Graphene Oxide-Polyelectrolyte Nanomembranes
Graphene Oxide-Polyelectrolyte Nanomembranes
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DOI：
10.1021/nn101204d
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发表时间：
2010-08-01
期刊：
影响因子：
17.1
通讯作者：
Tsukruk, Vladimir V.
中科院分区：
文献类型：
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作者：
Kulkarni, Dhaval D.;Choi, Ikjun;Tsukruk, Vladimir V.
石墨烯是一种碳原子层，由于其优异的电学、热学和机械性能，被认为是一种优异的二维填料，用于聚合物纳米复合材料，具有优异的机械强度沿着优异的电学和热学性能。常规填料的关键限制之一是实现机械性能的显著改善所需的加载分数相对较高，通常达到最大强度的50%。在这里，我们证明了通过掺入少量的平面氧化石墨烯（GO）薄片的致密单层，可以显著增强叠层纳米复合材料的机械性能。将带负电荷的官能化氧化石墨烯层并入到经由Langmuir-Blodgett（LB）沉积在逐层（LbL）组装中制造的多层膜（PEM）中。这些LbL-LB氧化石墨烯纳米复合材料膜被释放为具有大的横向尺寸（厘米）和约50 nm的厚度的坚固的自由站立的膜。微机械测量显示弹性模量提高了一个数量级，从纯LbL膜的1.5 GPa提高到仅8.0体积%氧化石墨烯包封的LbL膜的约20 GPa。这些坚韧的纳米复合PEM可以自由地悬挂在大（几毫米）孔径上并承受大的机械变形。
Owing to its remarkable electrical, thermal, and mechanical properties, graphene, an atomic layer of carbon, is considered to be an excellent two-dimensional filler for polymer nanocomposites with outstanding mechanical strength along with the potential for excellent electrical and thermal properties. One of the critical limitations with conventional fillers is that the loading fraction required for achieving significant improvement in mechanical properties is relatively high, frequently reaching 50% for maximum strength. Here, we demonstrate that the mechanical properties of ultrathin laminated nanocomposites can be significantly enhanced by the incorporation of small amounts of a dense monolayer of planar graphene oxide (GO) flakes. Negatively charged functionalized graphene oxide layers were incorporated into polyelectrolyte multilayers (PEMs) fabricated in a layer-by-layer (LbL) assembly via Langmuir-Blodgett (LB) deposition. These LbL-LB graphene oxide nanocomposite films were released as robust freely standing membranes with large lateral dimensions (centimeters) and a thickness of around 50 nm. Micromechanical measurements showed enhancement of the elastic modulus by an order of magnitude, from 1.5 GPa for pure LbL membranes to about 20 GPa for only 8.0 vol % graphene oxide encapsulated LbL membranes. These tough nanocomposite PEMs can be freely suspended over large (few millimeters) apertures and sustain large mechanical deformations.