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Mapping the location of grafted PNIPAAM in mesoporous SBA-15 silica using gas adsorption analysis.

Reichhardt, Nina LU ; Guillet-Nicolas, Rémy; Thommes, Matthias; Klösgen, Beate; Nylander, Tommy LU ; Kleitz, Freddy and Alfredsson, Viveka LU (2012) In Physical chemistry chemical physics : PCCP 14(16). p.5651-5661
Abstract
The thermoresponsive polymer poly-N-isopropylacrylamide (PNIPAAM) was grafted in mesoporous SBA-15 silica. The grafting process consists of three steps: (i) increasing the amount of surface silanol groups of SBA-15 by hydroxylation, (ii) attachment of an anchor (1-(trichlorosilyl)-2-(m/p-(chloromethylphenyl)ethane) and finally (iii) the polymerization of the monomers (NIPAAM) onto the anchor. After each step, the materials were characterized regarding the porosity, using inert gas (argon, nitrogen) physisorption measurements. Also, the structure was investigated by small-angle X-ray diffraction analysis and thermogravimetric analysis was used for determination of the amount of grafted material. A total of 17% by weight of organic material... (More)
The thermoresponsive polymer poly-N-isopropylacrylamide (PNIPAAM) was grafted in mesoporous SBA-15 silica. The grafting process consists of three steps: (i) increasing the amount of surface silanol groups of SBA-15 by hydroxylation, (ii) attachment of an anchor (1-(trichlorosilyl)-2-(m/p-(chloromethylphenyl)ethane) and finally (iii) the polymerization of the monomers (NIPAAM) onto the anchor. After each step, the materials were characterized regarding the porosity, using inert gas (argon, nitrogen) physisorption measurements. Also, the structure was investigated by small-angle X-ray diffraction analysis and thermogravimetric analysis was used for determination of the amount of grafted material. A total of 17% by weight of organic material was introduced in the porous host and the structure was preserved during the grafting process. Physisorption measurements revealed that the anchor is mainly located in the intrawall pores present in SBA-15. Consequently, the polymer is preferentially located in the intrawall pores or in the vicinity thereof. The final mesopore volume is 0.47 cm(3) g(-1) as compared to 0.96 cm(3) g(-1) for the pure SBA-15. The surprisingly large loss of mesopore volume and an almost constant mesopore diameter is consistent with a partial sealing of the mesopore volume in the composite materials. The potential thermocontrol combined with the large mesoporosity and the possible "storage space" provided by the sealed mesopore volume leads to a material with possibilities for various applications. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical chemistry chemical physics : PCCP
volume
14
issue
16
pages
5651 - 5661
publisher
Royal Society of Chemistry
external identifiers
  • wos:000302062200036
  • pmid:22428163
  • scopus:84859356048
ISSN
1463-9084
DOI
10.1039/c2cp22523a
language
English
LU publication?
yes
id
cea1c12c-3c29-434b-b1c5-0e65f82ab9bc (old id 2431672)
date added to LUP
2012-04-12 15:02:05
date last changed
2017-11-05 04:17:10
@article{cea1c12c-3c29-434b-b1c5-0e65f82ab9bc,
  abstract     = {The thermoresponsive polymer poly-N-isopropylacrylamide (PNIPAAM) was grafted in mesoporous SBA-15 silica. The grafting process consists of three steps: (i) increasing the amount of surface silanol groups of SBA-15 by hydroxylation, (ii) attachment of an anchor (1-(trichlorosilyl)-2-(m/p-(chloromethylphenyl)ethane) and finally (iii) the polymerization of the monomers (NIPAAM) onto the anchor. After each step, the materials were characterized regarding the porosity, using inert gas (argon, nitrogen) physisorption measurements. Also, the structure was investigated by small-angle X-ray diffraction analysis and thermogravimetric analysis was used for determination of the amount of grafted material. A total of 17% by weight of organic material was introduced in the porous host and the structure was preserved during the grafting process. Physisorption measurements revealed that the anchor is mainly located in the intrawall pores present in SBA-15. Consequently, the polymer is preferentially located in the intrawall pores or in the vicinity thereof. The final mesopore volume is 0.47 cm(3) g(-1) as compared to 0.96 cm(3) g(-1) for the pure SBA-15. The surprisingly large loss of mesopore volume and an almost constant mesopore diameter is consistent with a partial sealing of the mesopore volume in the composite materials. The potential thermocontrol combined with the large mesoporosity and the possible "storage space" provided by the sealed mesopore volume leads to a material with possibilities for various applications.},
  author       = {Reichhardt, Nina and Guillet-Nicolas, Rémy and Thommes, Matthias and Klösgen, Beate and Nylander, Tommy and Kleitz, Freddy and Alfredsson, Viveka},
  issn         = {1463-9084},
  language     = {eng},
  number       = {16},
  pages        = {5651--5661},
  publisher    = {Royal Society of Chemistry},
  series       = {Physical chemistry chemical physics : PCCP},
  title        = {Mapping the location of grafted PNIPAAM in mesoporous SBA-15 silica using gas adsorption analysis.},
  url          = {http://dx.doi.org/10.1039/c2cp22523a},
  volume       = {14},
  year         = {2012},
}