Arrangement Of Pores Research Articles

Interference of multi-pore collapse in explosive crystal under shock loading

Hotspots are generally recognized as the cause of ignition of heterogeneous explosives under shock loading, and the pores in the explosive crystal are the primary hotspots contributing to localized temperature rise and ignition. To investigate the interaction mechanism between pores in explosive crystals, the discrete element method is employed to numerically simulate the collapse processes of pores with various arrangements in explosive crystals under shock loading. The influence of the viscosity and plasticity of the explosive crystal on temperature rise is considered in the simulation. The results revealed that the interaction among the pores is essentially the interference of the upstream pore collapse on the shock wave front, which subsequently loads on the downstream pores and reflects back to the upstream pores. The perturbed shock wave loads on the downstream pores in various patterns due to the diversity in pore distance, size, and arrangement orientation, leading to different interference patterns. The causes of each interference pattern and its influence on localized temperature rise are further analyzed. Finally, the collapse patterns of downstream pores discovered in the simulation are summarized, identifying the six most representative downstream pore collapse patterns.

Quantifying Filter Layer Porosity: A Comparative Study of X-ray Microtomography, Fluid Injection and Fluid Saturation Techniques

Wastewater filtration for reuse is a practice applied to conserve water resources. However, its effectiveness is directly related to the permeability of the filter, which can be compromised by clogging processes due to the retention of suspended particles or by precipitated materials during the process of removing chemical contaminants. This study investigates the porous structure of filter layers by different techniques. The study explores porosity in porous media, emphasizing the importance of pores and the interconnected matrix. To evaluate the porosity, fluid injection techniques, fluid saturation techniques and XR-?CT were employed for porosity determination. It hypothesizes that fluid injection techniques, volumetric measurements, and imaging methods differ in their ability to accurately determine porosity. Nine reference columns of three different porous arrangements were mounted in an acrylic cylinder to study the sensitivity of the techniques to different sizes of matrix arrangements. Finally, the porosity results were compared statistically to determine the error. Fluid injection and saturation techniques are cost-effective methods for determining effective layer porosity. However, experimental studies show that water-based techniques often yield higher porosity values than helium gas porosimetry. This discrepancy may be attributed to operational errors inherent to the experimental method, leading to an overestimation of porosity. XR-?CT and gas porosimetry have been shown to be more suitable for quantifying smaller pores. Furthermore, XR-?CT allows for a deeper characterization of the porous medium, such as the determination of local porosity, and the application of fluid simulation techniques to observe the permeability and tortuosity of the medium.

Accounting for the Structure-Property Relationship of Hollow-Fiber Membranes in Modeling Hemodialyzer Clearance.

The relevance of the hemodialysis procedure is increasing worldwide due to the growing number of patients suffering from chronic kidney disease. Taking into account the structure of dialysis polymer membranes is an important aspect in their development to achieve the required performance of hemodialyzers. We propose a new mathematical model of mass transfer that allows hollow-fiber membrane structural parameters to be taken into account in simulating the clearance (CL) of hemodialyzers in a way that does not require difficult to achieve close approximation to the exact geometry of the membrane porous structure. The model was verified by a comparison of calculations with experimental data on CL obtained using a lab-made dialyzer as well as commercially available ones. The simulations by the model show the non-trivial behavior of the dialyzer clearance as a function of membrane porosity (fp) and the arrangement of pores (α). The analysis of this behavior allows one to consider two strategies for increasing the CL of the dialyzer by optimizing the polymer membrane structure: (1) creating a membrane with a well-structured pore system (where α → 1) since doubling α at a high enough fp can lead to an almost tenfold increase in CL; (2) increasing the porosity of the membrane characterized by a random arrangement of pores (α → 0), where, at a relatively low α, a sharp increase in CL is observed with a small increase in fp over a certain threshold value.

