAXS in its Blend with PVDF. CHINESE JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1007/s10118-022-2718-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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