Interlocked Structures Research Articles

A theoretical approach for water saturation estimation in shaly sandstones

The process of quantitative reservoir characterization is a crucial component spanning from the initial estimation of in-place reserves to the optimization of production design. Water saturation is a critical parameter in quantitative reservoir characterization that directly impacts the in-place reserve estimates. In the case of shale-free sandstones, the computation of water saturation using Archie's equation yields fairly accurate results. However, in shaly sandstone reservoirs, the presence of multiple conductive entities in the rock poses additional complexities. Currently, various empirical, semi-empirical and theoretical equations are available in literature to estimate water saturation; nevertheless, none of these models is such that it is both theoretically sound and practically applicable.In this study, we present a novel approach that is both theoretically sound and practically applicable in computing water saturation in shaly sandstones. The fluid-saturated rocks are treated as a system consisting of two interlocked lattice-like structures, namely grains and fluid in the interconnected pores. The composite fluid comprising water and hydrocarbon is modeled using the general mixture rule, while the Hanai-Bruggeman equation is employed to model the electrical conductivity of this system. The resulting electrical conductivity equation is then utilized to compute water saturation in shaly sandstones.The proposed equation was effectively validated using the published core data. Furthermore, we compare the new model with other grain conductivity-based models such as Mixing model and Berg's model. Our findings show that while describing core data the proposed equation gives a lower average Relative Root Mean Squared Error (RRMSE) of 2.05% as compared to 7.56% and 5.58% for the Mixing and Berg's model available in literature, respectively. Moreover, the range of porosity and water conductivity for which the proposed model is applicable, surpasses that of the current models. We also suggest that this equation can be extended to other systems with a similar two interlocked lattice-like structure, such as carbonates.

Bio-inspired, metal additive manufacturing interlocked structures: Geometrically design and fracture performance analysis

Suture-inspired interlocked interfaces in nature exhibit promising industrial applications potentials in advanced mechanical structures, devices and equipment. In this paper, the parametric design of interlocked interfaces is performed, and selective laser melting (SLM) additive manufacturing tensile specimens and compact tension (CT) fracture specimens with sutured interfaces are harvested, where AlSi10Mg raw materials are used as constituent materials. Afterwards, compact tension tensile fracture experiments and corresponding finite element simulations were performed and compared, where force-displacement curves for different interface structural geometrical parameters were harvested. The mechanical properties and failure modes of the interlocked interface structures were analyzed through experiments and simulations verification. Crack-tip opening displacement (CTOD) and fracture energy criteria were used to evaluate the fracture toughness of the interlocked specimen interfaces. In addition, parametric analysis was carried out to investigate the influence of different interlocked structural parameters on the interface mechanical performances and failure features. Accordingly, it can be concluded that the interface strength, toughness, and failure mechanisms can be rationally tuned through given geometrical parameters of the re-entrant interface microstructures.

Effects of characteristic hydrates on the pore structure and fracture behavior of CAC bonded alumina-spinel castables

In the present study, the characteristic hydrates (CAH10, C2AH8, and C3AH6) were evaluated at individual curing temperatures (10 °C, 25 °C, and 40 °C), and the influences of these characteristic hydrates on the pore structure and fracture behaviors of alumina-spinel castables were systematically investigated. The results revealed that the specimens cured at 10 and 25 °C showed refined and complicated pore structures (higher fractal dimension) after treatment at 1600 °C owing to a higher dispersion of CaO and closely interlocked CA6 structures. In comparison, the enhanced hydration degree at 40 °C (mostly C3AH6) had no positive effect on the formation of nano-pores. Consequently, the generation of plate-like C2AH8 at 25 °C contributed to higher bonding strength after demolding and firing. The optimized microstructures facilitated cracks propagation within the matrixes and along aggregate-matrix interfaces, improving the toughness of castables and obtaining optimal comprehensive properties.

