Control Viscoelasticity of Polymer Networks with Crosslinks of Superposed Fast and Slow Dynamics
Control Viscoelasticity of Polymer Networks with Crosslinks of Superposed Fast and Slow Dynamics
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DOI：
10.1002/anie.202105112
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发表时间：
2021-06-22
影响因子：
16.6
通讯作者：
Tan, Yebang
中科院分区：
文献类型：
--
作者：
Chen, Hao;Zhang, Jin;Tan, Yebang
取决于交联的动力学，聚合物网络可以具有不同的本体机械行为，从粘性液体到坚韧固体。在这里，通过设计一个可变分子动力学的交联，我们显示了在一个较宽的范围内定量控制聚合物网络的粘弹性。己酸酯-异喹啉@葫芦[7]脲（HIQ@CB[7]）交联表现出类似缔合亲和力但不同分子动力学的质子化和去质子化状态的组合。这种交联的分子性质是由两个状态下的参数的线性组合，这是精确调谐的pH值。使用这种交联，我们实现了准理想网络的粘弹性在5个数量级的定量控制，我们显示的机械响应的可逆控制，如刚度，强度和延伸性，坚韧的随机聚合物网络。这种策略提供了一种在分子水平上定制聚合物网络机械性能的方法，并为工程“智能”响应材料铺平了道路。
Depending on the dynamics of the crosslinks, polymer networks can have distinct bulk mechanical behaviors, from viscous liquids to tough solids. Here, by means of designing a crosslink with variable molecular dynamics, we show the control of viscoelasticity of polymer networks in a broad range quantitatively. The hexanoate-isoquinoline@cucurbit[7]uril (HIQ@CB[7]) crosslink exhibits in a combination of protonated and deprotonated states of similar association affinity but distinct molecular dynamics. The molecular property of this crosslink is contributed by linear combination of the parameters at the two states, which is precisely tuned by pH. Using this crosslink, we achieve the quantitative control of viscoelasticity of quasi-ideal networks in 5 orders of magnitude, and we show the reversible control of mechanical response, such as stiffness, strength and extensibility, of tough random polymer networks. This strategy offers a way to tailor the mechanical properties of polymer networks at the molecular level and paves the way for engineering "smart" responsive materials.