Property Relationships Research Articles

Co-orchestration of multiple instruments to uncover structure–property relationships in combinatorial libraries

Multimodal co-orchestration expedites the exploration of combinatorial libraries by leveraging real-time insights from one modality to accelerate the discovery of others, thereby enhancing the overall efficiency of characterization.

Pressure effects on both fluorescent emission and charge transport properties of organic semiconductors: a computational study.

External pressure can regulate the photophysical property and charge transport performance of organic semiconductors, however, the underlying mechanism at the microscopic level is still elusive. Using thermal vibrational correlation function coupled quantum mechanics/molecular mechanics and full quantum charge transfer rate theory, we systematically explore the influence of pressure on fluorescence emission and charge transport behaviours of representative cyclooctatetrathiophene (COTh). It is found that, upon pressurization, the intramolecular configurations of COTh became more twisted, leading to the blue-shifted emission. The fluorescence quantum efficiency (FQE) of COTh crystals decreases monotonically in a wide pressure range of 0-4.38 GPa, because the increase of intermolecular electronic energy transfer rate constant (keet) is larger than the decrease of internal conversion rate constant (kic), and the variation of keet is dominant. The decrease in kic is attributed to the decreasing reorganization energy, reflecting the suppression of the low-frequency flipping vibrations of four thiophene rings and the high-frequency stretching vibrations of central cyclooctatetraene, while the keet increase is due to the simultaneous increase in exciton coupling and spectra overlap. Moreover, we predicted that the hole mobility of COTh increases monotonically by nearly an order of magnitude from 0.39 to 3.00 cm2 V-1 s-1 upon compression, because of the increase in transfer integral and the decrease of charged reorganization energy. Furthermore, its hole mobility exhibits obvious anisotropy. Our work systematically builds the external pressure, molecular packing, luminescence and transport properties relationships of organic semiconductors and provides theoretical guidance for the rational design of pressure responsive organic semiconductors with excellent photoelectric performance.

The Tuning of Strain in Layered Structure Oxide Cathodes for Lithium-Ion Batteries

Layered structure oxides have emerged as highly promising cathode materials for lithium-ion batteries. In these cathode materials, volume variation related to anisotropic lattice strain during Li + insertion/extraction, however, can induce critical structural instability and electrochemical degradation upon cycling. Despite extensive research efforts, solving the issues of lattice strain and mechanical fatigue remains a challenge. This perspective aims to establish the “structure–property relationship” between the degradation mechanism of the layered oxide cathode due to lattice strain and the structural evolution during cycling. By addressing these issues, we aim to guide the improvement of electrochemical performance, thereby facilitating the widespread adoption of these materials in future high-energy density lithium-ion batteries.

Crystal engineering and sorption studies on CN- and dipyridyl-bridged 2D coordination polymers

Structure–property relationships were studied in two coordination polymers {[Ni(bpe)(H2O)2][Ni(CN)4]·2 H2O}n and {[Cu(bpe)(H2O)2][Ni(CN)4]·ethanol}n. We show that the length of the ligand does not control the synthesis of Hofmann-type polymers.

Sulfur-based ferroelectric nematic liquid crystals

We report a structure–property relationship in sulfur-based thermotropic ferroelectric nematic (NF) materials.

Unraveling the temperature-responsive solvation structure and interfacial chemistry for graphite anodes

Correlations between the temperature-responsive solvation structure, interfacial chemistry and performance of graphite anodes are revealed to understand the structure–property relationships, providing insights into designing temperature-adaptative batteries.

Active learning for regression of structure–property mapping: the importance of sampling and representation

We develop an active workflow for calibrating microstructure–property relationships when a large dataset of microstructures is available, but the cost associated with evaluating the properties associated is high.

Quantitative structure–property relationship study of constrained geometry catalysts for olefin polymerization

The quantitative structure–property relationship (QSPR) of constrained geometry catalysts (CGCs) has been analyzed by combining density functional theory (DFT) and multivariate linear regression (MLR).

Supramolecular polymerization and bulk properties relationship in ester-functionalized N-annulated perylenediimides.

The synthesis of a series of N-annulated perylenediimides (NPDIs) 1-4 with an ester group and an alkyl spacer of different length in the peripheral chains was carried out, and the influence of the side chain architecture on the self-assembly, both in solution and in the solid state, was investigated. Solution studies evidenced that the carbonyl group plays a key role in the supramolecular organization of these derivatives, changing from an H-type isodesmic polymerization (4) to a J-type cooperative process as the spacer length decreases (1-3). On the other hand, bulk assays revealed an odd-even effect that correlates with the length of the alkyl spacer. Whereas the odd-spaced derivatives (2 and 4) organize in a disordered columnar hexagonal fashion, the even-spaced ones (1 and 3) show the formation of multiple crystalline (and liquid crystalline) structures. The results presented herein highlight the importance of side chain functionalization in the design of building blocks for in-solution and bulk purposes.

