Desired Pore Structure Research Articles

Water Droplet Templating Technique to Design Three-Dimensionally Ordered Porous Structures of Polymer Film.

We developed a unique water droplet templating method to fabricate polymer films with three-dimensionally ordered porous structures. This technique is based on a polymer/solvent/H2O ternary system, and the key is to choose a volatile and hydrophobic solvent that is slightly miscible with H2O. With the fast evaporation of the solvent, water droplets separate from the casting solution and condense from the air to act as pore templates inside the film and on the surface, respectively. According to this law, nitrocellulose (NC) films were produced from the NC/methyl acetate (MA)/H2O system in which the solubility of H2O in MA is 8.1 wt %. By modulating the solution concentration (density) from 3% to 9% NC, the distribution of separated water droplets (pores) in the solution can be flexibly controlled from sinking to floating. On the other hand, substantial ordered honeycomb pores, originated from condensed water droplets, distribute uniformly on the surface of NC films. This water droplet templating technique can be extensively applied in various polymer films, providing an effective pathway to designing polymer films with a desirable porous structure and diverse functionalities.

Rheology dependent pore structure optimization of high-performance foam concrete

Rheology dependent pore structure optimization of high-performance foam concrete

A K2C2O4/nano-CaCO3 dual-templated method to prepare rich nitrogen-doped hierarchical porous carbon with excellent lithium storage performance

A K2C2O4/nano-CaCO3 dual-templated method to prepare rich nitrogen-doped hierarchical porous carbon with excellent lithium storage performance

High performance CaCO3-based composites using sodium tripolyphosphate as phase controlling additive: Bamboo fiber driven high strength development

High performance CaCO3-based composites using sodium tripolyphosphate as phase controlling additive: Bamboo fiber driven high strength development

Durability of slag-based alkali-activated materials: A critical review

As the world becomes increasingly aware of the devastating effects of climate change, the need for sustainable building materials that are both durable and environmentally friendly increases. Geopolymer and alkali-activated materials formed by a chemical reaction between an alkaline activator solution and an aluminosilicate source have gained popularity in recent years. The alkaline activator solution dissolves the aluminosilicate source, which then undergoes a polycondensation reaction to form a three-dimensional geopolymeric gel network. The development of this network ensures the strength and durability of the material. Today, this phenomenon of durability has been studied in detail to enable the development of superior construction materials, taking into account degradation mechanisms such as carbonation, leaching, shrinkage, fire, freezing and thawing, and exposure to aggressive environments (chlorides, acids, and sulphates). Although there are many unsolved problems in their engineering applications, slag-based alkali-activated materials appear to be more advantageous and are promising as alternative materials to ordinary Portland cement. First of all, it should not be ignored that the cure sensitivity is high in these systems due to compressive strength losses of up to 69%. Loss of strength of alkali-activated materials is considered an important indicator of degradation. In binary precursors, the presence of fly ash in slag can result in an improvement of over 10% in compressive strength of the binary-based alkali-activated materials after undergoing carbonation. The binary systems can provide superior resistance to many degradation mechanisms, especially exposure to high-temperature. The partial presence of class F fly ash in the slag-based precursor can overcome the poor ability of alkali-activated materials to withstand high temperatures. Due to the desired pore structure, alkali-activated materials may not be damaged even after 300 freeze–thaw cycles. Their superior permeability compared to cementitious counterparts can extend service life against chloride corrosion by more than 20 times. While traditional (ordinary Portland cement-based) concrete remains the most widely used material in construction, geopolymer concrete’s superior performance makes it an increasingly emerging option for sustainable and long-lasting infrastructure.

