Fabrication of porous alumina ceramics having cell windows with controlled size by PMMA template method

Kamitani, Kazutaka; Hyodo, Takeo; Shimizu, Yasuhiro; Egashira, Makoto

doi:10.1007/s10853-010-4406-7

Cited by 16 publications

(7 citation statements)

References 28 publications

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“…Polymethylmethacrylate (PMMA) beads and microbeads have been frequently employed for sacrificial fugitives. 8,[59][60][61][62][63][64]77,79,[82][83][84][85] For example, Colombo and his co-workers 8,59-61 fabricated SiOC ceramic foam as shown in Fig. 8, by dry mixing the silicon resin powder with a sacrificial template constituted by PMMA microbeads, and subsequent heat treatments.…”

Section: Sacrificial Fugitivesmentioning

confidence: 99%

Macro-porous ceramics: processing and properties

Ohji

Fukushima

2012

International Materials Reviews

625

319

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Porous ceramics are now expected to be used for a wide variety of industrial applications from filtration, absorption, catalysts and catalyst supports to lightweight structural components. During the last decade, tremendous efforts have been devoted for the researches on innovative processing technologies of porous ceramics, resulting in better control of the porous structures and substantial improvements of the properties. This article intends to review these recent progresses of porous ceramics. Because of a vast amount of research works reported in this field these days, the review mainly focuses on macro-porous ceramics whose pore size is larger than 50 nm. Followed by giving a general classification of porous ceramics, a number of innovative processing routes developed for critical control of pores are described, along with some important properties. The processes are divided into four categories including (i) partial sintering, (ii) sacrificial fugitives, (iii) replica templates and (iv) direct foaming. The partial sintering, the most conventional technique for making porous ceramics, has been substantially sophisticated in recent years. Very homogeneous porous ceramics with extremely narrow size distribution have been successfully prepared through sintering combined with in situ chemical synthesis. Carefully tailored micro-structure (size, morphology and orientation of grains and pores, etc.) of porous ceramics has led to unique mechanical properties, which cannot be attained even in the dense materials. Various types of the sacrificial fugitives have been examined for obtaining well-tuned shape and size of pores. The freeze-drying techniques using water or liquid as fugitive materials have been most frequently studied in recent years. Controlling growth of ice during freezing has led to unique porous structures and excellent performances of porous ceramics, e.g. excellent mechanical behaviour for highly porous lamellar hydroxyl-apatite scaffolds. Numerous approaches on the replica templates have been developed in order to produce highly porous ceramics having interconnected large pores and sufficiently strong struts without cracks. Natural template approaches using wood, for example, as positive replica, have been intensively studied in these years and have realised highly oriented porous open-porous structure with a wide range of porosity. As for the direct foaming technique, a variety of novel techniques which stabilise the bubbles in ceramic suspension have been developed to suppress large pore formation, e.g. evaporation of emulsified alkane droplets and use of surface-modified particles. We also briefly review porous ceramics with hierarchical porosity (incorporation of macro-, meso-and micropores), which have attracted much attention in both academic and industrial fields. Finally the article gives the summary and discusses the issues to be solved for further activating the potential of porous ceramics and for expanding their applicability.

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Section: Sacrificial Fugitivesmentioning

confidence: 99%

Macro-porous ceramics: processing and properties

Ohji

Fukushima

2012

International Materials Reviews

625

319

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“…Ceramic foams have been prepared using several methods such as direct foaming [2][3][4][5][6][7], sacrificial template or fugitives [8][9][10][11][12], replica methods [1,[13][14][15][16] and partial sintering [17,18]. Ceramic foam derived using the abovementioned methods is chemo-thermo-mechanically suitable for further processing.…”

Section: Introductionmentioning

confidence: 99%

Titania-Coated Alumina Foam Photocatalyst for Memantine Degradation Derived by Replica Method and Sol-Gel Reaction

et al. 2020

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In the present work, alumina (Al2O3) foam was prepared by the replica method where a polyurethane (PU) foam (30 pores per inch (ppi)) template was impregnated with a 60 wt.% Al2O3 suspension. Sintered Al2O3 foam was used as substrate for the deposition of sol-gel derived titania (TiO2) film using dip coating. For the preparation of TiO2 sol, titanium(IV) isopropoxide (Ti-iPrOH) was used as the precursor. The common problem of qualification and quantification of a crystalline coating on a highly porous 3D substrate with an uneven surface was addressed using a combination of different structural characterization methods. Using Powder X-ray Diffraction (PXRD) and synchrotron Grazing Incidence X-ray Diffraction (GIXRD) on bulk and powdered Al2O3 foam and TiO2-coated Al2O3 foam samples, it was determined Al2O3 foam crystallizes to corundum and coating to anatase, which was also confirmed by Fourier Transformed Infrared Spectroscopy (FTIR). Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM/EDS) revealed the structural and microstructural properties of the substrate and coating. Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA) were used to clarify the evolution of the porous microstructure. The Al2O3-TiO2 composite was evaluated as a photocatalyst candidate for the degradation of the micropollutant medication memantine. The degradation rate was monitored using a light-emitting diode (LED) lamp operating at electromagnetic (EM) wavelength of 365 nm. The photocatalytic activity of sol-gel-derived TiO2 film immobilized on the Al2O3 foam was compared with commercially available TiO2 nanoparticles, P25-Degussa, in the form of a suspension. The levels of memantine were monitored by High-Performance Liquid Chromatography–Tandem Mass Spectrometry (HPLC–MS/MS). The efficiency and rate of the memantine photodegradation by suspended TiO2 nanoparticles is higher than the TiO2-coated Al2O3 foam. But, from the practical point of view, TiO2-coated Al2O3 foam is more appropriate as a valuable photocatalytic composite material.

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“…[48,49] In addition, microscale pores have been successfully fabricated using packed PMMA beads (5-800 μm) as pore-forming agents, resulting in porosities ranging from 7% to 80%. [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65] Porous SiOC-bonded SiC ceramics with apparent porosity between 17% and 58% were produced using silicon resin and PMMA microbeads (40-60 μm) as porogens for high-temperature gas filtration. [66] Furthermore, porous yttria-stabilized zirconia (YSZ) ceramics (%45%-72% porosity) were produced using monodispersed PMMA microbeads (%18 μm) as sacrificial pore-forming agent.…”

Section: Introductionmentioning

confidence: 99%

Ceramic Foams with Controlled Geometries Through 3D‐Printed Sacrificial Templates

2023

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Powder‐based 3D printing was combined with sacrificial templating to realize highly porous yttria‐stabilized ZrO2 (YSZ) ceramic foam objects with well‐defined geometries. The porous sacrificial template is 3D printed using poly(methyl methacrylate) powder. Various methods are evaluated to optimize ceramic slurry infiltration into the 3D‐printed template and subsequent burn‐out. The optimized method yields ceramic foam objects with an open porosity of >66% and replicates the geometry of the 3D‐printed template with high fidelity.

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Fabrication of porous alumina ceramics having cell windows with controlled size by PMMA template method

Cited by 16 publications

References 28 publications

Macro-porous ceramics: processing and properties

Macro-porous ceramics: processing and properties

Titania-Coated Alumina Foam Photocatalyst for Memantine Degradation Derived by Replica Method and Sol-Gel Reaction

Ceramic Foams with Controlled Geometries Through 3D‐Printed Sacrificial Templates

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