Flexible and robust 2D arrays of silver nanowires encapsulated within freestanding layer-by-layer films
Flexible and robust 2D arrays of silver nanowires encapsulated within freestanding layer-by-layer films
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DOI：
10.1002/adfm.200600430
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发表时间：
2006-10-04
影响因子：
19
通讯作者：
Tsukruk, Vladimir V.
中科院分区：
文献类型：
--
作者：
Gunawidjaja, Ray;Jiang, Chaoyang;Tsukruk, Vladimir V.
制备了独立的单层（LbL）薄膜，封装了控制体积分数（phi = 2.5- 22.5%）的银纳米线。银纳米线被夹在聚（丙烯胺盐酸盐）/聚（苯乙烯磺酸盐）（PAH/PSS）薄膜之间，形成具有（PAH/PSS）（10）PAH Ag(PAH/PSS)(10)PAH的纳米复合结构。杨氏模量、韧性、极限应力和极限应变对支撑和独立式结构进行了评估。由于纳米线的直径（73 nm）大于LbL薄膜的厚度（总计约50 nm），因此观察到一种特殊的形貌，即银纳米线从平面LbL薄膜中伸出。含纳米线的LbL薄膜具有承受显著弹性变形的能力，其极限应变可达1.8%。杨氏模量随着纳米线含量的增加而增加，当纳米线体积分数最高时，杨氏模量达到6 GPa左右，这是由于复合材料中常见的填料增强效应。这些复合材料的极限强度在60-80 MPa之间，在中等纳米线含量下，其韧性达到1000 kJ m(-3)，与碳纳米管增强的LbL膜相当。这些坚固的独立二维银纳米线阵列具有独特的光学、机械和导电性能，并结合了优异的微机械稳定性，可以作为微观声学、压力和光热传感器的主动元件。
Freestanding layer-by-layer (LbL) films encapsulating controlled volume fractions (phi = 2.5-22.5 %) of silver nanowires are fabricated. The silver nanowires are sandwiched between poly(allylamine hydrochloride)/poly(styrene sulfonate) (PAH/PSS) films resulting in nanocomposite structures with a general formula of (PAH/PSS)(10)PAH Ag(PAH/PSS)(10)PAH. The Young's modulus, toughness, ultimate stress, and ultimate strain are evaluated for supported and freestanding structures. Since the diameter of the nanowires (73 nm) is larger than the thickness of the LbL films (total of about 50 nm), a peculiar morphology is observed with the silver nanowires protruding from the planar LbL films. Nanowire-containing LbL films possess the ability to sustain significant elastic deformations with the ultimate strain reaching 1.8 %. The Young's modulus increases with increasing nanowire content, reaching about 6 GPa for the highest volume fraction, due to the filler reinforcement effect commonly observed in composite materials. The ultimate strengths of these composites range from 60-80 MPa and their toughness reaches 1000 kJ m(-3) at intermediate nanowire content, which is comparable to LbL films reinforced with carbon nanotubes. These robust freestanding 2D arrays of silver nanowires with peculiar optical, mechanical, and conducting properties combined with excellent micromechanical stability could serve as active elements in microscopic acoustic, pressure, and photothermal sensors.