TY - JOUR
T1 - Programmable light-controlled shape changes in layered polymer nanocomposites
AU - Zhu, Zhichen
AU - Senses, Erkan
AU - Akcora, Pinar
AU - Sukhishvili, Svetlana A.
PY - 2012/4/24
Y1 - 2012/4/24
N2 - We present soft, layered nanocomposites that exhibit controlled swelling anisotropy and spatially specific shape reconfigurations in response to light irradiation. The use of gold nanoparticles grafted with a temperature-responsive polymer (poly(N-isopropylacrylamide), PNIPAM) with layer-by-layer (LbL) assembly allowed placement of plasmonic structures within specific regions in the film, while exposure to light caused localized material deswelling by a photothermal mechanism. By layering PNIPAM-grafted gold nanoparticles in between nonresponsive polymer stacks, we have achieved zero Poissons ratio materials that exhibit reversible, light-induced unidirectional shape changes. In addition, we report rheological properties of these LbL assemblies in their equilibrium swollen states. Moreover, incorporation of dissimilar plasmonic nanostructures (solid gold nanoparticles and nanoshells) within different material strata enabled controlled shrinkage of specific regions of hydrogels at specific excitation wavelengths. The approach is applicable to a wide range of metal nanoparticles and temperature-responsive polymers and affords many advanced build-in options useful in optically manipulated functional devices, including precise control of plasmonic layer thickness, tunability of shape variations to the excitation wavelength, and programmable spatial control of optical response.
AB - We present soft, layered nanocomposites that exhibit controlled swelling anisotropy and spatially specific shape reconfigurations in response to light irradiation. The use of gold nanoparticles grafted with a temperature-responsive polymer (poly(N-isopropylacrylamide), PNIPAM) with layer-by-layer (LbL) assembly allowed placement of plasmonic structures within specific regions in the film, while exposure to light caused localized material deswelling by a photothermal mechanism. By layering PNIPAM-grafted gold nanoparticles in between nonresponsive polymer stacks, we have achieved zero Poissons ratio materials that exhibit reversible, light-induced unidirectional shape changes. In addition, we report rheological properties of these LbL assemblies in their equilibrium swollen states. Moreover, incorporation of dissimilar plasmonic nanostructures (solid gold nanoparticles and nanoshells) within different material strata enabled controlled shrinkage of specific regions of hydrogels at specific excitation wavelengths. The approach is applicable to a wide range of metal nanoparticles and temperature-responsive polymers and affords many advanced build-in options useful in optically manipulated functional devices, including precise control of plasmonic layer thickness, tunability of shape variations to the excitation wavelength, and programmable spatial control of optical response.
KW - light-responsive materials
KW - metal nanoparticles
KW - nanocomposites
KW - photothermal effect
KW - poly(N-isopropylacrylamide)
KW - rheology
KW - shape-changing materials
KW - soft actuators
KW - zero Poisson's ratio
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U2 - 10.1021/nn204938j
DO - 10.1021/nn204938j
M3 - Article
C2 - 22452351
AN - SCOPUS:84860371855
SN - 1936-0851
VL - 6
SP - 3152
EP - 3162
JO - ACS Nano
JF - ACS Nano
IS - 4
ER -