Search results
Results from the WOW.Com Content Network
Cloth, treated to be hydrophobic, shows a high contact angle. The theoretical description of contact angle arises from the consideration of a thermodynamic equilibrium between the three phases: the liquid phase (L), the solid phase (S), and the gas or vapor phase (G) (which could be a mixture of ambient atmosphere and an equilibrium concentration of the liquid vapor).
Graphene oxide flakes in polymers display enhanced photo-conducting properties. [10] Graphene is normally hydrophobic and impermeable to all gases and liquids (vacuum-tight). However, when formed into graphene oxide-based capillary membrane, both liquid water and water vapor flow through as quickly as if the membrane was not present. [11]
The hydrophobic effect represents the tendency of water to exclude non-polar molecules. The effect originates from the disruption of highly dynamic hydrogen bonds between molecules of liquid water. Polar chemical groups, such as OH group in methanol do not cause the hydrophobic effect.
[1] [2] The word hydrophobic literally means "water-fearing", and it describes the segregation of water and nonpolar substances, which maximizes the entropy of water and minimizes the area of contact between water and nonpolar molecules. In terms of thermodynamics, the hydrophobic effect is the free energy change of water surrounding a solute. [3]
If water has a contact angle between < <, then the surface is classed as hydrophilic, whereas a surface producing a contact angle between < < is hydrophobic. In the special cases where the Contact angle is 150 ∘ < θ {\displaystyle 150^{\circ }<\theta } , then it is known as superhydrophobic.
The process, called "Graphair", is so effective that water samples from Sydney Harbor were safe to drink after being treated. Graphene film makes dirty water drinkable in a single step Skip to ...
In addition to experimental investigation of graphene and graphene-based devices, numerical modeling and simulation of graphene has also been an important research topic. The Kubo formula provides an analytic expression for the graphene's conductivity and shows that it is a function of several physical parameters including wavelength ...
Graphene doped with various gaseous species (both acceptors and donors) can be returned to an undoped state by gentle heating in vacuum. [22] [24] Even for dopant concentrations in excess of 10 12 cm −2 carrier mobility exhibits no observable change. [24] Graphene doped with potassium in ultra-high vacuum at low temperature can reduce ...