Application Of Porous Materials Research Articles

The implementation of M-integral in cross-scale correlation analysis of porous materials

The damage analysis caused by mesoscopic pores has attracted much attention in the development and application of porous materials. In this study, a novel application of M-integral is presented to establish a cross-scale correlation analysis of damaged porous materials. The multiscale damage analysis featured here can be proposed in two main steps. In detail, the first step is to construct a quantitative relationship between M-integral and porosity, where the values of M-integral for different porosity are calculated numerically. Subsequently, it applies the variation of M-integral with the material damage represented by a decrease in effective elastic modulus, and a cross-scale correlation between porosity and effective elastic modulus of porous material can be provided. In addition, an example is discussed to illustrate the specific application of this bridging parameter M-integral. The results confirm that M-integral can be an effective parameter bridging mesoscopic porosity and macroscopic damage, and is expected benefit to propose a convenient damage model of porous material. The findings should be of value in investigating the multiscale damage analysis of porous materials.

Emerging Mixed-Valence Porous Materials.

The development and applications of porous materials have been revolutionized over the past decades. To fine-tune their fascinating behaviors such as charge-transport, magnetic, and catalytic properties, one of the most effective strategies is incorporating mixed valency into the structures. This Concept provides recent progress on emerging crystalline porous materials, namely, metal-organic frameworks, metal-organic polyhedra, covalent organic frameworks, and hydrogen-bonded organic frameworks, where their mixed valency is either intrinsic or postsynthetically induced via an external stimulus. We further highlight the investigation of mixed valency and potential applications, which sheds light on the design and exploitation of mixed-valence crystalline porous materials.

Exploring the Micropore Functional Mechanism of N2O Adsorption by the Eucalyptus Bark-based Porous Carbon.

Nitrous oxide (N2O), recognized as a significant greenhouse gas, has received insufficient research attention in the past. In view of their low energy consumption and cost-effectiveness, the application of porous materials in adsorption is increasingly regarded as a potent strategy to reduce N2O pollution. In this study, a series of microporous porous carbons with a preeminent specific surface area (244.54-2018.08 m2 g-1), which are derived from the fast-growing eucalyptus bark, were synthesized by KOH activation at high temperatures. The obtained materials demonstrated a relatively fine N2O capture capability (0.19-0.68 mmol g-1) at normal temperature and pressure. More importantly, the optimal pore size affecting N2O adsorption (0.8 and 1.0 nm) has been detected, which is a meaningful view that has never been put forward in previous studies. The rationality of the N2O adsorption mechanism was also validated by combining the experimental analysis and Grand Canonical Monte Carlo (GCMC) simulation. The calculated results showed that 0.8 and 1.0 nm of the porous carbon were the preferred pore sizes for N2O adsorption, and the interaction force between N2O and the pore wall decreased with the increase of distance. This study provides a significant theoretical basis for the preparation of biomass porous carbon with excellent N2O adsorption performance and practical adsorption application.

Metal/covalent organic framework@silica double-layer core–shell composite: A high-performance liquid chromatographic stationary phase

Nowadays, metal/covalent organic frameworks (MOFs/COFs) have shown bright application prospects in the field of chromatographic separation due to their unique porous characteristics. However, chromatographic stationary phases prepared with only a single MOF or COF material have a few inherent defects, which keep them from satisfying the actual application fully. In contrast, MOF/COF composites have more superior properties that are more favorable for separation. Therefore, this study innovatively proposed a new strategy to apply MOF/COF modified silica composites for high performance liquid chromatography (HPLC). To be specific, using ethylenediamine as a linker, Zn-based MOF and imine-based COF were modified on the aminated silica gel layer by layer, and a MOF-5/COF@silica bilayer core–shell composite was successfully prepared. The composite of MOF and COF can complement each other in realizing the advantages of the two materials. The research results show that the MOF-5/COF composite can provide a large number of active sites with a variety of interaction forces for the analytes. The MOF-5/COF@silica stationary phase can separate a wide range of hydrophilic and hydrophobic substances, which can also be used for the effective detection of environmental hormones in lake water samples. This study verifies the feasibility of preparing MOF and COF co-modified silica gel composite to improve the separation performance of stationary phase, and demonstrates the superiority of the double-layer porous core–shell structure for efficient HPLC analysis. This provides a new idea for the further development and application of porous materials in the field of HPLC.

