Superhydrophobicity, Superfluidity, Superlubricity, and Supersolidity

Superhydrophobic materials have surfaces that are extremely difficult to wet, with water contact angles in excess of 150° or even greater, see Fig. 20.6 shows that surfaces with ultrahydrophobicity have aroused much interest with their potential applications in self-cleaning coatings, microfluidics, and biocompatible materials and so on. Many physical-chemical processes, such as adsorption, lubrication, adhesion, dispersion, friction, etc., are closely related to the wettability of materials surfaces [52, 53]. Examples of hydrophobic molecules include alkanes, oils, fats, wax, and greasy and organic substances with C, N, O, or F as the key constituent element. 

What is even more amazing is that the hydrophobic surface can switch reversibly between superhydrophobicity and superhydrophihcity when the solid surface is subject to UV radiation [63], which results in electron-hole pair creation [64]. After being stored in the dark over an extended period, the hydrophilicity is 

The demoDstratioD of ultralow friction between multi-walled CNT layers is a valuable confirmation that they will be useful mechanical components in molecular nanotechnology such as molecular bearing. 

The occurrence of quantum friction is a kinetic process of energy dissipation E — fr S with fr being the friction force and s the sliding distance) due to the phonon (heat) and electron excitation (electron-hole pair production) during sliding [76], A state of ultralow friction is reached when a sharp tip slides over a flat surface and the applied pressure is below a certain threshold, whose value is dependent on the surface potential sensed by the tip and the stiffness of the contacting materials [73, 77, 78], 

At temperature below 200 mK [83], Helium 4 ( He) crystal is readily decoupled into fragments in a torsional oscillator to exhibit superfluidic nature—frictionless motion without viscosity [84, 85] meanwhile, the He crystal fragments are stiffer than expected and hence react elastically to a shear stress [86]. The individual segment of the He crystal would be thus both superelastic and superfluidic in motion. 

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Polarization happens at sites with even lower atomic CN, which gives rise to the non-zero spin (carrier of topologic insulator), conductor-insulator transition, surface plasmonic enhancement, and the superhydrophobicity, superfluidity, superlubricity, and supersolidity. 

Superhydrophobicity, Superfluidity, Superlubricity, and Supersolidity High Wetting... 

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