Okay, so I think I have an answer....

My assumption was that, during an adiabatic transformation, since volume increases, the entropy of the system increases....WRONG! Though, the volume increases, since no heat can be supplied from the surroundings, the temperature decreases; these to processes essentially cancel one another out, and the change in entropy of the system is also equal to zero, therefore dstotal = 0.

This means that for any adiabatic transformation, the change in entropy is always equal to zero.

is this logically sound?