Mechanical properties of hierarchical porous lattices with microscopic porosity fabricated by combination of lattice design and HSSH process

The hierarchical porous lattice implant with microscopic porosity, which resembles the original human bone structure, has significant potential application value. The microscopic porosity in the hierarchical porous lattice implant plays a crucial role in transporting nutrients and promoting tissue regeneration. However, it is difficult to fabricate microscopic pores smaller than 200 μm by powder bed fusion (PBF) processes due to the limitations of the laser spot size. In this study, the preparation of a hierarchical porous lattice implant with microscopic porosity is proposed by coupling structure design with the high scanning speed - short hatch spacing (HSSH) process formation. The structure-versus-process relationship is used to control the size and distribution of the microscopic pores, which meets the requirements of modulus and high biocompatibility. This proposed process breaks the inherent law where the higher the porosity, the higher the modulus of the lattice for the same lattice type. The modulus and porosity of the hierarchical porous implants could be flexibly tuned over a wide range (0.1–1.8 GPa and 63–84 %, respectively). The microscopic porosity is mainly distributed near the contour of the core rod, and the macroscopic porosity and microscopic porosity are approximately 73.70 % and 8.22 %, respectively. The problem of large errors in fitting the hierarchical porous lattice modulus calculation model according to the Gibson-Ashby equation has been solved. The mechanism of microscopic porosity formation was also analyzed. Furthermore, this method has the advantage of universal applicability, providing a feasible way for the development and application of porous materials.

Investigation on the thermoelastic response of a porous microplate in a modified fractional-order heat conduction model incorporating the nonlocal effect

In recent years, the application of porous materials in practical engineering has become increasingly common. Under extreme thermal conditions, how to accurately describe the heat conduction and structural response of porous materials is a key issue in the structural safety and functional design of porous materials. Among them, it is particularly important to consider the size-dependent and memory-dependent effects for small-sized structures or microdevices of porous materials. To address these issues of porous structures and to guide their applications as well as optimization, this paper first investigates the thermoelastic transient response of porous microplates subjected to thermal and stress shocks at the left boundary based on the Atangana-Baleanu (AB) fractional-order generalized thermoelastic theory by considering nonlocal effects and fractional-order strain, which is combined with the thermoelasticity theory of porous materials and the dual-phase-lag (DPL) heat conduction model. The governing equations are then established and solved using the Laplace transform and its numerical inversion. Finally, the effects of newly defined fractional order parameters, nonlocal parameters and the initial magnitude of the mechanical shock on the dimensionless temperature, volume fraction field, displacement and stress distribution are discussed and displayed graphically.

How to Tailor Porous Boron Nitride Properties for Applications in Interfacial Processes.

The research of new porous materials for applications in interfacial processes is key to addressing global energy and sustainability challenges. For example, porous materials can be used to store fuels such as hydrogen or methane or to separate chemical mixtures reducing the energy currently required by thermal separation processes. Their catalytic properties can be exploited to convert adsorbed molecules into valuable or less hazardous chemicals, thereby reducing energy consumption or pollutants emissions. Porous boron nitride (BN) has appeared as a promising material for applications in molecular separations, gas storage, and catalysis owing to its high surface area and thermal stability, as well as its tunable physical properties and chemistry. However, the production of porous BN is still limited to the laboratory scale, and its formation mechanism, as well as ways to control porosity and chemistry, are yet to be fully understood. In addition, studies have pointed toward the instability of porous BN materials when exposed to humidity, which could significantly impact performance in industrial applications. Studies on porous BN performance and recyclability when employed in adsorption, gas storage, and catalysis remain limited, despite encouraging preliminary studies. Moreover, porous BN powder must be shaped into macrostructures (e.g., pellets) to be used commercially. However, common methods to shape porous materials into macrostructures often cause a reduction in the surface area and/or mechanical strength. In recent years, research groups, including ours, have started addressing the challenges discussed above. Herein, we summarize our collective findings through a selection of key studies. First, we discuss the chemistry and structure of BN, clarifying confusion around terminology and discussing the hydrolytic instability of the material in relation to its structure and chemistry. We demonstrate a way to reduce the instability in water while still maintaining high specific surface area. We propose a mechanism for the formation of porous BN and discuss the effects of different synthesis parameters on the structure and chemistry of porous BN, therefore providing a way to tune its properties for selected applications. While the syntheses covered often lead to a powder product, we also present ways to shape porous BN powders into macrostructures while still maintaining high accessible surface area for interfacial processes. Finally, we evaluate porous BN performance for chemical separations, gas storage, and catalysis. While the above highlights key advances in the field, further work is needed to allow deployment of porous BN. Specifically, we suggest evaluating its hydrolytic stability, refining the ways to shape the material into stable and reproducible macrostructures, establishing clear design rules to produce BN with specific chemistry and porosity, and, finally, providing standardized test procedures to evaluate porous BN catalytic and sorptive properties to facilitate comparison.

