Relation between temperature memory effect and multiple-shape memory behaviors based on polymer networks

RSC Advances ◽  
2014 ◽  
Vol 4 (39) ◽  
pp. 20364 ◽  
Author(s):  
Yaru Wang ◽  
Jing Li ◽  
Xingjian Li ◽  
Yi Pan ◽  
Zhaohui Zheng ◽  
...  
Keyword(s):  
Shape Memory ◽  
Memory Effect ◽  
Polymer Networks ◽  
Temperature Memory Effect

scholarly journals Thermally-Induced Shape-Memory Behavior of Degradable Gelatin-Based Networks

2021 ◽  
Vol 22 (11) ◽  
pp. 5892
Author(s):  
Axel T. Neffe ◽  
Candy Löwenberg ◽  
Konstanze K. Julich-Gruner ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Polymer Networks ◽  
Water Soluble ◽  
Compression Tests ◽  
Thermally Induced ◽  
Thermomechanical Process ◽  
Triple Helices

Shape-memory hydrogels (SMH) are multifunctional, actively-moving polymers of interest in biomedicine. In loosely crosslinked polymer networks, gelatin chains may form triple helices, which can act as temporary net points in SMH, depending on the presence of salts. Here, we show programming and initiation of the shape-memory effect of such networks based on a thermomechanical process compatible with the physiological environment. The SMH were synthesized by reaction of glycidylmethacrylated gelatin with oligo(ethylene glycol) (OEG) α,ω-dithiols of varying crosslinker length and amount. Triple helicalization of gelatin chains is shown directly by wide-angle X-ray scattering and indirectly via the mechanical behavior at different temperatures. The ability to form triple helices increased with the molar mass of the crosslinker. Hydrogels had storage moduli of 0.27–23 kPa and Young’s moduli of 215–360 kPa at 4 °C. The hydrogels were hydrolytically degradable, with full degradation to water-soluble products within one week at 37 °C and pH = 7.4. A thermally-induced shape-memory effect is demonstrated in bending as well as in compression tests, in which shape recovery with excellent shape-recovery rates Rr close to 100% were observed. In the future, the material presented here could be applied, e.g., as self-anchoring devices mechanically resembling the extracellular matrix.

Temperature memory effect in Cu–Al–Ni shape memory alloys studied by adiabatic calorimetry

2008 ◽  
Vol 56 (15) ◽  
pp. 3711-3722 ◽  
Author(s):  
Javier Rodríguez-Aseguinolaza ◽  
Isabel Ruiz-Larrea ◽  
Maria Luisa Nó ◽  
Angel López-Echarri ◽  
José María San Juan
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Memory Effect ◽  
Adiabatic Calorimetry ◽  
Temperature Memory Effect

Temperature Memory Effect of Ti-Ni-Hf-Y High Temperature Shape Memory Alloy

2017 ◽  
Vol 898 ◽  
pp. 598-603
Author(s):  
Jun Li ◽  
Xiao Yang Yi ◽  
Wei Hong Gao ◽  
Wen Long Song ◽  
Xiang Long Meng
Keyword(s):  
High Temperature ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Memory Effect ◽  
Thermal Cycle ◽  
Thermal Cycles ◽  
Solution Treated ◽  
Temperature Memory Effect ◽  
Lower Temperature ◽  
Complete Transformation

Temperature memory effect in the solution-treated Ti-Ni-Hf-Y high temperature shape memory alloy (HTSMA) was investigated. The results showed that the temperature memory effect induced by the partial cycling could be detected in the subsequent complete transformation cycling for the solution-treated Ti-Ni-Hf-Y alloy. The temperature memory effect is one-time phenomenon. However, the temperature memory effect could last at least 20 times when the sample was employed 10 times complete thermal cycles. Multiple-steps temperaure memory effect can be observed as the sample undergoes the lower temperature partial thermal cycle in sequence. The mechanisms of the temperature memory effect were discussed in this paper.

scholarly journals Temperature Memory Effect Induced by Incomplete Transformation in Ni-Mn-Ga-based Shape Memory Alloy

2015 ◽  
Vol 2 ◽  
pp. S867-S870 ◽  
Author(s):  
M.Z. Zhou ◽  
X. Zhang ◽  
X.L. Meng ◽  
W. Cai ◽  
L.C. Zhao
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Memory Effect ◽  
Temperature Memory Effect
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