Two-dimensional lattice structures with specific geometric features have been reported to a negative Poisson's ratio, termed as auxetic metamaterials, that is, stretching-induced expansion in the transversal direction. In this paper, we designed novel metamaterial; by utilizing shape memory effect of constituent materials, in-plane moduli and ratios can be continuously tailored. During deformation, curved meshes ensure rotation mesh joints achieve auxetics. The rotations these are governed...

We present a phenomenological thermodynamic model to study the constitutive relations and working mechanism of chemo-responsive shape memory effect (SME) in polymers (SMPs). On origin Hildebrand solubility parameter, Flory–Huggins interaction parameter relaxation theory, is proposed quantitatively identify factors influencing SMPs. After this, free-energy function implemented couple chemical potential stress as weight fraction solvent stretch, respectively. Furthermore, simulation compared...

This paper provides a brief review on the advanced shape memory technology (ASMT) with focus polymeric materials. In addition to introducing concept and fundamentals of ASMT, potential applications ASMT either alone or integrated an existing mature technique (such as, 3D printing, quick response (QR) code, lenticular lens) phenomena (e.g., wrinkling stress-enhanced swelling effect) in product design, manufacturing, recycling are demonstrated. It is concluded that indeed able provide range...

Abstract Shape memory polymers (SMPs) can be programmed to a temporary shape, and then recover its original shape by applying environmental stimuli when needed. To expands the application space of SMPs, polymer composites (SMPCs) were fabricated either improve mechanical properties, or incorporate more stimulus methods. With deepening research, filler arrangement also used reshape from two dimensional sheet three structure strain mismatch. Recently, SMPCs show interesting behaviors. gain...

With the aim of integrating a family functional composites, possessing conspicuous water-induced shape memory effect (SME), novel sodium dodecyl sulfate–epoxy composite was constructed. The original fabrication strategy designed based on chemical interaction constructed 3D microvoid surface. Compared with pure epoxy polymer, composites display gratifying effect. results indicate that recovery rate is accelerated through increasing temperature or decreasing specimen thickness. An immersion...

Abstract Can the laws of physics be unified? One most puzzling challenges is to reconcile and chemistry, where molecular meets condensed-matter physics, resulting from dynamic fluctuation scaling effect glassy matter at glass transition temperature. The pioneer Nobel Prize-winning physicist Philip Warren Anderson referred this gap as deepest interesting unsolved problem in 1995. In 2005, Science, its 125th anniversary publication, highlighted that question ‘what nature state?’ was one...

The present work studies the synergistic effect of carbon nanofiber (CNF) and nanopaper on shape recovery memory polymer (SMP) composite. combination CNF was used to improve thermal electrical conductivities SMP coated surface composite in order achieve actuation by resistive heating. CNFs were blended with resin conductivity facilitate heat transfer from underlying accelerate electroactive responses.

The present work studies the synergistic effect of self-assembly multi-walled carbon nanotube (MWCNT) nanopaper and sub-micro nickel nanostrand on electrical properties electro-active recovery behavior shape memory polymer (SMP) nanocomposite. combination MWCNT is used to improve thermal conductivities SMP was coated surface achieve nanocomposite induced by electricity. Electromagnetic nanostrands were blended with and, vertically aligned into resin in a magnetic field, conductivity. will...

For the thermal response of shape-memory polymer (SMP) it has been experimentally demonstrated that actuation can be achieved using interactive solvent. In this paper, effect solubility parameter solvent on shape recovery behavior and glass transition temperature polystyrene SMP was investigated experimentally. The activation energy separated qualitatively identified, as expected from relaxation theory Eyring equation. This approach should applicable to other SMPs their composites many...

The present paper studies the electrical and shape-memory behavior of self-assembled carbon nanofiber (CNF) nanopaper incorporated with polymer (SMP). morphology structure nanopapers were characterized scanning electron microscopy (SEM). A continuous compact network was observed from SEM images, which indicates that CNF could have highly conductive properties. conductivity measured by four-point probe method its temperature coefficient effect studied. Finally, actuation SMP demonstrated...

Abstract Shape‐memory polymer (SMP) materials have several drawbacks such as low strength, stiffness and natural insulating tendencies, which seriously limit their development applications. Much effort has been made to improve mechanical properties by adding particle or fiber fillers reinforce the matrix. However, this often leads being enhanced slightly, but shape‐memory effect of reinforced SMP composites drastically reduced. The experimental results reported here suggested that resistive...

The present work studies the synergistic effect of self-assembled carboxylic acid-functionalized carbon nanotube (CNT) and fiber on electrical property electro-activated recovery behavior shape memory polymer (SMP) nanocomposites. combination CNT results in improved conductivity SMP Carboxylic CNTs are grafted onto fibers then by deposition to significantly enhance reliability bonding between via van der Waals covalent crosslink. Furthermore, enable nanocomposites for Joule heating triggered...

A novel and facile strategy was proposed to construct a thermosetting/thermoplastic system with both shape memory self-healing properties based on commercial epoxy resin poly(-caprolactone)-PCL. Thermoplastic material is capable of re-structuring changing the stiffness/modulus when temperature above melting temperature. PCL microfiber used as plasticizer in resin–based blends, served 'hard segment' fix temporary composites during cycles. In this study, electrospun membrane porous network...

In this work, we present a phenomenological approach to study the state transition and working mechanism of chemo-responsive shape memory effect (SME) in polymers (SMPs). The thermodynamics polymer solution free-energy theory are initially applied quantitatively identify factors that trigger SME. After this, field is developed couple chemical potential, stress relaxation time system with functions. Furthermore, by means combining together utilizing Gordon–Taylor (GT) Free-Volume (FV) theory,...

All amorphous shape memory polymers (SMPs) are featured by their relaxation behavior above and below the switching transition temperature (TSW). Above TSW, glass secondary merge together, resulting in cooperative (α) movement polymer macromolecules. Below is non-cooperative (β). In this study, three thermodynamic constitutive frameworks for recovery SMPs proposed based on Arrhenius, Vogel–Fulcher–Tammann (VFT) Bässler laws, respectively, incorporated with parameters (stress, strain time) as...