Solvent-driven temperature memory and multiple shape memory effects

Soft Matter ◽  
2015 ◽  
Vol 11 (20) ◽  
pp. 3977-3985 ◽  
Author(s):  
Rui Xiao ◽  
Jingkai Guo ◽  
David L. Safranski ◽  
Thao D. Nguyen
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Memory Effects ◽  
Shape Memory Effects

Programmed Nafion specimens can achieve multi-staged shape recovery in multiple solvents.

Smart Materials of Cured Epoxy Polymer Modified by 6F-PEEK with Shape Memory Effect

2010 ◽  
Vol 152-153 ◽  
pp. 530-535 ◽  
Author(s):  
Jun Peng Gao ◽  
Chen Qian Zhang ◽  
Xian Cheng He ◽  
Hong Yi Ma ◽  
Xue Feng An ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Smart Materials ◽  
Shape Recovery ◽  
Epoxy Polymer ◽  
Memory Effects ◽  
Retention Rates ◽  
Thermally Induced ◽  
Shape Memory Effects

We demonstrated a method of fabricating thermosetting epoxy polymer with shape memory effect modified Poly (ether ether ketone) (6F-PEEK) based on the formation of a phase-segregated morphology. The peculiarities of shape memory effects of the epoxy resin modified by 6F-PEEK were investigated. DMA result showed two glass transition temperatures in this blended material. The cured epoxy phase showing high Tg of 223oC acted as hard-segment-forming phase the and was responsible for the permanent shape. The 6F-PEEK can be used as switching phase for a thermally induced shape-memory effect. The transition temperature (Ttran) was 150oC, which was between the Tg of cured epoxy and 6F-PEEK. At the special concentrations of 6F-PEEK, the shape memory effect accompanied by a significant increase in volume was observed. The highest shape memory effect was obtained for the blended material with 25.00 wt% of 6F-PEEK. The shape retention rates and the shape recovery rates were 96-99% and 100%, respectively. The times of shape-recovery were all defined in 2 min. The mechanism of shape memory effects and the mechanical properties of the cured resin were discussed.

Influence of Electrical Pulse on Shape Memory Effects and Phase Transition of FeMnSiCrNi Shape Memory Alloy

2011 ◽  
Vol 299-300 ◽  
pp. 562-565
Author(s):  
Xing Jiang Liu ◽  
Yan Gao ◽  
Jin Gang Qi
Keyword(s):  
Shape Memory Alloy ◽  
Liquid Metal ◽  
Shape Memory ◽  
Recovery Rate ◽  
Shape Recovery ◽  
Electric Pulse ◽  
Memory Effects ◽  
Grain Structure ◽  
Shape Memory Effects ◽  
Columnar Grain

This paper studies the electric-pulse applied in the solidification process of the FeMnSiCrNi shape memory alloy, by applying different pulse frequency and polarity on the FeMnSiCrNi shape memory alloy to improve the shape memory effects. The results show : electric-pulse was conducive to FeMnSiCrNi alloys grain refinement, the alloy can improve the shape memory effect of Compression deformation, the absolute shape recovery rate is improved from 2% to 3.2% which is not treated by the electric-pulse ; when the liquid metal was connected with the anode of the pulse, it is easy to get the columnar grain structure and the column spacing is smaller; when the liquid metal was connected with the cathode of the pulse, the column spacing is larger; Columnar grain is conducive to FeMnSiCrNi alloy specimens compressed shape recovery, it has the smaller column spacing, yet the shape recovery rate is higher; equiaxed is favor in bending back, columnar crystals impede the bending response.

scholarly journals Multiwalled Carbon Nanotube Reinforced Bio-Based Benzoxazine/Epoxy Composites with NIR-Laser Stimulated Shape Memory Effects

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 881 ◽  
Author(s):  
Wassika Prasomsin ◽  
Tewarak Parnklang ◽  
Chaweewan Sapcharoenkun ◽  
Sunan Tiptipakorn ◽  
Sarawut Rimdusit
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Recovery Process ◽  
Memory Effects ◽  
Molecular Characteristics ◽  
Multiwalled Carbon ◽  
Dynamic Mechanical ◽  
Good Shape ◽  
Shape Memory Effects ◽  
Nir Laser

