Article
Chemistry, Multidisciplinary
Ejaz Ahmed, Durga Prasad Karothu, Ahmed Slimani, Jad Mahmoud Halabi, Ibrahim Tahir, Kevin Quiros Canales, Pance Naumov
Summary: This study reports the remarkably rapid lattice switching of molecular martensitic materials, which exceeds other phase transitions by several orders of magnitude. These materials have the advantages of rapid response and lightweight, making them prospective substitutes for ultrafast and clean energy transduction.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Ritesh Singh Maurya, Swetha Jayanthi, Ch Gupta Chandaluri, T. P. Radhakrishnan
Summary: The impact of the mode of assembly of molecules on the properties and functions of molecular materials is a fundamental problem that was investigated through a novel diaminodicyanoquinodimethane derivative in this study. The compound exhibited enhanced fluorescence in the crystalline state, with a noticeable weak and red-shifted fluorescence in the amorphous state. The transformation from amorphous to crystalline state was monitored through imaging techniques and confirmed by diffraction methods.
CHEMISTRY OF MATERIALS
(2022)
Article
Physics, Multidisciplinary
Divya Ganapathi, Dibyashree Chakrabarti, A. K. Sood, Rajesh Ganapathy
Summary: Softness as a machine-learned structural quantity has been identified as a parameter characterizing glassy dynamics. Through imaging experiments, it was shown that soft colloidal glass can crystallize via two distinct pathways, smooth growth in poorly packed regions and abrupt jumps triggered by cooperative rearrangements in well-packed regions. Softness not only predicts where crystallization initiates in a glass, but is also sensitive to the crystallization pathway, suggesting strategies to manipulate softness could prove valuable in realizing long-lived glassy states.
Article
Physics, Multidisciplinary
Xipeng Wang, Bo Li, Mengmeng Li, Yilong Han
Summary: Premelting not only occurs as a thin liquid film on the surface of a crystal before melting, but also as a polymorphic crystalline layer before solid-solid transitions in colloidal crystals. This pre-solid-solid transition can happen under low-energy coherent interfaces. Simulations and experiments confirm the existence of surface crystals and their different kinetics and reversibilities in various systems. The coexistence of premelting and pre-solid-solid transition leads to double surface wetting layers. These surface phenomena may also exist in atomic and molecular crystals and could be used to tune material properties.
Article
Multidisciplinary Sciences
Hang Ping, Wolfgang Wagermaier, Nils Horbelt, Ernesto Scoppola, Chenghao Li, Peter Werner, Zhengyi Fu, Peter Fratzl
Summary: Collagen fibrils can form a mineral-collagen composite during bone formation, resulting in a material with excellent properties. The deposition of minerals leads to contraction of collagen fibrils, generating a composite with tensile fibers.
Article
Chemistry, Physical
Nina Lorenz, Christopher Wittenberg, Thomas Palberg
Summary: The formation and stabilization of a porous crystalline microstructure in low-salt suspensions of charged colloidal spheres containing aggregates has been investigated using optical microscopy. The transformation from an initially crystalline colloidal solid with homogeneously incorporated aggregates to individual, compositionally refined crystallites of perforated morphology coexisting with an aggregate-enriched fluid phase was observed. Preliminary kinetic characterization suggests the involvement of power laws in the process. This novel route to porous colloidal crystals has implications beyond single-component systems and specific initial microstructures.
Article
Nanoscience & Nanotechnology
Changsheng Chen, Xianren Zhang, Masao Doi
Summary: One permanent characteristic of small systems' thermodynamics is their dependence on the environment or ensemble. In this study, the gas-liquid transition in soft nano-confinement is discussed, with a focus on the change in phase behavior under different confinement conditions.
