Natural and Artificial Superwettable Surfaces-Superficial Phenomena: An Extreme Wettability Scenario

Abstract

With the help of biomimetics, superficial characteristics were transposed, through various methods, onto artificially obtained materials. Many industrial fields applied surface architecture modifications as improvements of classic materials/methods. The medico-pharmaceutical, biochemical, transportation, and textile fields are few examples of industrial areas welcoming a "structural change." Antibioadhesion was widely exploited by means of antibacterial or self-cleaning fabrics and cell culturing/screening/isolation. Anti-icing, antireflective, and anticorrosion materials/coatings gained attention in the transportation and optical device fields. Interdisciplinary approaches on extreme wettability include "solid-fluid" formations called liquid marbles, which will be further discussed as a superhydrophobic behavior exponent.

Bacterial Cellulose—A Remarkable Polymer as a Source for Biomaterials Tailoring

“…Nowadays, materials with extreme wetting properties gain scientists’ attention because these materials present multiple ascending applications. Following the trend of developing biomimetic materials with special surface properties (for example superhydrophobic materials structurally resembling the lotus leaf [ 203 , 204 ]), bacterial cellulose became of interest to scientists working on hybrid materials. Thus, biocomposites with improved interfacial wettability were created by chemical cross-linking with oligopeptides, promoting tissue repair, which is of high importance in regenerative medicine [ 205 ].…”

Perspectives to Describe Surface Properties of Raw Pharmaceutical Materials. A Fractal Approach on the Wetting of Powders

“…During the last decades, technological expansion projected itself upon diverse industrial areas, with appreciated and valuable acknowledgements. Among the scientific fields that benefited from industrial outgrow, microscopical analysis stood out, as many natural phenomena and properties were scientifically explained [9,10,16]. This progress was achieved due to the possibility to study surface properties at a macroscopic, microscopic and especially nanometric level [10,29].…”

“…Wetting phenomena are described through quantitative indexes: contact angle (CA(°)) and other quantitative indexes: "sliding" contact angle, hysteresis, dynamic contact angle, surface tension, length (mm), height (mm), volume (µL) and area (mm 2 ) of the drop, which is considered in this case, a spherical cap and not a perfect sphere [26,27]. The contact angle (θ or CA(°)) is determined using Young's equation: cosθ = (γSG -γSL)/γLG (Eq 1) Where γSG, γSL, γLG represent superficial tensions at the solid-gas, solid-liquid, liquid gas interfaces, and only applies to ideal, smooth surfaces [3,10,11]. It is important to emphasize that most of the surrounding surfaces are not perfectly smooth.…”