Symposium CE
ABSTRACTS
Session CE-1 Novel processing, microstructural and morphological control of porous ceramics, synthesis of porous ceramics (nano to macro), including Additive Manufacturing
CE-1:IL01 The Extruded Ceramic Membrane Support and Nanopore Coating: Recent Developments and Prospect
IN-HYUCK SONG, H.J. LEE, J.H. HA, J. LEE, Korea Institute of Materials Science (KIMS), Changwon, Gyeongnam, Republic of Korea
Ceramic membranes have limited applications until now owing to their high processing cost, despite their excellent properties such as long-term durability, high strength, and incredible thermal / chemical resistance compared with polymeric membranes. The filtration efficiency and permeability of ceramic membranes have rapidly increased, and manufacturing costs have continuously decreased due to continuous research. Nowadays, ceramics membrane market starts to open for field of withstanding harsh conditions such as oil, textile, semiconductor and hydrogen separation industry. In this study, we will present the recent developments and prospect of ceramic membranes for wastewater and gas separation. Also, the research results of the multi-channel ceramic membrane developed by the extrusion process in KIMS were reported. In the case of alumina and zirconia membranes, permeability could be improved through the sol-gel process and surface modification. For silicon carbide membrane, by developing an oxidation bonded SiC membrane, an original excellent membrane could be developed. Recently, in Korea, research program on the development of large area, high-strength, high-permeability extruded ceramic supports based on nanopores for the production of high-purity, high-flow hydrogen is carried out. We will introduce an extrusion process technology that can manufacture high-strength ceramic supports, control surface roughness, and coating technology that can form nanopores.
CE-1:IL02 Porous Materials by Weak Alkali Activation and Sinter Crystallisation of Alumino-silicate Waste
G. TAMENI1,2, M.J. ZAFAR1, F. CAROLLO1, P. SGARBOSSA1, A. MAZZI1, L. CONTRAFATTO3, E. BERNARDO1, 1University of Padova, Department of Industrial Engineering, Italy; 2Sheffield Hallam University, Sheffield, UK; 3University of Catania, Department of Civil Engineering and Architecture, Catania, Italy
Highly amorphous alumino-silicate waste from industrial operations or natural sources can be sustainably used as raw materials for new components. This study explores 'weak' alkali activation of vitreous alumino-silicates using low molarity alkali hydroxide solutions (3M NaOH, KOH). Unlike typical alkali-activated materials, this process causes only surface modifications. Particles join through condensation of surface Si-OH and Al-OH groups at 40-80°C. High Al2O3 content stabilizes the gel and promotes zeolite crystal formation. Low-temperature hardening produces porous bodies (~40% porosity), which can be transformed into foams through air incorporation or special additives. Sintering at 800-1000°C yields highly porous glass-ceramics, completing consolidation or offering a second life to low-temperature stabilized products. Including waste glass in slurries helps tune activation and balance viscous flow sintering with crystallization. This enhances strength-to-density ratios for building applications, while dominant open porosity suits filtering and catalytic degradation uses. The resulting materials offer environmental benefits through thermal insulation and filtration/catalytic destruction of pollutants from wastewaters.
CE-1:IL03 Fabrication of Lithium Silicate on Silica Porous Glass for Carbon Dioxide Removal
MIKI INADA, Department of Applied Chemistry, Faculty of Engineering, Kyushu University, and International Institute for Carbon-Neutral Energy Research, Kyushu University, Fukuoka, Japan
Li4SiO4 is one of the CO2 capture materials at high temperatures. To enhance the CO2 capture ability, a large surface area is effective. However, it is hard to synthesize the Li4SiO4 porous materials due to high covalent bonding of itself. In addition, thermal decomposition occurs at high temperature. Thus, in this study, we tried to modify the surface of silica (SiO2) porous glass with Li4SiO4 for CO2 capture materials. SiO2 porous glass was prepared according to our previous report [J. Ceram. Soc. Jpn., 132 (7), 446 - 452 (2024)]. The obtained SiO2 porous glass was dipped into Li2CO3 slurry and dried at room temperature for 24 h. The dried sample was heated at 400°C for 1 h and then at 800°C for 1 h under atmospheric pressure. Li4SiO4 porous structure on silica support were successfully fabricated by the reaction of Li2CO3 with amorphous SiO2 on the surface of silica porous structure at 800°C. The obtained Li4SiO4 porous structure can capture CO2 at 600°C and release it at 700°C, and could be used stably and repeatedly. This Li4SiO4 porous structure is expected to be useful as a CO2 capture material at high temperature [J. Ceram. Soc. Jpn., 132(10), 571–577 (2024)].
CE-1:IL04 Tuning of the Porosity in Geopolymers and Geopolymer Composites
V. MEDRI, E. PAPA, C. DI PIETRO, M.C. MARCHIONI, E. LANDI, National Research Council - Institute of Science, Technology and Sustainability for the Development of Ceramic Materials (ISSMC-CNR), Faenza, Italy
Geopolymers are synthetic alkali-aluminosilicates, constituting a family of materials with properties varying among those of ceramics, cements, zeolites, or refractories, depending on their formulation. They can be easily formed in complex shapes (spheres, monoliths, panels, honeycombs, etc.) and geopolymer matrices can act as binders for functionalizing fillers in composites. Finally, geopolymers can also be recycled. Since geopolymers are nanostructured and intrinsically mesoporous materials, a complex pore system can be prepared by combining mesopores with micro and macro-porosity. Geopolymers may be used to fabricate porous materials with a total pore volume from 30% up to 90% using different techniques, such as slurry route, foaming and cold sintering process. Furthermore, the addition of fillers such as zeolites, apatites, hydrotalcites and others modifies the porosity and related properties, such as the absorption of pollutants, etc.
