Laser-driven structural transformations in dextran-graft-PNIPAM copolymer/Au nanoparticles hybrid nanosystem: the role of plasmon heating and attractive optical forces

Abstract

Structural transformations in D-g-PNIPAM/AuNPs hybrid nanosystem arise from the synergetic action of plasmonic heating and attractive optical plasmonic forces.

Temperature Driven Transformation in Dextran-Graft-PNIPAM/Embedded Silver Nanoparticle Hybrid System

“…Meanwhile, the intensity of the low-energy peak corresponding to aggregated AgNPs increases at the increase of the temperature. Similar behavior was observed for the plasmonic absorption spectrum in D70-g-PNIPAM/AuNPs reported in our recent work [30]. Similar to the results of reference [30], the observed transformation of the plasmonic absorption spectrum proves the fact of the aggregation of AgNPs occurring during the conformational LCST phase transition.…”

“…Similar behavior was observed for the plasmonic absorption spectrum in D70-g-PNIPAM/AuNPs reported in our recent work [30]. Similar to the results of reference [30], the observed transformation of the plasmonic absorption spectrum proves the fact of the aggregation of AgNPs occurring during the conformational LCST phase transition. Indeed, the shrinking of D70-g-PNIPAM macromolecules leads to decrease of the distance between the Ag NPs and their consequent aggregation.…”

“…Meanwhile, the quite large fraction of AgNPs in a hybrid system exists in the form of the aggregates that caused an appearance of additional low-energy peak corresponding to aggregated AgNPs. Such two-component structure of the plasmonic absorption spectrum in the D70-g-PNIPAM/AgNP nanosystem is similar to the one observed in our recent work [30] where the laser-driven phase transformations were studied in D70-g-PNIPAM/AuNPs containing AuNPs.…”

Laser-Driven Aggregation in Dextran–Graft–PNIPAM/Silver Nanoparticles Hybrid Nanosystem: Plasmonic Effects

“…The influence of a light (laser) illumination on the structural transformations in hybrid thermosensitive polymers with embedded metal NPs is the actual topic of recent researches [30][31][32][33][34]. The physical nature of such influence is the light-induced excitation of the surface plasmon resonance (SPR) in metal NPs.…”

“…Namely, the heating is especially strong, when the laser frequency is in resonance with the SPR frequency of a metal NP [40,41]. The plasmonic heating has been shown to cause the phase transition in a surrounding medium, in particular, in hybrid thermosensitive polymer/metal NPs nanosystems [30][31][32][33][34]. Second, besides the thermal action, the excitation of SPR in metal NPs by the laser illumination leads to the mechanical action on them.…”