Abstract
Hollow silica and silica-polymer spheres with diameters between 720 and 1000 nanometers were fabricated by consecutively assembling silica nanoparticles and polymer onto colloids and subsequently removing the templated colloid either by calcination or decomposition upon exposure to solvents. Scanning and transmission electron microscopy images demonstrate that the wall thickness of the hollow spheres can be readily controlled by varying the number of nanoparticle-polymer deposition cycles, and the size and shape are determined by the morphology of the templating colloid. The hollow spheres produced are envisioned to have applications in areas ranging from medicine to pharmaceutics to materials science.
References
40
Referenced
3,887
-
Kawahashi N., Matijevic E., J. Colloid Interface Sci. 143, 103 (1991).
(
10.1016/0021-9797(91)90442-B
) / J. Colloid Interface Sci. by Kawahashi N. (1991) -
Giersig M., Ung T., Liz-Marzan L. M., Mulvaney P., Adv. Mater. 9, 570 (1997);
(
10.1002/adma.19970090712
) / Adv. Mater. by Giersig M. (1997) -
Giersig M., Liz-Marzan L. M., Ung T., Su D. S., Mulvaney P., Ber. Bunsenges. Phys. Chem. 101, 1617 (1997).
(
10.1002/bbpc.19971011110
) / Ber. Bunsenges. Phys. Chem. by Giersig M. (1997) -
Bamnolker H., Nitzan B., Gura S., Margel S., J. Mater. Sci. Lett. 16, 1412 (1997).
(
10.1023/A:1018565428355
) / J. Mater. Sci. Lett. by Bamnolker H. (1997) -
Walsh D., Mann S., Nature 377, 320 (1995).
(
10.1038/377320a0
) / Nature by Walsh D. (1995) -
Garg A., Matijevic E., J. Colloid Interface Sci. 126, 243 (1988);
(
10.1016/0021-9797(88)90118-X
) / J. Colloid Interface Sci. by Garg A. (1988) - Kawahashi N., Matijevic E., ibid. 138, 534 (1990); / ibid. by Kawahashi N. (1990)
-
; M. Ohmori and E. Matijevic ibid. 150 594 (1992).
(
10.1016/0021-9797(92)90229-F
) -
Liz-Marzan L. M., Giersig M., Mulvaney P., Langmuir 12, 4329 (1996);
(
10.1021/la9601871
) / Langmuir by Liz-Marzan L. M. (1996) - ; J. Chem. Soc. Chem. Commun. (1996) p. 731;
-
Correa-Duarte M. A., Giersig M., Liz-Marzan L. M., Chem. Phys. Lett. 286, 497 (1998).
(
10.1016/S0009-2614(98)00012-8
) / Chem. Phys. Lett. by Correa-Duarte M. A. (1998) -
Margel S., Weisel E., J. Polym. Sci. Chem. Ed. 22, 145 (1984).
(
10.1002/pol.1984.170220115
) / J. Polym. Sci. Chem. Ed. by Margel S. (1984) -
Philipse A. P., van Bruggen M. P. B., Pathmamanoharan C., Langmuir 10, 92 (1994).
(
10.1021/la00013a014
) / Langmuir by Philipse A. P. (1994) 10.1126/science.277.5330.1232
- and references therein;
-
Decher G., Hong J.-D., Makromol. Chem. Macromol. Symp. 46, 321 (1991).
(
10.1002/masy.19910460145
) / Makromol. Chem. Macromol. Symp. by Decher G. (1991) -
Caruso F., Niikura K., Furlong D. N., Okahata Y., Langmuir 13, 3427 (1997);
(
10.1021/la9608223
) / Langmuir by Caruso F. (1997) - ; Y. Lvov K. Ariga M. Onda I. Ichinose T. Kunitake ibid. p. 6195; E. R. Kleinfeld and G. S. Ferguson Science 265 370 (1994);
-
Sukhorukov G. B., Möhwald H., Decher G., Lvov Y. M., Thin Solid Films 285, 220 (1996);
(
10.1016/S0040-6090(95)08309-X
) / Thin Solid Films by Sukhorukov G. B. (1996) -
Lvov Y., Ariga K., Kunitake T., J. Am. Chem. Soc. 117, 6117 (1995);
(
10.1021/ja00127a026
) / J. Am. Chem. Soc. by Lvov Y. (1995) - ; S. W. Keller S. A. Johnson E. S. Brigham E. H. Yonemoto T. E. Mallouk ibid. p. 12879; Y. L. Liu
-
Zao M. Q., Bergbreiter D. E., Crooks R. M., Angew. Chem. Int. Ed. 36, 2114 (1997).
(
10.1002/anie.199721141
) / Angew. Chem. Int. Ed. by Zao M. Q. (1997) -
Donath E., Sukhorukov G. B., Caruso F., Davis S. A., Möhwald H., Angew. Chem. Int. Ed. 37, 2201 (1998);
(
10.1002/(SICI)1521-3773(19980904)37:16<2201::AID-ANIE2201>3.0.CO;2-E
) / Angew. Chem. Int. Ed. by Donath E. (1998) -
Sukhorukov G. B., et al., Polym. Adv. Technol. 9, 1 (1998).