Research activities were carried in the framework of the MUR PRIN 2022 Project GEA - GEopolymer based Adsorbents for effective adsorption and selective separation of CO2 and eutrophication pollutants, - Prot. 20229THRM2, funded by the European Union – Next Generation EU.
CE-1:IL05 Preparation, Properties and Performance of Porous Silicon Nitride with Marco Sized Pores for Biological Application
JIANFENG YANG, FENG LI, BO WANG, State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi’an, China
Si3N4 material exhibits excellent biocompatibility, and stable chemical and physical properties, promising significant application in hip arthroplasty and orthopedic fields. The surface of artificial acetabular cup adopts a porous structure design, which facilitates inward bone growth and stable integration of the prosthesis. The interior is of dense structure coordinate with the liner and femoral head. In this study porous/dense composite Si3N4 ceramic materials is prepared through the combination of in-situ solidification molding and template method. Based on the in-situ polymerization of organic monomers to achieve net size shaping, the preparation processes of dense Si3N4 and porous Si3N4 with marco size pore were investigated. The effects of sintering aid content and solid content on dense Si3N4, the effects of solid content and template holding time on porous Si3N4 were explored. Ultimately, successful preparation of porous/dense composite Si3N4 ceramic materials were achieved.
CE-1:IL06 MOFs Functionalization of Additively Manufactured Ceramics for CO2 Capture
A. BERTERO1, B. COPPOLA1, J. SCHMITT2, O. GIMELLO2, P. TRENS2, P. PALMERO1, J.-M. TULLIANI1, 1Politecnico di Torino, Department of Applied Science and Technology, INSTM R.U. Lince Laboratory, Italy; 2Institut Charles Gerhardt, UMR 5253, CNRS-ENSCM-UM, University of Montpellier, Cedex, France
This work focuses on the combination of a CO2 adsorbent coating (HKUST-1, Cu3(BTC)2) with porous and interconnected mullite (3Al2O3.2SiO2) structures produced by additive manufacturing. Thus, two triply periodic minimal surface (TPMS) architectures, Schwartz Primitive and gyroid, were first made by Digital Light Processing using two mullite powders with different compositions and particle size distributions. Then, the monoliths were functionalized with a continuous HKUST-1 coating. The textural properties and CO2 sorption capacity of the materials were investigated by N2 and CO2 sorption at 77 K and 298 K respectively. CO2 gas chromatography was done at different temperatures (32 °C - 80 °C) and gas flows (10 - 40 mL/min) using a filled column with the different materials. TPMS monoliths were compared to traditional adsorbent powder beds in terms of pressure drops, permeability, gas speed and retention time normalized by MOFs amount, evidencing the advantages of the printed structures with respect to powder beds in terms of permeability. Finally, monoliths also promoted CO2/adsorbent contact time, lowering the gas speed under 1.5 cm/s, compared to 2 to 5 cm/s, in the case of powder bed, and enhancing the CO2 retention time normalized by MOFs amount.
CE-1:L07 The porous Si3N4 Ceramics Prepared by Modified Water-based Gel Casting and Si Modification
YUPING ZENG, Shanghai Institute of Ceramics , Chinese Academy of Sciences, Shanghai, China
Porous Si3N4 ceramics were prepared using the low-toxicity monomer HEMA (2-hydroxyethyl Methacrylate) via a modified gel casting method. The rheological properties of Si3N4 slurries were investigated. Triethanolamine with high activity was used as a catalyst and modifier for gelation reactions, effectively improving the curing rate and suppressing the inherent surface oxygen inhibition in such process systems. With an increase in solid loading of the slurry, the drying shrinkage (12.3-5.4%) significantly decreased, while the green body density (44.0-49.0%) and flexural strength (9.65-16.46 MPa) increased, demonstrating excellent mechanical strength. After sintering at 1700°C, the porous Si3N4 ceramics prepared with 24-36 vol% solid loading slurry exhibited a flexural strength of 144.39-193.66 MPa and a porosity of 55.8-49.0%. In order to further improve the mechanical properties of the porous Si3N4 , a small amount of silicon (Si) powder was added, this process resulted in a refined and uniform microstructure characterized by significantly reduced grain size and pore diameter. Consequently, at a constant high porosity of ~56%, the flexural strength and fracture toughness were remarkably improved from 171.2 MPa to 234.9 MPa and from 2.41 MPa·m¹/² to 3.33 MPa·m¹/², respectively.
CE-1:L08 When Drying Matters: The Influence of an Overlooked Process Step
I. KLÖSEL, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Bavaria, Germany; T. FEY, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Bavaria, Germany, and NITech Doctoral Global Academy, Nagoya Institute of Technology, Nagoya, Aichi, Japan
A well-established technique for tailoring the microstructure and enhancing the mechanical and thermal properties of porous ceramics is gel casting. Gel casting offers a wide range of technological applications requiring lightweight materials with high permeability such as thermal insulation, filtration, catalysis or biomedical implants. High mechanical stability is achieved by using a polymer gel to solidify the ceramic network prior to sintering. Rapid drying of the gelled foams causes stresses within the gel network, often resulting in cracks. To prevent the formation of cracks, it is advisable to use drying under constant conditions of humidity and temperature. In this study, alumina gel casting foams were produced using agarose as gelation agent and drying was carried out in a climate chamber to maintain a constant temperature and humidity until complete drying. Different temperatures and humidity levels were used and the influence on time-dependent mass loss was recorded. The influence of the different drying conditions on microstructural, mechanical, and thermal properties was investigated. It was observed that slower drying conditions due to increased humidity result in an improvement in mechanical properties.