Beam-Like Topologically Interlocked Structures With Hierarchical Interlocking

Abstract Topologically interlocked materials and structures, which are assemblies of unbonded interlocking building blocks, are promising concepts for versatile structural applications. They have been shown to exhibit exceptional mechanical properties, including outstanding combinations of stiffness, strength, and toughness, beyond those achievable with common engineering materials. Recent work has established a theoretical upper limit for the strength and toughness of beam-like topologically interlocked structures. However, this theoretical limit is only attainable for structures with unrealistically high friction coefficients; therefore, it remains unknown whether it is achievable in actual structures. Here, we demonstrate that a hierarchical approach for topological interlocking, inspired by biological systems, overcomes these limitations and provides a path toward optimized mechanical performance. We consider beam-like topologically interlocked structures that present a sinusoidal surface morphology with controllable amplitude and wavelength and examine the properties of the structures using numerical simulations. The results show that the presence of surface morphologies increases the effective frictional strength of the interfaces and, if well-designed, enables us to reach the theoretical limit of the structural carrying capacity with realistic friction coefficients. Furthermore, we observe that the contribution of the surface morphology to the effective friction coefficient of the interface is well described by a criterion combining the surface curvature and surface gradient. Our study demonstrates the ability to architecture the surface morphology in beam-like topological interlocked structures to significantly enhance its structural performance.

Multicomponent flexible organic crystals

AbstractFlexible organic crystals are emerging as a potential candidate for smart materials and have aroused great interest over the past decade. In view of multicomponent supramolecular synthesis with a distinct advantage over single‐component approach on the control of molecular arrangements and physicochemical properties, we take note of various multicomponent flexible organic crystals in the range from organic co‐crystals, supramolecular salts, solvates, doping organic crystals to solid solution crystals, showing a great diversity of supramolecular architectures such as one‐dimensional columns, two‐dimensional layer packing, and three‐dimensional interlocked structures. Some of them serve as promising multifunctional materials with both flexibility and photoelectric properties such as fluorescence, optical waveguide, and ferroelectricity. In this review, we focus on the packing structures of multicomponent flexible organic crystals and their related mechanical properties, highlight typical research works, and point out the main possible directions that remain to be developed in this field. From the perspectives of crystal engineering and supramolecular chemistry, the flexible crystals outlined here should offer helpful information for further design and investigation on the elusive class of mechanically compliant crystalline compounds.

Dynamic Metalloporphyrin-Based [2]Rotaxane Molecular Shuttles Stimulated by Neutral Lewis Base and Anion Coordination.

A series of dynamic metalloporphyrin [2]rotaxane molecular shuttles comprising of bis-functionalised Zn(II) porphyrin axle and pyridyl functionalised macrocycle components are prepared in high yield via active metal template synthetic methodology. Extensive variable temperature 1 H NMR and quantitative UV-Vis spectroscopic titration studies demonstrate dynamic macrocycle translocation is governed by an inter-component co-ordination interaction between the macrocycle pyridyl and axle Zn(II) metalloporphyrin, which serves to bias a 'resting state' co-conformation. The dynamic shuttling behaviour of the interlocked structures is dramatically inhibited by the addition of a neutral Lewis base such as pyridine, but can also be tuned via post-synthetic rotaxane demetallation of the porphyrin axle core to give free-base, or upon subsequent metallation, Ni(II) [2]rotaxane analogues. Importantly, the Lewis acidic Zn(II) porphyrin axle component is also capable of coordinating anions which induces mechanical bond shuttling behaviour resulting in a novel optical sensing response.

Enhanced antimony removal within lamellar nanoconfined interspaces through a self-cleaning MXene@CNF@FeOOH water purification membrane

MXenes as two dimensional nanocarriers are promising candidate materials for advanced water purification membranes. Nevertheless, the practical applications of MXene-based membranes are hindered by their poor mechanical strength and widespread fouling issue. Herein, we report a free-standing nanocomposite membrane for the adsorptive separation of antimony (Sb) species from wastewater. Cellulose nanofibrils (CNFs) are adopted as functional scaffolds to assemble with Ti3C2Tx MXenes by forming interlocked structures that significantly promote the mechanical strength and toughness of the membrane, meanwhile, the in situ anchored β-FeOOH nanorods in the nanoconfined interspaces offer abundant active sites for enhanced pollutants removal. The as-prepared MXene@CNF@FeOOH (MCF) membranes demonstrate stable and pH-independent static removal capacities for Sb species. Also, their excellent interception performances for treating Sb containing synthetic effluents are confirmed in continuous flow-through modes, presenting a rapid wastewater purification with allowable emission standards under a high feeding flux of 102.3 L m−2h−1 bar−1. More importantly, the MCF membranes exhibit unique self-cleaning capability via photo-Fenton degradation of the adsorbed organic dye by 90% within 1 h. Molecular dynamics simulations further support their superior dynamic removal performance toward Sb species. This work sheds light on designing mechanically robust MXene-based water purification membranes with favourable self-cleaning property.

