Confined hexadecane (linear); and squalane (branched) films were simulated.
Friction anisotropy was significant for hexadecane and was negligible for squalane.
Friction anisotropy for hexadecane depends on the film thickness and sliding velocity.
Mosaic like structures formed for the hexadecane.
Such structures and film rigidity are sources of friction anisotropy for hexadecane.