Water is known to endure very high tension (in the order of tens of MPa) in small capillary tubes. This allows trees to transpire, even if they are 100m tall. However, it is impossible to suck water up more than approx 10 meters in hydraulic pumps. Then water starts cavitating. The hydrostatic pressure at a given height is the same both for the capillary tube (small diameter) and for the suction pipe (large diameter). Does this suggest that water in capillary tubes has a different structure that allows for higher tensile stress than the 'bulk' water in the suction pipe?
The structure of water remains the same in either case.
Water climbs in tall trees due to three (2+1) physical properties. First, water molecules are cohesive, i..e, they attract each other, (similar analogy would be melted liquid glass). Second, capillarity action; smaller the radius of the tube, the greater the height that the water column can reach. So, unbroken fluid column throughout the height of the tree!
The third and main property for transport of water in tall tress is the evaporative pull through the xylem. This force becomes more effective under the influence of cohesiveness and capillarity. In effect, water moves through capillary movement along tiny intercellular spaces in cellulose whose size is of the order of 10^-8 m enhancing all 3 properties.
Also see this, https://www.youtube.com/watch?v=BickMFHAZR0
Hope that clarifies.
The structure of water remains the same in either case.
Water climbs in tall trees due to three (2+1) physical properties. First, water molecules are cohesive, i..e, they attract each other, (similar analogy would be melted liquid glass). Second, capillarity action; smaller the radius of the tube, the greater the height that the water column can reach. So, unbroken fluid column throughout the height of the tree!
The third and main property for transport of water in tall tress is the evaporative pull through the xylem. This force becomes more effective under the influence of cohesiveness and capillarity. In effect, water moves through capillary movement along tiny intercellular spaces in cellulose whose size is of the order of 10^-8 m enhancing all 3 properties.
Also see this, https://www.youtube.com/watch?v=BickMFHAZR0
Hope that clarifies.
On the changed structure of water, you might like to check "anomalous water" in Wikpedia. We have been here before, but in the end the changed structure was due to dissolved silica from the glass tube...
please visit the following link
https://www.youtube.com/watch?v=BickMFHAZR0
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