Solvato-morphologically controlled, reversible photo-actuated hydrogels, operative in neutral environments

Author

Dunne, A.C.M. ; Florea, L. ; Diamond, D.

Author_Institution

Insight Centre for Data Analytics, Dublin City Univ., Dublin, Ireland

fYear

2015

fDate

21-25 June 2015

Firstpage

1885

Lastpage

1888

Abstract

In this study photo-actuator hydrogels operating in neutral environments were generated using N-isopropylacrylamide-co-acrylated-spiropyran-co-acrylic acid, p(NIPAAM-co-SPA-co-AA) copolymer, in a 100-1-5 mole ratio. Acrylic acid dissociates in neutral environments, triggering spiropyran (SP) moiety conversion to the more hydrophilic protonated merocyanine form (MC-H⁺). MC-H⁺ allows water uptake, causing hydrogel expansion. Exposure to white light causes the expanded hydrogel to contract due to the photonic-conversion of MC-H⁺ to the more hydrophobic SP form. Different ratios of deionised water: organic solvent (tetrahydrofuran (THF), dioxane and acetone) were used as the polymerisation solvent. Varying the polymerisation solvent mixtures resulted in hydrogels with different pore sizes and therefore different swelling/shrinking properties and photo-actuation kinetics.

Keywords

association; dissociation; hydrogels; hydrophilicity; hydrophobicity; mixtures; polymer blends; polymerisation; porosity; porous materials; shrinkage; swelling; N-isopropylacrylamide-co-acrylated-spiropyran-co-acrylic acid; THF; acetone; deionised water; dioxane; dissociation; hydrophilic protonated merocyanine form; hydrophobic SP form; mole ratio; neutral environment; organic solvent; p(NIPAAM-co-SPA-co-AA) copolymer; photoactuation kinetics; photonic conversion; polymerisation solvent mixtures; pore size; reversible photoactuated hydrogels; solvato-morphologically controlled hydrogels; spiropyran moiety conversion; swelling-shrinking properties; tetrahydrofuran; water uptake; white light; Curing; Kinetic theory; Morphology; Polymers; Radiation effects; Scanning electron microscopy; Solvents; Hydrogels; Morphology control; Photo-actuation; Spiropyran;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS), 2015 Transducers - 2015 18th International Conference on

Conference_Location

Anchorage, AK

Type

conf

DOI

10.1109/TRANSDUCERS.2015.7181318

Filename

7181318