title: Light-induced disintegration of robust physically cross-linked polymer networks.
abstract: Photodegradable physically cross-linked polymer networks are prepared from self-assembly of photolabile triblock copolymers. Linear triblock copolymers composed of poly (o-nitrobenzyl methacrylate) and poly(ethylene glycol) (PEG) segments of variable molecular weights were synthesized using atom transfer radical polymerization. Triblock polymers with low-molecular-weight PEG segments form solid films upon hydration with robust mechanical properties including a Young's modulus of 76 ± 12 MPa and a toughness of 108 ± 31 kJ m⁻³. Triblock polymers with high-molecular-weight PEG segments form physically cross-linked hydrogels at room temperature with a dynamic storage modulus of 13 ± 0.6 kPa and long-term stability in hydrated environments. Both networks undergo photodegradation upon irradiation with long wave UV light.
authors.affiliation: Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.
authors.forename: Congcong
authors.initials: C
authors.lastname: Zhu
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Bettinger
mesh_terms: D008689:Methacrylates / Q000737:chemistry*; D010782:Photolysis; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D008689:Methacrylates; D011108:Polymers; D011092:Polyethylene Glycols
keywords: hydrogel; light-sensitive; network; polymer; self-assembly