Design of microstructure of zirconia foams from the emulsion template properties

Rosa, M; Martins, Leandro; Pulcinelli, Sandra Helena; Santilli, Celso Valentim

doi:10.1039/c2sm26842f

Cited by 24 publications

(14 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The emulsion can be shaped into a component by solvent drying or in combination with a quick setting technique such as gelcasting or freeze casting. Typically, emulsion templating is combined with sol‐gel routes to create a dual template process that results in porous structures of Al 2 O 3, ZrO 2 and SiO 2, with narrow pore size distributions in the lower ranges of the macroporosity spectrum, between 2 and 5 μm. This approach has also been used with mixtures of polysiloxanes and polycarboxylosanes to generate a porous scaffold that after calcination leads to SiOC or SiC ceramics.…”

Section: Macroporous Ceramic Structures Enabled By Colloidal Processingmentioning

confidence: 99%

Colloidal processing: enabling complex shaped ceramics with unique multiscale structures

et al. 2017

View full text Add to dashboard Cite

Colloidal processing of fine ceramic powders enables the production of complex shaped ceramics with unique micro and macro structures which are not possible to produce via conventional dry processing routes. Because of this enhanced structural control and shaping capabilities, colloidal processing has been exploited to produce ceramic components with ever increasing complexity and functionalities. In this review, we revisit some of the research efforts on this topic to highlight its relevance and growing importance for the advanced manufacturing of functional ceramics. Selected examples of colloidal systems with increasing level of complexity are discussed to showcase the wide range of structures that can be generated through wet processing approaches. The historical development and background knowledge pertaining to colloids and surface interactions is first briefly reviewed. The major colloidal shape forming and additive manufacturing processes that utilize colloidal pastes and inks are then reviewed, highlighting the control of suspension rheology needed in these techniques. Next, methodologies that combine suspended particles with a pore‐forming phase are discussed as a means to produce porous ceramic materials. Further control over the interactions between anisotropic particles and their alignment in suspensions can be gained via externally applied fields (such as magnetic) to produce texturally aligned green bodies. This leads to bioinspired ceramics that can programmably morph into complex shaped objects upon sintering. Hierarchical porous structures with high mechanical efficiency are also shown as an example of the multiscale designs that can be generated through advanced colloidal processing. As drying of ceramic bodies is an inevitable consequence of wet colloidal processing, the current understanding of this critical processing step is reviewed. Finally, the gaps in knowledge in these fields are discussed to provide our perspective on where the field may support advances in ceramics in the future.

show abstract

Section: Macroporous Ceramic Structures Enabled By Colloidal Processingmentioning

confidence: 99%

Colloidal processing: enabling complex shaped ceramics with unique multiscale structures

et al. 2017

View full text Add to dashboard Cite

show abstract

“…As a result, sol can contain several types of particles [19]. The first one is non-aggregated particles; their merging leads to formation of larger ones.…”

Section: Discussionmentioning

confidence: 99%

Composite inorganic membranes containing nanoparticles of hydrated zirconium dioxide for electrodialytic separation

et al. 2014

View full text Add to dashboard Cite

The aim of the work was to elucidate the nature of charge-selective properties of macroporous composite inorganic membranes modified with nanoparticles of hydrated zirconium dioxide. The membranes have been investigated using methods of standard contact porosimetry, potentiometry, electron microscopy and small-angle X-ray scattering. The ion exchanger has been found to deposit inside pores of ceramics. Differential curves of pore volume distribution have been resolved using Lorentz functions; each maximum has been related to structure elements of the matrix and ion exchanger by means of calculations according to homogeneous and heterogeneous geometrical models. It was found that the voids, the radius of which is 4 to 8 nm, are responsible for charge selectivity of the composite membranes. These pores are formed due to blocking of macropores of ceramics with aggregates of nanoparticles of the ion exchanger; the radius of these aggregates is 20 to 24 nm. The membranes were applied to desalination of the solution containing NaCl. The removal degree of the salt from the solution reached 95% and 9% for the composite and unmodified membranes, respectively.

show abstract

“…Though this method is quite simple and has very good control over the pore size, it produces macroporous ceramics having relatively low porosity. In the third method, immiscible liquid (oil) droplets are dispersed in a ceramic precursor sol or ceramic powder suspension using a suitable emulsifying agent to form an emulsion [17][18][19][20][21][22][23]. The emulsion is then set by gelation of the sol or ceramic powder suspension.…”

Section: Introductionmentioning

confidence: 99%

“…High alkane phase emulsions based on decane in aqueous alumina powder suspension have been studied for the preparation of macroporous ceramics [20][21][22]. In this, the emulsions cast in an open mould could be removed from the mould only after partial or complete drying.…”

Section: Introductionmentioning

confidence: 99%

Effect of emulsion composition on gel strength and porosity in the preparation of macroporous alumina ceramics by freeze gelcasting

Vijayan

Narasimman

Prabhakaran

2015

Journal of Asian Ceramic Societies

View full text Add to dashboard Cite

Please cite this article in press as: S. Vijayan, et al., Effect of emulsion composition on gel strength and porosity in the preparation of macroporous alumina ceramics by freeze gelcasting, J. Asian Ceram. Soc. (2015), http://dx.a b s t r a c tThe freeze gelcasting of hydrogenated vegetable oil-in-aqueous alumina slurry (HVO-in-AAS) emulsions of HVO to AAS volume ratios in the range of 1.34-2.69 prepared from slurries of various alumina concentrations were studied to prepare macroporous ceramics of high porosity. The compressive strength (20-150 kPa) and Young's modulus (120-1550 kPa) of the gelled emulsion bodies increased with an increase in alumina slurry concentration and HVO to AAS volume ratio. Easy HVO removal from gelled emulsion bodies by extraction at room temperature with petroleum ether, a less toxic solvent, was achieved. The highest porosity achieved at a HVO to AAS volume ratio of 2.69 increased from 84 to 92.5% when the alumina concentrations in the slurry decreased from 30 to 10 vol.%. The cell size and cell interconnectivity of the ceramics depended on the alumina slurry concentration and HVO to AAS volume ratio. The Young's modulus of the macroporous ceramics modelled using the equation proposed by Gibson and Ashby showed large deviation in the model parameters, n and C, from the proposed values.

show abstract

Design of microstructure of zirconia foams from the emulsion template properties

Cited by 24 publications

References 46 publications

Colloidal processing: enabling complex shaped ceramics with unique multiscale structures

Colloidal processing: enabling complex shaped ceramics with unique multiscale structures

Composite inorganic membranes containing nanoparticles of hydrated zirconium dioxide for electrodialytic separation

Effect of emulsion composition on gel strength and porosity in the preparation of macroporous alumina ceramics by freeze gelcasting

Contact Info

Product

Resources

About