Soil Substrate Characteristics for Planting Hole Greening Technology for High, Steep, Rocky Slope Vegetation in Semi-Arid Areas

Soil substrate plays a central role in the vegetation restoration of high and steep slopes, especially in semi-arid regions. This study aims to develop an optimal soil substrate that can provide a favorable environment for the vegetation growth of the high and steep rocky slopes in semi-arid areas. Within the framework of planting hole greening technology, we developed a synthetic substrate comprising base soil, peat, water-retaining and agglomerating agents, biochar, and controlled-release compound fertilizer. We conducted pot experiments to assess the impact of compound additions on soil properties and Parthenocissus himalayana growth. Field tests on exposed, high, and steep rocky slopes in a semi-arid region validated the optimal ratio of substrate components. The results showed that the base soil-to-peat ratio significantly influenced soil density, moisture, pH, organic matter, nitrogen content, and vegetation growth (Ps < 0.05). The controlled-release compound fertilizer significantly affected soil electrical conductivity and alkali-hydrolyzable nitrogen content (Ps < 0.05). Meanwhile, the water-retaining agent, biochar, and agglomerating agent had inconsequential effects on soil characteristics and plant growth. The optimal substrate composition included a 7:3 ratio of base soil to peat, 1.5 g/L of water retainer, 10 mg/L of agglomerating agent, 5 g/L of biochar, and 5 g/L of controlled-release compound fertilizer. The field verification showed that the developed optimal substrate possessed desirable pore structure, moisture, and nutrients, resulting in excellent growth of Parthenocissus himalayana. This optimal soil substrate could be suitable for establishing vegetation on high, steep, rocky slopes in semi-arid areas using planting hole greening technology.

Synergistic chemo-photothermal therapy using gold nanorods supported on thiol-functionalized mesoporous silica for lung cancer treatment

Cancer therapy necessitates the development of novel and effective treatment modalities to combat the complexity of this disease. In this project, we propose a synergistic approach by combining chemo-photothermal treatment using gold nanorods (AuNRs) supported on thiol-functionalized mesoporous silica, offering a promising solution for enhanced lung cancer therapy. To begin, mesoporous MCM-41 was synthesized using a surfactant-templated sol–gel method, chosen for its desirable porous structure, excellent biocompatibility, and non-toxic properties. Further, thiol-functionalized MCM-41 was achieved through a simple grafting process, enabling the subsequent synthesis of AuNRs supported on thiol-functionalized MCM-41 (AuNR@S-MCM-41) via a gold-thiol interaction. The nanocomposite was then loaded with the anticancer drug doxorubicin (DOX), resulting in AuNR@S-MCM-41-DOX. Remarkably, the nanocomposite exhibited pH/NIR dual-responsive drug release behaviors, facilitating targeted drug delivery. In addition, it demonstrated exceptional biocompatibility and efficient internalization into A549 lung cancer cells. Notably, the combined photothermal-chemo therapy by AuNR@S-MCM-41-DOX exhibited superior efficacy in killing cancer cells compared to single chemo- or photothermal therapies. This study showcases the potential of the AuNR@S-MCM-41-DOX nanocomposite as a promising candidate for combined chemo-photothermal therapy in lung cancer treatment. The innovative integration of gold nanorods, thiol-functionalized mesoporous silica, and pH/NIR dual-responsive drug release provides a comprehensive and effective therapeutic approach for improved outcomes in lung cancer therapy. Future advancements based on this strategy hold promise for addressing the challenges posed by cancer and transforming patient care.

Recent progress in 2D and 3D metal–organic framework-based membranes for water sustainability

Metal–organic frameworks (MOFs) have emerged as promising candidates for high-performance separation processes due to their desirable porous structure and highly tunable properties.

Silicon Radical-Induced CH4 Dissociation for Uniform Graphene Coating on Silica Surface.