Solid phase extraction-diffuse reflectance infrared Fourier transform spectroscopy method for the detection of low concentrations of methylene blue pigment in aqueous matrices using MCM-41

The efficiency and high sensitivity of the combination between solid phase extraction (SPE) with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) as a method for the monitoring of emerging contaminants (ECs) in water, was evaluated and optimized through the detection of aqueous methylene blue (MB) at low concentrations using MCM-41 as solid active phase. Through the sol–gel route and post-synthetic treatments three mesoporous ordered silica with MCM-41 pores arrangement were synthesized and deeply characterized in order to determine the physicochemical properties of the mesoporous solid phases. One has silanol surface groups while the others feature a mixture of aminopropyl/silanol or methyl/silanol surface moieties. The batch separation experiments at pH = 7.0 ± 0.2 showed that the pristine and methylated MCM-41 solid phases had the highest affinities toward MB with removal efficiencies greater than 99 % for these samples, while the aminopropyl-modified MCM-41 retained only 32.5 %. MB detection by DRIFTS was done through the appearance of the absorption bands at 1488, 1390 and 1337 cm−1 associated with C–H and CS+ bending vibrations, with a limit of detection of 0.10 % w/w MB/MCM-41. When applied the SPE-DRIFTS method the necessary w/w ratio (0.10 %) was reached when a distilled water MB solution of 0.01 mg/L was passed through the SPE cartridge filled with 50 mg of MCM-41 and using a flow rate of 1.5 ml/min. The MB detection limit was successfully evaluated in a real water sample extracted to from río Negro, Patagonia, Argentina. The method presented here features the advantage of avoiding the use of expensive and toxic solvents as well as extra handling steps which could interfere with the detection process. The findings here reported suggest great potential of MCM-41-based SPE step prior to DRIFTS for ECs detection.

(Invited) Non-Intuitive Failure Mechanics in Solid State Batteries

Solid electrolyte failure can occur through a range of different mechanisms. Electrochemical delamination at electrode and electrolyte interfaces is a prominent failure mechanism during high capacity and low N/P operating conditions, and filament formation is prevalent during high rate and long cycle-life deposition. Interface coherency and solid electrolyte microstructure both impact the ultimate degradation mode. Solid electrolyte microstructure, described in part by the density, periodicity, and interconnected arrangement of pores, plays a role in failure. Herein, we combine modeling, synchrotron imaging, and electrochemical experiments to systematically understand how densification and processing of solid electrolyte influences filament formation. The work reveals that the density of pores does not correlated with failure. Instead, the periodicity, size and arrangement of pores is a driver for failure in amorphous solid electrolytes absent of grain boundaries.

Formation of Ordered Nanostructures By Anodization of Ag Substrates with Depression Patterns

The anodization of metals is an effective technique for preparing metal oxide nanohole arrays on substrate surfaces. It has been reported that nanohole arrays can be formed by anodizing various metals, not only Al and Ti. The variety of metals that can be anodized has increased, and the range of applications for the resulting nanohole arrays has expanded. In various applications using nanohole arrays obtained by the anodization of metals, control of the geometrical structure of the nanohole arrays is essential because its geometrical structure affects the performance of the device. However, structural control of nanohole arrays has not been achieved in the anodization of many metals. We previously reported that nanohole arrays with regularly arranged pores can be obtained by anodizing metal substrates with ordered depression patterns [1–3]. This is because the depressions formed on the metal surface served as the starting point for pore generation. We have previously reported that this method is applicable to various metals such as W, Fe, Cu, and SUS. In this report, we describe the preparation of ordered nanostructures of Ag oxide by the anodization of an Ag substrate with ordered depression patterns. A depression pattern was formed on the Ag substrate surface by Ar ion milling using an ordered anodic porous alumina mask. An anodic porous alumina mask with an ordered pore arrangement was prepared by a previously reported two-step anodization process. The resulting alumina mask was placed on an Ag substrate, with the barrier layer facing upward and the pore-forming surface facing downward. Ar ion milling was performed for 60 min at 5 kV to penetrate the alumina mask and form depression patterns on the Ag substrate surface. The alumina mask remaining on the Ag substrate surface was dissolved using a mixture of 0.17 M chromic acid and 0.07 M hydrofluoric acid at 20℃, which can dissolve only alumina without dissolving Ag. Ag sheets with the depression pattern were anodized in 0.05–0.13 M NH4F ethylene glycol electrolyte containing 0-0.13 M KOH or 0.1 M CH3COONa at 10℃ under a constant voltage of 2 V. For anodization of the Ag sheet, a two-electrode cell was used with a Pt plate as the counter electrode, and the distance between the electrodes was adjusted to 5 mm. The surface structures of the obtained samples were observed using field-emission scanning electron microscopy (SEM). The compositions and crystallinities of the obtained samples were evaluated using X-ray photoelectron spectroscopy and X-ray diffraction. Anodization of the Ag substrate with a depression pattern in an ethylene glycol solution containing NH4F and KOH induced pore generation from depressions, resulting in ordered nanohole array structures [4]. In addition, ordered nanopillar array structures were obtained by the anodization of an Ag substrate with depression patterns in an ethylene glycol solution containing NH4F and CH3COONa. This is the first report on the formation of ordered nanohole array structures of Ag oxide by the anodization of an Ag substrate. This is also the first report of the successful fabrication of ordered nanohole and nanopillar array structures from the same metal substrate by changing anodization conditions. The ordered nanostructures of Ag oxides obtained by this method are expected to be applicable in various functional devices, such as sensors, catalysts, and batteries.

