Might be the 1st piece of shape memory hybrid (PDMS + rosin). Shape recovered in 3 s upon heating in hot water.
​​UV cross-linkable hybrid resins for additive manufacturing to achieve high performance and body-temperature programmable shape memory effect

​Modify Formlabs' UV resin for high performance and body-temperature programmable SME
​Bicontinuous microstructures are essential to the function of diverse natural and synthetic systems. Their synthesis has been based on two approaches: arrested phase separation or self-assembly of block copolymers. The former is attractive for its chemical simplicity and the latter, for its thermodynamic robustness. Here we introduce elastic microphase separation (EMPS) as an alternative approach to make bicontinuous microstructures. Conceptually, EMPS balances the molecular-scale forces that drive demixing with large-scale elasticity to encode a thermodynamic length scale. This process features a continuous phase transition, reversible without hysteresis. Practically, EMPS is triggered by simply supersaturating an elastomeric matrix with a liquid, resulting in uniform bicontinuous materials with a well-defined microscopic length scale tuned by the matrix stiffness. The versatility of EMPS is further demonstrated by fabricating bicontinuous materials with superior mechanical properties and controlled anisotropy and microstructural gradients. Overall, EMPS presents a robust alternative for the bulk fabrication of homogeneous bicontinuous materials.
Nature Materials volume 23, pages124–130 (2024)
Composite viscosity versus temperature relationships of liquid mixture (before UV cross-linking) upon thermal cycling
(FYP) Lim YS, Shaune
​Volumetric additive manufacturing of body temperature programmable shape memory hybrid: proof-of-concept
by Dr Wang TX's group

DIY shape memory polymeric foam

Elastic shape memory hybrid: highly elastic and able to capture finger print

Comparison with wax
​1. Finger prints are about the same
2. Finger print capture: before wax solidification vs. body/room temperature of shape memory hybrid
3. Wax: normally brittle vs this shape memory hybrid: highly elastic
4. Upon heating, wax melts vs shape memory hybrid recovers its original shape

FEM simulation

by (intern)
Pranav Krishnan, Subham Mohapatra, Vivek Pendharkar
​Formation of eyeball in stretching of shape memory hybrid: FEM simulation
​Evolution of Shore Hardness under Uniaxial Tension/Compression in Body-Temperature Programmable Elastic Shape Memory Hybrids

Water as the transition part
​Elastic silicone+water
to achieve ±0oC recovery temperature
​(Wet hydrogel)
Shape fixed in fridge at ​-20°C
(a) Original shape; (b) after bent and kept at -20°C for one hour; (c-e) shape recovery sequence at around 25°C; (f) after immersed in room temperature water for 30 minutes.

Shape memory hybrid structure
​Body-temperature remodelable soft elastic shape memory hybrid

​Heating/cooling-responsive shape memory hybrid
​Ref. ​Stimulus-responsive shape memory materials: a review
两种聚合物在高温下混合，想要成功生成优质的共聚物（copolymer），需要满足以下几个关键条件：
  1. 化学相容性：两种聚合物的分子结构需要具备一定的化学相容性，才能在高温下通过化学反应生成共聚物。例如，聚合物的官能团必须能够在适当的条件下反应，形成新的共价键。如果两者之间没有化学相互作用，可能只能形成物理混合物，而不是共聚物。
  2. 反应温度和反应条件：高温下的反应温度需要足够高，以克服聚合物之间的化学势垒，同时又不能过高，导致聚合物的降解。选择适当的催化剂、压力和时间来促进共聚反应也是非常关键的。
  3. 反应机制：确保存在合适的聚合反应机制，如自由基聚合、阴离子聚合、阳离子聚合等，以便两种聚合物能够在高温条件下结合形成共聚物。根据反应机理，不同类型的单体需要相应的引发剂或催化剂。
  4. 相容剂或增容剂：如果两种聚合物的相容性较差，可以通过加入增容剂（compatibilizer）来提高它们的相容性，帮助形成均匀的共聚物。
  5. 熔体相容性：在高温下，两种聚合物的熔融态必须相容，即它们的粘度和分子量应相似，以确保它们能够均匀混合。如果两者在熔融状态下不相容，可能会导致相分离，无法形成高质量的共聚物。
  6. 热稳定性：两种聚合物在高温下需要有足够的热稳定性，以避免在反应过程中发生分解或交联。
通过这些条件的优化，可以实现两种聚合物的高温混合，生成优质的共聚物。
To successfully mix two polymers at high temperatures and form a high-quality copolymer, the following key conditions need to be met:
  1. Chemical Compatibility: The molecular structures of the two polymers must have some degree of chemical compatibility so that they can react under high temperatures to form a copolymer. Functional groups in both polymers should be capable of reacting with each other to form new covalent bonds. Without chemical interaction, a physical blend rather than a true copolymer may form.
  2. Reaction Temperature and Conditions: The reaction temperature needs to be high enough to overcome the activation energy required for the polymers to react, but not so high that it causes polymer degradation. The proper use of catalysts, pressure, and reaction time is also crucial to promote successful copolymerization.
  3. Reaction Mechanism: Ensure that an appropriate polymerization mechanism is in place, such as free-radical polymerization, anionic polymerization, or cationic polymerization, depending on the chemistry of the polymers. Specific initiators or catalysts may be required to facilitate the reaction between the two polymers.
  4. Compatibilizers: If the two polymers have poor inherent compatibility, adding a compatibilizer can improve their interaction, leading to a more uniform copolymer.
  5. Melt Compatibility: At high temperatures, the polymers should have compatible melt viscosities and molecular weights to ensure they can mix evenly. If the polymers are not miscible in the molten state, phase separation may occur, preventing the formation of a high-quality copolymer.
  6. Thermal Stability: Both polymers must have sufficient thermal stability to prevent degradation or unwanted cross-linking during the high-temperature process.
By optimizing these conditions, it’s possible to mix two polymers at high temperatures and produce a high-quality copolymer.
​如何用丙烯酸盐制备水驱动形状记忆杂交材料？

