Rapid Color-Switching of MnO2 Hollow-Nanosphere Films in Dynamic Water Vapor for Reversible Optical Encryption.Drop-casting manganese oxide (MnO2 ) hollow nanospheres synthesized via a simple surface-initiated redox route produces thin films exhibiting angle-independent structural colors.  The unique selective response originates from the nanoscale porosity formed in the shells by randomly stacked MnO2 nanosheets, which enhances the capillary condensation of dynamic water vapor and promotes the change of their effective refractive index for rapid color switching.  The repeated color-switching tests over 100 times confirm the durability and reversibility of the MnO2 film. 
MnO2
Rapid Color-Switching of MnO2 Hollow-Nanosphere Films in Dynamic Water Vapor for Reversible Optical Encryption.Drop-casting manganese oxide (MnO2 ) hollow nanospheres synthesized via a simple surface-initiated redox route produces thin films exhibiting angle-independent structural colors.  The unique selective response originates from the nanoscale porosity formed in the shells by randomly stacked MnO2 nanosheets, which enhances the capillary condensation of dynamic water vapor and promotes the change of their effective refractive index for rapid color switching.  The repeated color-switching tests over 100 times confirm the durability and reversibility of the MnO2 film. 
MnO2
Rapid Color-Switching of MnO2 Hollow-Nanosphere Films in Dynamic Water Vapor for Reversible Optical Encryption.Drop-casting manganese oxide (MnO2 ) hollow nanospheres synthesized via a simple surface-initiated redox route produces thin films exhibiting angle-independent structural colors.  The unique selective response originates from the nanoscale porosity formed in the shells by randomly stacked MnO2 nanosheets, which enhances the capillary condensation of dynamic water vapor and promotes the change of their effective refractive index for rapid color switching.  The repeated color-switching tests over 100 times confirm the durability and reversibility of the MnO2 film. 
MnO2