A sequential infiltration synthesis apparatus comprising: a reaction chamber constructed and arranged to hold at least a first substrate; a precursor distribution and removal system to provide to and remove from the reaction chamber a vaporized first or second precursor; and, a sequence controller operably connected to the precursor distribution and removal system and comprising a memory provided with a program to execute infiltration of an infiltrateable material provided on the substrate when run on the sequence controller by: activating the precursor distribution and removal system to provide and maintain the first precursor for a first period T1 in the reaction chamber; activating the precursor distribution and removal system to remove a portion of the first precursor from the reaction chamber for a second period T2; and, activating the precursor distribution and removal system to provide and maintain the second precursor for a third period T3 in the reaction chamber. The program in the memory is programmed with the first period T1 longer than the second period T2.