Physical networks typically employ enthalpy-dominated crosslinking interactions that become more dynamic at elevated temperatures. Here, the authors report an entropy-driven physical network based on polymer-nanoparticle interactions that exhibits mechanical properties that are invariant with temperature.
Materials science and chemistry
Materials science and chemistry encompasses experimental and computational research that aims to understand and exploit relationships between structures and properties of materials. On this page, we highlight exciting research in materials design, fabrication, physicochemical characterization, and functional properties.
Designing a next generation solar crystallizer for real seawater brine treatment with zero liquid discharge
Proper disposal of industrial brine remains a critical environmental challenge. Here, the authors devise a solar crystallizer and propose a salt crystallization inhibition strategy, which together provide a low-cost and sustainable solution for industrial brine disposal with zero liquid discharge.
Artificial superhydrophobic coatings that are simple to prepare and practical to use are sought after. Here, the authors create versatile, complete-waterproof coatings based on a single-step, stoichiometrically controlled reaction of organosilanes with water.
Metallization of pure hydrogen via overlapping of electronic bands requires high pressure above 3 Mbar. Here the authors study the Ba-H system and discover a unique superhydride BaH12 that contains molecular hydrogen, which demonstrates metallic properties and superconductivity below 1.5 Mbar.
Crystal defects critically influence surface chemical reactions in nanomaterials, yet the basic mechanisms at play are still elusive. Here, the authors show the atomic-scale dynamics of surface oxidation at coherent planar defects in Ag and Pd, revealing how twins and stacking-faults selectively oxidize metallic nanocrystals.
Four-dimensional (4D) printing of shape memory polymer (SMP) imparts time responsive properties to 3D structures. Here, the authors explore 4D printing of a SMP in the submicron length scale, extending its applications to nanophononics.
Homopolymer self-assembly of poly(propylene sulfone) hydrogels via dynamic noncovalent sulfone–sulfone bonding
Natural biomolecules such as peptides and DNA can dynamically self-organize into diverse hierarchical structures. Here the authors report experiments and simulations on the dynamic network self-assembly and subsequent collapse of the synthetic homopolymer poly(propylene sulfone).
Biomineral armour is known in a number of diverse creatures but has not previously been observed in insects. Here, the authors report on the discovery and characterization of high-magnesium calcite armour which overlays the exoskeletons of leaf-cutter ants.
Hemicelluloses are an essential constituent of plant cell walls, but the individual biomechanical roles remain elusive. Here the authors report on the interaction of wood hemicellulose with bacterial cellulose during deposition and explore the resultant fibrillar architecture and mechanical properties.
Phosphor-glass/ceramic composites are attractive for high-power white light-emitting diodes, but interfacial reaction leads to loss of quantum efficiency. Here the authors report a reduction sintering method for embedment of phosphors into silica glass with limited interfacial reaction.
The description of quasicrystal structures by only one repeating unit is desirable. Here the authors experimentally identify a quasi-unit-cell corresponding to a Lück decagon to describe the randomly ordered structure of a decagonal quasicrystalline phase.
Metal-organic frameworks constitute a family of glass formers that is distinct from those that are polymeric, metallic, or inorganic. Here the authors show that they can be combined with different inorganic aluminophosphate glasses to produce a composite with mechanical properties intermediate between the two end-members.
Structural and electronic switching of a single crystal 2D metal-organic framework prepared by chemical vapor deposition
The realization of advanced devices from metal-organic frameworks requires the preparation of uniform and crystalline thin-films of these materials. Here the authors use chemical vapor deposition to grow single-crystal frameworks that exhibit a reversible structural transition and large conductivity response.
Covalently 2D-patterning graphene with different chemical functionalities is an attractive way to tailor its physical and chemical properties. Here, the authors realize spatially defined 2D-hetereoarchitectures of graphene via a strategy of molecular embroidering.
In situ NMR reveals real-time nanocrystal growth evolution via monomer-attachment or particle-coalescence
Understanding nanocrystal growth pathways under their native fabrication environment remains a central goal of science. By synthesizing nanofluorides under in-situ NMR conditions, the authors are able to probe their sub-nm growth evolution, elucidating their formation by coalescence or monomer-attachment.
Properties of perovskite oxides can be changed by manipulating anion-vacancy order patterns, but they are difficult to control. Here the authors show strain-induced creation and switching of anion vacancies in perovskite films in which the direction or periodicity of anion-vacancy planes is altered depending on the substrate employed.
Scintillation-based X-ray detection is promising for applications in various areas ranging from security to healthcare, and low-cost and eco-friendly scintillation materials would be beneficial. Here the authors report a facile solution growth of organic manganese halide for efficient X-ray scintillation.
Fabrication of superconducting 3D nanoarchitectures, using standard nanofabrication methods, is challenging. Here, the authors demonstrate the fabrication of a nanostructured 3D superconducting array of Josephson junctions, exploiting self-assembled DNA origami lattices as a template.
Metal-organic framework adsorbents are promising materials for gas separation and purification. Herein, the authors present a metal-organic framework that selectively captures CO2 over small hydrocarbons; this separation is relevant for the purification of natural gas and industrial feedstocks.
The production of hydrogen peroxide by electrochemical oxygen reduction is an attractive alternative to the industrial process, but catalysts should be optimized. Here, the authors enhance hydrogen peroxide production in acidic media with epoxy groups near cobalt centers on carbon nanotubes.
As the field of metal-organic frameworks is maturing, understanding the dynamics of open frameworks is progressing and rational approaches are under development. Here, the authors outline challenges and potential routes to engineering the spatio-temporal evolution of dynamic metal-organic frameworks.
Infrared spectroscopy data- and physics-driven machine learning for characterizing surface microstructure of complex materials
Knowing compositional motifs of nanoparticle catalysts in operando conditions is crucial towards understanding their catalytic behavior. Here, the authors develop a physics-driven machine learning approach to predict adsorption sites for a CO molecule over platinum nanoparticles in a multitude of coordination environments.
Controllable modulation of precursor reactivity using chemical additives for systematic synthesis of high-quality quantum dots
Synthesis of high crystal quality quantum dots (QDs) requires optimization of reaction temperature and precursor reactivity. Here, the authors report precursor chemistry that enables controllable modulation of precursor reactivity using chemical additives, and systematically grow high-quality QDs from cores of various sizes and materials.
Uncovering the effects of interface-induced ordering of liquid on crystal growth using machine learning
Crystallization is a challenging process to model quantitatively. Here the authors use machine learning and atomistic simulations together to uncover the role of the liquid structure on the process of crystallization and derive a predictive kinetic model of crystal growth.
Imaging how thermal capillary waves and anisotropic interfacial stiffness shape nanoparticle supracrystals
Interfacial fluctuations at the nanoscale, such as shape evolution of a growing crystal, are prohibitively difficult to study experimentally. Here, the authors are able to map the kinetic and thermodynamic parameters involved in shaping of nanoparticle supracrystals by directly imaging the fluctuating crystal surface by liquid-phase TEM, and analyzing it in the context of capillary wave theory.
The stability of perovskite solar cells can be improved by using hybrid-organic perovskites capping-layers atop the active material. Here the authors use machine learning to optimize capping layers by monitoring time to degradation of differently capped lead-halide perovskite solar cells.
Machine learning driven research holds big promise towards accelerating materials’ discovery. Here the authors demonstrate CAMEO, which integrates active learning Bayesian optimization with practical experiments execution, for the discovery of new phase- change materials using X-ray diffraction experiments.