Synthesis of a Hard Anodic Oxide Coating with a Structure Allowing for Its Modification by Nanoparticles

A hard anodic oxide coating’s characteristic porous structure allows for its modification by the incorporation of nanoparticles. However, achieving an appropriate microstructure requires an optimal pore arrangement and shape, which is influenced by the electrolyte composition, current densities, temperature, and processing time. To achieve pores with a diameter of about 50 nm and the most regular structure, a range of these parameters were tested. Using a two-stage manufacturing process had a beneficial effect on increasing the microporosity of the coating. The addition of phthalic acid at 0 °C did not increase the pore diameter, but allowed for the process to be carried out at higher temperatures. However, the coating produced at 20 °C had a larger pore diameter, but numerous defects. The coating obtained from the three-component solution had the most regular structure, but the smallest pore diameter.

Refractive index sensing characteristics of PCF-SPR based on dual-plasmon materials

Abstract In this paper, a photonic crystal fiber (PCF) refractive index sensor based on surface plasmon resonance with dual plasmonic materials (indium tin oxide and gold) is proposed. We innovatively designed a dual-core PCF structure and pore arrangement effectively enhancing the coupling effect. Using two different plasma materials, phase matching is achieved at two different wavelengths for the evanescent and surface plasmon waves, resulting in dual resonance peaks. The refractive index sensing is accomplished by measuring the dual-peak resonance shift, which expands the detection wavelength and RI detection ranges. The sensor can detect analytes with refractive indices ranging from 1.32 to 1.43 at wavelengths between 0.4 µm and 1.4 µm. We optimized the PCF structure and studied the sensing performance of the sensor, improving its sensitivity. Simulation results indicate that the designed PCF sensor exhibits outstanding maximum dual-peak shift sensitivity, reaching up to 28 000 RIU−1, along with maximum amplitude sensitivity and wavelength sensitivity of 18 500 RIU−1 and 34 500 RIU−1, respectively, in the direction of y-polarization. Furthermore, the sensor achieves high resolution, and the figure of merit (FOM) values can reach up to 5.134 × 10−7 and 2758. Consequently, the proposed sensor can provide high-precision and extensive-range measurements of solution refractive indices within the visible and infrared light spectrum, and it holds potential application prospects in numerous fields, such as food safety testing and chemical substance detection.

Tuning the geometry of porous alumina layers via anodization in mixtures of different acids

AbstractPorous anodic aluminum oxide (AAO) layers have been obtained by two-step anodization of high-purity Al in two types of acid mixtures, i.e., in H2C2O4–H3PO4 and, for the first time, in H2SO4–H3PO4 systems. The kinetics of oxide formation was examined by monitoring the current vs. time curves while the morphology of the resulting layers was carefully verified by scanning electron microscopy (SEM). A special emphasis was put on establishing correlations between electrolyte composition, the kinetics and effectiveness of oxide growth, and the morphological features of AAO layers (pore and cell diameter, porosity), as well as pore arrangement. It was confirmed that the addition of H3PO4 to both H2C2O4 and H2SO4 electrolytes results in a significant decrease in oxide growth rate, and worsening of pore arrangement, while the values of pore diameter and interpore distance are much less affected. Moreover, the presence of a small amount of phosphoric acid in the reaction mixture allowed for a noticeable increase in pore ordering if anodization was carried out beyond the self-ordering regime, or performing controlled anodization even at voltages at which the burning phenomenon is typically observed. It is strongly believed that manipulating the electrolyte composition by adding another acid may provide another degree of freedom to control the morphology of the resulting nanostructured alumina layers.