CE-1:L09 Porous Silicon Nitride with Tailored Porosity and Flexural Strength
DONGXU YAO, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China
Porous silicon nitride (Si3N4) shows superior properties in strength, toughness, thermal shock resistance due to the formation of interlocking microstructure. In order to fabricate porous Si3N4 ceramics with high porosity and high strength, several molding methods were investigated. Porous Si3N4 ceramics with porosity of 35~55% and with mono pore size distribution were obtained by controlled die molding pressure and pressureless sintering. Furthermore, high porosity of 70~90% can be achieved by freeze drying and foaming method. Gradient porous Si3N4 ceramics has been fabricated by the combination of slip casting and vacuum foaming methods. With the pressure decrease from 80KPa to 9KPa, the porosity increased from 59.01% to 80.85% and the gradient structure became more clearly.
CE-1:IL10 Low-temperature Binding of Chemically Bonded Phosphate for the Production of Porous Ceramics via Phosphate Condensation and Photonic Irradiation
N. SOMERS1,2, E. OZMEN2, M. LOSEGO2, R. CLOOTS1, F. BOSHINI1, 1GREEnMat, CESAM Research Unit, Chemistry Department, University of Liège, Belgium; 2School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, USA
Conventional ceramic Additive Manufacturing (AM) requires long, high-temperature post-processing, limiting rapid production and complex multi-material integration due to mismatched thermal expansion and shrinkage kinetics. This research presents a novel, single-step, low-temperature AM route for fabricating porous ceramic parts, removing the need for conventional sintering. We employ Chemically Bonded Phosphate Ceramics (CBPCs), utilizing Aluminum Dihydrogen Phosphate (ADP) as an inorganic binder. The binding mechanism relies on acid-base reactions and subsequent O-crosslinking and phosphate condensation, which typically occurs below 500°C. The key innovation lies in triggering this ceramization layer-by-layer using photonic irradiation (IR or Flash Lamp Annealing), which selectively delivers high-intensity energy in a few seconds. This process is demonstrated via spray-casting ADP-ceramic slurries. IR irradiation rapidly drives phosphate condensation at 350°C, binding various oxide powders (Al2O3, Fe2O3, TiO2, etc) into free-standing, porous and robust sheets. This low-temperature, layer-specific binding approach offers a pathway to overcome thermal mismatch challenges for multi-material 3D structures, especially for fully resorbable bioceramic scaffolds.
CE-1:IL11 Alkali-modified CaO/SiOC Nanocomposites for CO₂ Capture
S. KAUR1, K. REZWAN1,2, M. WILHELM1, 1Advanced Ceramics, Department of Production Engineering, University of Bremen, Bremen, Germany; 2MAPEX - Centre for Materials and Processes, University of Bremen, Germany
In light of the global energy crisis and continued reliance on fossil fuels, efficient CO₂ capture technologies are increasingly important. CaO-based sorbents are attractive due to low cost, abundance, and high theoretical capacity. In Ca-looping, CaO reacts with CO₂ at 500–700 °C to form CaCO₃, regenerated by calcination at 800–900 °C. Performance loss arises mainly from sintering during high-temperature decarbonation and the energy penalty. Polymer-Derived Ceramics (PDCs) offer a promising alternative, enabling homogeneous dispersion of metal oxides in a microporous matrix. Our studies on CaO/SiC(O)-based ceramics showed nanosized CaO in the SiC(O) matrix, achieving 1.5–2.0 wt% CO₂ uptake at 500 °C. While pure CaO exhibited higher uptake (19%), it lacked decarbonation at this temperature. In contrast, polymer-derived CaO/SiC(O) reached 66% decarbonation. Further improvement was achieved by adding alkali hydroxides (LiOH, NaOH, KOH). Li-modified SMP-based composites reached 6.1 wt% CO₂ uptake and 57% desorption efficiency, while Na-modified variants achieved full desorption at ~500 °C. These results underline the potential of alkali-modified CaO/SiOC nanocomposites as regenerable solid sorbents for efficient CO₂ capture and enabling direct conversion to methane at 500°C.
CE-1:IL12 Modified Slip-casting for Lean Manufacturing of Flow Engineered and Graded Porous Structures
R. TRIHAN1, N. ZAUGG2, B. MINNIG2, P. HOFFMANN2, M. STUER1, 1Nanopowders and Ceramics Group, High Performance Ceramics Laboratory, Swiss Federal Laboratories for Materials Science and Technology (Empa), Dübendorf, Switzerland; 2Laboratory for Advanced Materials Processing, Swiss Federal Laboratories for Materials Science and Technology (Empa), Thun, Switzerland
Porous structures are essential in diverse processes, ranging from food engineering to catalysis. While additive manufacturing allows the creation of intricate geometries, its limited throughput, long cycle times, and high production costs often restrict large-scale implementation and alternative approaches are therefore needed. To address these limitations, we present a modified slip-casting approach suitable for fabricating ceramic films and components with micrometer-scale resolution. The method combines a one-time laser process for the versatile shaping of 2.5D mold masters with a slip-casting process. This enables scalable shaping of ceramic parts with complex architectures. Subsequent stacking, and eventually rolling steps, facilitate the assembly of porous structures with intricate geometries, furthermore compatible with functional grading and multi-material integration.
CE-1:L13 High Throughput Development of Porous Piezoelectric Ceramics
E. WOLF, C. BLECHINGER, U. ECKSTEIN, K.G. WEBBER, T. FEY, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Bavaria, Germany
Porous piezoelectric ceramics are used in various fields such as ultrasonic transducers, energy harvesting devices or sonar applications. Traditionally, publications in this field investigate ten or less different porosities, as the high accuracy needed to obtain exact target porosities increases the production and characterization time drastically. However, a high sample number can lead to a more intricate understanding of porosity property relationships, such as the influence of pore geometries. In this work porous lead free piezoceramics with more than 30 different total porosities were fabricated from K0.5Na0,5NbO3 (KNN) via the incorporation of four geometrically different sacrificial templates (spherical and fibrous). To upscale the process, an automated dispensing system was employed. The microstructure of samples was analyzed via µ-CT analysis and SEM imaging. The piezo and ferroelectric measurements were carried out with partially automated equipment to realize lower human interaction times. This works shows the enormous potential of High Throughput processing and testing in the field of porous piezoelectric ceramics.