The Application of Porous Material in the Capillary Barrier System for Residual Soil Slope Stabilization

A drainage system that is used to flow excess rainfall infiltration is an excellent alternative to enhance lateral diversion capacity at the interface of Grade VI and Grade V soil slope layers thus delaying breakthrough occurrences. This study aims to explore the performance of porous transport layer on slope behavior via numerical simulation by GeoStudio SEEP/W. In this study, a 2-dimensional non-homogenous residual soil configuration model, which is composed of Grade VI and Grade V residual soil was constructed. Laboratory tests were conducted on the soil samples collected from the Faculty of Engineering, UTM JB to determine the soil properties as input parameters in numerical modeling. The soil slope model is designed as an infinite residual soil slope according to Jabatan Kerja Raya (JKR) design specification on the cut slope and fill slope with 27 ° inclination respectively. High rainfall intensities were chosen to represent rainfall infiltration in Johor. The slope model was modeled with a porous transport layer at the Grade VI and Grade V layer interfaces. The porous transport layer is introduced as the transport layer and its effectiveness is expected to be similar to the optimum compacted soil mix in the previous study. In addition, porous concrete as a transport layer is introduced and it must meet the adequate porosity and hydraulic conductivity requirements. The suction distribution pattern with depth and time was subsequently observed to identify the volume of infiltrated water and retention time in the transport layer. The porous transport layer is also expected to be efficient in diverting infiltrating water and decreasing the interface's suction distribution between Grade VI and Grade V soil layers. HIGHLIGHTS The water built up within the residual soil slope is one of the common factors of rainfall-induced residual soil slope failure thus porous transport layer introduced The detailed laboratory testing and numerical modelling conducted in order to identify the performance of porous transport layer within residual soil slope The application of porous transport layer sandwiched between residual soil is effective to decrease the water built up and matric suction thus decrease the risk of slope failure GRAPHICAL ABSTRACT

Electrodeposition of Polyporous Sn-Ni Coating in Deep Eutectic Solvents for Removing Organic Dyes.

Materials with a high specific surface area including a porous structure have been widely researched due to the applicability in the adsorption of various organic dyes. However, further application of porous materials is limited by the complicated and expensive preparation process. Herein, a Sn-Ni coating with a polyporous structure is successfully prepared via a simple and high-efficiency electrodeposition approach in deep eutectic solvents (DESs). The prepared Sn-Ni coating exhibits a uniform polyporous structure with a diameter of 15 μm. Furthermore, the coating shows excellent adsorption capacity in the removal of acid grain black organic dyestuff. With the rise of preparation temperature from 85 to 105 °C, the electrochemical active surface area and the ratio of nickel increase, which further enhance dye adsorption capacity.

Application of porous materials and structures for improving optical and thermal performance of inorganic and organic light-emitting diodes: A review

Light-emitting diodes (LEDs) are considered the most promising technology for future display and lighting applications due to their high efficiency, durability, long lifespan, and eco-friendliness. Inorganic and organic LEDs (LEDs and OLEDs) are the key components in current display and lighting applications. Porous materials are a fast-developing field of study that has unraveled and expanded an extensive array of novel properties and applications. The structural and morphological parameters of the hosted semiconductor can be controlled by modifying the pore size distribution, thickness, composition of the pore walls, geometry of the pore system, and its topology. Porous hosts provide the guest semiconductor with enhanced stability and versatility in terms of processing, which favors its integration in devices. This article reviews the current progress in the applications of porous materials and structures to improve the performance of LEDs and OLEDs. The use of the porous materials to enhance the optical performance of GaN-/InGaN-/ and AlGaN-based LEDs, porous silicon LEDs, OLEDs are presented. Furthermore, the applications of porous materials for the thermal management of LEDs are discussed.

