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A Unified Material Description for Light Induced Deformation in Azobenzene Polymers.

Bin J, Oates WS - Sci Rep (2015)

Bottom Line: It is shown that dipole forces strongly respond to polarized light in contrast to higher order quadrupole forces that are often used to describe surface relief grating deformation through a field gradient constitutive law.The modeling results and comparisons with a broad range of photomechanical data in the literature suggest that the molecular structure of the azobenzene monomers dramatically influences the photostrictive behavior.The results provide important insight for designing azobenzene monomers within a polymer network to achieve enhanced photo-responsive deformation.

View Article: PubMed Central - PubMed

Affiliation: Florida Center for Advanced Aero Propulsion (FCAAP), Department of Mechanical Engineering, Florida State University. Tallahassee, FL, 32310, USA.

ABSTRACT
Complex light-matter interactions in azobenzene polymers have limited our understanding of how photoisomerization induces deformation as a function of the underlying polymer network and form of the light excitation. A unified modeling framework is formulated to advance the understanding of surface deformation and bulk deformation of polymer films that are controlled by linear or circularly polarized light or vortex beams. It is shown that dipole forces strongly respond to polarized light in contrast to higher order quadrupole forces that are often used to describe surface relief grating deformation through a field gradient constitutive law. The modeling results and comparisons with a broad range of photomechanical data in the literature suggest that the molecular structure of the azobenzene monomers dramatically influences the photostrictive behavior. The results provide important insight for designing azobenzene monomers within a polymer network to achieve enhanced photo-responsive deformation.

No MeSH data available.


Related in: MedlinePlus

The material response to uniform light.(a) Plots of the polarized electric field component and the electronic material oscillation for the 100% trans state . The one dimensional plots along the z direction, (0.5, 0.5, z), have been taken through the center line normal to the xy plane. Simulation was run with λ = 370 nm. (b) Azobenzene microstructure evolution of the trans state before and after light exposure. (c) Deformation due to light absorption and photoisomerization through the thickness where the color contour represents the displacement in the x direction. A rectangular parallelepiped of black lines represents the reference undeformed shape.
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f4: The material response to uniform light.(a) Plots of the polarized electric field component and the electronic material oscillation for the 100% trans state . The one dimensional plots along the z direction, (0.5, 0.5, z), have been taken through the center line normal to the xy plane. Simulation was run with λ = 370 nm. (b) Azobenzene microstructure evolution of the trans state before and after light exposure. (c) Deformation due to light absorption and photoisomerization through the thickness where the color contour represents the displacement in the x direction. A rectangular parallelepiped of black lines represents the reference undeformed shape.

Mentions: In this case, photomechanical trans-cis behavior of the azo-polymer is described in a monodomain film. Linearly polarized light in the x direction propagates in the z direction through the azo-polymer from a light source in the vacuum. Figure 4(a) represents the light and material response for the fully trans states (100% trans state) given previously in Fig. 3 when the polarized light source of wavelength λ = 370 nm (UV light) is applied. As shown in this figure, while the electric field waves propagate through the material, the azobenzene starts to absorb light energy. Once it reaches steady state oscillation, the magnitude of the electric field and the electronic displacement of the trans state decreases monotonically through the material’s thickness.


A Unified Material Description for Light Induced Deformation in Azobenzene Polymers.

Bin J, Oates WS - Sci Rep (2015)

The material response to uniform light.(a) Plots of the polarized electric field component and the electronic material oscillation for the 100% trans state . The one dimensional plots along the z direction, (0.5, 0.5, z), have been taken through the center line normal to the xy plane. Simulation was run with λ = 370 nm. (b) Azobenzene microstructure evolution of the trans state before and after light exposure. (c) Deformation due to light absorption and photoisomerization through the thickness where the color contour represents the displacement in the x direction. A rectangular parallelepiped of black lines represents the reference undeformed shape.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4594130&req=5

f4: The material response to uniform light.(a) Plots of the polarized electric field component and the electronic material oscillation for the 100% trans state . The one dimensional plots along the z direction, (0.5, 0.5, z), have been taken through the center line normal to the xy plane. Simulation was run with λ = 370 nm. (b) Azobenzene microstructure evolution of the trans state before and after light exposure. (c) Deformation due to light absorption and photoisomerization through the thickness where the color contour represents the displacement in the x direction. A rectangular parallelepiped of black lines represents the reference undeformed shape.
Mentions: In this case, photomechanical trans-cis behavior of the azo-polymer is described in a monodomain film. Linearly polarized light in the x direction propagates in the z direction through the azo-polymer from a light source in the vacuum. Figure 4(a) represents the light and material response for the fully trans states (100% trans state) given previously in Fig. 3 when the polarized light source of wavelength λ = 370 nm (UV light) is applied. As shown in this figure, while the electric field waves propagate through the material, the azobenzene starts to absorb light energy. Once it reaches steady state oscillation, the magnitude of the electric field and the electronic displacement of the trans state decreases monotonically through the material’s thickness.

Bottom Line: It is shown that dipole forces strongly respond to polarized light in contrast to higher order quadrupole forces that are often used to describe surface relief grating deformation through a field gradient constitutive law.The modeling results and comparisons with a broad range of photomechanical data in the literature suggest that the molecular structure of the azobenzene monomers dramatically influences the photostrictive behavior.The results provide important insight for designing azobenzene monomers within a polymer network to achieve enhanced photo-responsive deformation.

View Article: PubMed Central - PubMed

Affiliation: Florida Center for Advanced Aero Propulsion (FCAAP), Department of Mechanical Engineering, Florida State University. Tallahassee, FL, 32310, USA.

ABSTRACT
Complex light-matter interactions in azobenzene polymers have limited our understanding of how photoisomerization induces deformation as a function of the underlying polymer network and form of the light excitation. A unified modeling framework is formulated to advance the understanding of surface deformation and bulk deformation of polymer films that are controlled by linear or circularly polarized light or vortex beams. It is shown that dipole forces strongly respond to polarized light in contrast to higher order quadrupole forces that are often used to describe surface relief grating deformation through a field gradient constitutive law. The modeling results and comparisons with a broad range of photomechanical data in the literature suggest that the molecular structure of the azobenzene monomers dramatically influences the photostrictive behavior. The results provide important insight for designing azobenzene monomers within a polymer network to achieve enhanced photo-responsive deformation.

No MeSH data available.


Related in: MedlinePlus