Surface is a significant part of science that contacts all features of our lives. It has as of late pulled in a gigantic measure of consideration in both scholarly community and industry because of the well known self-cleaning impact showed by the Lotus leaves in nature.(1, 2) Research exercises on surfaces with uncommon wettability, prevalent repellency, and controllable grip have been amazingly dynamic, and a huge number of papers have been distributed every year in late years.(3) Just in 2013, five survey articles have as of now appeared.(4-8) Static and dynamic contact point estimations are ordinarily utilized to examine the wetting, dewetting, and bond qualities of these surfaces.(9) Figure 1 delineates the schematics for the different edges decided from these estimations: static contact edge θ, propelling edge θA, retreating edge θR, and sliding edge α. Contact point hysteresis is basically the contrast among θA and θR.
. Schematics for the different contact edges: (a) static (obvious) contact point θ, (b) sliding edge α, (c) propelling edge θA, and (d) subsiding edge θR.
The most unmistakable definitions in surface science are hydrophobicity and hydrophilicity. In the Greek words, hydro implies water, philicity implies proclivity, and phobicity implies absence of partiality. In mainstream researchers, we have come to acknowledge the definition that a surface is hydrophobic when its static water contact edge θ is >90° and is hydrophilic when θ is <90°. There is in reality next to no legitimization as why the surface changes from being hydrophilic to hydrophobic when θ changes just 2° from 89 to 91°. What is the sub-atomic root or main impetus to help this definition? Indeed, Gao and McCarthy detailed watching solid bond associations among water and fluoroalkyl monolayers and Teflon surfaces in 2008, and they even expressed that "Teflon is hydrophilic" in their article.(10) Therefore, there is a positive requirement for a decent definition in surface science that is upheld by specialized information.
Just in 2013, five survey articles have as of now appeared.(4-8) Static and dynamic contact point estimations are ordinarily utilized to examine the wetting, dewetting, and bond qualities of these surfaces.