Thermosensitive block copolymer micellar network hydrogels have potential applications in a wide variety of areas. These injectable hydrogels often exhibit weak mechanical strengths because of the formation of loops. We have developed a method to strengthen thermosensitive ABC linear triblock copolymer micellar network hydrogels by incorporating thermosensitive polymer brush-grafted nanoparticles (hairy NPs). A linear ABC triblock copolymer, composed of a hydrophilic middle block and two thermosensitive outer blocks with different lower critical solution temperatures (LCSTs), and two batches of hairy NPs with distinct thermosensitive properties are prepared. From rheological studies, adding hairy NPs with a LCST similar to that of the higher LCST block of the ABC copolymer leads to a significant increase in dynamic storage modulus (G'); for 6 wt% aqueous solutions of the ABC triblock copolymer, a 45% increase in the maximum value of G' (G'<sub>max</sub>) is observed at the NP-to-polymer mass ratio of 60 : 100. This increase results from the hairy NPs acting as "seeds" to adsorb the collapsed, higher LCST block, which promotes the formation of bridging chains and thus enhances the gelation. In contrast, when hairy NPs with a much higher LCST are incorporated, the G'<sub>max</sub> exhibits little change with increasing NP-to-polymer mass ratio.

Strengthening thermosensitive ABC linear triblock copolymer micellar hydrogels with thermosensitive hairy nanoparticles

253rd National Meeting (2017)

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