The functional core-shell poly(styrene-acrylamide) latex microspheres with different diameters were prepared by one-step emulsion polymerization method by adjusting the dosage of the initiator.The core-shell structures and the diameters of latex microspheres were characterized by transmission electron microscope.The diameters of the as-prepared microspheres were 195

217

234 and 255 nm

respectively.The chemical composition of the microspheres was characterized by IR spectra

which testified that the polystyrene was wrapped by polyacrylamide successfully.The photonic crystals films of the as-prepared core-shell microspheres were fabricated by vertical deposition self-assembly method.The morphology of the as-prepared photonic crystals films were characterized by scanning electron microscope.The photonic stopbands were measured by reflectance and transmittance spectra.The results demonstrate that the polymer microspheres are in a face-centered cubic arrangement with a close-packed plane (111) oriented parallel to the substrate

and the stopbands of the photonic crystals can be varied when the diameters of the microspheres are different.In this work

photonic crystals films with different stopbands were obtained

and the stopbands occurred at 473

515

574 and 630 nm

respectively.The corresponding colors of the films were blue

green

yellow and red

respectively.It is very important for the development and application of photonic crystals.