Scaling, saturation, and upper bounds in the failure of topologically interlocked structures

Topological Interlocking Structures (TIS) have been increasingly studied in the past two decades. However, some fundamental questions concerning the effects of Young’s modulus and the friction coefficient on the structural mechanics of the most common type of TIS application – centrally loaded panels – are not yet clear. Here, we present a first-of-its-kind parametric study that aims to clarify how these two parameters affect multiple aspects of the behavior and failure of centrally-loaded TIS panels. This includes the evolution of the structural response up to and including failure, the foremost structural response parameters, and the residual carrying capacity. We find that the structural response parameters in TIS panels scale linearly with Young’s modulus, that they saturate with the friction coefficient, and that the saturated response provides an upper-bound on the capacity of centrally loaded TIS panels reported in the literature. This, together with additional findings, insights, and observations, comprise a novel contribution to our understanding of the interlocked structural form.

Investigations of the failure mode for additive manufactured interlocked interface structure based on X-Ray CT image guided finite element analysis and experimental comparisons

Suture-inspired interlocked interfaces in nature exhibit promising industrial application potentials for advanced mechanical structures, devices and equipment. It is of significant scientific interest for studying the pull-out response and failure mode of interlocked structure as well as internal stress variations during the loading process. In this paper, finite element analysis (FEA) simulation based on X-Ray tomographic images is proposed for understanding the effects of manufacturing defects on the performances of interlocked structures, which are of critical importance for controlling the stress evolution of the interface structure and corresponding failure modes. Firstly, X-ray micro computed tomography (micro-CT) was applied for non-destructive scanning inspection of aluminum alloy additive manufacturing samples, high spatial resolution and calculation efficiency can be realized through tomographic image guided FEA scheme for generating high fidelity simulation results. Afterwards, non-uniform rational B-splines fitting method was employed for optimizing sample boundaries harvested from CT images, which allows smooth conversion from CT pixel images to high precision fitted finite element model. The B-spine fitting model can significantly improve the computational efficiency for finite element simulation without losing calculation reliability and resolution, overcoming the inherent contradictions between efficiency and resolution of the traditional pixel image finite element method. Finally, considering the mechanical contributions and interactions of external and internal porosity defects, the failure modes of the interlocked structures were further analyzed based on the results of finite element analysis.

Formation of Direction-Controllable Pseudorotaxane and Catenane Using Chemically Cyclized Oligodeoxynucleotides and Their Noncovalent RNA Labeling.

The formation of interlocked structures, such as rotaxane and catenane, enables noncovalent conjugations. We previously confirmed that the chemically cyclized pseudorotaxane-forming oligodeoxynucleotides (prfODNs) with double-tailed parts formed a pseudorotaxane structure with the target DNA and RNA via the slipping process. Here, we report the one-step synthesis of cyclized prfODNs from alkyne-modified ODNs, after which we investigated the properties and mechanism of the slipping process and performed noncovalent RNA labeling with prfODNs. Additionally, the catenane structure was formed by the combination of pseudorotaxane formation with a 5'-end-phosphorylated RNA and enzymatic ligation. The newly synthesized prfODN represents a new tool for achieving the noncovalent conjugation of various functional moieties to RNAs.

