Gradient copolymer comprising at least 50 wt.% of a monomer (M1) whose homopolymer has a glass transition temperature (Tg) below 20degreesC and up to 50 wt.% of a monomer (M2) whose homopolymer has a Tg above 20degreesC, where at least one of the monomers is hydrophilic and makes up at least 5% of the total weight of the copolymer, comprises a monomer Mi such that the probability of finding Mi at any normalized position x in the polymer chain is nonzero. Independent claims are also included for: (1) production of a gradient copolymer by solution or bulk polymerization of a monomer mixture in the presence of a radical initiator and a chain transfer agent, where the monomer mixture comprises at least 50 wt.% M1 and up to 50 wt.% M2 and at least one of the monomers is hydrophilic and makes up at least 5% of the total weight of the mixture; (2) preparing an aqueous solution of a gradient copolymer as above by dissolving the copolymer in a ketone solvent to form a 20-90% solution, neutralizing the solution (if necessary) by adding a molar solution of an acid or base, adding water or water/alcohol (99/1-50/50) with vigorous agitation to give a 1-80% solution, and evaporating the ketone; (3) aqueous solutions prepared as above.