Stimuli-responsive mechanically adaptive polymer nanocomposites.
Stimuli-responsive mechanically adaptive polymer nanocomposites.
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DOI：
10.1021/am9006337
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发表时间：
2010-01
影响因子：
9.5
通讯作者：
Weder, Christoph
中科院分区：
文献类型：
--
作者：
Shanmuganathan, Kadhiravan;Capadona, Jeffrey R.;Rowan, Stuart J.;Weder, Christoph
制备并研究了一系列新的仿生刺激响应纳米复合材料，它们在暴露于生理条件下时会改变其机械性能。这些材料是通过将源自被囊类动物的纤维素纳米纤维或“晶须”的渗透网络引入聚醋酸乙烯酯（PVAc）、聚甲基丙烯酸丁酯（PBMA）以及这些聚合物的共混物中来生产的，目的是确定聚合物基质的疏水性和玻璃化转变温度（Tg）如何影响水诱导的机械动态行为。在 Tg (~60–70 °C) 以下，晶须 (15.1 – 16.5% v/v) 的加入使纯聚合物的拉伸储能模量 (E') 从 0.6 GPa (PBMA) 和 2 GPa (PVAc) 适度增加到 3.8 GPa (PBMA) 和 5.2 GPa (PVAc)。高于 Tg 时，增强效果更加显着，其中 E' 从 1.2 增加至 690 MPa (PVAc)，从 ~1 GPa (PBMA) 增加至 1.1 GPa。暴露于生理条件（浸入人工脑脊液，ACSF，37°C）后，所有材料均表现出 E' 下降。最显着的对比出现在 PVAc 中；例如，16.5% v/v PVAc/晶须纳米复合材料的 E' 从 5.2 GPa 降至 12.7 MPa。 PBMA/晶须纳米复合材料的模量仅略有下降；此处，15.1% v/v PBMA/晶须纳米复合材料的 E' 从 3.8 GPa 降至 1.2 GPa。系统研究表明，机械对比度的大小与 ACSF 的溶胀程度有关，随着晶须含量、温度和基质极性 (PVAc > PBMA) 的增加而增加。新材料的机械变形可以在纳米复合材料增强的渗流模型和 Halpin-Kardos 模型的框架中进行描述，并且是纳米粒子之间的相互作用改变以及膨胀时基质塑化的结果。
A new series of biomimetic stimuli-responsive nanocomposites, which change their mechanical properties upon exposure to physiological conditions, was prepared and investigated. The materials were produced by introducing percolating networks of cellulose nanofibers or “whiskers” derived from tunicates into poly(vinyl acetate) (PVAc), poly(butyl methacrylate) (PBMA), and blends of these polymers, with the objective of determining how the hydrophobicity and glass-transition temperature (Tg) of the polymer matrix affect the water-induced mechanically dynamic behavior. Below the Tg (~60–70 °C), the incorporation of whiskers (15.1 – 16.5% v/v) modestly increased the tensile storage moduli (E′) of the neat polymers from 0.6 to 3.8 GPa (PBMA) and from 2 to 5.2 GPa (PVAc). The reinforcement was much more dramatic above Tg, where E′ increased from 1.2 to 690 MPa (PVAc) and ~1 to 1.1 GPa (PBMA). Upon exposure to physiological conditions (immersion in artificial cerebrospinal fluid, ACSF, at 37 °C) all materials displayed a decrease of E′. The most significant contrast was seen in PVAc; for example the E′ of a 16.5% v/v PVAc/whisker nanocomposite decreased from 5.2 GPa to 12.7 MPa. Only a modest modulus decrease was measured for PBMA/whisker nanocomposite; here the E′ of a 15.1% v/v PBMA/whisker nanocomposite decreased from 3.8 to 1.2 GPa. A systematic investigation revealed that the magnitude of the mechanical contrast was related to the degree of swelling with ACSF, which was shown to increase with whisker content, temperature, and polarity of the matrix (PVAc > PBMA). The mechanical morphing of the new materials can be described in the framework of both the percolation and Halpin-Kardos models for nanocomposite reinforcement, and is the result of changing interactions among the nanoparticles and plasticization of the matrix upon swelling.
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影响因子：
3.4
作者：
FAVIER, V;CANOVA, GR;GAUTHIER, C
通讯作者：
GAUTHIER, C
影响因子：
5.5
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影响因子：
38.3
作者：
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通讯作者：
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影响因子：
5.5
作者：
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作者：
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通讯作者：
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