Versatile light actuated matter manipulation in transparent non-dilute polymer solutions

A local polymer concentration enhancement upon moderately weak laser irradiation was recently discovered in non-absorbing entangled polymer solutions. Here, we uncover the reverse effect: depending on the (good) solvent environment, macromolecules are either effectively attracted or repelled by visible laser light independently of the optical contrast. The versatile effect, qualitatively different from well-known mechanisms, may lead to new ways for macromolecular manipulation and micropatterning by optical fields. Polydienes in non-dilute solutions can be effectively attracted or repelled by a visible laser beam, depending on the solvent environment.