Aggregation of Gold Nanoparticles in Presence of the Thermoresponsive Cationic Diblock Copolymer PNIPAAM48-b-PAMPTMA6

• Published in: Polymers Vol. 13; no. 23; p. 4066
• Main Authors: Robalino, David Herrera, Durán del Amor, María del Mar, Almagro Gómez, Carmen María, Hernández Cifre, José Ginés
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 23.11.2021; MDPI
• Subjects: Agglomeration; Aggregates; Block copolymers; Catalysis; dynamic light scattering; Gold; gold nanoparticles; Nanocomposites; Nanoparticles; Photon correlation spectroscopy; Polyisopropyl acrylamide; Polymers; surface plasmon resonance; thermoresponsive copolymers; Transmission electron microscopy; United Kingdom > UK; United States > US
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym13234066

The adsorption of the thermoresponsive positively charged copolymer poly(N-isopropylacrylamide)-block-poly(3-acrylamidopropyl)trimethylammonium chloride, PNIPAAM48-b-PAMPTMA6(+), onto negatively charged gold nanoparticles can provide stability to the nanoparticles and make the emerging structure tunable by temperature. In this work, we characterize the nanocomposite formed by gold nanoparticles and copolymer chains and study the influence of the copolymer on the expected aggregation process that undergoes those nanoparticles at high ionic strength. We also determine the lower critical solution temperature (LCST) of the copolymer (around 42 °C) and evaluate the influence of the temperature on the nanocomposite. For those purposes, we use dynamic light scattering, UV-vis spectroscopy and transmission electron microscopy. At the working PNIPAAM48-b-PAMPTMA6(+) concentration, we observe the existence of copolymer structures that trap the gold nanoparticles and avoid the formation of nanoparticles aggregates. Finally, we discuss how these structures can be useful in catalysis and nanoparticles recovery.