Dense bottlebrushes enable supersoft solvent-free networks

Daniel et al. 1 demonstrated the effectiveness of dense bottlebrush polymers in lowering the entanglement density, that is, reducing the physical interaction level, by stiffening the main chains through the growth of numerous side chains—the bottlebrush structure. This breakthrough work is based on earlier works of the late Pakula. 2 Sheiko’s group has been working on this topic for several years (as summarized in Lee et al. 3 and Sheiko et al. 4 ), but they have reported only results on minute amounts of materials. Hence, the physical behavior of bottlebrushes has not been tested on a macroscopic level. To do so effectively means diluting polymer chains by themselves instead of adding a solvent, as it has classically been done with gels and solutions.