TY - JOUR
T1 - Facile synthesis of gold core-polymer shell responsive particles
AU - D'Souza-Mathew, Mark
AU - Cayre, Olivier J.
AU - Hunter, Timothy N.
AU - Biggs, Simon R.
PY - 2013/10/1
Y1 - 2013/10/1
N2 - The free adsorption of an end-functionalised weak polybase, poly dimethylaminoethyl methacrylate (pDMAEMA), on the surface of colloidal gold nanoparticles (AuNPs) as a route to produce a responsive core-shell nanoparticle is explored here. Optimal conditions for the physisorption of the polymeric chains onto the colloidal nanoparticles are explored. A dense coverage is facilitated by rapidly mixing the well solvated pH responsive homopolymer, at low pH, into a relatively poor solvent environment, at higher pH, containing a stable dispersion of charge-stabilised gold nanoparticles. The rapid pH change causes the polymer chains to concurrently collapse and adsorb onto the gold nanoparticles. In order to achieve sterically stable, monodisperse and responsive core shell nanoparticles, a crucial factor is the pH difference of the systems prior to their mixing. Once adsorbed, end-functional thiol groups on the adsorbed polymer chains can form more permanent covalent attachments with the core particles. Dynamic light scattering coupled with mobility data of pH titration experiments show that the core-shell particles exhibit a responsive character consistent with the observed potentiometric titration data of the polymer. The same particles demonstrate reversible aggregation when cycled between pH extremes. This is confirmed by shifts in the SPR peak of the corresponding UV-Vis absorption profile. The ease and flexibility of this strategy for core-shell particle production, coupled with the stability and responsiveness of the product, make this a promising colloidal coating mechanism.
AB - The free adsorption of an end-functionalised weak polybase, poly dimethylaminoethyl methacrylate (pDMAEMA), on the surface of colloidal gold nanoparticles (AuNPs) as a route to produce a responsive core-shell nanoparticle is explored here. Optimal conditions for the physisorption of the polymeric chains onto the colloidal nanoparticles are explored. A dense coverage is facilitated by rapidly mixing the well solvated pH responsive homopolymer, at low pH, into a relatively poor solvent environment, at higher pH, containing a stable dispersion of charge-stabilised gold nanoparticles. The rapid pH change causes the polymer chains to concurrently collapse and adsorb onto the gold nanoparticles. In order to achieve sterically stable, monodisperse and responsive core shell nanoparticles, a crucial factor is the pH difference of the systems prior to their mixing. Once adsorbed, end-functional thiol groups on the adsorbed polymer chains can form more permanent covalent attachments with the core particles. Dynamic light scattering coupled with mobility data of pH titration experiments show that the core-shell particles exhibit a responsive character consistent with the observed potentiometric titration data of the polymer. The same particles demonstrate reversible aggregation when cycled between pH extremes. This is confirmed by shifts in the SPR peak of the corresponding UV-Vis absorption profile. The ease and flexibility of this strategy for core-shell particle production, coupled with the stability and responsiveness of the product, make this a promising colloidal coating mechanism.
KW - AuNPs
KW - Core-shell particles
KW - Gold nanoparticles
KW - Grafting-to
KW - Nanoparticles
KW - PDMAEMA
KW - PH responsive particles
KW - Polymer grafting
UR - http://www.scopus.com/inward/record.url?scp=84881541273&partnerID=8YFLogxK
U2 - 10.1016/j.jcis.2013.06.046
DO - 10.1016/j.jcis.2013.06.046
M3 - Article
C2 - 23891444
AN - SCOPUS:84881541273
VL - 407
SP - 187
EP - 195
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
SN - 0021-9797
ER -