Superhydrophobic Natural and Artificial Surfaces—A Structural Approach

Abstract

Since ancient times humans observed animal and plants features and tried to adapt them according to their own needs. Biomimetics represents the foundation of many inventions from various fields: From transportation devices (helicopter, airplane, submarine) and flying techniques, to sports’ wear industry (swimming suits, scuba diving gear, Velcro closure system), bullet proof vests made from Kevlar etc. It is true that nature provides numerous noteworthy models (shark skin, spider web, lotus leaves), referring both to the plant and animal kingdom. This review paper summarizes a few of “nature’s interventions” in human evolution, regarding understanding of surface wettability and development of innovative special surfaces. Empirical models are described in order to reveal the science behind special wettable surfaces (superhydrophobic /superhydrophilic). Materials and methods used in order to artificially obtain special wettable surfaces are described in correlation with plants’ and animals’ unique features. Emphasis is placed on joining superhydrophobic and superhydrophilic surfaces, with important applications in cell culturing, microorganism isolation/separation and molecule screening techniques. Bio-inspired wettability is presented as a constitutive part of traditional devices/systems, intended to improve their characteristics and extend performances.

Fabrication of PVA polymer films with improved antibacterial activity by fine-tuning via organic acids for food packaging applications

“…•− ) radicals, hydroxyl radical (OH •− ), and hydrogen peroxide (H 2 O 2 ), and (2) the deposition of carboxyl groups on the surface of the bacteria (Wu et al 2018). Similar results are observed with LA-cross-linked films, which show good bacteriostatic properties against the pathogenic bacterial species S. aureus could be utilized in medical applications and protective packaging (Avrămescu et al 2018). Based on the obtained results it is proposed that the nature of the surface together with surface topography play an important role in determining antibacterial activity.…”

Comprehensive Property Investigation of Mold Inhibitor Treated Raw Cotton and Ramie Fabric

“…Mold inhibitor additives in this work are organic small molecules which have little influence on changing the surface roughness of the cotton. [26] However, the additives were all fine crystal powders which had higher surface energy than that of raw cotton. The increased wettability of the treated cotton samples was mainly caused by the additives changing the surface energy.…”

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

“…Thus, smaller drops stay stable, while raindrops slide off, since they are bigger [21]. Figure 4 illustrates a comparison between the rose petal (a) and the lotus leaf (b) surface structure [22].…”

“…(a) Rose petal surface structure (Cassie impregnating wetting state) and (b) lotus leaf surface structure(Cassie state) [22].…”