Smart materials with light-actuated shape memory effects are developed from renewable resources in this work. Bio-based benzoxazine resin is prepared from vanillin, furfurylamine, and paraformaldehyde by utilizing the Mannich-like condensation. Vanillin-furfurylamine-containing benzoxazine resin (V-fa) is subsequently copolymerized with epoxidized castor oil (ECO). When the copolymer is reinforced with multiwalled carbon nanotubes (MWCNTs), the resulting composite exhibits shape memory effects. Molecular characteristics of V-fa resin, ECO, and V-fa/ECO copolymers are obtained from Fourier transform infrared (FT-IR) spectroscopy. Curing behavior of V-fa/ECO copolymers is investigated by differential scanning calorimetry. Dynamic mechanical properties of MWCNT reinforced V-fa/ECO composites are determined by dynamic mechanical analysis. Morphological details and distribution of MWCNTs within the copolymer matrix are characterized by transmission electron microscopy. Shape memory performances of MWCNT reinforced V-fa/ECO composites are studied by shape memory tests performed with a universal testing machine. After a significant deformation to a temporary shape, the composites can be recovered to the original shape by near-infrared (NIR) laser actuation. The shape recovery process can be stimulated at a specific site of the composite simply by focusing NIR laser to that site. The shape recovery time of the composites under NIR actuation is four times faster than the shape recovery process under conventional thermal activation. Furthermore, the composites possess good shape fixity and good shape recovery under NIR actuation.

scholarly journals Harnessing reversible dry adhesion using shape memory polymer microparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (32) ◽  
pp. 19616-19622
Author(s):  
Wenbing Li ◽  
Junhao Liu ◽  
Wanting Wei ◽  
Kun Qian
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Memory Effects ◽  
Reversible Adhesion ◽  
Dry Adhesion ◽  
Bonding Property ◽  
Shape Memory Effects ◽  
Polymer Microparticles

Shape memory polymers can provide excellent bonding property because of their shape memory effects. This paper proposes an adhesive unit that is capable of repeatable smart adhesion and exhibits reversible adhesion under heating.

Multi-shape-memory effects in a wavelength-selective multicomposite

2015 ◽  
Vol 3 (26) ◽  
pp. 13953-13961 ◽  
Author(s):  
Li Yu ◽  
Qian Wang ◽  
Jian Sun ◽  
Chenyue Li ◽  
Cheng Zou ◽  
...  
Keyword(s):  
Shape Memory ◽  
Memory Effects ◽  
Shape Memory Effects

Tuneable shape-memory effects can be achieved in a wavelength-selective multicomposite.

Polyurethane foam/silica chemical hybrids for shape memory effects

2012 ◽  
Vol 27 (22) ◽  
pp. 2837-2843 ◽  
Author(s):  
S.M. Kang ◽  
M.J. Kim ◽  
S.H. Kwon ◽  
H. Park ◽  
H.M. Jeong ◽  
...  
Keyword(s):  
Shape Memory ◽  
Polyurethane Foam ◽  
Memory Effects ◽  
Shape Memory Effects ◽  
Image Position

Abstract

scholarly journals Epoxy Resin Composite Bilayers with Triple-Shape Memory Effect

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xixi Li ◽  
Yaofeng Zhu ◽  
Yubing Dong ◽  
Meng Liu ◽  
Qingqing Ni ◽  
...  
Keyword(s):  
Glass Transition ◽  
Electron Microscope ◽  
Shape Memory ◽  
Memory Effects ◽  
Epoxy Composites ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Shape Memory Effects ◽  
Triple Shape Memory ◽  
Nanosilica Particles

Triple-shape memory epoxy composites with bilayer structures of well-separated glass transition temperatures have been successfully prepared. The different glass transition temperatures of the epoxy composites were obtained by physically incorporating various amounts of nanosilica particles, which were introduced into the epoxy by utilizing polyethylene glycol. A scanning electron microscope and a transmission electron microscope were used to analyze the dispersibility of the nanosilica particles. The effects of nanosilica particles on the mechanical properties as well as on the dual-shape memory effects (DSME) and triple-shape memory effects (TSME) of the nanocomposites were studied. The nanosilica particles were homogenously dispersed in the matrix and well incorporated into the epoxy matrix. The resulting nanocomposites exhibited excellent TSME, and their shape fixity properties were significantly improved by nanosilica particles.

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