Color electrophoretic layer including microcapsules with nonionic polymeric walls

A method for producing a capsule encapsulating an electrophoretic medium, the method comprising:

• providing a first polymer solution comprising a nonionic, water-soluble or water-dispersible first starting polymer in an aqueous solvent, wherein the first starting polymer is a polyol;
• providing a second polymer solution comprising a polyvinyl lactam in an aqueous solvent;
• mixing the first polymer solution with the second polymer solution to form a third polymer solution;
• providing an electrophoretic fluid comprising a suspending solvent and pigment particles;
• mixing the third polymer solution and the electrophoretic fluid to create a reaction mixture;
• heating the reaction mixture to a temperature above the lowest critical solution temperature of the third polymer solution to form a coacervate, thereby forming an oil-in-water emulsion including the electrophoretic fluid;
• adding a cross-linking agent to the oil-in-water emulsion, thereby forming a curing mixture;
• and
• heating the curing mixture to form capsules encapsulating an electrophoretic medium.