CE-1:L14 Preparation and Characterization of Porous MgAl2O4 Spinel Ceramic
J. ŽIVOJINOVIĆ1, A. FELTRIN2, S. MARKOVIC1, A. MARINKOVIĆ3, N. OBRADOVIĆ1, 1Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Belgrade, Serbia; 2Materials Research Center, Missouri University of Science and Technology, Rolla, MO, USA; 3Faculty of Technology and Metallurgy, University of Belgrade, Belgrade, Serbia
Nowadays, ceramic filters aim to solve the problems associated with waterborne diseases by removing harmful microorganisms from water sources before they are consumed. Previous research has shown that magnesium aluminum spinel (MAS) is recognized as a good ceramic filter due to its non-toxicity, good chemical stability, and faster filter regeneration after use. In this research, obtaining an adsorption-based ceramic filter, porous magnesium-aluminum spinel (MAS), was achieved by the addition of poly(methyl methacrylate) (PMMA) (sintered at 1100°C). Commercial MAS was doped with PMMA at different weight percentages (10, 20, and 30 wt.%) to obtain a porous ceramic for wastewater filtration, aiming to remove a specific type of bacteria. The properties of MAS porous ceramic were examined using X-ray diffraction (XRD), Scanning electron microscopy (SEM), Particle size analysis (PSA), BET and Thermogravimetric/Differential thermal (TG/DTA) analyses. XRD analysis revealed the presence of a single MAS phase, while SEM analysis indicated an increase in porosity with increasing weight percentages of PMMA. Values of specific surface area and density decrease from 23.94 to 6.57 m2g-1 and from 1.60 to 1.13 gcm-3 with increasing an amounts of PMMA. The particle size distribution is dominantly bimodal with a range of 1.38-21 μm for all samples. From TG/DTA results, it was observed that the maximum decomposition of PMMA was below 400 °C; therefore, the sintering temperature for the fabrication of MAS porous ceramic was 1100 °C. Adsorption capacities showed that porous MAS ceramics could be efficient for wastewater purification.
Funds for the realization of this work are provided by the Ministry of Science, Technological Development and Innovation of the Republic of Serbia, Agreement on the realization and financing of research work of the Institute of Technical Sciences of SASA in 2025 (Record number: 451-03-136/2025-03/200175).
Session CE-2 Structure and functional, mechanical and thermal properties of porous ceramics; structure/transport/functional properties relationships; properties modelling
CE-2:IL15 Preparation, Modification and OER Performance of (FeCoNiCrMn)3O4 High-entropy Hollow Porous Nanofibers
HAIJUN ZHANG, The State Key Laboratory of Advanced Refractories, Wuhan University of Science and Technology, Wuhan, China
High-entropy oxides have emerged as a research hotspot in OER catalysis owing to their multi-metal synergistic effects and exceptional structure stability. This presentation employs electrospinning to prepare spinel-type (FeCoNiCrMn)3O4 high-entropy oxide nanofibers (HEOFs). Furthermore, H2 reduction and phosphating treatments are applied to reduce overpotential and enhance stability of the HEOs catalyst. The prepared HEOFs achieved an OER overpotential of 305 mV at 10 mA•cm-2 and a Tafel slope of 88.5 mV dec-1. After H2 reduction treatment, the synergistic effects of oxygen vacancies and alloy nanoparticles of the MnNi/(FeCoNiCrMn)3Ox composite fibers reduced the overpotential to 276 mV at 10 mA•cm-2 , an Tafel slope of 67.4 mV dec-1, the catalyst exhibited exceptional cycling stability at 20 mA•cm-2 for 100 h. After phosphating modification, the prepared mesoporous FeCoNiCrMnPi nanofibers achieved a remarkably low overpotential of 237 mV at 10 mA•cm-2. Furthermore, phosphate tetrahedra modulated charge distribution, strengthened metal-oxygen covalency, and activated lattice oxygen, finally changing the OER mechanism from the conventional adsorbate evolution to the lattice oxygen-mediated way.
CE-2:IL16 Thermal Conductivity of Porous Ceramics: Influence of Microstructure, Environment, and Service Conditions
B. NAIT-ALI, D. VITIELLO, N. TESSIER-DOYEN, D.S. SMITH, University of Limoges, IRCER, UMR CNRS 7315, Limoges, France
Thermal conductivity is a key parameter controlling the performance of porous ceramics in many industrial applications. It depends strongly on microstructural parameters such as grain and pore size, pore volume fraction, and spatial arrangement. The orientation of elongated pores can also induce anisotropic heat transfer, offering opportunities for thermal management optimization. Environmental factors also influence heat transport: temperature affects both solid and gas conductivities, while radiative transfer becomes important at high temperatures. High levels of humidity in the atmosphere can significantly increase heat conduction through porous insulating ceramics. These aspects were investigated on oxide ceramics and extended to refractory materials used in steel ladle linings. Different components of the lining, including alumina–spinel bricks and insulating boards, were analysed to understand the combined influence of porosity, grain boundaries, and secondary phases on thermal transport. Complementary studies on post-service samples highlighted the role of environmental interactions in modifying thermal conductivity during operation. The results provide an integrated view of how microstructure and service conditions govern thermal conductivity in porous ceramics.
