Poly(N-isopropylacrylamide)-SiO2 nanocomposites interpenetrated by starch: Stimuli-responsive hydrogels with attractive tensile properties

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389013%3A_____%2F17%3A00471497" target="_blank" >RIV/61389013:_____/17:00471497 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1016/j.eurpolymj.2017.01.038" target="_blank" >http://dx.doi.org/10.1016/j.eurpolymj.2017.01.038</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.eurpolymj.2017.01.038" target="_blank" >10.1016/j.eurpolymj.2017.01.038</a>

Result language

angličtina

Original language name

Poly(N-isopropylacrylamide)-SiO2 nanocomposites interpenetrated by starch: Stimuli-responsive hydrogels with attractive tensile properties

Original language description

Doubly filled nanocomposite poly(N-isopropylacrylamide)-SiO2-starch hydrogels were prepared via simultaneous polymerization of N-isopropylacrylamide (NIPAm) and tetramethoxysilane hydrolysis, in the presence of colloid amylopectin starch (4–30 wt.% in dry gel). Besides bulk hydrogels, also highly porous ones were prepared, the latter via solvent freezing during synthesis (cryogels). The branched starch molecules, which interpenetrate PNIPAm, appear to enforce less crosslinked but more regular PNIPAm network with a wider mesh, in place of the irregular one, which is normally obtained in divinyl-crosslinked PNIPAm. The hydroxyl groups of starch form efficient hydrogen bonds to the PNIPAm matrix, as well as to the SiO2 nanofiller, which in turn also has strong H-bonds to PNIPAm. In bulk gels, a strong synergy of both fillers is clearly observed, leading to a marked increase in moduli, in spite of the wider network mesh. Very distinct is the improvement of tensile properties if starch is incorporated: the elongation at break increases 2 times in porous gels and 3–6 times in bulk ones. The gels’ toughness is also tremendously improved. The porous PNIPAm-SiO2-starch gels further display an ultra-fast swelling response to temperature jumps, both deswelling and re-swelling. Interestingly, starch-rich bulk PNIPAm-starch and PNIPAm-SiO2-starch gels also display a very fast (and also very extensive) temperature-induced deswelling, while their re-swelling is very slow (as would be expected). This behaviour practically represents a strong ‘one way response’ to temperature jumps. The specific properties of the interface between swollen PNIPAm and starch enable the rapid water escape from the bulk gels, especially if starch-rich domains are present.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10404 - Polymer science

Project

<a href="/en/project/LD14010" target="_blank" >LD14010: Organic-inorganic hybrids with controlled structure and tailored properties</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

European Polymer Journal

ISSN

0014-3057

e-ISSN

—

Volume of the periodical

88

Issue of the periodical within the volume

March

Country of publishing house

GB - UNITED KINGDOM

Number of pages

24

Pages from-to

349-372

UT code for WoS article

000396952500031

EID of the result in the Scopus database

2-s2.0-85012149780