15809
The as - prepared superhydrophobic surfaces show water controllable adhesion that ranges from ultrahigh to ultralow by adjusting the extent of overlap of the adjacent microwells , on which the sliding angle can be controlled from 180 degrees ( a water droplet can not slide down even when the as - prepared surface is turned upside down ) to 3 degrees .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
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