Article
Chemistry, Multidisciplinary
Noorul Huda, Abani K. Bhuyan
Summary: Describing how electric field (EF) assists in crystal growth has been difficult due to various factors involved in the process. However, this report shows that EF-aided crystallization of five commercially available globular proteins can be achieved using a weak DC field. The electric field mechanically unfolds the proteins, facilitating amorphous aggregation and reducing the energy barrier for nucleation. It is demonstrated that EF-assisted crystallization is a simple and enjoyable experiment that does not require special equipment or additional physical agents.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Engineering, Geological
Fan Fei, Andre Costa, John E. Dolbow, Randolph R. Settgast, Matteo Cusini
Summary: In this paper, a novel phase-field model is proposed to simulate the nucleation and propagation of hydraulic fractures. The model accurately captures the material strength and considers the contribution of fluid pressure on crack driving force through external driving force and damage function. Numerical results demonstrate the accuracy and applicability of the proposed model.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Physics, Multidisciplinary
Puspa Upreti, Matthew Krogstad, Charlotte Haley, Mihai Anitescu, Vishwas Rao, Lekh Poudel, Omar Chmaissem, Stephan Rosenkranz, Raymond Osborn
Summary: The paper investigates structural correlations in the quasiskutterudites using single crystal x-ray diffraction and finds temperature-independent local atomic displacements below the transition, which persist to well above the transition, indicating order-disorder behavior.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Mohamed El Ketara, Hirokazu Kobayashi, Etienne Brasselet
Summary: This study reveals vectorial optomechanical effects mediated by the material anisotropy and the longitudinal field component inherent to real-world beams. Experimental verification on an elastic anisotropic medium prone to exhibit a sensitive and reversible effect, a nematic liquid crystal, demonstrates a feasible alternative approach to limit irreversible damaging methods.
Article
Materials Science, Multidisciplinary
Vladimir M. Fokin, Alexander S. Abyzov, Nikolay S. Yuritsyn, Juern W. P. Schmelzer, Edgar D. Zanotto
Summary: Applying the Classical Nucleation Theory to glass crystallization faces difficulties due to overlooking the influence of structural relaxation. Experimental findings demonstrate that glass relaxation significantly affects nucleation kinetics, leading to an increase in nucleation rate.
Article
Chemistry, Inorganic & Nuclear
Wang Luo, Na Wang, Hua-Kai Li, Ze-Jiang Xu, Yan Feng, Xiao-bin Fu, Chao Shi, Heng-Yun Ye, Le-Ping Miao
Summary: In this study, a two-dimensional (2D) Ruddlesden-Popper (RP) type hybrid perovskite ferroelastic material (TFCA)(2)CdCl4 is reported, which exhibits a critical temperature of 402 K and a spontaneous strain of 0.071. The rapid rotating motions of polar rotors lead to fast reorientation of dipoles, resulting in a large dielectric response. The study reveals that the 2D RP hybrid perovskite molecular rotor platform provides a new avenue to explore dynamic functional materials.
INORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Physical
Chengrong Cao, Wei Tang, John H. H. Perepezko
Summary: The kinetics of first order liquid-liquid transition in a single-component liquid D-mannitol was examined using high rate of flash differential scanning calorimetry measurements, revealing the distinction between nucleation-growth and spinodal-decomposition types of LLT by controlling the annealing temperature. The portion covering the nucleation-growth type of LLT on the time-temperature-transformation curve was well fitted with a classical nucleation theory analysis.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Liyun Tao, Yahong Liu, Lianlian Du, Meize Li, Xin Yuan, Xiang Xiao, Miguel Navarro-Cia, Xiaopeng Zhao
Summary: This article investigates the evolution of topological valley-Hall edge states and higher-order corner states in a honeycomb valley-Hall topological metamaterial under different perturbations. It is found that the edge states can exhibit different modes and a complete gap appears. The localization of the corner states becomes stronger. These findings provide a platform for the realization of optical topological insulators.