Due to the manufacturability of highly well-defined structures and wide-range versatility in its microstructure, SiO2 is an attractive template for synthesizing graphene frameworks with the desired pore structure. However, its intrinsic inertness constrains the graphene formation via methane chemical vapor deposition. This work overcomes this challenge by successfully achieving uniform graphene coating on a trimethylsilyl-modified SiO2 (denote TMS-MPS). Remarkably, the onset temperature for graphene growth dropped to 720°C for the TMS-MPS, as compared to the 885°C of the pristine SiO2. This is found to be mainly from the Si radicals formed from the decomposition of the surface TMS groups. Both experimental and computational results suggest a strong catalytic effect of the Si radicals on the CH4 dissociation. The surface engineering of SiO2 templates facilitates the synthesis of high-quality graphene sheets. As a result, the graphene-coated SiO2 composite exhibits a high electrical conductivity of 0.25Scm-1. Moreover, the removal of the TMP-MPS template has released a graphene framework that replicates the parental TMS-MPS template on both micro- and nano- scales. This study provides tremendous insights into graphene growth chemistries as well as establishes a promising methodology for synthesizing graphene-based materials with pre-designed microstructures and porosity.

Coal fly ash-bound limestone-derived sorbent pellets for high-temperature CO2 capture

Coal fly ash-bound limestone-derived sorbent pellets for high-temperature CO2 capture

Valorization of mineral wool waste in Class F fly ash geopolymer: Geopolymerization, macro properties, and high temperature behavior

Valorization of mineral wool waste in Class F fly ash geopolymer: Geopolymerization, macro properties, and high temperature behavior

Physicochemical and in vitro investigation of trace element-incorporated hydroxyapatite and starPCL@chitosan composite scaffold for bone tissue engineering

Physicochemical and in vitro investigation of trace element-incorporated hydroxyapatite and starPCL@chitosan composite scaffold for bone tissue engineering

Biological treatment as a green approach for enhancing electrochemical performance of wood derived carbon based supercapacitor electrodes

Biological treatment as a green approach for enhancing electrochemical performance of wood derived carbon based supercapacitor electrodes

Biomass-derived functional carbon material for CO2 adsorption and electrochemical CO2 reduction reaction

Biomass-derived functional carbon material for CO2 adsorption and electrochemical CO2 reduction reaction

Polyaniline-Coated ZIF-67-Derived Co/C Nanostructures for Efficient Electromagnetic Wave Absorption

Metal–organic frameworks (MOFs) have diverse structures, thus sparking strong research interest in the field of electromagnetic wave (EMW) absorption. In this work, zeolitic imidazolate framework-67 (ZIF-67) was hydrothermally synthesized and thermally annealed to form rhombic dodecahedral Co/C nanocomposites with desirable porous structures. Then, a layer of rod-shaped polyaniline was coated on the surface of the Co/C nanocomposites through in situ polymerization. The effect of the mass ratio of polyaniline to Co/C on the electromagnetic properties of the nanocomposites was studied. The sample Co/C@PANI-2 exhibited an optimal reflection loss of −67.67 dB and an effective absorption bandwidth of 5.02 GHz at a filling ratio of 50%. The rod-like polyaniline coating effectively enhanced the electromagnetic properties and impedance matching of the nanocomposites. This work provides a reference for the composite of MOF-derived nanomaterials and conducting polymers in EMW absorption studies.

The Toughness of Polypropylene Fiber-Reinforced Foam Concrete under Various Uni- and Tri-Axial Compression Loads

The Toughness of Polypropylene Fiber-Reinforced Foam Concrete under Various Uni- and Tri-Axial Compression Loads

Humidity sensitivity reducing of moisture swing adsorbents by hydrophobic carrier doping for CO2 direct air capture

