The development of energy-efficient solutions for indoor air control systems is a key challenge in sustainable processes. Metal–Organic Frameworks (MOFs) offer great potential for this purpose; however, their practical implementation in HVAC (Heating, Ventilation, Air Conditioning) is often hindered by difficulties in material handling and effective confinement within operating devices, mainly due to their powdered form.

This study addresses these limitations by developing MOF-based composites: hybrid materials obtained by embedding Al-fumarate MOF particles into a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrix. The obtained samples successfully combine the water adsorption properties of the dispersed crystalline phase with the mechanical robustness and flexibility of the polymer. Two easily scalable fabrication strategies were used: Mixed-Matrix Membranes (MMMs) via solvent casting and non-woven fabrics via electrospinning.

The MMMs retain approximately 90% of the pristine MOF surface area and water vapor adsorption capacity, with minimal loss of active sites. The membranes exhibit remarkable water vapor adsorption characteristics, including fast kinetics and negligible hysteresis, which are key parameters for efficient dehumidification and passive cooling cycles, contributing to reduced energy consumption. Notably, these hybrid systems outperform traditional desiccants in both adsorption capacity and reversibility, highlighting their potential for sustainable HVAC applications. The non-woven architecture is particularly promising for maximizing MOF particle accessibility, thanks to its typical texture.

Developed composites also offer solutions in different fields, such as anti-fogging systems in packaging and humidity sensing. Work is currently underway to assess the performance of developed composite systems in prototypical devices.

Architected metamaterials derive their exceptional mechanical performance from precisely tailored topologies, enabling access to regions of materials selection charts unattainable by conventional materials. While substantial advances have been achieved at micro-, meso-, and macroscales, further improvements are increasingly constrained, motivating exploration of nanoscale architected materials, where surface and size effects dominate. Here, we resort to molecular dynamics simulations to systematically explore the mechanical response of nickel-based nano-architected metamaterials. By varying topology, relative density, crystallinity, and grain size, we demonstrate the broad tunability of elastic moduli, strength, and Poisson’s ratio enabled by the rational design of underlying nano-architecture. Notably, the proposed nano-architected metamaterials outperform most previously reported architected materials at comparable densities, highlighting the effectiveness of nanoscale topology-driven design. Atomistic analyses reveal that nanoscale free surfaces promote dislocation nucleation while inhibiting dislocation propagation, leading to flow stresses exceeding those of bulk counterparts. To bridge length scales and draw inspiration from crystallography, we further design and 3D print hierarchical polymeric metamaterials and experimentally characterize their mechanical behavior. Despite being fabricated from an intrinsically brittle polymer, these structures exhibit topology-dependent stiffness and strength, alongside ductile plastic deformation and enhanced toughness, attributable to their hierarchical architectures. Together, this work establishes a crystallography-inspired architectural design paradigm for mechanical metamaterials and imparts scalable design guidelines for achieving lightweight, mechanically efficient structures across multiple length scales.

Purpose

This study aims to explore the crystallographic properties and microstructural development of Al6061-TiC-borophene hybrid composite materials and their impact on mechanical and tribological properties. Crystal engineering in aluminum-based composite materials is a crucial step toward enhancing their mechanical properties, hardness, and wear resistance. The addition of titanium carbide particles as a reinforcing agent in the Al6061-TiC-borophene composite material provides a hybrid strengthening mechanism. Crystal engineering in Al6061-TiC-borophene composite materials aims to explore their crystal structure formation and the interaction between the phases, which enhance the structural and functional properties.

Approach

The crystallographic characteristics of Al6061-TiC-borophene hybrid composite materials are studied using microstructural characterization and phase characterization methods. In the composite synthesis process, heterogeneous nucleation is carried out using TiC particles, which refine the aluminum crystal structure. Borophene helps in nanoscale reinforcement and interfacial bonding. X-ray diffraction, scanning electron microscopy, and electron backscatter diffraction methods are used to study the crystallographic characteristics.

