Could you say more Karl, as I need more explanation! I am not very good in physics...
Adsorbents are minerals with extremely large inner surfaces and strong van der Waals and other surface forces.
Adsorbents have many hundreds, some far over thausand square meters per gramm.
Bentonite 400–600 m²/g.
Silica gel about 600 m²/g
Zeolithes can have far over 1,000 m²/g
Under normal conditions every surface on earth is covered by a thin layer of water.
If surfaces are heated the surface forces will be weakened and water released,
but the water will come back as soon it cools again.
By heating adsorbents in a sealed box one can control the water flow.
One needs just to connect the sealed adsorbent box to a sealed water box
and remove the air in the connection, then the adsorbent will start to draw vapour
until the whole inner surface is covered with water again.
To move to the drawing adsorbent water molecules have to change their phase,
the needed heat will be taken from the other water, which will cool down.
After arrival at the drawing adsorbents surface the heat will be released and heat up the adsorbent.
The adsorbent works as a heat pump, moving heat from one place to another.
The air can be removed by a vacuum pump.
However there is also a far simpler way to do that.
For this valves at each end of the connection are required
and a box with a third valve containing a small amount of water
hast to be placed in the connection.
With the first two valves closed and the third opened the water
in the box has to be heated until steam comes out of the open valve.
The open valve can now be closed and the other two opened.
If the phase of water changes the volume changes depending on the temperature by 1200 to 1600 times,
which can create a strong vacuum while cooling.
