title: Responsive PET nano/microfibers via surface-initiated polymerization.
abstract: Poly(ethylene terephthalate) (PET) is one of the most important thermoplastics in ubiquitous use today because of its mechanical properties, clarity, solvent resistance, and recyclability. In this work, we functionalize the surface of electrospun PET microfibers by growing poly(N-isopropylacrylamide) (PNIPAAm) brushes through a chemical sequence that avoids PET degradation to generate thermoresponsive microfibers that remain mechanically robust. Amidation of deposited 3-aminopropyltriethoxysilane, followed by hydrolysis, yields silanol groups that permit surface attachment of initiator molecules, which can be used to grow PNIPAAm via "grafting from" atom-transfer radical polymerization. Spectroscopic analyses performed after each step confirm the expected reaction and the ultimate growth of PNIPAAm brushes. Water contact-angle measurements conducted at temperatures below and above the lower critical solution temperature of PNIPAAm, coupled with adsorption of Au nanoparticles from aqueous suspension, demonstrate that the brushes retain their reversible thermoresponsive nature, thereby making PNIPAAm-functionalized PET microfibers suitable for filtration media, tissue scaffolds, delivery vehicles, and sensors requiring robust microfibers.
authors.affiliation: Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors.forename: A Evren
authors.initials: AE
authors.lastname: Özçam
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Roskov
authors.forename: Jan
authors.initials: J
authors.lastname: Genzer
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Spontak
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000180:Acrylic Resins; D057139:Nanofibers / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011093:Polyethylene Terephthalates; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D011093:Polyethylene Terephthalates; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D011092:Polyethylene Glycols