CE-2:IL17 Composition Design and Properties of Rare-earth-zirconate High-entropy Porous Ceramics
JIE XU, JINGZHI WU, QINGYUN YANG, FENG GAO, State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an, China
Thermal insulation materials with high temperature resistance, high strength, and low thermal conductivity are key materials in the development of hypersonic vehicles. Based on the design of high-entropy concept, rare-earth-zirconate high-entropy ceramics with various components were prepared. The influence of size/mass disorder factor, ‘Rattler’ effect and order-disorder transition (ODT) on the structure, morphology, and properties of rare-earth-zirconate high-entropy ceramics was explored. Based on the optimized components design, porous ceramics were fabricated using gel-casting and direct foaming, and the influence of solid content and sintering temperature on pore structure, morphology, and properties of porous high-entropy ceramics was explored. Due to the scattering of high-temperature radiation by micrometer pore structure, the high-entropy zirconates porous ceramics shows low thermal conductivity while maintaining high mechanical properties. The porous high-entropy ceramics exhibit a high compressive strength and relatively lower high temperature thermal conductivity. These promising properties indicating that rare-earth-zirconate high-entropy porous ceramics could be used as potential insulation materials for hypersonic vehicles.
CE-2:L18 Si-Based Polymer-Derived Ceramic Aerogels
C.V. AHMETOGLU, A. GURLO, Technische Universität Berlin, Fakultät III Prozesswissenschaften, Institut für Werkstoffwissenschaften und technologien, Sekretariat BA3, Berlin, Germany
This work presents the synthesis, characterization, and functional assessment of monolithic preceramic, hybrid, and ceramic aerogels fabricated via the polymer-derived ceramic (PDC) route using both ambient pressure drying (ambigels) and CO₂ supercritical drying. Despite differences in processing, the resulting materials exhibit comparable structural features, demonstrating that the more economical and straightforward ambient pressure drying can effectively replace supercritical drying without significant compromise in performance. In addition to neat aerogels, foam–aerogel composites are developed by infiltrating aerogels into foams, yielding highly porous, lightweight monoliths that remain machinable into diverse shapes while retaining their intrinsic properties. Both aerogels and foam–aerogel composites are evaluated for oil–water separation, thermal insulation, and flammability, underscoring their versatility and potential for a broad range of applications.
CE-2:L19 Nano X-ray CT based Microstructural Characterization of Low-Emissivity Porous Ceramics
SHUKO AKAMINE, Mechanical Systems Engineering, National Institute of Technology, Okinawa College, Nago-shi, Okinawa, Japan; SHOGO FURUTA, MASAKAZU KOBAYASHI, Department of Mechanical Engineering, Toyohashi University of Technology, Japan
MgAl₂O₄ ceramics are stable oxide material at temperatures exceeding 2000 °C and do not absorb light in the wide range from visible to near-infrared regions. Therefore, by forming a porous structure with a controlled microstructure corresponding to the wavelength emitted from the heat source, Mie scattering occurs, resulting in a porous MgAl₂O₄ ceramics that suppresses radiation input. In other words, this material has the ability of high thermal and oxidation resistance low-emissivity material. This property can be applied to radiation shielding for components exposed to high temperature, and thus is expected to be used in thermal protection systems for reusable space vehicles. Evaluation of the thermal radiation insulating properties of this material revealed that it effectively suppresses radiation from heat sources and is effective for temperature control. In this presentation, the results of microstructure analysis using nano-X-ray CT are reported to further clarify the relationship between the thermal radiation insulating properties and microstructures.
Session CE-3 Advances in the characterization and modelling of the porous structure (adsorption and intrusion porosimetry, thermophotometry, high resolution microscopy, image analysis, scattering techniques, computed tomography, etc.)
CE-3:IL21 Three-Dimensional Imaging Techniques for Porous Ceramics Using Confocal Laser Fluorescence Microscopy
MASAKO UEMATSU, T. KIMURA, Japan Fine Ceramics Center, Nagoya, Aichi, Japan; K. ISHII, Nagoya Institute of Technology, Nagoya, Aichi, Japan; T. UCHIKOSHI, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
The pore structure of porous materials is a key factor that significantly influences the properties of the final product. Common evaluation methods include pore size distribution analysis via gas adsorption isotherms or mercury porosimetry, as well as qualitative observation using electron microscopy. However, these techniques are limited in their ability to assess the three-dimensional (3D) pore network. While methods such as micro X-ray computed tomography and focused ion beam-scanning electron microscopy enable 3D observation, they require precise sample preparation, which is challenging for fragile porous materials. To enable a simpler method for evaluating 3D pore structures, a liquid with a refractive index matching that of the material was infiltrated into the porous sample to reduce light scattering at pore interfaces, thereby allowing internal optical observation. A fluorescent dye was added to the liquid, and depth-resolved cross-sectional images were acquired using confocal fluorescence microscopy. These images were then reconstructed into 3D representations of the pore structure. This presentation introduces examples of pore structure evaluation in porous materials fabricated using pore-forming agents with different structural characteristics.