Findings

The reinforcement of TiC and borophene contributes to better crystallographic stability and enhanced mechanical properties in Al6061. The development of refined equiaxed grains and stable interfacial compounds improves hardness and wear properties. In addition, it improves load-carrying properties. The reinforcement of TiC improves stiffness and acts as barriers to dislocations. Borophene contributes to strengthening and stress transfer. The crystal structure refinement contributes to reducing microstructural defects and improving uniformity in the composite matrix. This improves microstructural properties compared to conventional aluminum alloys.

Practical Implication

The optimized crystal structure of Al6061-TiC-borophene composites provides strong potential for use in lightweight structural components used in the aerospace, automotive, and advanced manufacturing industries. The enhanced wear resistance, strength-to-weight ratio, and thermal stability of the composites make them appropriate for the development of advanced engineering systems.

The development of sustainable porous materials for gas capture and environmental remediation is a central challenge in materials chemistry. Herein, we report the green, scalable synthesis and multifunctional integration of a novel Fe(II)-based metal–organic framework, Fe(trz₂An)·3H₂O (trz₂An = 3,6-N-ditriazolyl-2,5-dihydroxy-1,4-benzoquinone), designed for CO₂ capture and pollutant removal. The material is obtained via an optimized aqueous synthetic route under mild conditions achieving high crystallinity and yields up to 85%. The use of NH₃ as a weak base significantly enhances sustainability metrics, leading to a space–time yield of ~10,000 kg m^-3 day^-1, among the highest reported for green MOF syntheses.

Single-crystal X-ray diffraction reveals a 3D neutral framework with ultramicroporous channels (~3.8 Å), closely matching the kinetic diameter of CO₂. The structure exhibits high porosity (28.8% void volume), excellent thermal stability up to 300 °C, and remarkable stability in aqueous environments across a pH range of 3-8.

CO₂ adsorption studies show an uptake of ~2500 μmol g^-1 at 30 °C, with low differential heats of adsorption indicative of physisorption and facile regeneration. Beyond gas capture, the material demonstrates promising ion-exchange capabilities toward toxic heavy metals, such as Cd²⁺ and Pb²⁺, with uptake capacities up to 300-500 mg g^-1, highlighting its potential for water remediation.

Furthermore, the MOF has been successfully incorporated into biopolymer-based matrices, specifically carboxymethylcellulose (CMC), to form composite membranes. Ongoing studies indicate good reproducibility and promising separation performance, supporting the development of hybrid materials for practical applications.

These results establish Fe(trz₂An)·3H₂O as a versatile and scalable platform for integrated gas capture and environmental remediation technologies.

Poly(butylene terephthalate) (PBT)/multiwalled carbon nanotube (MWCNT) composites were prepared using a simple and reliable melt mixing technique to understand how the addition of nanotubes affects the crystallization behavior and thermal properties of PBT. The non-isothermal crystallization process was studied using differential scanning calorimetry (DSC), while hot-stage polarized optical microscopy (HSPOM) was used to observe changes in microstructure at different cooling rates.

From a practical point of view, adding MWCNTs changes how PBT crystallizes. As the nanotube content increases, the viscosity of the system also increases, which restricts the movement of PBT chains and makes crystallization more difficult. Kinetic analysis shows that the basic crystallization mechanism remains similar, but the rate is influenced by the presence of MWCNTs. For pure PBT, the modified Avrami exponent (n) is 3.0 at a cooling rate of 15 °C min⁻¹ and increases to 3.7 at 30 °C min⁻¹. When 1 wt% MWCNT is added, the values slightly decrease to 2.9 and 3.1 at 15 °C min⁻¹ and 30 °C min⁻¹, respectively, indicating heterogeneous nucleation with minor changes in growth behavior. Kissinger analysis also suggests that higher energy is required for crystallization after adding MWCNTs.

Another important observation is the reduction in the crystal growth parameter after adding MWCNTs. It decreases from 6.1× 10⁴ for pure PBT to 3. × 10⁴ for the 1 % MWCNT into PBT. This shows that although MWCNTs help in nucleation, they also act as barriers that slow down the growth of crystals.

X-ray diffraction (XRD) results confirm that the crystal structure of PBT does not change with the addition of MWCNTs, as no new peaks are observed. However, a slight increase in crystallinity is seen due to the nucleating effect of the nanotubes.

