Question

is electrostatic double layer force the same as the direct electrostatic interaction between charged objects?

Answer 1

The source of the force is the same - that is, it is the same phenomenon that results in the force between two charged objects. However, electrostatic double layer force in our case can be considered as a special kind of charged object.

If I'm not wrong, electrostatic double layer is electrically neutral (or atleast has the same charge as the object that it is enclosing.) in that case, it's net force at a large distance is zero. However, at a local level, this charge will cause disturbances. Don't hammer yourself with these details if you do not want to get into an indepth analysis!