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Flexible and Robust 2D Arrays of Silver Nanowires Encapsulated within Freestanding Layer‐by‐Layer Films
Author(s) -
Gunawidjaja R.,
Jiang C.,
Peleshanko S.,
Ornatska M.,
Singamaneni S.,
Tsukruk V. V.
Publication year - 2006
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200600430
Subject(s) - materials science , nanowire , composite material , nanocomposite , toughness , volume fraction , composite number , layer by layer , carbon nanotube , layer (electronics) , modulus , elastomer , elastic modulus , nanotechnology
Abstract Freestanding layer‐by‐layer (LbL) films encapsulating controlled volume fractions (ϕ = 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.