Aesthete Pattern Diversity in Chiton Clades (Mollusca: Polyplacophora): Balancing Sensory Structures and Strength in Valve Architecture.

Chitons possess the most elaborate system of shell pores found in any hard-shelled invertebrate. Although chitons possess some anteriorly located sense organs, they lack true cephalization, as their major sensory systems are not concentrated in a distinct head region. Instead, the aesthete system within their shells forms a dense sensory network that overcomes the barrier of their hard dorsal armour. The basic arrangement of neural structures embedded within a solid, opaque matrix, has confounded understanding of the overall network. In this study, we use synchrotron X-ray μCT to visualise the aesthete canal networks inside chiton valves. We selected representatives from all three major chiton clades: Lepidopleurida, the basal branching clade, and Callochitonida and Chitonida, which both havemore complex shell morphology, to compare internal structure. Lepidopleurida aesthete canals are oriented vertically and pass directly through the shell to connect with the body. By contrast, aesthetes canals in Callochitonida and Chitonida have complex internal structures with extended horizontal passages, coalescing at the shell diagonal that corresponds to the valve insertion slits. This represents a stepwise evolution of chiton shell form, where thicker and more complex valves require a diverting and rewiring of the entire sensorynetwork. Aspects of the aesthete system, such as the microscopic arrangement of surface pores, have long been used in chiton taxonomy for species diagnoses; insertion slits should also be understood as a secondary feature of the aesthete system. Chiton shell structures that are used for morphological systematics are driven by sensory adaptations.

Investigation of the mechanical strength and pore characteristics of undisturbed loess exposed to acid solutions

In order to gain a deeper understanding of the changes in pore characteristics of undisturbed loess under the influence of acid pollution and the underlying microscopic mechanisms, this study investigates the alterations in pore characteristics caused by acid pollution and their relationship with macroscopic strength. Strength tests, scanning electron microscopy (SEM), and nuclear magnetic resonance (NMR) tests were conducted on undisturbed loess under various acid pollution conditions to comprehend the evolution of these characteristics. The research findings indicate the presence of a critical acid pollution level in soil. Below this level, increasing acid pollution results in a more uniform distribution of pores, a decrease in the difference between the long and short axes, and a complex edge shape. The arrangement of pores also tends to be disordered. However, when the acid pollution exceeds the critical level, it leads to uneven distribution of pores and an increase in the difference between the long and short axes. The shape of the edges becomes more regular and the pore arrangement becomes more orderly. As the acid pollution intensifies, the total volume of pores between aggregates decreases, while the total volume of pores within aggregates increases. This study examines the impact of acid pollution on the characteristics of loess pores, providing valuable insights into the soil-water-acid properties and deformation management of loess in practical engineering applications. These findings are of practical significance for the construction and protection of loess engineering in loess areas.

A new species of narrow-banded Cyrtodactylus (Gekkonidae) from northern New Guinea.

We describe a new species of Cyrtodactylus from the northern lowlands and foothills of mainland New Guinea. Cyrtodactylus mamberamo sp. nov. is distinguished from all other Melanesian Cyrtodactylus except C. aaroni and C. mimikanus by the combination of moderate size (max SVL <100 mm), widened subcaudals, dorsal pattern of numerous narrow light bands with dark-brown anterior borders, and a tripartite pore arrangement in males. It differs from these two most-similar species in details of colour pattern, scalation and the number of precloacal pores. Cyrtodactylus mamberamo sp. nov. occurs at elevations between 0-870 m above sea level (a.s.l.) across a wide area spanning the Mamberamo Basin and nearby regions. It co-occurs with at most one or two other congeners. Low Cyrtodactylus alpha diversity across Melanesia emphasises beta turnover as the key factor underpinning species richness in this genus. The new species brings the total number of recognised Melanesian Cyrtodactylus to 35, with the real total certain to be over 40 species.

