Aggregates of a polymethylene-block-poly(dimethyl siloxane)-block-polymethylene (PM-PDMS-PM) sample were prepared in toluene by cooling down a toluene solution of the sample slowly front 105 degrees C to room temperature. Atomic force microscopic (AFM) and electron microscopic (ENT) studies revealed that the aggregates included triblock crystal plates with sizes of upto tens of micrometers and PM-PDMS-PM nanodiscs. Surprisingly and interestingly, we discovered that the topographic images of the nanodiscs obtained by tapping- mode AFM changed from nanodiscs at light tapping to strikingly beautiful nanodonuts at moderate tapping and then filled nanodonuts at heavy tapping. Justification for such observations is provided. Crown Copyright (c) 2007 Published by Elsevier Ltd. All rights reserved.