Porous hybrid poly(N-isopropylacrylamide) hydrogels with very fast volume response to temperature and pH
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389013%3A_____%2F19%3A00508103" target="_blank" >RIV/61389013:_____/19:00508103 - isvavai.cz</a>
Result on the web
<a href="https://www.sciencedirect.com/science/article/pii/S0014305719313965?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0014305719313965?via%3Dihub</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.eurpolymj.2019.109213" target="_blank" >10.1016/j.eurpolymj.2019.109213</a>
Alternative languages
Result language
angličtina
Original language name
Porous hybrid poly(N-isopropylacrylamide) hydrogels with very fast volume response to temperature and pH
Original language description
Super-porous hydrogels were prepared, which are able of fast to ultra-fast volume response to temperature and to pH, and thus show a promise as soft actuators. The hydrogels are based on the poly(N-isopropylacrylamide) (PNIPAm)/silica nanocomposite, in which the filler strongly raises the modulus and also stabilizes the pore walls against collapse during deswelling. The well-interconnected sub-millimetre-sized porosity was generated via solvent freezing during synthesis. The gels morphology makes possible both ultra-fast deswelling and re-swelling (5.5 s for 70% in both directions, in response to T). This work focused on introducing pH-responsiveness into the gels. To this end, 1–10 mol% of sodium methacrylate (SMA) were incorporated as co-monomer. Distinct pH-responsiveness was achieved already at 1 mol% of SMA. Increase of SMA content markedly expands the temperature range of the pH-responsiveness and raises its amplitude. At the same time the increase of SMA content reduces the amplitude of the T-responsiveness, which is only moderate at 10 mol% SMA. The rate of pH-response was found to be always slower than in case of the T-response: 75 s are needed for 70% of de-swelling, and 90 min for 70% of re-swelling. The vast difference in the rates of pH- and T- response can be explained by different mechanisms of stimulus propagation (momentum transfer for T, vs. diffusion for pH) and by the mechanical effect of a contracting stiff and porous surface layer (much faster pH-deswelling than re-swelling). More generally, in case of the pH-stimulus, the mechanistic limits of its propagation in ‘simple’ porous gels become evident.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10404 - Polymer science
Result continuities
Project
<a href="/en/project/GA19-04925S" target="_blank" >GA19-04925S: Advanced smart and self-healing nanocomposite hydrogels sensitive to external stimuli</a><br>
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
European Polymer Journal
ISSN
0014-3057
e-ISSN
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Volume of the periodical
120
Issue of the periodical within the volume
November
Country of publishing house
GB - UNITED KINGDOM
Number of pages
14
Pages from-to
1-14
UT code for WoS article
000498309000005
EID of the result in the Scopus database
2-s2.0-85071879458