Polymeric Shape-Memory Micro-Patterned Surface for Switching Wettability with Temperature

Abstract

An innovative method to switch the wettability of a micropatterned polymeric surface by thermally induced shape memory effect is presented. For this purpose, first polycyclooctene (PCO) is crosslinked with dicumyl peroxide (DCP) and its melting temperature, which corresponds with the switching transition temperature (T trans ), is measured by Dynamic Mechanical Thermal Analysis (DMTA) in tension mode. Later, the shape memory behavior of the bulk material is analyzed under different experimental conditions employing a cyclic thermomechanical analysis (TMA). Finally, after creating shape memory micropillars by laser ablation of crosslinked thermo-active polycyclooctene (PCO), shape memory response and associated effect on water contact angle is analyzed. Thus, deformed micropillars cause lower contact angle on the surface from reduced roughness, but the original hydrophobicity is restored by thermally induced recovery of the original surface structure.Polymers 2015, 7 1675

Influence of the soft segment nature on the thermomechanical behavior of shape memory polyurethanes

“…The fixing ( R f ) and recovery ( R r ) ratios were calculated for each sample using Eqs. and . …”

Smart Wetting Control on Shape Memory Polymer Surfaces

“…For example, through laser ablation of cross‐linked polycyclooctene (PCO), which is characterized by a fast recovery velocity, García‐Huete et al. prepared a surface with a shape memory pyramid‐like microstructure (Figure a) . The water CA on the surface is about 136° (Figure b), which means the surface has general hydrophobicity.…”

“…a) Schematic illustration of surface microstructure variation after pressing and recovery.S hapeso faw ater droplet on the surfacecorresponding to the original (b), deformed( c), and recovered microstructure (c) shapes. Reproduced with permission from ref [17]…”

Programmable microscale stiffness pattern of flat polymeric substrates by temperature-memory technology

“…Besides the shape-memory effects on macroscopic specimens, the topographical recovery of microstructures on the surfaces of SMP films has also been reported, where programming was realized by vertical or tilted compression of the substrates, or via stretching the specimen in an elastic mold. [24][25][26][27][28] Among the SMP materials, polymer networks with broad melting or glass transition temperatures are of particular interest, as these allow the adjustment of the switching temperature (the temperature of maximum recovery rate) by variation of the deformation temperature within the thermal transition. [7,[28][29][30][31][32][33] In this study we explored whether flat polymeric substrates with a distinct mechanical pattern can be obtained by applying temperature-memory programming to microstructured polymer substrates.…”