Impact of a tert-butyl alcohol-cyclohexane system used in unidirectional freeze-casting of SiOC on compressive strength and mass transport
Macroporous SiOC monoliths were prepared by solution-based freeze-casting of a polymethyl siloxane using cyclohexane (CH) and tert-butyl alcohol (TBA) as a novel template media. Samples with TBA amounts of 100, 90, 80 and 0 wt% were stable during preparation at −20 °C. Using TBA or CH creates prisma...
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| Format: | Article |
| Language: | English |
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Elsevier
2021-12-01
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| Series: | Materials & Design |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0264127521007413 |
| _version_ | 1818366650939867136 |
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| author | Pedro Henrique da Rosa Braun Kurosch Rezwan Michaela Wilhelm |
| author_facet | Pedro Henrique da Rosa Braun Kurosch Rezwan Michaela Wilhelm |
| author_sort | Pedro Henrique da Rosa Braun |
| collection | DOAJ |
| description | Macroporous SiOC monoliths were prepared by solution-based freeze-casting of a polymethyl siloxane using cyclohexane (CH) and tert-butyl alcohol (TBA) as a novel template media. Samples with TBA amounts of 100, 90, 80 and 0 wt% were stable during preparation at −20 °C. Using TBA or CH creates prismatic or dendritic pore structures, respectively, while a mixture of these solvents generates honeycomb-like pore structures. A constant freezing rate produces homogeneous pore window sizes while freezing with velocity gradients produces inhomogeneous pore window sizes. Variations in the amount of TBA led to pore sizes between 11 and 57 µm and consequently to water permeabilities of 4.4 × 10-13 to 1.4 × 10- 11m2. The dendritic pore structure has the highest compressive strength (39 MPa) due to its smallest pore sizes (16–20 µm) and secondary dendrites. In wicking experiments, these structural properties and the lowest permeability resulted in the slowest wicking rate in contrast to prismatic pore structures with the biggest pore sizes (31–57 µm) and highest permeability. Honeycomb-like pore structures allow medium wicking rates with the pore size being the main influencing factor. The adjustment of the solvent allows tailoring the mass transport and mechanical properties as key elements in capillary transport applications. |
| first_indexed | 2024-12-13T22:39:32Z |
| format | Article |
| id | doaj.art-42cc3858570c459d85a455387261af92 |
| institution | Directory Open Access Journal |
| issn | 0264-1275 |
| language | English |
| last_indexed | 2024-12-13T22:39:32Z |
| publishDate | 2021-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Materials & Design |
| spelling | doaj.art-42cc3858570c459d85a455387261af922022-12-21T23:28:53ZengElsevierMaterials & Design0264-12752021-12-01212110186Impact of a tert-butyl alcohol-cyclohexane system used in unidirectional freeze-casting of SiOC on compressive strength and mass transportPedro Henrique da Rosa Braun0Kurosch Rezwan1Michaela Wilhelm2University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, IW3, GermanyUniversity of Bremen, Advanced Ceramics, Am Biologischen Garten 2, IW3, Germany; MAPEX—Center for Materials and Processes, University of Bremen, Am Fallturm 1, Bremen, GermanyUniversity of Bremen, Advanced Ceramics, Am Biologischen Garten 2, IW3, Germany; Corresponding author.Macroporous SiOC monoliths were prepared by solution-based freeze-casting of a polymethyl siloxane using cyclohexane (CH) and tert-butyl alcohol (TBA) as a novel template media. Samples with TBA amounts of 100, 90, 80 and 0 wt% were stable during preparation at −20 °C. Using TBA or CH creates prismatic or dendritic pore structures, respectively, while a mixture of these solvents generates honeycomb-like pore structures. A constant freezing rate produces homogeneous pore window sizes while freezing with velocity gradients produces inhomogeneous pore window sizes. Variations in the amount of TBA led to pore sizes between 11 and 57 µm and consequently to water permeabilities of 4.4 × 10-13 to 1.4 × 10- 11m2. The dendritic pore structure has the highest compressive strength (39 MPa) due to its smallest pore sizes (16–20 µm) and secondary dendrites. In wicking experiments, these structural properties and the lowest permeability resulted in the slowest wicking rate in contrast to prismatic pore structures with the biggest pore sizes (31–57 µm) and highest permeability. Honeycomb-like pore structures allow medium wicking rates with the pore size being the main influencing factor. The adjustment of the solvent allows tailoring the mass transport and mechanical properties as key elements in capillary transport applications.http://www.sciencedirect.com/science/article/pii/S0264127521007413PolysiloxaneSiOCFreeze-castingTert-butyl alcohol-cyclohexane systemIsothermal wickingPorous monolith |
| spellingShingle | Pedro Henrique da Rosa Braun Kurosch Rezwan Michaela Wilhelm Impact of a tert-butyl alcohol-cyclohexane system used in unidirectional freeze-casting of SiOC on compressive strength and mass transport Materials & Design Polysiloxane SiOC Freeze-casting Tert-butyl alcohol-cyclohexane system Isothermal wicking Porous monolith |
| title | Impact of a tert-butyl alcohol-cyclohexane system used in unidirectional freeze-casting of SiOC on compressive strength and mass transport |
| title_full | Impact of a tert-butyl alcohol-cyclohexane system used in unidirectional freeze-casting of SiOC on compressive strength and mass transport |
| title_fullStr | Impact of a tert-butyl alcohol-cyclohexane system used in unidirectional freeze-casting of SiOC on compressive strength and mass transport |
| title_full_unstemmed | Impact of a tert-butyl alcohol-cyclohexane system used in unidirectional freeze-casting of SiOC on compressive strength and mass transport |
| title_short | Impact of a tert-butyl alcohol-cyclohexane system used in unidirectional freeze-casting of SiOC on compressive strength and mass transport |
| title_sort | impact of a tert butyl alcohol cyclohexane system used in unidirectional freeze casting of sioc on compressive strength and mass transport |
| topic | Polysiloxane SiOC Freeze-casting Tert-butyl alcohol-cyclohexane system Isothermal wicking Porous monolith |
| url | http://www.sciencedirect.com/science/article/pii/S0264127521007413 |
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