The application of quaternary ammonium-based moisture-swing adsorbent provides an effective strategy for direct air capture (DAC) with low energy consumption of regeneration. This study optimized a fabrication method of shaped adsorbents and a hydrophobicity regulation method by doping polyvinylidene difluoride (PVDF). Characterization of the shaped adsorbents showed a desirable surface area and pore structure. Experiments of CO2 adsorption revealed that the adsorbents exhibited excellent CO2 adsorption capacity (∼0.90 mmol/g) in relative humidity (RH) range of 20 ∼ 85% was enhanced by 160% of that before doping. Meanwhile, a high CO2 adsorption rate (with a half-time of 3.6 ∼ 3.82 min) at 84.7% RH was displayed. The optimal doping ratio of PVDF was found to be 25% (QAR-25% PVDF). It can effectively release CO2 with 100% RH, and heat assistance (<60 °C) can be considered for optimal results. QAR-25% PVDF exhibited a cyclic capacity of 0.90 mmol/g after ten cycles, demonstrating its stability and reusability. DFT and microscopic characterization revealed the key role of C-F bond in promoting the hydrophobicity of adsorbents. Meanwhile, the isotherm of H2O/CO2 adsorption illustrated that doping PVDF could effectively reduce the humidity sensitivity of shaped adsorbents and improve CO2 adsorption rate significantly. Among DAC adsorbents reported previously, the adsorbents developed in this study showed higher functional group efficiency (ηQA = 0.89) at high humidity conditions. The fabrication method of shaped adsorbent provides a viable strategy for its large-scale deployment. Doping hydrophobic carriers into the adsorbent material is a simple yet effective way to reduce its humidity sensitivity, enabling it to better adapt to complex environmental conditions.

C-axis oriented ZIF-95 sheets intermixed with polyimide matrix with enhanced gas separation performance

C-axis oriented ZIF-95 sheets intermixed with polyimide matrix with enhanced gas separation performance

Effect of Metal Complexing on Mn–Fe/TS-1 Catalysts for Selective Catalytic Reduction of NO with NH3

TS-1 zeolite with desirable pore structure, an abundance of acidic sites, and good thermal stability promising as a support for the selective catalytic reduction of NO with NH3 (NH3-SCR). Herein, a series of Mn-Fe/TS-1 catalysts have been synthesized, adopting tetraethylenepentamine (TEPA) as a metal complexing agent using the one-pot hydrothermal method. The introduced TEPA can not only increase the loading of active components but also prompts the formation of a hierarchical structure through decreasing the size of TS-1 nanocrystals to produce intercrystalline mesopores during the hydrothermal crystallization process. The optimized Mn-Fe/TS-1(R-2) catalyst shows remarkable NH3-SCR performance. Moreover, it exhibits excellent resistance to H2O and SO2 at low temperatures. The characterization results indicate that Mn-Fe/TS-1(R-2) possesses abundant surface Mn4+ and Fe2+ and chemisorbed oxygen, strong reducibility, and a high Brønsted acid amount. For comparison, Mn-Fe/TiO2 displays a narrower active temperature window due to its poor thermostability.

Shape Fidelity Evaluation of Alginate-Based Hydrogels through Extrusion-Based Bioprinting.

Extrusion-based 3D bioprinting is a promising technique for fabricating multi-layered, complex biostructures, as it enables multi-material dispersion of bioinks with a straightforward procedure (particularly for users with limited additive manufacturing skills). Nonetheless, this method faces challenges in retaining the shape fidelity of the 3D-bioprinted structure, i.e., the collapse of filament (bioink) due to gravity and/or spreading of the bioink owing to the low viscosity, ultimately complicating the fabrication of multi-layered designs that can maintain the desired pore structure. While low viscosity is required to ensure a continuous flow of material (without clogging), a bioink should be viscous enough to retain its shape post-printing, highlighting the importance of bioink properties optimization. Here, two quantitative analyses are performed to evaluate shape fidelity. First, the filament collapse deformation is evaluated by printing different concentrations of alginate and its crosslinker (calcium chloride) by a co-axial nozzle over a platform to observe the overhanging deformation over time at two different ambient temperatures. In addition, a mathematical model is developed to estimate Young's modulus and filament collapse over time. Second, the printability of alginate is improved by optimizing gelatin concentrations and analyzing the pore size area. In addition, the biocompatibility of proposed bioinks is evaluated with a cell viability test. The proposed bioink (3% w/v gelatin in 4% alginate) yielded a 98% normalized pore number (high shape fidelity) while maintaining &gt;90% cell viability five days after being bioprinted. Integration of quantitative analysis/simulations and 3D printing facilitate the determination of the optimum composition and concentration of different elements of a bioink to prevent filament collapse or bioink spreading (post-printing), ultimately resulting in high shape fidelity (i.e., retaining the shape) and printing quality.