Use of Porous Titanium Trabecular as a Bone Defect Regenerator: In Vivo Study

The application of porous materials is increasingly being used in orthopaedic surgery due to its good results. Bone growth within the pores results in excellent mechanical fixation with the bone, as well as good bone regeneration. The pores, in addition to being colonised by bone, produce a decrease in the modulus of elasticity that favours the transfer of loads to the bone. This research shows the results of an experimental study where we have created critical osteoperiosteal defects of 10 mm on rabbit’s radius diaphysis. In one group of 10 rabbits (experimental group) we have implanted a bioactive porous titanium cylinder, and in another group we have allowed spontaneous regeneration (control group). Mechanical tests were performed to assess the material. Image diagnostic techniques (X-ray, scanner and 3D scan: there are no references on the literature with the use of CT-scan in bone defects) and histological and histomorphometric studies post-op and after 3, 6 and 12 months after the surgery were performed. All the control cases went through a pseudoarthrosis. In 9 of the 10 cases of the experimental group complete regeneration was observed, with a normal cortical-marrow structure established at 6 months, similar to normal bone. Titanium trabecular reached a bone percentage of bone inside the implant of 49.3% on its surface 3 months post-op, 75.6% at 6 months and 81.3% at 12 months. This porous titanium biomaterial has appropriate characteristics to allow bone ingrowth, and it can be proposed as a bone graft substitute to regenerate bone defects, as a scaffold, or as a coating to achieve implant osteointegration.

Review of the fabrication and application of porous materials from silicon-rich industrial solid waste

Review of the fabrication and application of porous materials from silicon-rich industrial solid waste

Homogeneously Mixing Different Metal-Organic Framework Structures in Single Nanocrystals through Forming Solid Solutions.

Pore engineering plays a significant role in the applications of porous materials, especially in the area of separation and catalysis. Here, we demonstrated a metal–organic framework (MOF) solid solution (MOSS) strategy to homogeneously and controllably mix NU-1000 and NU-901 structures inside single MOF nanocrystals. The key for the homogeneous mixing and forming of MOSS was the bidentate modulator, which was designed to have a slightly longer distance between two carboxylate groups than the original tetratopic ligand. All of the MOSS nanocrystals showed a uniform pore size distribution with a well-tuned ratio of mesopores to micropores. Because of the appropriate pore ratio, MOSS nanocrystals can balance the thermodynamic interactions and kinetic diffusion of the substrates, thus showing exceedingly higher separation abilities and a unique elution sequence. Our work proposes a rational strategy to design mixed-porous MOFs with controlled pore ratios and provides a new direction to design homogeneously mixed MOFs with a high separation ability and unique separation selectivity.

Environmental Application of Porous Materials: From Natural Zeolite to Metal Organic Framework Materials

Environmental Application of Porous Materials: From Natural Zeolite to Metal Organic Framework Materials

Adsorption behavior of metal-organic frameworks: From single simulation, high-throughput computational screening to machine learning

Recently, the development and application of porous materials have attracted increasing attention, and metal-organic frameworks (MOFs) have become “stars” in the emerging material field because of their high porosities and ultra-high specific surface areas. In this review, the calculated works of MOFs in this field in the past ten years were summarized, especially for MOF adsorbents. With the continuous growth of the number of adsorbent materials, simulations have gradually transitioned from the single simulation, high-throughput computational screening (HTCS) to machine-learning (ML)-assisted HTCS. The purpose of this paper is to sort out the research progress and current ideas for the adsorption simulations of MOFs. Finally, we highlight the bottlenecks and challenges for the future commercialization of HTCS based on ML and the ML-assisted HTCS methods that are suitable for solving the research problems in this field. We also speculate about the future development directions of this field, hoping to promote the practical application of porous adsorbents.

Reaction: Porous Organic Polymers for Uranium Capture

Cafer T. Yavuz received his PhD from Rice University in 2008 with a Welch scholarship under the supervision of Vicki Colvin. He then worked as a postdoctoral scholar at the University of California, Santa Barbara, with Galen Stucky. He started his independent group in 2010 at KAIST, Korea. He is currently a professor of chemistry at the King Abdullah University of Science and Technology in Saudi Arabia. His research focuses on the design and synthesis of nanoscale and porous materials for applications in energy and the environment. He uses fine chemistry in confined spaces to enable rapid and targeted transformations of CO2, methane, and water.

