Tamaño de fuente:
NOVEL POLYMERIC NANOCOMPOSITES RESPONSIVE TO RADIOFREQUENCY FOR HYPERTHERMIA APPLICATIONS
Última modificación: 06-08-2016
Resumen
A polymeric nanocomposite consists in nanoparticules dispersed inside crosslinked polymeric matrix as hydrogels (HG). Different methods to generate composites based on thermosensitive hydrogels and conducting polymers were development in our laboratory.[1,2,3] In this work, a novel method to produce nanocomposite materials is proposed and describe. Firstly, nanopaticules with conductive characteristics as polypirrol nanoparticles (PPy NP), polyaniline nanofibers (PANI NF) and nanoparticles (PANI NP) were synthesized using knower methods [4,5,6] and then characterized by Scanning Electronic Microscopy and spectroscopic techniques. In a second step, thermosensitive hydrogels based on poly(N-isopropylacrylamide) (PNIPAM) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) were synthesized by radical polymerization into a diluted dispersion of the mentioned nanostructures in water. The synthetic process resulted in three kinds of nanocomposites that involucre the combination of two materials a conducting and a thermosensitive matrix: HG-PPy NP, HG-PANI NF and HG-PANI NP. Physicochemical properties of these materials: Swelling behaviour in water, Phase transition temperature by Differential Scanning Calorimetry and the physical state of the water are studied. Thermogravimetric Analysis was used as a complementary technique to characterise the materials. The nanocomposites were exposure to a radiofrequency field at 30 kHz and 1100 W and the capacity to absorb low energy was demonstrated. The results obtained show that the three kinds of composite materials increase considerably the local temperature into the hydrogel. It suggests that these could be applied in hyperthermia and drug delivery systems after toxicity probes.