Overall, MWCNTs play a dual role in the PBT matrix: they promote nucleation while also restricting chain movement and crystal growth. This balance leads to a more controlled crystallization process, which can be useful for improving material performance in practical applications.

Metal–organic frameworks (MOFs) are porous materials formed by the self-assembly of metal nodes and organic linkers. MOFs based on redox-active ligands represent versatile platforms for the design of functional materials, while the inclusion of chiral moieties introduces additional stereochemical complexity. Therefore, the combined influence of chirality and redox activity on framework formation and resulting properties has not yet been comprehensively investigated.

Here, we report the design and synthesis of novel redox-active linker benzoquinone derivatives functionalized at the 2,5-positions with chiral amino acid moieties, with the goal of introducing chirality into the ligand framework. These chiral linkers were employed in the assembly of MOFs with both transition metal and lanthanide ions under solvothermal conditions. Synthetic parameters, i.e., i) solvent choice, ii ) temperature, iii) reaction time, and iv) precursor ratios, were systematically varied to investigate their influence on framework formation, crystallinity and linker incorporation.

The synthesized MOFs were fully characterized by single-crystal and powder X-ray diffraction and spectroscopic and elemental analyses to assess their structural framework and chemical composition.

The obtained results show that both the chirality of the linkers and the choice of metal ion play an important role in the assembly of the frameworks, influencing structural characteristics and coordination environment. The comparison with non-chiral analogues emphasizes the effect of amino acid-derived chirality. These observations outline consistent trends that can support the further design of chiral redox-active MOFs.

The diverse optical, magnetic, and electronic behaviors of crystalline materials arise from their structure and the nature of their coordination environment. Metal–organic frameworks (MOFs) based on anilate linkers possess rich composition tunability with complex multidimensional architectures, yet multivariate architectures incorporating secondary ligands remain comparatively underinvestigated. Here, we report a comprehensive investigation of the synthetic conditions governing the assembly of multivariate MOFs constructed from anilate and secondary linkers, enabling precise control over their composition and peripheral functionalities. Controlled assembly was achieved by systematically varying synthetic parameters (solvothermal, hydrothermal, and reflux conditions), with particular attention to mild reaction regimes and reaction times to assess their effect on linker incorporation. In addition, post-synthetic linker exchange was explored as a complementary approach to assess the effective tunability of the framework functional properties and to gain insight into coordination dynamics, particularly in how electron-withdrawing substituents modulate exchange efficiency and incorporation patterns. The resulting materials were characterized by single-crystal and powder X-ray diffraction, spectroscopy, and elemental analysis to confirm framework structures, ligand incorporation, and functional integrity. Our findings reveal that careful control of synthetic conditions and post-synthetic linker exchange enables frameworks with predictable multivariate ligand distributions, tunable photophysical properties, and defined coordination dynamics, highlighting design principles for multifunctional MOFs with enhanced compositional and functional control.

This study investigates the electrical behavior of conductive polypyrrole (PPy) thin films designed for flexible electrode applications in wearable sensing systems. A reference p-toluenesulfonic acid-doped PPy (PPy-TSA) film was compared with graphene-modified PPy composites developed to enhance mechanical robustness and electrical stability under deformation.
Morphological analysis (SEM) shows that the reference PPy–TSA exhibits a typical cauliflower-like structure, while graphene incorporation induces elongated, layered features associated with well-dispersed nanosheets, without disrupting the polymer matrix integrity. XPS confirms that the chemical structure and doping state of PPy are preserved after graphene incorporation.
Mechanical characterization reveals that the reference PPy-TSA film exhibits a low Young’s modulus (~0.008 GPa), while graphene increases stiffness (~0.016 GPa) and improves mechanical robustness. In contrast, the PPy-PEG graphene system maintains a low elastic modulus (~0.009 GPa), indicating an optimal balance between flexibility and reinforcement.
Electrical measurements show that PPy-TSA exhibits a conductivity of ~208 S/cm, while graphene-modified films show reduced conductivity (~62 S/cm) due to incomplete percolation. However, these films retain conductivity within the range required for electrocardiographic (ECG) sensing, and temperature-dependent measurements (25-85 °C) confirm stable semiconducting behavior. Optical analysis reveals a redshift in the π–π* transition and enhanced VIS–NIR absorption, indicating a modified electronic structure without proportional improvement in macroscopic conductivity.
Overall, graphene incorporation improves mechanical robustness and signal stability while maintaining adequate conductivity for ECG applications. The PPy-PEG–graphene composite has the best balance between flexibility, conductivity, and signal quality, making it a promising candidate for flexible, gel-free wearable electrodes.

