Issue 47, 2021

PNIPAM-immobilized gold-nanoparticles with colorimetric temperature-sensing and reusable temperature-switchable catalysis properties

Abstract

Multifunctional hybrid particles have been attracting tremendous interest over decades. Herein we demonstrated the functionality of poly(N-isopropylacrylamide) immobilized gold nanoparticles (PNIPAMs-AuNP) as both colorimetric temperature-sensors and reusable temperature-switchable catalysts. The hybrid nanoparticles composed of a gold core (diameter = 14.8 ± 0.2 nm) and a PNIPAM shell (thickness = 2.6 ± 0.2 nm) exhibit reversible color changes and size adjustment in aqueous dispersion upon salt and environment temperature variation. Visual observation or colorimetric monitoring of the PNIPAMs-AuNP dispersion through a UV-vis spectrometer, we were able to detect and calibrate the changes in color between red–purple–red as the environmental temperature changes. The synergetic effect of different types of salt has been systematically investigated. It is observed that the sensitivity of the colorimetric temperature-sensor could be significantly improved by adding salts (NaCl < KCl < MgCl2) or controlling salt concentrations. Moreover, the temperature-switchable PNIPAMs-AuNP hybrid nanoparticles were applied to catalyze the reduction reaction of 4-nitrophenol to 4-aminophenol. The reduction process can be sped-up or slowed-down by controlling the system temperature, which switches the catalytic AuNPs surface on and off as the reversible PNIPAM chains collapse (hydrodynamic size = 41 ± 1 nm) and expand (49 ± 1 nm). Moreover, the switchable catalysts can be recycled through centrifugation and reused. The polymer-engineered core–shell PNIPAMs-AuNP hybrid nanoparticles are promising to enrich the development of temperature-responsive systems such as ambient temperature alarms and smart catalysts.

Graphical abstract: PNIPAM-immobilized gold-nanoparticles with colorimetric temperature-sensing and reusable temperature-switchable catalysis properties

Supplementary files

Article information

Article type
Paper
Submitted
01 Eyl 2021
Accepted
12 Kas 2021
First published
12 Kas 2021

Polym. Chem., 2021,12, 6903-6913

PNIPAM-immobilized gold-nanoparticles with colorimetric temperature-sensing and reusable temperature-switchable catalysis properties

S. Wu, L. Lei, Y. Xia, S. Oliver, X. Chen, C. Boyer, Z. Nie and S. Shi, Polym. Chem., 2021, 12, 6903 DOI: 10.1039/D1PY01180D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements