Fabrication of elastic colloidal crystal films from pure soft spheres

Elastic colloidal crystal films with brilliant color and good elongation properties were simply fabricated by depositing P(MMA-BA) copolymer spheres. Distinguished from conventional elastic colloidal crystal films formed by a core–shell spheres with a hard core and a soft shell, the film was derived from pure soft spheres, thus it can withstand elongation by no less than 500%, benefiting from the absence of a rigid frame. Unlike the common soft spheres merging into a continuous matrix during the film fabrication process, our latex spheres remain separated because of their hydrophobicity, provided the film was in wet state. The results show that the basic condition for preparing elastic film is the ratio of BA to MMA in the sphere greater than 1.22. When this ratio is between 1.86 and 2.33, the film has the best elongation property.