Article
Chemistry, Organic
Jonas Everaert, Maarten Debruyne, Flore Vanden Bussche, Kristof Van Hecke, Thomas S. A. Heugebaert, Pascal Van der Voort, Veronique Van Speybroeck, Christian Stevens
Summary: This paper presents the synthesis of new nitrile-functionalized N-heterocyclic ligands, which vary in the extent of the aromatic system and denticity. These ligands can be used for rational design of enhanced support materials in catalysis.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Physical
Sander Vandenhaute, Maarten Cools-Ceuppens, Simon DeKeyser, Toon Verstraelen, Veronique Van Speybroeck
Summary: In this study, an incremental learning scheme is proposed to construct accurate and data-efficient machine learning potentials for metal-organic framework materials. The scheme combines equivariant neural network potentials with parallelized enhanced sampling and on-the-fly training to explore and learn the phase space iteratively. With only a few hundred single-point density functional theory evaluations per material, accurate and transferable potentials are obtained, even for flexible frameworks with multiple structurally different phases. This incremental learning scheme is universally applicable and may pave the way to model framework materials in larger spatiotemporal windows with higher accuracy.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Sander Borgmans, Sven M. J. Rogge, Juul S. De Vos, Pascal van der Voort, Veronique Van Speybroeck
Summary: Soft porous crystals with stimuli responsiveness are widely studied for various applications. However, the structural flexibility in 3D covalent organic frameworks (COFs) is not well understood. This study investigates the factors affecting the phase transformations of diamondoid COFs, including structural decoration, interpenetration, temperature, and guest adsorption. It provides a comprehensive understanding of the design principles for flexible diamondoid COFs.
COMMUNICATIONS CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jiamin Sun, Himanshu Sekhar Jena, Chidharth Krishnaraj, Kuber Singh Rawat, Sara Abednatanzi, Jeet Chakraborty, Andreas Laemont, Wanlu Liu, Hui Chen, Ying-Ya Liu, Karen Leus, Henk Vrielinck, Veronique Van Speybroeck, Pascal Van Der Voort
Summary: Four highly porous covalent organic frameworks (COFs) containing pyrene units were prepared and explored for photocatalytic H2O2 production. Experimental studies and density functional theory calculations showed that the pyrene unit has higher activity for H2O2 production compared to bipyridine and (diarylamino)benzene units. The distribution of pyrene units over a large surface area of COFs was found to be crucial for catalytic performance.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Multidisciplinary Sciences
Veronique Van Speybroeck
Summary: The article discusses the capability of current modelling strategies to simulate dynamic phenomena in realistic nanostructured materials at operating conditions. Nanostructured materials used in applications exhibit a wide range of spatial and temporal heterogeneities. The material's dynamics are influenced by spatial heterogeneities at different scales and the operating conditions. There is a significant gap between the theoretical length-time scales and experimentally relevant scales. The article highlights three key challenges in molecular modelling to bridge this length-time scale gap.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Engineering, Environmental
Kim Phan, Sibel Ugduler, Lies Harinck, Ruben Denolf, Martijn Roosen, Galahad O'Rourke, Dirk De Vos, Veronique Van Speybroeck, Karen De Clerck, Steven De Meester
Summary: This study investigates the selective chemical dissolution of elastane from blended textiles using biobased solvents. It was found that tetrahydrofurfuryl alcohol and ?-valerolactone have comparable elastane dissolution capabilities to classical solvents. The selective solvent-based dissolution process saves 60% CO2-eq./kg textile waste compared to incineration, as shown by the LCA study.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Article
Nanoscience & Nanotechnology
Maarten Debruyne, Sander Borgmans, Sambhu Radhakrishnan, Eric Breynaert, Henk Vrielinck, Karen Leus, Andreas Laemont, Juul De Vos, Kuber Singh Rawat, Siebe Vanlommel, Hannes Rijckaert, Hadi Salemi, Jonas Everaert, Flore Vanden Bussche, Dirk Poelman, Rino Morent, Nathalie De Geyter, Pascal Van Der Voort, Veronique Van Speybroeck, Christian V. Stevens
Summary: Covalent organic frameworks (COFs) are a new type of photoactive organic semiconductors with ordered structures and high surface areas. The band gaps of COFs can be tuned by the choice of building blocks and linkages, making them tailor-made for specific (photocatalytic) applications. However, there are still many unexplored building blocks for COFs as photocatalytic moieties, and the scope of photocatalyzed reactions by COFs is limited.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Amrita Chatterjee, Jiamin Sun, Kuber Singh Rawat, Veronique Van Speybroeck, Pascal van der Voort
Summary: Two donor-acceptor type tetrathiafulvalene (TTF)-based covalent organic frameworks (COFs) were studied as electrodes for symmetric supercapacitors in different electrolytes. The charge storage mechanism of IL electrolyte based supercapacitors depends on the micro pore size and surface charge density of COFs, which can be altered by different electron acceptor building blocks. The combination of these factors enhances the charge storage in highly microporous COFs. DFT calculations support this finding.