Evaluation of surface texturing on chrome-coated cylinder liners via deterministic mixed lubrication simulation

This study investigates the mixed lubrication performance of various surface texture configurations in the piston ring/cylinder liner conjunction of a two-stroke internal combustion engine using a deterministic mixed lubrication model. The numerical model simultaneously solves the Reynolds equation with mass-conserving cavitation to calculate inter-asperity hydrodynamic pressures and an elastic, perfectly plastic, rough contact model to determine contact pressures at each asperity interaction. Gaussian Mixture Model clustering was employed to enhance surface characterization. The deterministic simulation approach considers the full-scale representation of the cylinder liner topography to accurately capture the influence of surface features on the hydrodynamic support and friction under mixed lubrication conditions. The investigated cylinder liners were initially hard-chrome-coated and honed, resulting in a stochastic arrangement of surface pores, and then deterministic patterns of surface pockets were created by micro electrodischarge machining (EDM). Surface measurements were performed using laser interferometry, providing input for the mixed lubrication simulations. The study also explored the virtual removal of ridges formed around the pockets by the EDM technique. Key findings indicate that the stochastic texture outperformed the hybrid texture (stochastic + deterministic) in the boundary and mixed lubrication regimes, showing higher hydrodynamic support at low separations but increased hydrodynamic shear stresses at higher speeds. Conversely, deterministic textures exhibited a significant decrease in average hydrodynamic shear stress at high velocities. These results highlight the critical role of surface texture in tribological behavior and suggest that localized textures on cylinder liners can potentially optimize engine performance. The study recommends further exploration of a broader range of texture geometries, densities, and distribution patterns to enhance engine design strategies.

Porous Metal Organic Framework (MOF) derived dimorphic (n-ZnO/p-NiO) Z-scheme heterojunction anchored with MWCNTs (ternary nano-architecture): A novel approach for optimization of photodegradation mechanism and kinetics of Congo red (CR) dye

Global efforts to combat water pollution, especially from organic dyes like Congo red, emphasize the use of advanced nanomaterials for sewage purification. Metal-Organic Frameworks (MOFs), known for their crystalline structures and versatile properties, have become pivotal in wastewater treatment research. Integrating MWCNTs into MOF derived composite nanostructures is a strategic advancement, boosting the efficiency of photocatalytic systems and addressing environmental concerns. This study details the synthesis of a novel Z-scheme heterojunction nanocomposite (n-ZnO/p-NiO) incorporating multi-walled carbon nanotubes (MWCNTs), achieved via a solvothermal method using metal-organic framework (MOF) as a template. The study uses XRD, FTIR, FESEM, BET, UV, and PL for comprehensive nanocomposite characterization, offering insights into its structural, morphological, and optical properties. The resultant nanocomposite displays high surface area, sturdy pore arrangement, and consistent morphology. MWCNTs influence crystal growth and optical absorption, enhancing surface hydroxyl group concentration and acting as electron acceptors. This results in decreased photo oxidation and improved overall stability under light exposure in the composite. The composite achieves 92 % Congo red degradation in 60 min under UV light, showcasing superior dye adsorption capacity. This underscores its potential as an efficient photocatalyst for environmental remediation and wastewater treatment.

Effect of Scaffold Geometrical Structure on Macrophage Polarization during Bone Regeneration Using Honeycomb Tricalcium Phosphate.

The polarization balance of M1/M2 macrophages with different functions is important in osteogenesis and bone repair processes. In a previous study, we succeeded in developing honeycomb tricalcium phosphate (TCP), which is a cylindrical scaffold with a honeycomb arrangement of straight pores, and we demonstrated that TCP with 300 and 500 μm pore diameters (300TCP and 500TCP) induced bone formation within the pores. However, the details of the influence of macrophage polarization on bone formation using engineered biomaterials, especially with respect to the geometric structure of the artificial biomaterials, are unknown. In this study, we examined whether differences in bone tissue formation due to differences in TCP geometry were due to the polarity of the assembling macrophages. Immunohistochemistry for IBA-1, iNOS, and CD163 single staining was performed. The 300TCP showed a marked infiltration of iNOS-positive cells, which are thought to be M1 macrophages, during the osteogenesis process, while no involvement of CD163-positive cells, which are thought to be M2 macrophages, was observed in the TCP pores. In addition, 500TCP showed a clustering of iNOS-positive cells and CD163-positive cells at 2 weeks, suggesting the involvement of M2 macrophages in the formation of bone tissue in the TCP pores. In conclusion, we demonstrated for the first time that the geometrical structure of the artificial biomaterial, i.e., the pore size of honeycomb TCP, affects the polarization of M1/2 macrophages and bone tissue formation in TCP pores.

