Environment-sensitive stabilisation of silver nanoparticles in aqueous solutions

Abstract

We describe the preparation and characterisation of inorganic-organic hybrid block copolymer silver nanoparticles via the preparation of spherical multi-responsive polymeric micelles of poly(N-methyl-2-vinyl pyridinium iodide)-block-poly(ethylene oxide), P2MVP 38 -b-PEO 211 and poly(acrylic acid)-blockpoly(isopropyl acrylamide), PAA 55 -b-PNIPAAm 88 in the presence of AgNO 3 . Hence, the P2MVP and PAA segments were employed to fix Ag + ions within the micellar core (25°C) or shell (60°C), while the PEO segments ensured spontaneous reduction of Ag + ions into metallic Ag, as well as colloidal stabilisation. Spherical and elongated composite core-shell(-corona) nanoparticles (CNPs) were formed containing several small, spherical silver nanoparticles within the micellar core or shell. As the co-assembly of the oppositely charged copolymers into micelles is electrostatically driven, the CNPs can be destabilised by, for example, addition of simple salts, i.e., the CNPs are stimuli responsive. CNP size and morphology control can be achieved via the preparation protocol. For example, heating to 60°C, i.e., above the PNIPAAm LCST, results in core-shell-corona CNPs with the Ag-NPs situated in the aggregate shell.

On Complex Coacervate Core Micelles: Structure-Function Perspectives

“…For example, the reduction of Ag ions in spherical C3Ms does not yield spherical silver nanoparticles, but elongated, silver nanowires [ 199 ]. The internal structure and composition of C3Ms may be exploited to direct the internal distribution of the produced and/or encapsulated nanoparticles [ 177 , 200 ]. Systematic studies on the influence of PAA molecular weight in C3Ms of PEG- b -PAA block copolymers complexed with HAuCl 4 revealed that the size of the Au NPs formed after reduction was independent of the PAA block length [ 174 , 181 ].…”

Antibacterial activity of poly(vinyl alcohol)-b-poly(acrylonitrile) based micelles loaded with silver nanoparticles

“…However, the main disadvantage of these systems is the use of organic solvents such as toluene, which is not environment friendly and makes their application for biomedical application impossible. Recently, silver nanoparticles formation in complex coacervate core micelles (C3Ms) consisting of poly(N-methyl-2-vinyl pyridinium iodide)-b-poly(ethylene oxide) and poly(acrylic acid)-b-poly(isopropyl acrylamide) in aqueous solutions have been demonstrated in which the size and location of Ag-NPs within the micelles could be controlled through preparation of the complexes depending on the temperatures [20]. In another strategy shell-cross-linked cylindrical poly(ferrocenylsilane) block copolymer micelles in aqueous solutions have been developed for the formation and encapsulation of silver nanoparticles [21].…”

Green Method for the Preparation of Durable Superhydrophobic Antimicrobial Polyester Fabrics with Micro-Pleated Structures

“…Due to its low adhesion and poor dispersion, nanosilver necessitates encapsulation within a polymer carrier material to maintain its antibacterial efficacy [ 37 ]. In this study, we prepared aqueous nanosilver adhesive solutions with high dispersion, stability, and adhesion properties using waterborne polyurethane (WPU) as a protective agent.…”