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Outset of the Morphology of Nanostructured Silica Particles during Nucleation Followed by Ultrasmall-Angle X-ray Scattering

Schmitt, Julien LU ; Kjellman, Tomas LU ; Kwaśniewski, Pawe; Meneau, Florian; Pedersen, Jan Skov; Edler, Karen J. LU ; Rennie, Adrian R.; Alfredsson, Viveka LU and Impéror-Clerc, Marianne (2016) In Langmuir 32(20). p.5162-5172
Abstract

Nucleation and growth of SBA-15 silica nanostructured particles with well-defined morphologies has been followed with time by small-angle X-ray scattering (SAXS) and ultrasmall-angle X-ray scattering (USAXS), using synchrotron radiation. Three different morphologies have been compared: platelets, toroids, and rods. SEM observations of the particles confirm that two key physical parameters control the morphology: the temperature and the stirring of the solution. USAXS curves demonstrate that primary particles with a defined shape are present very early in the reaction mixture, immediately after a very fast nucleation step. This nucleation step is detected at 10 min (56 °C) or 15 min (50 °C) after the addition of the silica precursor. The... (More)

Nucleation and growth of SBA-15 silica nanostructured particles with well-defined morphologies has been followed with time by small-angle X-ray scattering (SAXS) and ultrasmall-angle X-ray scattering (USAXS), using synchrotron radiation. Three different morphologies have been compared: platelets, toroids, and rods. SEM observations of the particles confirm that two key physical parameters control the morphology: the temperature and the stirring of the solution. USAXS curves demonstrate that primary particles with a defined shape are present very early in the reaction mixture, immediately after a very fast nucleation step. This nucleation step is detected at 10 min (56 °C) or 15 min (50 °C) after the addition of the silica precursor. The main finding is that the USAXS signal is different for each type of morphology, and we demonstrate that the difference is related to the shape of the particles, showing characteristic form factors for the different morphologies (platelet, toroid, and rod). Moreover, the size of the mesocrystal domains is correlated directly with the particle dimensions and shape. When stirred, aggregation between primary particles is detected even after 12 min (56 °C). The platelet morphology is promoted by constant stirring of the solution, through an oriented aggregation step between primary particles. In contrast, toroids and rods are only stabilized under static conditions. However, for toroids, aggregation is detected almost immediately after nucleation.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
32
issue
20
pages
11 pages
publisher
The American Chemical Society
external identifiers
  • scopus:84971201854
  • wos:000376826200016
ISSN
0743-7463
DOI
10.1021/acs.langmuir.6b00572
language
English
LU publication?
yes
id
58ff8e3d-f37f-4ced-863a-bdc0bf2c7735
date added to LUP
2017-01-30 09:25:59
date last changed
2017-11-12 04:28:29
@article{58ff8e3d-f37f-4ced-863a-bdc0bf2c7735,
  abstract     = {<p>Nucleation and growth of SBA-15 silica nanostructured particles with well-defined morphologies has been followed with time by small-angle X-ray scattering (SAXS) and ultrasmall-angle X-ray scattering (USAXS), using synchrotron radiation. Three different morphologies have been compared: platelets, toroids, and rods. SEM observations of the particles confirm that two key physical parameters control the morphology: the temperature and the stirring of the solution. USAXS curves demonstrate that primary particles with a defined shape are present very early in the reaction mixture, immediately after a very fast nucleation step. This nucleation step is detected at 10 min (56 °C) or 15 min (50 °C) after the addition of the silica precursor. The main finding is that the USAXS signal is different for each type of morphology, and we demonstrate that the difference is related to the shape of the particles, showing characteristic form factors for the different morphologies (platelet, toroid, and rod). Moreover, the size of the mesocrystal domains is correlated directly with the particle dimensions and shape. When stirred, aggregation between primary particles is detected even after 12 min (56 °C). The platelet morphology is promoted by constant stirring of the solution, through an oriented aggregation step between primary particles. In contrast, toroids and rods are only stabilized under static conditions. However, for toroids, aggregation is detected almost immediately after nucleation.</p>},
  author       = {Schmitt, Julien and Kjellman, Tomas and Kwaśniewski, Pawe and Meneau, Florian and Pedersen, Jan Skov and Edler, Karen J. and Rennie, Adrian R. and Alfredsson, Viveka and Impéror-Clerc, Marianne},
  issn         = {0743-7463},
  language     = {eng},
  month        = {05},
  number       = {20},
  pages        = {5162--5172},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Outset of the Morphology of Nanostructured Silica Particles during Nucleation Followed by Ultrasmall-Angle X-ray Scattering},
  url          = {http://dx.doi.org/10.1021/acs.langmuir.6b00572},
  volume       = {32},
  year         = {2016},
}