CE-3:IL22 The Role of Controlled Porosity in Solid Oxide Materials for Cold Plasma Catalysis and Energy Conversion Applications
J. GURAUSKIS1,2, A.F. GARCIA1, E. GÁLVEZ1, 1Instituto de Nanociencia y Materiales de Aragón (INMA-CSIC/UNIZAR), Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Zaragoza, Zaragoza, Spain; 2Fundación Agencia Aragonesa para la Investigación y el Desarrollo (ARAID), Zaragoza, Spain
The intensification of cold plasma catalysis for energy-efficient processes like CO2 hydrogenation is limited by suboptimal catalyst-plasma interaction in conventional reactors. This work, performed within the Horizon Europe project C2FUe-LS, presents a methodology for the design and fabrication of digitally structured solid oxide supports with tailored hierarchical porosity to enhance catalytic performance in Dielectric Barrier Discharge (DBD) systems. Computational Fluid Dynamics (CFD) simulations are employed to optimize macrostructural designs for superior mass flow dynamics and heat management. An innovative manufacturing route combining 3D conformation and sacrificial pore formers is utilized to achieve scaffolds with controlled porosity across multiple scales. These structures provide an improved environment for anchoring active catalytic phases. The resulting cold plasma modules are anticipated to enhance catalytic performance and stability under DBD reaction systems. Therefore, increasing conversion efficiency and selectivity in low-temperature CO2 valorization processes based on cold plasma.
CE-3:IL23 Study of Geopolymer Porosity through Adsorption and Intrusion Porosimetry
E. PAPA, C. DI PIETRO, M.C. MARCHIONI, F. SERVADEI, V. MEDRI, E. LANDI, National Research Council - Institute of Science, Technology and Sustainability for Ceramics (CNR-ISSMC), Faenza, RA, Italy
Geopolymers are a versatile type of synthetic porous inorganic material with a broad range of potential applications. The porosity of the geopolymers is considered as a secondary functional phase and its control is important to endow materials with brand-new and useful properties. The geopolymer production process allows to tailor porosity from nanometric to millimetric range, while, ultra-macroporosity can be induced exploiting different techniques, obtaining hierarchical pore systems. Different analyses must be combined in order to have a complete view of the geopolymer porosity. The intrinsic geopolymer porosity is well investigated combining N2 adsorption/desorption measurements with mercury intrusion porosimetry to have complementary information covering a pore range from 5 nm up to 100 µm. Parameters derived from these analyses are useful in establishing property-microstructure relations, since geopolymer properties have strong relationship with the pore structure, porosity and pore size distribution.
Research activities were carried in the framework of the MUR PRIN 2022 Project GEA - GEopolymer based Adsorbents for effective adsorption and selective separation of CO2 and eutrophication pollutants, Prot. 20229THRM2, funded by the European Union, Next Generation EU.
CE-3:IL24 Microstructure Evaluation of Porous Ceramics
T. FEY, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
Cellular materials have a wide range of applications, including as support structures for catalysts, lightweight structural components, energy absorption systems, energy storage media and filtration units. For filtration applications in particular, an open-cell architecture is essential for effective fluid transport and particle retention. Historically, microstructural analyses of such materials were conducted using light microscopy on multiple cross-sectional cuts. However, the advent of X-ray microcomputed tomography (µCT) now makes it possible to obtain a comprehensive three-dimensional (3D) representation of the microstructure at a defined spatial resolution. µCT can be used to characterise various porous ceramic foams, periodic cellular architectures, and composite systems, yielding high-resolution 3D volumetric datasets for quantitative microstructural analysis. Additionally, determining a representative volume element of interest (REVOI) within the porous domain is critical for ensuring statistically meaningful simulations and reliable property evaluation. In the context of additive manufacturing, microstructural characterisation is pivotal in quantifying the fidelity of the fabricated component relative to its original CAD design.
Session CE-4 Progress in applications of porous ceramics
CE-4:IL25 Hierarchical Porous Materials for Resource-efficient Chemical Processes
F. SCHEFFLER, L. MATTHIES, Z. AYAS, M. SCHWIDDER, A. LIEB, Otto-von-Guericke University, Magdeburg, Germany Faculty of Process & Systems Engineering, Institute for Chemistry, Magdeburg, Germany
Mankind faces unprecedented challenges, particularly with regard to reducing emissions, conserving energy, and saving resources. The development of new multifunctional materials plays a key role in a number of these technical processes. The tailor-made combination of cellular structure, micro- and macroporosity, and surface chemical or catalytic activity opens up possibilities for various sub-steps such as material separation, ~storage and chemical reaction to take place in a single technical reaction unit. The first part of this contribution provides an overview of preparation methods to obtain composites combining macroporous support structures with microporous compounds to provide a separation as well as adsorption and/or catalytic function, with a focus on the application of ceramic supports. In the second part, a collection of different examples will be shown, e.g. ceramic membrane reactors functionalized with a zeolite layer to combine the valorization of green methanol to several bulk products, or the separation and transformation of carbon dioxide with a composite made by the synthesis of a metal-organic framework (MOF) on graphene.
CE-4:IL26 Environmental-friendly in-situ Mullite Whisker Reinforced Porous Ceramics for Environmental Applications Research
KAIHUI HUA, Dongguan University of Technology, Dongguan, China
Using construction waste as the main raw material, Al2O3 as the supplementary aluminum source, AlF3 as the whisker catalyst, MoO3, B2O3, CeO2, etc. as the sintering aids, in-situ mullite whisker-reinforced porous ceramics were prepared by comprehensively adopting in-situ crystal generation method, pore-forming agent addition method and vacuum freeze-drying method. The results showed that when the addition amount of AlF3 is 12 wt.%, the addition amounts of B2O3 and activated carbon are both 2 wt.%, with the sintering temperature of 1100 °C, the comprehensive performance of the prepared porous ceramics is the best. In addition to mullite whiskers in the cross-sectional morphology of the samples, some aluminum borate whiskers are also introduced. The whiskers are evenly and finely distributed, presenting a downy texture. Subsequently, detailed studies were conducted on the applications of different types of porous ceramics in various fields such as oil-water separation, photocatalytic degradation of dye wastewater, sound absorption and noise reduction, and heat insulation and preservation. All of these applications demonstrated excellent performance. The flexural strength of the porous ceramic is 10.3±0.5 MPa, the porosity is 92.3±0.7%, the bulk density is as low as 0.24 g cm-3, the thermal conductivity is 0.06 W·m K-1, and at a frequency of 2000 Hz, its sound absorption coefficient is approximately 0.81. When the catalyst was loaded to treat azo dye wastewater, the degradation rate of methyl orange/Rhodamine B exceeded 99% after 120 minutes of unit sunlight exposure, and it had good reusability. Using whisker skeleton porous ceramics as the ceramic membrane support and coating the nano-membrane layer for oil-water separation, the permeation flux is as high as 2166.403 L·m-2·h-1.
