Details
| Original language | English |
|---|---|
| Article number | 1701392 |
| Journal | SMALL |
| Volume | 13 |
| Issue number | 34 |
| Early online date | 7 Sept 2017 |
| Publication status | Published - 13 Sept 2017 |
| Externally published | Yes |
Abstract
One efficient method to obtain disordered colloidal packing is to reduce the stability of colloidal particles by adding electrolytes to the colloidal dispersions. But the correct amount of additional electrolytes must be found empirically. Here, the effect of CaCl2 on polystyrene colloidal dispersions is studied, and a link between the amount of CaCl2 and the corresponding glassy colloidal structure is quantitatively built. A threshold concentration of CaCl2 is found by dynamic light scattering. When exceeding this threshold, different nanoparticle oligomers are observed in the dispersions by analytical ultracentrifugation. The second objective is to achieve free-standing samples, which is required for many optical measurements. A universal method is established, using a centrifugal field to produce robust samples by polymerizing coassembled hydrophilic monomers to form a network, which traps the glassy colloidal structures. Photon time of flight measurements shows that the CaCl2 concentration threshold should not be exceeded. Otherwise an optical shortcut may take place. Thus, the work provides a feasible universal route to prepare macroscopic free-standing photonic glasses from electrostatically stabilized nanoparticles, suitable for further optical investigation.
Keywords
- analytical ultracentrifugation, colloidal assembly, free-standing materials, light localization, photonic glasses
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Biotechnology
- Chemistry(all)
- General Chemistry
- Materials Science(all)
- Biomaterials
- Materials Science(all)
- General Materials Science
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In: SMALL, Vol. 13, No. 34, 1701392, 13.09.2017.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Free-Standing Photonic Glasses Fabricated in a Centrifugal Field
AU - Chen, Mengdi
AU - Fischli, Danja
AU - Schertel, Lukas
AU - Aubry, Geoffroy J.
AU - Häusele, Benedikt
AU - Polarz, Sebastian
AU - Maret, Georg
AU - Cölfen, Helmut
N1 - Funding Information: M.C. is funded by a Chinese Scholarship Council stipend. L.S., G.J.A., G.M., and H.C. acknowledge support from the Center for Applied Photonics (Universität Konstanz). G.J.A. acknowledges support from the Zukunftkolleg (Universität Konstanz) for an Independent Research Start-up Grant.
PY - 2017/9/13
Y1 - 2017/9/13
N2 - One efficient method to obtain disordered colloidal packing is to reduce the stability of colloidal particles by adding electrolytes to the colloidal dispersions. But the correct amount of additional electrolytes must be found empirically. Here, the effect of CaCl2 on polystyrene colloidal dispersions is studied, and a link between the amount of CaCl2 and the corresponding glassy colloidal structure is quantitatively built. A threshold concentration of CaCl2 is found by dynamic light scattering. When exceeding this threshold, different nanoparticle oligomers are observed in the dispersions by analytical ultracentrifugation. The second objective is to achieve free-standing samples, which is required for many optical measurements. A universal method is established, using a centrifugal field to produce robust samples by polymerizing coassembled hydrophilic monomers to form a network, which traps the glassy colloidal structures. Photon time of flight measurements shows that the CaCl2 concentration threshold should not be exceeded. Otherwise an optical shortcut may take place. Thus, the work provides a feasible universal route to prepare macroscopic free-standing photonic glasses from electrostatically stabilized nanoparticles, suitable for further optical investigation.
AB - One efficient method to obtain disordered colloidal packing is to reduce the stability of colloidal particles by adding electrolytes to the colloidal dispersions. But the correct amount of additional electrolytes must be found empirically. Here, the effect of CaCl2 on polystyrene colloidal dispersions is studied, and a link between the amount of CaCl2 and the corresponding glassy colloidal structure is quantitatively built. A threshold concentration of CaCl2 is found by dynamic light scattering. When exceeding this threshold, different nanoparticle oligomers are observed in the dispersions by analytical ultracentrifugation. The second objective is to achieve free-standing samples, which is required for many optical measurements. A universal method is established, using a centrifugal field to produce robust samples by polymerizing coassembled hydrophilic monomers to form a network, which traps the glassy colloidal structures. Photon time of flight measurements shows that the CaCl2 concentration threshold should not be exceeded. Otherwise an optical shortcut may take place. Thus, the work provides a feasible universal route to prepare macroscopic free-standing photonic glasses from electrostatically stabilized nanoparticles, suitable for further optical investigation.
KW - analytical ultracentrifugation
KW - colloidal assembly
KW - free-standing materials
KW - light localization
KW - photonic glasses
UR - http://www.scopus.com/inward/record.url?scp=85028958343&partnerID=8YFLogxK
U2 - 10.1002/smll.201701392
DO - 10.1002/smll.201701392
M3 - Article
C2 - 28722343
AN - SCOPUS:85028958343
VL - 13
JO - SMALL
JF - SMALL
SN - 1613-6810
IS - 34
M1 - 1701392
ER -