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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10404 - Polymer science

Projekt

<a href="/cs/project/LD14010" target="_blank" >LD14010: Anorganicko-organické hybridy s kontrolovaně řízenou strukturou</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

European Polymer Journal

ISSN

0014-3057

e-ISSN

—

Svazek periodika

88

Číslo periodika v rámci svazku

March

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

24

Strana od-do

349-372

Kód UT WoS článku

000396952500031

EID výsledku v databázi Scopus

2-s2.0-85012149780