CE-4:L27 Plasma-Catalytic CO₂-to-O₂ Conversion Using Boron-Alumina/Silica Nanofiber Membranes for ISRU on Mars
R.A. YAGER, A. STANISHEVSKY, University of Alabama at Birmingham, Birmingham, AL, USA
Boron–alumina/silica nanofibrous membranes were developed and integrated into dielectric barrier discharge (DBD) plasma reactors for CO2 conversion under simulated Martian conditions. These high-surface-area, thermally stable composites serve as multifunctional plasma–catalyst interfaces, promoting charge stabilization, oxygen radical formation, and enhanced molecular dissociation in low-pressure CO2 environments. Transition-metal dopants (Ni, Fe, Cu) were incorporated to tailor electron density and adsorption behavior, improving CO2 activation pathways toward oxygen generation. FTIR and in-situ O2 sensor measurements confirmed active oxygen formation and CO2 consumption, while Lissajous and I–V analysis characterized plasma behavior and discharge stability. Complementary XRD, SEM, and mechanical testing verified the phase integrity, nanofiber morphology, and robustness of the membranes after plasma exposure. Together, these results demonstrate a tunable boron–alumina/silica nanofiber architecture capable of supporting long-duration CO2-to-O2 conversion for in-situ resource utilization (ISRU) and life-support applications on Mars.
CE-4:L28 Mechanically Driven Catalytic Activity of Highly Porous Ceramics
T. STÖTZEL, S. FUNK, T. FEY, Friedrich-Alexander University, Erlangen, Germany
In recent years, catalytic technologies have been attracting increasing interest as a potential time- and energy-saving alternative to conventional water treatment methods. These new emerging approaches utilize different types of energy to enable the degradation of pollutants by generating charge carriers and reactive oxygen species. Since a large surface area is crucial for catalytic processes, most research about ceramic catalysts focuses on micro- or nano-sized powder to increase efficiency. However, catalysts in particulate form also bear disadvantages like secondary pollution and limited reusability. A possible solution to these challenges is the design of porous structures which also provide an enlarged surface area but are easier to separate from aqueous systems. In this work the mechanically driven catalytic activity of ceramics with a very high porosity of 80 % is analyzed. Additive manufacturing and the replica technique have been used to produce different structures out of barium titanate and alumina which were then stimulated with ultrasound to degrade Rhodamine B as an organic contaminant. The performance and suitability of the different structures and materials as well as the mechanisms involved in the degradation are discussed.
CE-4:L29 Clay-based Ceramics for Hydrogen Production and Gas Separation
I. REIMANIS1, R. MCGINNIS1, S. RICOTE1, G. COORS2, R. MARDER3, W. KAPLAN3, 1Colorado School of Mines, Golden, CO, USA; 2Hydrogen Helix, Golden, CO, USA; 3Technion - Israel Institute of Technology, Haifa, Israel
Kaolinite-based clay exhibits a very porous microstructure with high surface area. When bisque fired it retains the desirable morphology and is ideal for use as a catalyst support as well as for gas separation due to naturally forming porous microchannels. Recent experiments with Ni-infiltrated bisque-fired kaolinite have demonstrated that hydrogen can be produced from ethanol (ethanol steam reforming, ESR) at rates that are of high commercial interest. Additionally, the high surface area and fine pore channels lead to excellent gas separation performance. The talk will describe the processing, microstructure evolution, and mechanical integrity of kaolinite-based ceramics in the context of ESR and gas separation.
CE-4:IL30 Correlations between Geopolymer Composition, Material Characteristics, and Performance in Adsorption Applications
T. LUUKKONEN, F. HOSSAIN, A. HOSSAIN, Fibre and Particle Engineering Research Unit, University of Oulu, Finland
Geopolymers commonly revolve around the nominal composition of Na2O•Al2O3•4SiO2 (i.e., Na1Al1Si2) since it results in, for example, optimum strength as a binder. However, geopolymers are also studied actively for several more advanced applications, including adsorbents, in which the detailed information about the correlations between composition, materials properties, and performance is lacking. In the present study, 20 different geopolymers (and Ca-containing alkali-activated materials, AAMs) were synthesized with a sol-gel method in the composition range of Si1Al1Na1–Si20Al1Na1Ca21. The geopolymers/AAMs were thoroughly characterized by XRF, XRD, XPS, SEM, FTIR, 29Si NMR, N2 adsorption/desorption, and zeta potential measurement. The adsorption applications considered were the uptake of aqueous cations with an increasing radii: ammonium (NH4+), methylene blue, rhodamine 6G as well as hydrogen storage. The results show that the Ca-free geopolymers had an increasing uptake of NH4+ when decreasing the Si/Al ratio while the trends were reversed for organic dyes and gaseous H2. The inclusion of Ca generally decreased the adsorption performance for most of the compositions. These results can be used to design the future geopolymers formulations that require certain properties.
