Surface Structures, Particles, and Fibers of Shape-Memory Polymers at Micro-/Nanoscale

Abstract

Shape-memory polymers (SMPs) are one kind of smart polymers and can change their shapes in a predefined manner under stimuli. Shape-memory effect (SME) is not a unique ability for specific polymeric materials but results from the combination of a tailored shape-memory creation procedure (SMCP) and suitable molecular architecture that consists of netpoints and switching domains. In the last decade, the trend toward the exploration of SMPs to recover structures at micro-/nanoscale occurs with the development of SMPs. Here, the progress of the exploration in micro-/nanoscale structures, particles, and fibers of SMPs is reviewed. The preparation method, SMCP, characterization of SME, and applications of surface structures, free-standing particles, and fibers of SMPs at micro-/nanoscale are summarized.

Recent trends in thermo‐responsive elastomeric shape memory polymer nanocomposites

“…There has been a lot of research on the various types of SMEs present in SMPs, from simple one‐way SMEs to the most complex two‐way SMEs, and from a single SME to a triple SME and beyond 90 . As the variety of SMP materials grows, it will become possible to acquire two or even three distinct types of shape‐memory functions in a single SMP material 91,92 . Multiple SMPs with different properties are often combined to make these kinds of materials.…”

“…90 As the variety of SMP materials grows, it will become possible to acquire two or even three distinct types of shapememory functions in a single SMP material. 91,92 Multiple SMPs with different properties are often combined to make these kinds of materials. Figure 7A shows a simplified diagram of SMPs with one-way, two-way, dual-shape, and triple-shape capabilities, Figure 7B illustrates the one-way thermos-responsive Shape-Memory Polymer Nanocomposites of SBS/PCL blend with metal oxides and Figure 7C illustrates the triple-SMPs based on dual dynamic bonds.…”

Shape Memory Polymer Composites: 4D Printing, Smart Structures, and Applications

“…When the temperature is reduced to below T t , the reversible unit freezes, and the temporary shape of the SMP is fixed. However, when the temperature rises above T t again, the reversible unit is no longer frozen, and its chain segments will return to the initial state under the action of internal stress and molecular thermal motion, resulting in the SMP returning to its permanent shape [ 57 , 58 ].…”

Reconfigurable and Actuating Microbowls with Variable Steps

“…In this way, the crystalline domains can be divided into actuation domains, which induce the reversible elongation during cooling or contraction upon heating, and skeleton forming domains, which maintain a scaffold that guides the geometry of the actuation . These effects are highly relevant as they might enable technologies to fabricate materials, especially on the micro-/nanoscale, showing tailored shape changes or actuation at individual temperatures on purpose . Besides, methods that can allow us to perform programing on the micro-/nanoscale are important to realize the control of the targeted shape reconfiguration.…”

“…9 These effects are highly relevant as they might enable technologies to fabricate materials, especially on the micro-/nanoscale, showing tailored shape changes or actuation at individual temperatures on purpose. 10 Besides, methods that can allow us to perform programing on the micro-/nanoscale are important to realize the control of the targeted shape reconfiguration. In our previous work, we studied the effect of geometrical change on the microlevel and surface nanoroughness variation of individual microcuboids implemented with a one-way shape memory effect.…”