Co-additive effects of ytterbium (Yb) and neodymium (Nd) for efficient and stable CH₃NH₃PbI₃ (MAPbI₃) perovskite solar cells were investigated. Compared to single addition, co-addition of 0.5 at% Yb and Nd supported improvements in the photovoltaic characteristics, resulting in an increase in open-circuit voltage (Voc), short-circuit current density (Jsc), conversion efficiency (η) and stability. Morphological observation and crystal structure analysis showed that the grain boundaries within the perovskite layer were reduced, and stable, dense films were formed through crystal growth and orientation. Surface observation and composition analysis using energy-dispersive X-ray spectroscopy confirmed the presence of Pb, I, Yb and Nd elements in the perovskite crystal grain. The band structure and density of states predicted the state of carrier mobility near the valence and conduction band states. The electron density distribution of 4f and 5d orbitals of Yb and Nd ions and 5p orbital of the I ion was expected to promote the charge transfer related to the semi-conductive properties. The optical properties from ultraviolet to near-infrared regions were based on the excitation process between the 4f and 5d orbitals of Yb and Nd ions in the crystal. The co-doped system had stabilization while suppressing distortion in the coordination structure. The photovoltaic characteristics were discussed by comparing experimental and calculated results in J-V curves of the solar cell using SCAPS-1D simulation. The photovoltaic characteristics originate from the state of carrier diffusion while suppressing carrier recombination near the grain boundaries and interface between the perovskite film and hole-transporting layer. In the co-addition system, passivation occurred more effectively than in the single-addition system, resulting in photovoltaic characteristics with an increase in Jsc, Voc, η and stability.

The formation of hybrid crystalline materials based on organic and inorganic components is of considerable interest due to their structural diversity and potential applications in agrochemical and functional materials. In this work, the physicochemical interactions and phase equilibria in the ternary aqueous system Ca(ClO₃)₂·2CO(NH₂)₂ – CH₂ClCOOH·(C₂H₄OH)₃N – H₂O were systematically investigated over a temperature range from −24 to 60 °C. The study was carried out using the visual-polythermal method, which allowed the determination of solubility relationships and the construction of a complete polythermal phase diagram of the system. Analysis of the phase diagram revealed several crystallization regions corresponding to ice, Ca(ClO₃)₂·2CO(NH₂)₂·2H₂O, CH₂ClCOOH·(C₂H₄OH)₃N, and a newly formed crystalline phase with the composition CH₂ClCOOH·Ca(ClO₃)₂·(C₂H₄OH)₃N. The presence of a distinct crystallization field for this compound indicates the formation of a stable individual hybrid crystalline material in the studied system. The compound was isolated from solutions corresponding to its crystallization domain and subjected to chemical and physicochemical characterization. Elemental analysis results showed good agreement between experimental and calculated values for calcium, chlorate ions, and nitrogen, confirming the proposed stoichiometric composition. Infrared spectroscopy further supported the formation of the new hybrid compound. The spectra revealed characteristic vibrational bands associated with chlorate ions and carboxylate groups, as well as changes in the hydroxyl and amino group vibrations, indicating structural reorganization during complex formation. The obtained results demonstrate that the investigated system forms a stable organic–inorganic hybrid crystalline compound under specific temperature and concentration conditions. The constructed phase diagram provides valuable information on crystallization boundaries and phase stability. These findings contribute to a deeper understanding of intermolecular interactions and phase behavior in multicomponent aqueous systems and may serve as a physicochemical basis for the development of new complex-action defoliants and functional crystalline materials.