Thermoresponsive Colloidal Crystals Built from Core−Shell Poly(styrene/α-tert-butoxy-ω-vinylbenzylpolyglycidol) Microspheres

• Published in: Langmuir Vol. 26; no. 13; pp. 11550 - 11557
• Main Authors: Griffete, Nebewia, Dybkowska, Monika, Glebocki, Bartosz, Basinska, Teresa, Connan, Carole, Maître, Agnès, Chehimi, Mohamed M, Slomkowski, Stanislaw, Mangeney, Claire
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 06-07-2010
• Subjects: Chemistry; Condensed Matter; Devices and Applications: Sensors, Fluidics, Patterning, Catalysis, Photonic Crystals; Exact sciences and technology; General and physical chemistry; Physics; Solid-liquid interface; Surface physical chemistry; Elaboration; Modification; Microsphere; Hydrocarbon; Wetting; Bragg diffraction; Crystals; Temperature effect; Polymer; Hydrophobicity; Phase transitions; Hydrophily; Ethylene oxide polymer; Crystalline material; Particle; Photonic crystal; Optical properties; Styrene; Benzenic compound; Diameter; Reflectance
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la100537v

Core−shell particles of poly(styrene/α-tert-butoxy-ω-vinylbenzylpolyglycidol) P(S/PGL) were used as new building blocks for the assembly of a colloidal crystal. The added-value properties of these particles for photonic crystal architectures are their high hydrophilicity together with their thermoresponsivity. Indeed, the poglycidol-rich shell undergoes a phase transition above 45 °C, which leads to its collapse at the particle surface accompanied by a decrease in the particle diameter. The three-dimensional crystalline arrays display Bragg diffraction properties, as judged by angle-resolved reflectance spectroscopy. The thermoresponsivity of the colloidal assemblies was observed through modifications of their optical properties with respect to the temperature used during the assembly process. The wetting properties of the crystalline material were also shown to reversibly switch from hydrophilic to hydrophobic as a function of the assembly temperature, thus evidencing the reorganization of the surface polyglycidol chains during the polymer phase transition. This work shows conclusively that P(S/PGL) particles are promising alternatives to poly(N-isopropylacrylamide) and poly(ethylene glycol) particles for the elaboration of thermoresponsive colloidal crystals, with a phase transition situated in between those of these two polymers.