Sustainable and Tough MXene Hydrogel Based on Interlocked Structure for Multifunctional Sensing

Traditional hydrogel sensors containing MXenes as a conductive substrate will inevitably face the problem of excessive stacking of MXene nanosheets, which limits electron transport, thus reducing conductivity and sensitivity. Moreover, existing MXene hydrogels generally exhibit poor mechanical properties and fragility. In addition, it is necessary to prepare degradable electronic skins for reducing environmental pollution and recycling energy materials─MXene. How to find a balance between mechanical properties and degradation properties is a challenge. In this work, we overcome this challenge by combining a dynamic covalent strategy and establishing a self-modified interlocked structure. A biodegradable physically cross-linked hydrogel (OMDDH─ordered MXene dynamic degradable hydrogel) is constructed, and a highly interconnected three-dimensional (3D) MXene@CS-Pba network is prepared, thus endowing the sensor with excellent conductivity (24 × 10–4 S cm–1). For excellent mechanical properties, dynamic covalent interactions, hydrogen-bonding interactions between the dual networks, and chain entanglement of poly(vinyl alcohol) (PVA) totally build interlocked structures, thus endowing the hydrogel with excellent mechanical strength (1000 kPa). In an acidic environment, the dynamic covalent bond is broken, and the chain entanglement of PVA is also disentangled due to the disruption of the electrostatic equilibrium, resulting in the release of MXene for recycling (recycling conductivity: 22 × 10–4 S cm–1). Undoubtedly, we exhibit a strategy to construct ordered and degradable MXene hydrogels possessing excellent conductivity, high mechanical strength, and degradation performance, which lays the sensors’ wide applications in smart devices.

Solvent-Controlled Quadruple Catenation of Giant Chiral [8+12] Salicylimine Cubes Driven by Weak Hydrogen Bonding.

Mechanically interlocked structures are fascinating synthetic targets and the topological complexity achieved through catenation offers numerous possibilities for the construction of new molecules with exciting properties. In the structural space of catenated organic cage molecules, only few examples have been realized so far, and control over the catenation process in solution is still barely achieved. Herein, we describe the formation of a quadruply interlocked catenane of giant chiral [8+12] salicylimine cubes. The formation could be controlled by the choice of solvent used in the reaction. The interlocked structure was unambiguously characterized by single crystal X-ray diffraction and weak hydrogen bonding was identified as a central driving force for the catenation. Furthermore, scrambling experiments using partially deuterated cages were performed, revealing that the catenane formation occurs through mechanical interlocking of preformed single cages.

Solvent‐Controlled Quadruple Catenation of Giant Chiral [8+12] Salicylimine Cubes Driven by Weak Hydrogen Bonding

AbstractMechanically interlocked structures are fascinating synthetic targets and the topological complexity achieved through catenation offers numerous possibilities for the construction of new molecules with exciting properties. In the structural space of catenated organic cage molecules, only few examples have been realized so far, and control over the catenation process in solution is still barely achieved. Herein, we describe the formation of a quadruply interlocked catenane of giant chiral [8+12] salicylimine cubes. The formation could be controlled by the choice of solvent used in the reaction. The interlocked structure was unambiguously characterized by single crystal X‐ray diffraction and weak hydrogen bonding was identified as a central driving force for the catenation. Furthermore, scrambling experiments using partially deuterated cages were performed, revealing that the catenane formation occurs through mechanical interlocking of preformed single cages.

Interlocked structures on active duty

Interlocked structures on active duty

Post‐Mechanical Bond Formation Desymmetrization Approach to Obtain Mechanically Planar Chiral Rotaxanes

AbstractThe preparation of chiral mechanically interlocked molecules has experienced a great development in the last decade, showing a wide range of applications, including catalysis and molecular machinery. New types of chirality have emerged as a consequence of the mechanical bond, such as mechanically planar chirality, which can exist even when both components are achiral. The mechanically planar chirality in such interlocked structures is usually created during the assembly of the rotaxane architecture. Recently, Tian, Zhu and coworkers decoupled the creation of mechanically planar chirality and assembly of the mechanical bond by using a desymmetrizing Suzuki‐Miyaura reaction of a series of mechanically prochiral rotaxanes. This strategy afforded the target chiral interlocked products showing up to 96.5 : 3.5 enantiomeric ratio.