Application of porous materials in heat exchangers of heat supply system

Heat exchange capacity increase is one of the main concerns in the process of manufacturing modern heat exchange equipment. Constructing heat exchangers with porous metals is an advanced technique of heat exchange increase. A construction of heat exchangers with porous aluminum is described in this paper. The first heat transfer agent (hot water) flows through thin copper tubes installed within the porous aluminum. The second heat transfer agent (freon) flows through the pores of aluminum. Laboratory facility was created to study such a heat exchanger. Series of experiments were carried out. The purpose of the research presented here is to create a mathematical model of heat exchangers with porous metals, to perform analytical calculation of the heat exchangers and to confirm the results with the experimental data. In this case, one can`t use the standard methods of heat exchangers calculation because the pores inner surface area is indeterminate. The developed mathematical model is based on the equation describing the process of cooling the porous plate. A special mathematical technique is used to take into account the effect of tubes with water. The model is approximate but its solution is analytic. It is convenient. One can differentiate it or integrate it, which is very important. Comparison of calculated and experimental data is performed. Divergence of results is within the limits of experimental error. If freon volatilizes inside the heat exchanger, the heat of phase transition has to be taken into account alongside with heat capacity. The structure of the mathematical model makes it possible. The results presented in this paper prove the practicability of using porous materials in heat exchange equipment.

Implementation of compressible porous-fluid coupling method in an aerodynamics and aeroacoustics code – Part II: Turbulent flow

Due to the potential advantages and applications of porous materials in aerodynamic and aeroacoustic applications, a porous-fluid coupling solver under compressible turbulence circumstances is of significance for CFD researchers. In this paper, a porous-fluid coupling method for compressible turbulence problems based on a k−ω model is proposed and implemented in the finite-volume-based in-house code Aeroacoustic and Aerodynamic Investigation Simulator (AAISIM). At the porous-fluid interface, the conservation equations of mass, energy, turbulent kinetic energy, specific dissipation rate and isentropic condition are solved to balance the flux through the interface. The stress jump condition and turbulence wall function are also employed for the treatment of the permeable wall. For the Beavers and Joseph’s problem, the current results show good agreement with previous Direct Numerical Simulation results for a Reynolds number of 5500. Flat plates with a porous section in the middle and at the trailing edge are simulated and compared against experimental data thus providing a validation of this porous-fluid coupling method.

Facile fabrication of sponge-like porous micropillar arrays via an electrochemical process.

A large variety of synthetic methods have been developed for hierarchically porous materials by which the performance of a wide range of applications can be dramatically enhanced. Herein, hierarchically porous micropillar arrays are demonstrated by employing electrochemical etching to silicon micropillars. The approach relies on the steering of current flow through the three-dimensional silicon-electrolyte interface to enable nanopores to grow on the entire surface of the micropillars, simultaneously. The pores grow perpendicular to the surface of the micropillars, whereas the pore diameter and porosity vary depending on the locations of the surfaces. The finite element analysis shows that the spatial variation of the pore diameter and porosity is determined by the distribution of current density. Further, the thickness of the porous layer can be tuned by etching time so that sponge-like porous structures are conveniently obtained by regulating the etching time. In addition to the effect of current density flowing through the etched surfaces, the growth of pores also depends on the crystal orientations of the etched surfaces. The etching results on square micropillar arrays and microgroove arrays show that the growth direction and rate of nanopores inside the microstructure also depend on the exposed crystal planes. The facile characteristics of the fabrication method can serve as an effective route for a wide range of applications of porous materials with enhanced capabilities.

Design, Experimental and Numerical Characterization of 3D-Printed Porous Absorbers.

The application of porous materials is a common measure for noise mitigation and in room acoustics. The prediction of the acoustic behavior applies material models, among which most are based on the Biot-parameters. Thereby, it is expected that, if more Biot-parameters are used, a better prediction can be obtained. Nevertheless, an estimation of the Biot-parameters from the geometric design of the material is possible for simple structures only. For common porous materials, the microstructure is typically unknown and characterized by homogenized quantities. This contribution introduces a methodology that enables the design and optimization of porous materials based on the Biot-parameters and connects these to microscopic geometric quantities. Therefore, artificial porous materials were manufactured using 3D-printing technology with a prescribed geometric design and the influence of different design variables was investigated. The Biot-parameters were identified with an inverse procedure and it can be shown that different Biot-parameters can be influenced by adjusting the geometric design variables. Based on these findings, a one-parameter optimization procedure of the material is set up to maximize the absorption characteristics in the frequency range of interest.