Article
Materials Science, Multidisciplinary
Sven M. J. Rogge, Sander Borgmans, Veronique Van Speybroeck
Summary: This article introduces strain engineering as a general approach to rationalize and design materials by modifying their atomic level structure. The potential of strain engineering is demonstrated through two examples, showing how it can be used to design state-of-the-art materials for challenging applications.
Article
Chemistry, Physical
Pieter Cnudde, Michel Waroquier, Veronique Van Speybroeck
Summary: The influence of pore topology and acid strength on the adsorption of (iso)butene in Bronsted acid zeolites has been studied using calculations and simulations. The adsorbed intermediates - physisorbed alkene, chemisorbed carbenium ion, and alkoxide - were evaluated for different zeolite topologies and acid site strengths. The stabilization of the carbenium ion depends on zeolite confinement and acid site strength, while alkoxides are not found at high temperature. The adsorption energies and protonation barriers can be predicted using universal descriptors such as dispersion component and ammonia adsorption energy.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Alexander E. J. Hoffman, Irena Senkovska, Leila Abylgazina, Volodymyr Bon, Veronika Grzimek, Anna Maria Dominic, Margarita Russina, Marvin A. Kraft, Inez Weidinger, Wolfgang G. Zeier, Veronique Van Speybroeck, Stefan Kaskel
Summary: This study utilizes spectroscopic techniques and density functional theory calculations to investigate the vibrational properties of DUT-8(M) materials with different metal nodes (M = Ni, Co, Zn, Cu). Experimental results show that the closed pore phase of the Ni-based compound is stiffer than those containing Co and Zn, while the open pore phase is softer. Theoretical calculations suggest that changing the metal atom mainly affects the phonon modes inducing changes in the paddle wheel unit. These findings provide valuable insights into the flexibility and phase transition mechanism of switchable MOFs.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Nanoscience & Nanotechnology
Alexander E. J. Hoffman, Rafikul Ali Saha, Sander Borgmans, Pascal Puech, Tom Braeckevelt, Maarten B. J. Roeffaers, Julian A. A. Steele, Johan Hofkens, Veronique Van Speybroeck
Summary: Metal-halide perovskites (MHPs) have excellent properties for optoelectronic devices, but their long-term stability and phase transitions need to be understood. This study used GIWAXS, Raman spectroscopy, and theoretical calculations to investigate the structural phase transitions and phonon modes in CsPbBr3. The results provided direct evidence for the existence of these phase transitions and identified the Raman active phonon modes. This work enhances our understanding of the structure and lattice dynamics of CsPbBr3 and similar MHPs.
Article
Chemistry, Multidisciplinary
Jonas Everaert, Karen Leus, Hannes Rijckaert, Maarten Debruyne, Kristof Van Hecke, Rino Morent, Nathalie De Geyter, Veronique Van Speybroeck, Pascal Van Der Voort, Christian V. Stevens
Summary: Covalent triazine frameworks (CTFs) based on polydentate ligands are promising catalyst supports that combine the reactivity of homogeneous catalysts with the robustness and recyclability of heterogeneous ones. In this study, a rhodium (III) complex was immobilized on a bipyridine-based CTF for the transfer hydrogenation of N-heteroarenes in water using sodium formate as the hydrogen source. The immobilized catalyst showed excellent activity for various quinoxalines and other N-heteroarenes, and maintained high activity during recycling, making it suitable for continuous flow synthesis.
Article
Chemistry, Physical
Juul S. De Vos, Sander Borgmans, Pascal Van Der Voort, Sven M. J. Rogge, Veronique Van Speybroeck
Summary: This article introduces a database called ReDD-COFFEE, which contains 268,687 covalent organic frameworks (COFs) with accompanying ab initio derived force fields that outperform generic ones. The database provides a large number of computer-ready structures with high diversity in terms of geometric properties, linker cores, and linkage types. Additionally, the textural properties of the database are analyzed and the most promising COFs for vehicular methane storage are identified. By making the database freely accessible, it is hoped that it can inspire others to further explore the potential of these intriguing functional materials.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)