ChatGPT said:
ChatGPT用丙烯酸盐制备水驱动形状记忆杂交材料涉及几个关键步骤，包括材料的选择、聚合、形状记忆效应的引入和性能测试。以下是一个大致的流程：
1. 材料选择
  • 丙烯酸盐：选择合适的丙烯酸盐单体（如丙烯酸或甲基丙烯酸酯）作为基体材料。这类材料易于聚合且具有良好的机械性能。
  • 交联剂：添加适量的交联剂（如二乙烯基苯、乙二醇二甲基丙烯酸酯），提高聚合物网络的稳定性。
  • 水敏感性成分：选择一种或多种对水敏感的材料（如聚乙二醇、聚乙烯醇、壳聚糖）与丙烯酸盐混合，以赋予材料水驱动的形状记忆功能。
2. 聚合与杂交材料的制备
  • 混合与聚合：将丙烯酸盐单体、交联剂和水敏感性成分混合，加入引发剂（如过硫酸钾、偶氮二异丁腈）引发自由基聚合。该过程可以通过热引发、光引发或其它方法进行。
  • 成型与固化：将混合物倒入模具中，并在合适的条件下进行固化（如加热或紫外光照射），形成具有均匀交联网络的固态材料。
3. 形状记忆效应的引入
  • 形状编程：将固化后的材料加热到其玻璃化转变温度（Tg）以上，施加应力使其变形，然后在施加应力的同时快速冷却，使材料保持在变形状态。
  • 水驱动响应：将形状记忆材料置于水中，材料中的水敏感性成分吸水膨胀，触发形状恢复。水的吸收可以改变材料的玻璃化转变温度或其他热力学参数，从而引发形状记忆效应。
4. 性能测试与优化
  • 形状记忆行为测试：测试材料的形状恢复率、恢复速度及循环性能，评估其作为形状记忆材料的实际应用潜力。
  • 机械性能测试：通过拉伸、压缩等测试手段，评估材料的机械性能，确保其在应用中的稳定性和耐久性。
  • 水敏感性测试：研究材料在不同湿度或水环境下的响应行为，优化材料配方以提高其水驱动形状记忆效应。
5. 应用开发
  • 根据水驱动形状记忆杂交材料的性能，可以进一步探索其在柔性传感器、可穿戴设备、自适应结构和生物医学器件中的应用。
通过以上步骤，可以制备出一种基于丙烯酸盐的水驱动形状记忆杂交材料，具备优异的形状记忆特性和水响应行为。
如何用丙烯酸盐制备水驱动形状记忆杂交材料？

ChatGLM
查询 1 次，打开 3 个网页并总结
引用关于如何使用丙烯酸盐制备水驱动的形状记忆杂交材料，以下是一些关键的步骤和概念：
  1. 形状记忆水凝胶的原理：形状记忆水凝胶通过亲水性聚合物网络与水的相互作用来实现体积膨胀并形成水凝胶。要实现水凝胶在改变形状的同时不产生体积变化，需要复杂的化学反应和结构设计。这涉及到弹性聚合物网络结构、材料的预设形变过程以及分子开关提供额外的临时交联点，以实现非等熵构象下的可逆固定聚合物网络1。
  2. 水致硬化聚合物凝胶材料：香港中文大学（深圳）朱世平院士团队开发了一种基于水驱动相分离的聚合物凝胶材料。这种材料在相分离的基础上表现出显著且可逆的水致硬化现象，不同于传统材料在水合时的软化。这种材料的杨氏模量在水合和脱水过程中表现出极大的刚度变化，而体积几乎保持不变，使其适用于湿度诱导的形状记忆应用2。
  3. 分级光热固化形状记忆复合材料：通过分级光热固化方法，可以制备出融合了环氧基形状记忆聚合物（EP）和聚乙烯醇基形状记忆聚合物（PVA）的新型形状记忆复合材料。这种材料具有适用的刚度和多刺激响应性能，解决了大多数水驱动形状记忆聚合物力学性能不理想的问题，从而扩大了水驱动形状记忆聚合物的应用范围3。
总结来说，制备水驱动的形状记忆杂交材料需要理解并应用复杂的化学原理和材料科学知识，特别是在设计聚合物网络和利用水致硬化现象方面。通过这些高级材料，可以实现形状记忆效应，并应用于多种智能材料和系统。