A theory of the conformational behavior and analysis of the persistence len
gth of molecular bottle-brushes strongly adsorbed on a flat surface in a go
od solvent is presented. For long enough side chains we have shown that the
adsorption of a small fraction of side chains already leads to significant
increase of the stiffness and drastic conformational changes of the brush
in comparison with the 3D case, For a symmetrical distribution of the adsor
bed side chains with respect to the backbone, the equilibrium conformation
of the brush is close to a rod-like one due to the very large stiffness of
the molecule. Under certain conditions the excluded-volume interactions of
the side chains of an asymmetrical brush can lead to its bending or twistin
g in spiral. The obtained results are in good agreement with computer simul
ations.