CE-4:IL31 Alkali-Activated Materials and Geopolymers as Bulk Sorbents for Wastewater Treatment: Current Status and Future Outlook
R.M. NOVAIS1, M.M. ALMEIDA1, A.P.F. CAETANO1, J.G. CUADRA1, N.P.F. GONÇALVES2, J.A. LABRINCHA1, 1Department of Materials and Ceramic Engineering / CICECO-Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal; 2Department of Chemistry / CICECO-Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
Decades of intensive research on alkali-activated materials (AAMs) and geopolymers as potential replacements for Portland cement have not yet translated into their large-scale adoption, owing to both technical and non-technical limitations. Nevertheless, their sustainable synthesis routes, coupled with their tuneable physicochemical properties, have sparked growing interest in alternative applications beyond construction. One particularly promising field is environmental remediation, where AAMs and geopolymers are increasingly investigated as bulk sorbents for wastewater treatment. Acid mine drainage (AMD), one of the most persistent and hazardous waste streams generated by mining activities, exemplifies the scale and urgency of this challenge, as it can pose severe and long-lasting environmental risks if left untreated. Recent studies have begun to explore the feasibility of using AAMs for the depollution of both synthetic wastewaters and real AMD, including those collected from abandoned Portuguese mines. This lecture will address the current status of such approaches, examine their merits and limitations, and discuss future prospects for advancing AAM- and geopolymer-based sorbents as sustainable solutions for wastewater treatment.
CE-4:IL32 Self-Cleaning BCTZ-Based Piezoelectric Porous Ceramic Membranes for Advanced Microfiltration: A New Strategy for Fouling Control
P. GALIZIA, A. TAVOLARO, C. BALDISSERRI, D. GARDINI, E. MERCADELLI, CNR-ISSMC, National Research Council of Italy - Institute of Science, Technology and Sustainability for Ceramics, Faenza, Italy; F. CRACIUN, F. CORDERO, CNR-ISM, National Research Council of Italy - Institute of Structure of Matter, Tor Vergata, Italy; C. GALASSI, F. BERTOLINI, D. MOMBELLI, N. LECIS, Department of Mechanical Engineering, Politecnico di Milano, Milano, Italy; C. CONIDI, A. CASSANO, CNR-ITM, National Research Council of Italy - Institute on Membrane Technology, University of Calabria, Rende, Cosenza, Italy
Microfiltration (MF) membranes are a key technology for water recovery from agro-food wastewater, but their performance is strongly limited by fouling, which reduces permeability and operating life. Ceramic membranes (CMs) outperform polymeric ones in chemical stability, mechanical strength, and longevity, yet their high cost requires strategies to improve antifouling efficiency. Among CMs, self-cleaning piezoelectric membranes are emerging as a new solution, where mechanical vibrations generated under electric field promote impurity detachment and surface regeneration. Within the SELWA project (funded by the European Union – Next Generation EU – Grant Assignment Decree No. 20229PNWM7), porous lead-free (Ba,Ca)(Zr,Ti)O3 (BCTZ) membranes are developed through sacrificial template methods, freeze casting, and binder jetting. This work presents the first results on the correlation between microstructure, piezoelectric properties, and self-cleaning behaviour. The challenges of transitioning from dense to porous architectures are discussed, together with preliminary water permeability and filtration tests that demonstrate the potential of piezoelectric ceramics as a new strategy for fouling control in advanced MF processes.
CE-4:L33 Synthesis and Surface Modification of Porous Nanoceramics for Energy Storage
I. ZHITOMIRSKY, Department of materials Science and Engineering, McMaster University, Hamilton, Canada
Porous nanoceramics were obtained for applications in supercapacitors. Electrodes containing oxides of manganese or vanadium showed capacitances of 8-10 F cm-2, low impedance, high power and energy. Magnetically ordered supercapacitor materials, such as spinels, hexagonal ferrites and perovskite manganites showed capacitances of 4-6 F cm-2 and room temperature magnetization of 40-70 emu g-1. They outperform multiferroics in both electrical capacitance and magnetization by several orders of magnitude. Enhanced performance was achieved using new strategies in nanotechnology. New capping agents with various chelating ligands showed enhanced adsorption on nanoparticles and facilitated particle size control during chemical precipitation or hydrothermal synthesis. Conceptually new catecholate type dispersants-charge transfer mediators facilitated electron transfer, resulting in enhanced capacitance. The use of multifunctional organic alkalizers-capping agents instead of inorganic alkalis for synthesis allowed for reduction of particle size, improved dispersion and enhanced performance. Liquid-liquid extraction techniques and extractors were discovered, which facilitated agglomerate-free processing and direct nanoparticle transfer from synthesis medium to the device processing medium.
CE-4:L34 Optical Gas Sensing Using Terahertz Time-Domain Spectroscopy with porous ceramics
KEIJI KOMATSU1, TOSHIYUKI IWAMOTO2,3, MASAMI AONO4, 1Department of Materials Science and Bioengineering, Nagaoka University of Technology, Niigata, Japan; 2Nippo Precision Co., Ltd., Yamanashi, Japan; 3Institute of Laser Engineering, Osaka University, Osaka, Japan; 4Electrical and Electronics Engineering Program, Graduate School of Science and Engineering, Kagoshima University, Japan
Volatile organic compounds(VOCs) and volatile sulfur compounds (VSCs) are produced and released from different industries including pulp and paper (P&P), refineries,distilleries, foods, and waste water treatment plants. This study proposed room-temperature THz gas sensing using terahertz time-domain spectroscopy (THz-TDS) with porous ceramics. The transmission method was used in THz-TDS. A stainless hand-made gas cell with a Si window was applied for THz gas sensing. We defined “Difference of Phase” equals sensing gases response amounts of Volatile sulfur-containing compounds (VSCs) such as NH3, CH3SH, H2S. Hence, Sub ppm-order THz gas sensing was performed.
(Previous study:K.Komatsu et al, ACS Omega 7(35) 30768-30772 (2022))