Spherical polymer brushes, poly(acrylic acid) (PAA)-grafted polystyrene nanoparticle (PAA@PS), are employed as the macro-crosslinker to prepare PAA hydrogels. Benefitting from the innumerable hydrogen bonds between highly entangled PAA chains both in bulk and on the polymer brush, the PAA/PAA@PS hydrogels combine desirable stretchability, toughness, and notch-insensitivity. The uniaxial tensile tests show a very high fracture elongation up to 9.1 × 10 % while the fracture toughness reaches 3.0 MJ m and the maximum swelling ratio of the hydrogel can be 2.0 × 10 as well. After being loaded with silver nanoparticles, the PAA/PAA@PS hydrogels are employed as a recyclable catalyst successfully.

This work describes a facile and green method about the ultrasonic degradation of polymer chains amplified by magnetic field.

The process of PS-PAA brush adsorbs dyes selectively and separates the aggregation assisted by the compressed CO2. With the help of NaCl solution, PS-PAA is regenerated and retains high adsorption capacity even after five times.