A novel bulk (Nb,Zr,Pt)67Ti33 high-entropy alloy superconductor: synthesis and structure–property relationship

We report a novel multi-phase (Nb,Zr,Pt)67Ti33 high-entropy alloy superconductor with a focus on understanding the relationship between its functional properties and microstructure.

Probing the structure–property relationships of supported copper oxide nanoclusters for methane activation

Amorphous metal-oxide nanoclusters are investigated using DFT and machine learning for selective oxidation of methane.

Oxidation Tuned Cu 1.94 S Nanostructures for Ultrafast Charge and Discharge

Morphological control is an effective approach to enhance the rate performance of nanostructured electrode materials, offering a promising solution for alleviating energy concerns. We have utilized a seed-mediated growth method to synthesize hexagonal djurleite (Cu 1.94 S) nanoplates and nanoflowers under N 2 and air, respectively. The influence of the morphology on the ion interaction has been investigated in the storage process through half-cell electrochemical energy storage. Cu 1.94 S nanoplates performed a higher specific capacity of 193 mAh g −1 at a high rate of 8 A g −1 than nanoflowers and showed excellent cycle stability over 4,000 cycles with capacity retention of 80.8%. The relationship between morphology and electrochemical performance was explored through further electrochemical characterization. It is found that the stacking of hexagonal surfaces of nanoplates increases the contact area of the electrode material and reduced resistance, leading to faster ion migration and a more complete redox process, ultimately contributing to a higher specific capacity. Our study has enhanced the understanding of structure–property relationships for electrode material, providing an insightful approach for the preparation of electrode materials suitable for ultrafast charge and discharge.

Size and orientation of polar nanoregions characterized by PDF analysis and using a statistical model in a Bi(Mg1/2Ti1/2)O3–PbTiO3 ferroelectric re-entrant relaxor

Local structure information of relaxor ferroelectrics is key to a clear understanding of their structure–property relationships. The size of polar nanoregions is determined based on the local atomic displacement and dielectric response.

Structure–mechanical property relationships of 3D-printed porous polydimethylsiloxane films

Abstract Complex microstructures can be produced from different base materials by combining three-dimensional (3D) printing technology and ink formulations. The surface wettability of the 3D-printed porous polydimethylsiloxane (PDMS), particularly its superhydrophobic property, strongly depends on its physical structure. However, the mechanism underlying the effect of the microporous structure on the mechanical properties is not understood, which seriously constrains the structural–functional integration design of the 3D-printed superhydrophobic porous PDMS. To solve this problem, we studied the influence of the printing parameters on the mechanical properties in the compression and tension directions using a finite element method. The results showed that the load transfer path of the 3D-printed porous PDMS was along the overlapping area of the adjacent filaments. As the filament spacing decreased or the filament diameter increased, the elastic modulus of the porous PDMS was enhanced, improving its resistance to tensile and compressive deformation. A quantitative relationship was established between the relative densities of the porous PDMS films and their relative elastic moduli. This study provides theoretical guidance for the structural–functional integration design of 3D-printed superhydrophobic porous PDMS.

TOPOLOGICAL ASPECTS ON CORONENE GRAPH USING SOME GRAPH OPERATORS

The Topological index is a numerical parameter of molecular graph which correlates its QSPR(Quantitative Structure Property Relationships) and QSAR(Quantitative Structure Activity Relationships). In this article, we compute topological indices of some graphs obtained from k-Coronene graph using some graph operations.

The Origin of Collective Dielectric Relaxation Process in Ferroelectric and Antiferroelectric Phases of Liquid Crystals

Dielectric spectroscopy has proven as an important tool for the characterization of ferroelectric and antiferroelectric phases observed in the thermotropic chiral liquid crystals compounds. These compounds generally have paraelectric smectic A (SmA*) phase, ferroelectric smectic C (SmC*) phase and antiferroelectric smectic C (SmCA*) phase. In some compounds, ferroelectric (SmCg*) phase is also found. Dielectric spectra of these phases under planar alignment of the molecules are sometimes complex but rich in information and are very helpful in the determination of the structure of these phases. In the SmA* phase, a mode in high kHz region is observed. In the SmC* phase, a relaxation mode observed in low kHz region having high dielectric strength. However, in the SmCg* phase observed mode relaxation frequencies lies in same frequency window as SmC* phase but their dielectric strength was less than at least one order magnitude in comparison to observed mode of SmC* phase. In the SmCA* phase, dielectric spectrum contains two relaxation modes observed in kHz and MHz regions respectively. The dielectric strengths of these two modes are very small and less than at least one/two order magnitude in comparison to observed mode of SmA*/ SmC* phases. These observed relaxation processes are discussed as a function of temperature and bias electric field and their origin is also examined in the light of the experimental work. Dielectric parameters of the above phases observed in such material are discussed with regards to their structure property relationship.

