Bio-inspired adhesive superhydrophobic polyimide mat with high thermal stability

Abstract

Superhydrophobic surface with high solid/liquid adhesion is of great fundamental and technological importance. However, the fabrication of adhesive superhydrophobic polymer surfaces with high stability is rare, which limits the utilization of such surfaces in harsh environments. This paper illustrates a simple electrospinning way to produce fluorinated polyimide nanofibric mat with adhesive superhydrophobicity as well as high thermal stability. The water contact angle on the mat reaches as high as 157.8 and the adhesive force to a water drop is up to 98.3 mN. Moreover, the adhesive superhydrophobic polyimide mat is able to stand extreme heat up to 300 C. By virtue of the facile electrospinning technique, large-area flexible mats can be easily achieved. Such an electrospun fluorinated polyimide mat will possess broader applications than ordinary organic superhydrophobic surfaces owing to its excellent stability in harsh environments.

Analysis of wear abrasion resistance of superhydrophobic acrylonitrile butadiene styrene rubber (ABS) nanocomposites

“…An attempt was also made to enhance the thermal stability [3,[57][58][59][60][61][62] of these wear abrasion resistant coatings. By thermal stability we mean the ability of the nanocomposites to maintain their water repellency after being exposed to temperatures in excess of 400°C.…”

Adhesion Tuning at Superhydrophobic States: From Petal Effect to Lotus Effect

“…On the Petal Effect surfaces, as shown in the enlargement of (a), when water touches the surface, numerous fiber/water interfaces will be created and the interfacial interactions generate considerable adhesions; while on Lotus Effect surface, as shown in the enlargement of (b), water partially wets the particle packs, but the contact areas are limited, due to the lack of contacting interfaces, the interfacial adhesion was small. generate considerable forces, they became sticky to water, [21] only the gecko-foot inspired surfaces had tipcontact mode to water while ours had a body-contact mode to the liquid phase. Conclusively, it was as if that the water droplet was entangled by the fibrous structures as demonstrated in Figure 4a, resulting in a superhydrophobic adhesive state.…”

“…Such unique wetting behavior is typically found on the rose petal and termed ''Petal Effect''. [16] Petal Effect has been proved to be valuable in non-loss micro fluid control, localized liquid chemical reactions, in-situ detections, etc.. [17][18][19][20][21][22] So one urgent and fundamental question has been raised. What makes the difference between the Lotus Effect and the Petal Effect and how does it influence on them?…”

Superhydrophobic polyimide films with high thermal endurance via UV photo-oxidation

“…The WCA larger than 150° and SA less than 5° after annealing of the superhydrophobic films demonstrated the highly stable superhydrophobicity. To the contrary, most well-known polymers such as PS cannot sustain their superhydrophobicity at high temperature due to unstable micro/nanostructures [6]. The remained superhydrophobicity of PI films can be ascribed to the thermally stable surface topography and composition.…”