title: Demonstration of thermo-sensitive tetra-gel with implication for facile and versatile platform for a new class of smart gels.
abstract: A tertiary branched poly(N-isopropylacrylamide) with controlled molecular weight, distribution and the end amino-functionalization (tetra-PNIPAAm-NH2) was studied for the ability to form a gel via in situ chain-end reaction with a counterpart tertiary branched poly(ethyleneglycol) bearing N-hydroxysuccinimide end groups (tetra-PEG-NHS), a well-documented class of building block to yield the tetra-gel. Some of these polymers, both comparable and distinct (relative to the counterpart) extended chain length pairs, provided a self-standing and macroscopically homogeneous gel, which was capable of undergoing thermo-sensitive and reversible change in hydration in line with the nature of PNIPAAm. Phantom network model based calculation indicated that a half molar fraction of the polymer chains in the network remained unreacted, revealing further room for optimizing the reaction condition. Since such tetra-PNIPAAm based motif can be readily tailored to a variety of other physicochemical stimuli-responsive analogues, our finding may give important insight into a platform for 'smart' tetra-gels with exceptional mechanical properties and potentially highly controllable molecular cut-off capability.
authors.affiliation: a Institute of Biomaterials and Bioengineering , Tokyo Medical and Dental University , Tokyo , Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Matsumoto
authors.affiliation: b Department of Materials Science and Engineering, Graduate School of Engineering Science , Tokyo University of Science , Tokyo , Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Sato
authors.affiliation: a Institute of Biomaterials and Bioengineering , Tokyo Medical and Dental University , Tokyo , Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Sakamaki
authors.affiliation: a Institute of Biomaterials and Bioengineering , Tokyo Medical and Dental University , Tokyo , Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Sanjo
authors.affiliation: a Institute of Biomaterials and Bioengineering , Tokyo Medical and Dental University , Tokyo , Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Tabata
authors.affiliation: a Institute of Biomaterials and Bioengineering , Tokyo Medical and Dental University , Tokyo , Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Goda
authors.affiliation: c Advanced Research Institute for Natural Science and Technology, Graduate School of Science , Osaka City University , Osaka-shi , Japan.
authors.forename: Taka-Aki
authors.initials: TA
authors.lastname: Asoh
authors.affiliation: b Department of Materials Science and Engineering, Graduate School of Engineering Science , Tokyo University of Science , Tokyo , Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kikuchi
authors.affiliation: a Institute of Biomaterials and Bioengineering , Tokyo Medical and Dental University , Tokyo , Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Miyahara
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D004548:Elasticity; D005782:Gels; D011092:Polyethylene Glycols / Q000737:chemistry; D058105:Polymerization; D013696:Temperature; D014783:Viscosity
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D005782:Gels; C052970:poly-N-isopropylacrylamide; D011092:Polyethylene Glycols
keywords: Star polymers; environment-sensitivity; gels; n-isopropylacrylamide