Temperature-responsive hybrid nanomaterials based on modified halloysite nanotubes uploaded with silver nanoparticles

Abstract

New temperature-responsive hybrid nanomaterials based on modified halloysite nanotubes (HNTs) containing grafted polymer brushes with silver nanoparticles have been successfully fabricated. We used a three steps process including synthesis of the initiating coatings onto HNTs surface, fabrication of the POEGMA – poly(oligo(ethylene glycol)ethyl ether methacrylate) grafted brushes and synthesis of the silver nanoparticles (AgNPs). The synthesis and properties of hybrid nanomaterials were studied by FT-IR, TGA and DLS methods. It is shown that the introduction of AgNPs, formed from 0.005 M AgNO3 solution leads to a significant reduction of low critical solution temperature (LCST) of the polymer layer from 29.7 to 21.6 °C. The samples fabricated from 0.05 M AgNO3 solution did not evidence a temperature-induced transition, despite of the contents of AgNPs obtained for both solutions are almost identical (≈ 4%w). The presence of AgNPs with sizes of ca. 20 nm was confirmed in the hybrids prepared from both AgNO3 concentrations by UV–vis spectroscopy, and electron microscopy. These temperature-responsive hybrid nanomaterials may be used for conservation of solid substrates, production of advanced medical facemasks, photothermal therapy against microorganisms and tumors etc.