Details

Autor(en) / Beteiligte

• FERNANDEZ, V. V. A
• TEPALE, N
• SANCHEZ-DIAZ, J. C
• MENDIZABAL, E
• PUIG, J. E
• SOLTERO, J. F. A

Titel

Thermoresponsive nanostructured poly (N-isopropylacrylamide) hydrogels made via inverse microemulsion polymerization

Ist Teil von

• Colloid and polymer science, 2006, Vol.284 (4), p.387-395

Ort / Verlag

Berlin: Springer

Erscheinungsjahr

2006

Quelle

SpringerNature Journals

Beschreibungen/Notizen

• The synthesis of nanostructured poly(N-isopropylacrylamide) (polyNIPA) hydrogels by a two-stage polymerization process is reported here. The process involves the synthesis of slightly crosslinked polyNIPA nanoparticles by inverse (w/o) microemulsion polymerization; then, these particles are dried, cleaned and dispersed in an aqueous solution of NIPA and a crosslinking agent (N,N-methylene-bis-acrylamide or NMBA) and polymerized to produce the nanostructured hydrogels. Their swelling and de-swelling kinetics, volume phase transition temperatures (T^sub VPT^) and mechanical properties at the equilibrium swollen state are investigated as a function of the weight ratio of polyNIPA particles to monomer (NIPA). The nanostructured gels exhibit larger equilibrium water uptake, faster swelling and de-swelling rates and similar T^sub VPT^ than those of the conventional ones; moreover, the elastic and Young moduli are larger than those of the conventional hydrogels at similar swelling ratios. The fast swelling and de-swelling kinetics are explained in terms of the controlled inhomogeneities introduced by the method of synthesis.[PUBLICATION ABSTRACT]