A physico-chemical investigation of poly(ethylene oxide)-block-poly(L-lysine) copolymer adsorption onto silica nanoparticles
LOUGUET, Stéphanie
Laboratoire de Chimie des Polymères Organiques [LCPO]
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
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Laboratoire de Chimie des Polymères Organiques [LCPO]
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
LOUGUET, Stéphanie
Laboratoire de Chimie des Polymères Organiques [LCPO]
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
< Reduce
Laboratoire de Chimie des Polymères Organiques [LCPO]
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Language
en
Article de revue
This item was published in
Journal of Colloid and Interface Science. 2011, vol. 359, n° 2, p. 413-422
Elsevier
English Abstract
The adsorption behavior of poly(ethylene oxide)-b-poly(t-lysine) (PEO(113)-b-PLL(10)) copolymer onto silica nanoparticles was investigated in phosphate buffer at pH 7.4 by means of dynamic light scattering, zeta potential, ...Read more >
The adsorption behavior of poly(ethylene oxide)-b-poly(t-lysine) (PEO(113)-b-PLL(10)) copolymer onto silica nanoparticles was investigated in phosphate buffer at pH 7.4 by means of dynamic light scattering, zeta potential, adsorption isotherms and microcalorimetry measurements. Both blocks have an affinity for the silica surface through hydrogen bonding (PEO and PLL) or electrostatic interactions (PLL). Competitive adsorption experiments from a mixture of PEO and PLL homopolymers evidenced greater interactions of PLL with silica while displacement experiments even revealed that free PLL chains could desorb PEO chains from the particle surface. This allowed us to better understand the adsorption mechanism of PEO-b-PLL copolymer at the silica surface. At low surface coverage, both blocks adsorbed in flat conformation leading to the flocculation of the particles as neither steric nor electrostatic forces could take place at the silica surface. The addition of a large excess of copolymer favoured the dispersion of flocs according to a presumed mechanism where PLL blocks of incoming copolymer chains preferentially adsorbed to the surface by displacing already adsorbed PEO blocks. The gradual addition of silica particles to an excess of PEO-b-PLL copolymer solution was the preferred method for particle coating as it favoured equilibrium conditions where the copolymer formed an anchor-buoy (PLL-PEO) structure with stabilizing properties at the silica-water interfaceRead less <
English Keywords
Silica nanoparticles
Poly(ethylene oxide)
Adsorption
ITC
Diblock copolymer
Poly(L-lysine)
Origin
Hal imported