Interpretable attention-based multi-encoder transformer based QSPR model for assessing toxicity and environmental impact of chemicals

The rising demand from consumer goods and pharmaceutical industry is driving a fast expansion of newly developed chemicals. The conventional toxicity testing of unknown chemicals is expensive, time-consuming, and raises ethical concerns. The quantitative structure–property relationship (QSPR) is an efficient computational method because it saves time, resources, and animal experimentation. Advances in machine learning have improved chemical analysis in QSPR studies, but the real-world application of machine learning-based QSPR studies was limited by the unexplainable ‘black box’ feature of the machine learnings. In this study, multi-encoder structure-to-toxicity (S2T)-transformer based QSPR model was developed to estimate the properties of polychlorinated biphenyls (PCBs) and endocrine disrupting chemicals (EDCs). Simplified molecular input line entry systems (SMILES) and molecular descriptors calculated by the Dragon 6 software, were simultaneously considered as input of QSPR model. Furthermore, an attention-based framework is proposed to describe the relationship between the molecular structure and toxicity of hazardous chemicals. The S2T-transformer model achieved the highest R2 scores of 0.918, 0.856, and 0.907 for logarithm of octanol-water partition coefficient (Log KOW), octanol-air partition coefficient (Log KOA), and bioconcentration factor (Log BCF) estimation of PCBs, respectively. Moreover, the attention weights were able to properly interpret the lateral (meta, para) chlorination associated with PCBs toxicity and environmental impact.

Synthesis of Vis/NIR BOPYINs and their Dual-emission, AIE, and Viscosity Response Properties

Near infrared (NIR) organic dyes with fast fluorescence response in solution, aggregation and solid states are useful in bioimaging field. Here, BOPYIN derivatives featuring electron-donating (triphenylamine) and/or the electron-accepting group (p-cyanophenyl) on BOPYIN core with aggregation-induced emission (AIE), dual-emission, and viscosity response in visible (BOPYIN-1, 3, 5) and NIR (BOPYIN-2, 4, 6, 7, 8) region were synthesized and characterized. Typical dual-emission phenomenon is detected in BOPYIN-2, the fluorescence quantum yields are 40.19 % and 28.5 % in solid and solution state, respectively. BOPYIN-2, 4, 6 show significant increase in fluorescence intensity with the addition of water (AIE). With the increasing of viscosity, the fluorescence intensity increased significantly from 1.79 to 3.54-fold for BOPYIN-3-6, 8. The structure-optical properties relationship was further discussed by single crystals and DFT calculation. We firmly believe that this study will provide guidance for the rational design of versatile NIR luminescent materials.

Fracture behavior of high‐performance carbon fiber composites toughened by reactive polyetherimide

AbstractCarbon fiber‐reinforced epoxy composites (CFECs) continue to grow in demand for aerospace, mass transportation, electric vehicle, and energy efficient architecture due to their lightweight, high strength, and high modulus. However, CFECs are susceptible to delamination upon impact which can lead to premature structural failure. This paper investigates the interlaminar fracture toughness of unidirectional CFECs based on reactive polyetherimide (rPEI) modified multifunctional epoxy matrix system. The matrices were cured formulations of tetraglycidyl diamino diphenyl methane, triglycidyl para‐amino phenol, rPEI having different molecular weights (MW) and diaminodiphenyl sulfone. Multi‐phase morphologies were observed from the resin castings and CFECs containing different MW rPEI modifiers. Results show that the mode I fracture toughness (GIC) of the rPEI‐toughened CFECs can be increased by as much as 150% over the unmodified CFECs based on the MW and type of phase morphology that promotes crack‐bridging mechanism. In addition, rPEI‐modified CFECs exhibit better property retention (~80% of GIC) after prolonged solvent exposure.Highlights A processing‐structure–property relationship based on CFECs is established. The amine‐terminated rPEI facilitates the formation of a strong bonding. The molecular weight effect of rPEI on the phase morphology was investigated. The rPEI enhances the interlaminar fracture toughness of the composites. The rPEI particle bridging is found to be responsible for the toughening effect.

Structure–Property Interplay Within Microporous Manganese Dioxide Tunnels For Sustainable Energy Storage

AbstractTunnel‐structured manganese dioxides (MnO2), also known as octahedral molecule sieves (OMS), are widely studied in geochemistry, deionization, energy storage and (electro)catalysis. These functionalities originate from their characteristic sub‐nanoscale tunnel framework, which, with a high degree of structural polymorphism and rich surface chemistry, can reversibly absorb and transport various ions. An intensive understanding of their structure–property relationship is prerequisite for functionality optimization, which has been recently approached by implementation of advanced (in situ) characterizations providing significant atomistic sciences. This review will thus timely cover recent advancements related to OMS and their energy storage applications, with a focus on the atomistic insights pioneered by researchers including our group: the origins of structural polymorphism and heterogeneity, the evolution of faceted OMS crystals and its effect on electrocatalysis, the ion transport/storage properties and their implication for processing OMS. These studies represent a clear rational behind recent endeavors investigating the historically applied OMS materials, the summary of which is expected to deepen the scientific understandings and guide material engineering for functionality control.