Preparation of Ordered Nanohole Arrays by Two-Step Anodization of Austenitic Stainless Steel Substrates.

An anodic oxide film with a regular pore arrangement was formed by the two-step anodization of an austenitic stainless steel (JIS SUS304) substrate. In this study, we determined the anodization conditions under which the pore arrangement in the anodic oxide film became self-organized. After removing the anodic oxide film formed by the first anodization with a mixture containing CrO3 and HF, the residual substrate was anodized under the same conditions as those in the first anodization. As a result, we found that it was possible to form an anodic oxide film with pores arranged in a regular pattern from the surface to the bottom. This is the first report on the formation of anodic oxide films with ordered nanohole array structures by the two-step anodization of austenitic stainless steel. The interpore distance of the resulting nanohole array structures can be controlled by changing the anodization conditions. By measuring the capacitance of the anodic oxide film, we confirmed that its properties depended on the heat-treatment temperature and pore depth. In addition, no significant decrease in the capacity of anodic oxide films with ordered nanohole array structures was observed, even when the scan rate of the cyclic voltammogram measurement was increased. This is considered to be because the cylindrical pores facilitate ion diffusion to the bottom of the holes. Anodic oxide films obtained by the anodization of austenitic stainless steel substrates can be applied as electrodes for capacitors.

Effect of Pore Architecture of 3D Printed Open Porosity Cellular Structures on Their Resistance to Mechanical Loading: Part I – Experimental Studies

Abstract The development of additive manufacturing (AM) techniques has sparked interest in porous structures that can be customized in terms of size, shape, and arrangement of pores. Porous lattice structure (LS, called also lattice struct) offer superior specific stiffness and strength, making them ideal components for lightweight products with energy absorption and heat transfer capabilities. They find applications in industries such as aerospace, aeronautics, automotive, and bone ingrowth applications. One of the main advantages of additive manufacturing is the freedom of design, control over geometry and architecture, cost and time savings, waste reduction, and product customization. However, the designation of appropriate struct/pore geometry to achieve the desired properties and structure remains a challenge. In this part of the study, five lattice structs with various pore sizes, with two volume fractions for each, and shapes (ellipsoidal, helical, X-shape, trapezoidal, and triangular) were designed and manufactured using selective laser sintering (SLS) additive manufacturing technology. Mechanical properties were tested through uniaxial compression, and the apparent stress-strain curves were analyzed. The results showed that the compression tests revealed both monotonic and non-monotonic stress-strain curves, indicating different compression behaviors among the structures. The helical structure exhibited the highest resistance to compression, while other structures showed similarities in their mechanical properties. In Part II of this study provides a comprehensive analysis of these findings, emphasizing the potential of purpose-designed porous structures for various engineering applications.

Recycling and reuse of waste banded iron formation as fine aggregate in the production of lightweight foamed concrete: Fresh-state, mechanical, thermal, microstructure and durability properties assessment

