Hydrated behavior of multilayer polyelectrolyte-nanoclay coatings on porous materials and demonstration of shape memory effect
Hydrated behavior of multilayer polyelectrolyte-nanoclay coatings on porous materials and demonstration of shape memory effect
复制标题
DOI：
10.1016/j.surfcoat.2023.129335
复制
发表时间：
2023-02
影响因子：
5.4
通讯作者：
J. Acheson;Aoife McFerran;Dichu Xu;M. Ziminska;S. Goel;A. Lennon;N. Dunne;A. Hamilton
中科院分区：
文献类型：
--
作者：
J. Acheson;Aoife McFerran;Dichu Xu;M. Ziminska;S. Goel;A. Lennon;N. Dunne;A. Hamilton
逐层组装是一种制备具有多种组分、性质和功能的纳米复合薄膜涂层的强大技术。这些涂层的模板化沉积使得机械性能从薄膜的微观尺度转化为纳米复合材料涂覆的多孔材料的宏观尺度，并且已经用于定制涂覆的开孔泡沫的弹性模量和孔隙率，以用于包括轻质结构和工程组织支架的潜在应用。然而，在这些应用环境中水分的存在预计会影响纳米复合材料涂层的物理机械行为。在这项工作中，开孔泡沫涂有纳米复合材料组成的聚（乙烯亚胺），聚（丙烯酸），和Na+-蒙脱土的特点是在高相对湿度和完全浸没在水中。当在环境条件下测试时，纳米复合材料涂层赋予压缩弹性模量从0.08 ± 0.00 MPa至4.90 ± 0.46 MPa的显著增加，但是当水合时几乎没有机械效应，并且在干燥时，涂覆的泡沫的机械性能恢复到预水合水平。聚合物内胺基的化学交联导致水合时保持2.91 ± 0.49 MPa的显著压缩弹性模量。初始试验表明，未交联的涂覆泡沫表现出水合诱导的形状记忆效应，其可用于使先前被动的开孔泡沫能够致动或膨胀。
Layer-by-layer (LbL) assembly is a powerful technique for fabricating nanocomposite thin-film coatings with a diverse range of constituents, properties, and functionalities. Templated deposition of these coatings has enabled the translation of mechanical properties from the microscale of thin-films to the macro-scale of nanocomposite-coated porous materials and has been used to tailor the elastic modulus and porosity of coated open-cell foams for potential applications including lightweight structures and engineered tissue scaffolds. However, the presence of moisture in these application environments is expected to affect the physico-mechanical behavior of the nanocomposite coating. In this work, open-cell foams coated with nanocomposites consisting of poly(ethyleneimine), poly(acrylic acid), and Na+-montmorillonite were characterised under high relative humidity and upon complete submersion in water. The nanocomposite coating imparted a substantial increase in compressive elastic modulus when tested under ambient conditions, from 0.08 ± 0.00 MPa to 4.90 ± 0.46 MPa, but had little to no mechanical effect when hydrated, and upon drying the mechanical properties of coated foams recovered to pre-hydrated levels. Chemical crosslinking of amine groups within the polymers resulted in the retention of significant compressive elastic modulus of 2.91 ± 0.49 MPa when hydrated. Initial trials showed that un-crosslinked coated foams exhibit a hydration induced shape memory effect that could be used to enable the actuation or expansion of a previously passive open-cell foam.