Programmable Transition between Adhesive/Anti-Adhesive Performances on Porous PVDF Spheres Supported by Shape Memory PLLA

Abstract

Superhydrophobic surfaces with switchable adhesive/anti-adhesive performances are highly desired but still challenging. Herein, by loading porous poly (vinylidene fluoride) (PVDF) spheres on a shape memory polylactic acid (PLLA) film, a quasi-superhydrophobic surface of composite film (PVDF@PLLA) with the ability to tailor its surface structures/composition and related adhesive behaviors was fabricated. The as-prepared surface is covered by porous PVDF spheres. The combination of hydrophobicity of PVDF and hierarchical roughness resulted from porous spheres contributing to the high contact angle and low sliding angle, corresponding to Cassie state and lotus leaves effect. Upon uniaxial or biaxial tension, the distance among hydrophobic spheres is so high that more and more hydrophilic defects (PLLA film) have been exposed to water droplets, accounting for the quasi-superhydrophobic surface with a higher sliding angle. This is the reason for the Wenzel state and rose petals effect. After heating, PLLA film recovers to its original state. The porous PVDF spheres cover the whole film again, leading to the enhanced mobility of water droplets on the surface. The transition between the rose petals effect and the lotus leaves effect is programmable and reversible. Our result provides a novel strategy to tailor adhesive behaviors by combining (quasi-)superhydrophobic surface with shape memory effect.

Anti-Adhesive Surfaces Inspired by Bee Mandible Surfaces

“…There are many recent papers on the anti-adhesive properties of various microstructures [47][48][49][50][51][52][53][54][55][56]. We wanted to investigate the influence of surface microstructures on propolis adhesion through adhesion experiments on various bioinspired substrates.…”

Multifunctional properties optimization and stimuli‐responsivity of shape memory polymeric nanoarchitectures and applications

“…Moreover, prevalent nanoparticulates majorly include nanoparticulates, [35][36][37][38][39][40] nanotubes, [41][42][43][44][45] nanofibers, [46,47] nanowires, [48] nanorods, [49,50] as well as nanopaper. [51] Fundamentally, there exists 3 D of space (length [l], width [w], and height [h]), and so are materials. Relative to NM dimension fixed at 100 nm, NM with 0-D implies that all its dimensions (l, w, and h are <100 nm each).…”

“…Finally, 3-D implies that all three dimensions of l, w, and h, all >100 nm. [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] Prevalent traditional construction strategies, like filament winding, vacuum assisted resin transfer molding, resin film infusion, and resin transfer molding, still remain efficient choices for the fabrication of SMP nanoarchitectures. [52] Nevertheless, novel procedures have continually evolved for the fabrication of multifunctional nanoarchitectures.…”