This study investigates the possibility of using BIFs as sustainable fine aggregates to produce lightweight foam concrete (LWFC) by replacing sand with 5, 10, 15, 20, and 25 % banded iron formations (BIFs). The fresh concrete properties, such as slump flow, density, and setting time, as well as its mechanical properties, including compressive strength, splitting strength, and flexural strength, were investigated. The thermal conductivity, specific heat, porosity, gas permeability, pore distribution, and sorptivity were measured to determine durability and thermal performance. Microstructural analysis of the mixes was performed using SEM, energy-dispersive X-ray spectroscopy (EDX), and mapping. The results recommended a 10 % replacement ratio to achieve an increased compressive strength ratio of 55.88 % compared to the control mix at 7 days (d). The strength at later ages increased compared to that of the control mix by 33.9 %, 30 %, 42.48 %, and 42.4 % at 14, 28, 56, and 180 d, respectively. In addition, the flexure increased by 42.7 % at 7 d, 49.6 % at 14 d, and 45.6 % at 28 d compared to the control mix. In addition, the UPV also increased gradually from 2757 to 3699 km/s with increase in BIFs content. Furthermore, the porosity decreased at 7 d, 14 d, 28 d, and 90 d. Moreover, chloride penetration decreased by 2.5 %, where an improvement in thermal conductivity was achieved with BIFs to 0.342 W/mK compared to that of the control mix. In addition, a reduction in the specific heat of the material from 1042 J/kg K to 1007 J/kg K was observed. SEM showed a better arrangement of pores when BIFs were utilized compared with that of control mix without BIFs. In conclusion, the incorporation of waste BIFs as fine aggregates in lightweight foam concrete demonstrates a promising potential for enhancing the mechanical and thermal properties of construction materials, paving the way for durable building materials in the construction industry.

Hardening properties and microstructure of 3D printed engineered cementitious composites based on limestone calcined clay cement

Comparison of three-dimensional (3D) printing and cast methods on the mechanical properties of cementitious materials is the basis for intelligent construction development. To achieve this, a series of experiments including the uniaxial tensile, compressive, flexural and interlayer bonding tests of mould-cast and 3D printed (3DP) specimens are conducted to investigate the effects of different preparation technologies on the microstructure and hardening properties of limestone calcined clay cement (LC3) based engineered cementitious composites (ECC). Results indicate that the tensile strength and strain capacity of the printed LC3-ECC decrease by 16.6%–22.7 % and 43.3%–54.6 % compared to the cast specimens, while it still possesses a strain capacity of 2 % and multiple cracking behaviour. The compressive and flexural properties of the printed LC3-ECC both show significant anisotropy, the maximum values of which are observed in the Z- and Y- directions, respectively. The interlayer bonding strength increases by 54.3%–91.9 % at 28 d compared to that at 7 d due to the hydration of LC3. The pore structure of the printed LC3-ECC is denser than that of the cast LC3-ECC, with more regular arrangement and finer size of pores. The macro-micro properties correlation analysis proves the better comprehensive performance of printed LC3-ECC relative to casted LC3-ECC, as well as reveals the relationship between pore structure and anisotropy. In terms of material sustainability, 3DP-LC3-ECC has a significant reduction in energy and carbon emissions compared to typical M45-ECC, contributing to the environmental development.

The pH dependent structural and viscoelastic behavior of Ovomucin-Complex isolated from egg white under alkaline conditions

Ovomucin-Complex (OVM) is responsible for providing the natural gel-like properties of egg white, especially in alkali-induced egg white gels. In this study, OVM was modified by alkaline to produce gel-type materials. The structure, physicochemical and viscoelastic properties of OVMs under different pH (7–12) were probed using FTIR, HPLC, SEM, CLSM and rheometer. The results of rheological measurements in linear viscoelastic region revealed that alkaline modified OVMs exhibited a soft viscoelastic gel in alkaline conditions, with the transition occurring near pH 8, compared with a viscoelastic solution at neutral pH. In addition to the pH-dependent gelation behavior of OVMs, further rheological studies under nonlinear deformations reveal shear thinning and an apparent yield stress, which were also highly affected by pH. The results from HPLC and molecular interactions suggest that the alkaline modification led to the depolymerization of OVMs in alkaline conditions, enhancing the formation of intermolecular disulfide bonds, electrostatic force and hydrophobic interactions. The differences in these mechanical properties were also reflected in the OVM structure. The SEM and CLSM images demonstrated that the arrangement of gel pores under pH 10 conditions is denser and well-distributed than those under other conditions. The FTIR results verified that alkaline modification leads to the decreased content of β-sheet. Nevertheless, prolonged exposure to pH 12.0 resulted in a gradual liquefaction of the gel due to increased electrostatic repulsion and surface hydrophobicity, as well as the reduced disulfide bond and an increase in the disordered structure. These findings provide a novel insight for the development of mucin gel foods.