title: Tailored stimuli-responsive interaction between particles adjusted by straightforward adsorption of mixed layers of Poly(lysine)-g-PEG and Poly(lysine)-g-PNIPAM on anionic beads.
abstract: We report a simple and versatile method to functionalize anionic colloid particles and control particle solubility. Poly(lysine)-based copolymers (PLL) grafted with polyethylene oxide (PLL-g-PEG) or poly(N-isopropylacrylamide) (PLL-g-PNIPAM) spontaneously adsorb on bare beads dispersed in aqueous solutions of the copolymers. The final composition of the mixed ad-layers formed (i.e. PEG/PNIPAM ratio) was adjusted by the polymer concentrations in solutions. While the (PLL-g-PEG)-coated particles were stable in a wide range of temperature, the presence of PLL-g-PNIPAM in the outer layer provided a reversible temperature-triggered aggregation at 32±1 °C. In the range of PNIPAM fraction going from 100% (beads fully covered by PLL-g-PNIPAM) down to a threshold 20% weight ratio (with 80% PLL-g-PEG), the particles aggregated rapidly to form micrometer size clusters. Below 20% weight fraction of PLL-g-PNIPAM, the kinetic was drastically lowered. Using PLL derivatives provides a straightforward route allowing to control the fraction of a functional chain (here PNIPAM) deposited on PEGylated particles, and in turn to adjust surface interaction and here the rate of particle-particle aggregation as a function of the density of functional chains. This approach can be generalized to many anionic surfaces onto which PLL is known to adhere tightly, such as glass or silica.
authors.affiliation: Ecole Normale Supérieure-PSL Research University, Département de Chimie, 24, rue Lhomond, 75005 Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005 Paris, France; CNRS, UMR 8640 PASTEUR, F-75005 Paris, France.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Malinge
authors.affiliation: Ecole Normale Supérieure-PSL Research University, Département de Chimie, 24, rue Lhomond, 75005 Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005 Paris, France; CNRS, UMR 8640 PASTEUR, F-75005 Paris, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: Mousseau
authors.affiliation: Ecole Normale Supérieure-PSL Research University, Département de Chimie, 24, rue Lhomond, 75005 Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005 Paris, France; CNRS, UMR 8640 PASTEUR, F-75005 Paris, France; Université de Paris 7 Denis Diderot, 5 rue Thomas Mann, 75013 Paris, France.
authors.forename: Drazen
authors.initials: D
authors.lastname: Zanchi
authors.affiliation: Ecole Normale Supérieure-PSL Research University, Département de Chimie, 24, rue Lhomond, 75005 Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005 Paris, France; CNRS, UMR 8640 PASTEUR, F-75005 Paris, France.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Brun
authors.affiliation: Ecole Normale Supérieure-PSL Research University, Département de Chimie, 24, rue Lhomond, 75005 Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005 Paris, France; CNRS, UMR 8640 PASTEUR, F-75005 Paris, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Tribet
authors.affiliation: Ecole Normale Supérieure-PSL Research University, Département de Chimie, 24, rue Lhomond, 75005 Paris, France; Sorbonne Universités, UPMC Univ. Paris 06, PASTEUR, F-75005 Paris, France; CNRS, UMR 8640 PASTEUR, F-75005 Paris, France. Electronic address: emmanuelle.marie@ens.fr.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Marie
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D000838:Anions / Q000737:chemistry; D015394:Molecular Structure; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D011107:Polylysine / Q000031:analogs & derivatives* / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D000838:Anions; C443714:polylysine-graft-(poly(ethylene glycol)); D011107:Polylysine; C052970:poly-N-isopropylacrylamide; D011092:Polyethylene Glycols
keywords: PLL-g-PEG; PLL-g-PNIPAM; Thermoresponsive particle