Structural Insight into Chitosan Supports Functionalized with Nanoparticles

LAMARRA, J.; DAMONTE, L.; RIVERO, S.; PINOTTI, A.

Advances in Materials Science and Engineering

Hindawi

Lugar: Londres; Año: 2018 vol. 2018 p. 1 - 11

1687-8434

-e incorporation of suspensions of nanoparticles functionalized with gallic acid (GA) was used as a strategy to obtainnanocomposite active films with different both chitosan : tripolyphosphate (CH : TPP) and nanoparticles:chitosan (N : CH)ratios. -e thermal analysis carried out by modulated differential scanning calorimetry (MDSC) allowed observing the shift ofan endothermic event towards higher temperatures with a greater N:CH ratio. Analyzing ATR-FTIR spectra throughprincipal component analysis (PCA) can be inferred that the incorporation of the nanoparticles produced a discrimination ofthe samples into clusters when the region 1400?1700 cm−1 was considered. -e decrease in crystalline size with the inclusionof nanoparticles (NA and NB) proved the existence of interactions among CH, TPP, and GA, resulting in a more amorphousstructure. -e positron annihilation lifetime spectroscopy (PALS) technique was adequate to correlate the glass transitiontemperatures (Tg) obtained by using the MDSC technique with parameters τ2 and I2 ascribed to the annihilation of positronsin the interface. -e cross section of nanocomposites obtained by scanning electron microscopy (SEM) clearly showeda homogeneous distribution of the nanoparticles without aggregation, suggesting their compatibility with the CH matrix. Byvirtue of the obtained results, the nanocomposites with the greatest nanoparticle proportion and the highest TPP concentrationattained significant modifications in relation to CH matrices because of the crosslinking of the biopolymer with GAand TPP.