(
10.1002/(SICI)1099-1581(1998100)9:10/11<759::AID-PAT846>3.0.CO;2-Q
) / Polym. Adv. Technol. by Sukhorukov G. B. (1998) -
Caruso F., Lichtenfeld H., Giersig M., Möhwald H., J. Am. Chem. Soc. 120, 8523 (1998).
(
10.1021/ja9815024
) / J. Am. Chem. Soc. by Caruso F. (1998) - The solution pH was adjusted to between 5 and 6 so that the SiO 2 nanoparticles (Ludox TM40 Dupont) were negatively charged and PDADMAC (Aldrich molecular weight <200 000) was positively charged. The SiO 2 nanoparticles have an isoelectric point of about 3.
- The precursor polyelectrolyte layers [PDADMAC/poly(styrenesulfonate sodium salt) (PSS)/PDADMAC] were consecutively deposited onto the negatively charged sulfate-stabilized PS latices from 1 mg ml −1 polyelectrolyte solutions containing 0.5 M NaCl with an adsorption time of 20 min. SiO 2 nanoparticles were subsequently deposited by exposing the polyelectrolyte-coated PS latices to a 2 weight % SiO 2 suspension in 0.1 M NaCl (pH ∼5 to 6) for 15 min. In each step nonadsorbed polyelectrolyte or SiO 2 was removed by four repeated centrifugation (13500g)/water wash/redispersion) cycles.
- Electrophoretic mobility measurements yielded a zeta potential of approximately 50 mV for the [PDADMAC/PSS/PDADMAC]-coated PS particles.
- SEM measurements were performed with a Zeiss DSM 940 instrument operated at an accelerating voltage of 20 kV. SEM samples (on carbon or quartz surfaces) were coated with about 5 nm of Pd or Au. TEM images were recorded on a Phillips CM12 microscope operating at 120 kV. Samples for TEM were sonicated in water for 1 min (to redisperse the hollow spheres) and subsequently deposited onto a carbon grid.
- The thickness of the precursor polyelectrolyte layers on the PS latices is approximately 5 nm; that is the average diameter of the coated particles before SiO 2 deposition is approximately 650 nm. The PDADMAC layer thickness accounts for at most only 2 nm of the total multilayer (SiO 2 -PDADMAC) film thickness.
- Silica and inorganic-hybrid hollow spheres were produced by drying the sample of PS latices coated with SiO 2 -PDADMAC multilayers on aluminum sheets or quartz slides at room temperature and then calcining (heating rate 5 K min −1 ) at 500°C under N 2 for 4 hours and a further 8 hours under O 2 .
- Only intact complete shells were imaged on aluminum substrates. However broken shells were observed solely in samples that were transferred from aluminum (on which they were calcined) to carbon surfaces for SEM analysis. The breakage was a result of pressure applied during the transfer by scraping with a metal object or by pressing the calcined sample on the carbon surface to effect transfer of the spheres. No other differences were observed between samples imaged on aluminum or carbon surfaces.
- AFM images were obtained with a Digital Instruments Nanoscope IIIa AFM in tapping mode. Samples were deposited onto quartz slides.
- Monomeric molecules with dimensions of 1 to 2 nm can readily permeate multilayer films [see
-
Caruso F., Donath E., Möhwald H., J. Phys. Chem. B 102, 2011 (1998);
(
10.1021/jp980198y
) / J. Phys. Chem. B by Caruso F. (1998) - ; R. v. Klitzing and
-
Möhwald H., Macromolecules 29, 6901 (1996)].
(
10.1021/ma960240s
) / Macromolecules by Möhwald H. (1996) - F. Caruso R. A. Caruso H. Möhwald unpublished results.
-
M. Kerker The Scattering of Light and Other Electromagnetic Radiation (Academic Press New York 1969).
(
10.1016/B978-0-12-404550-7.50008-7
) - F.C. acknowledges the Alexander von Humboldt Foundation for support in the form of a research fellowship. We thank J. Hartmann for assistance with preliminary SEM measurements and M. Giersig for use of the TEM.
Dates
Type | When |
---|---|
Created | 23 years ago (July 27, 2002, 5:44 a.m.) |
Deposited | 1 year, 7 months ago (Jan. 13, 2024, 12:12 a.m.) |
Indexed | 1 week, 2 days ago (Aug. 12, 2025, 5:33 p.m.) |
Issued | 26 years, 9 months ago (Nov. 6, 1998) |
Published | 26 years, 9 months ago (Nov. 6, 1998) |
Published Print | 26 years, 9 months ago (Nov. 6, 1998) |
@article{Caruso_1998, title={Nanoengineering of Inorganic and Hybrid Hollow Spheres by Colloidal Templating}, volume={282}, ISSN={1095-9203}, url={http://dx.doi.org/10.1126/science.282.5391.1111}, DOI={10.1126/science.282.5391.1111}, number={5391}, journal={Science}, publisher={American Association for the Advancement of Science (AAAS)}, author={Caruso, Frank and Caruso, Rachel A. and Möhwald, Helmuth}, year={1998}, month=nov, pages={1111–1114} }