On Quasi-Static and Dynamic Compressive Behaviors of Interlocked Composite Kagome Lattice Structures

Abstract The quasi-static and dynamic compressive behaviors of carbon fiber-reinforced plastic (CFRP) Kagome lattice structures subjected to quasi-static load and low-velocity impact were investigated experimentally and numerically. CFRP Kagome lattice structures were fabricated by using the interlocking method. The quasi-static compression and low-velocity impact experiments were carried out and the failure mechanisms of CFRP Kagome lattice structures were explored. A user-defined material subroutine (VUMAT) involving three-dimensional Hashin criterion and progressive damage evolution was developed and implemented in the refined finite element (FE) model to model the failure of composite lattice structures. Good agreement is achieved between FE simulations and experimental results. It is shown that both in-plane stiffness and the failure mode of CFRP Kagome lattice structure are sensitive to the load directions. CFRP Kagome lattice structures subjected to quasi-static load experience elastic deformation, bending/kinking failure, rib fracture, and structure collapse sequentially. CFRP Kagome lattice structures subjected to low-velocity impact suffer from the multiple fractures at the slots and the maximum peak loads of dynamic response increase with increasing the impact velocity.

Perception‐to‐Cognition Tactile Sensing Based on Artificial‐Intelligence‐Motivated Human Full‐Skin Bionic Electronic Skin (Adv. Mater. 31/2022)

Electronic Skin In article number 2202622, by integrating the triboelectric effect with the supercapacitive iontronic effect, Yang Li, Guozhen Shen, and co-workers report an artificial intelligence (AI)-motivated full-skin bionic (FSB) e-skin based on bionic vellus hair and epidermis–dermis–hypodermis double interlocked microcone structures and demonstrate its smart application prospects from tactile perception to advanced intelligent tactile cognition.

Outpatient care through cross-sector prehabilitation and rehabilitation concepts in outpatient hip and knee arthroplasty

Kein noch so flammender Appell eines Gesundheitspolitikers hat alle Versorgungsstrukturen unseres Gesundheitssystems so zur Überprüfung eigener Effizienz und Einsparpotenziale gezwungen, wie das SARS-CoV‑2. Fast-Track-Chirurgie, lange vor der aktuellen Pandemie entwickelt, kann auch unter Einbindung verzahnter Versorgungsstrukturen ein unverzichtbares Element moderner Krankenhausroutinen werden. Durch deutlich kürzere Krankenhausverweildauern, sinkende Komplikationsraten sowie durch zusätzliche Stärkung der Eigenkompetenz und Motivation der betroffenen Patientinnen und Patienten, kann die Patientenzufriedenheit und das klinische Outcome verbessert werden. Krankenhauspersonal könnte entlastet und Gesamtkosten, auch durch Einbindung externer Prähabilitationszentren, gespart werden. Es gilt nun, weiter Standards zum Aufbau und zur Umsetzung entsprechend abgestimmter Prähabilitations- und Rehabilitationskonzepte bei geplanter endoprothetischer Versorgung von Hüft- und Kniegelenken zu entwickeln und idealerweise gleichzeitig Ressourcen durch regionale Vernetzung zu sparen.

Computer modeling approach for multilayer interlocked woven structures

Abstract This study aimed to simulate the geometric modeling of the multilayer interlocked woven structures in three dimensions (3D) using computer aided design (CAD). The simulation of yarn was composed of fibers assembled together for presenting the structures. Two and three layers for multilayer interlocked woven structures were simulated with a filament assemble model and compared with yarn path of single line model. The result showed that the new model developed was more realistic than the previous works. The strength of these models is required as an input to many computational methods such as simulation the tensile/bending properties of fabrics structure or composite parts, forecasting the fiber volume fraction of fabrics.

Mechanically interlocked networks cross-linked by a molecular necklace

Molecular necklaces have attracted much research attention due to their unique topological structures. Although numerous molecular necklaces with exquisite structures have been constructed, it remains a major challenge to exploit the functions and applications associated with their fascinating architectural and dynamic characteristics. Herein, we report a class of mechanically interlocked networks (MINs) cross-linked by a molecular necklace, in which multiple crown ethers are threaded on a hexagonal metallacyclic framework to furnish a cross-linker with delicate interlocked structures. The molecular necklace cross-linker possesses multiple peculiar advantages: multivalent interactions and rigid metallacycle framework guarantee robust features of MINs while the motion and dissociation of the interlocked structures bring in notable mechanical adaptivity. Moreover, the MINs could respond to the stimuli of K+ and Br−, which lead to the dethreading of crown ether and even the complete decomposition of molecular necklace, respectively, showing abundant active properties. These findings demonstrate the untapped potential of molecular necklaces as cross-linkers and open the door to extend their advanced applications in intelligent supramolecular materials.