TY  - JOUR
A1  - Yadavalli, Nataraja Sekhar
A1  - König, Tobias
A1  - Santer, Svetlana
T1  - Selective mass transport of azobenzene-containing photosensitive films towards or away from the light intensity
JF  - Journal of the Society for Information Display
N2  - Here, we report on two photosensitive amorphous polymers showing opposite behavior upon exposure to illumination. The first polymer (PAZO) consists of linear backbone to which azobenzene-containing side chains are covalently attached, while in the second polymer (azo-PEI), the azobenzene side chains are attached ionically to a polyelectrolyte backbone. When irradiated through a mask, the PAZO goes away from the intensity maxima, leaving behind topography trenches, while the direction of the mass transport of the azo-PEI polymer points towards the intensity maxima. This kind of behavior has been reported only for certain liquid crystalline polymers that exhibit in-phase reaction on illumination, that is, topography maxima coincides with the intensity maxima. Furthermore, flat nanocrystals placed on top of azo-PEI film was found to be moved together with the mass transport of the underlying polymer film as visualized using in situ atomic force microscopy (AFM) measurements. It was also demonstrated that the two polymer films respond differently on irradiation with the polarization and intensity interference patterns (IPs). To record the kinetic of the surface relief grating formation within two polymers during irradiation with different IPs, we utilized a homemade setup combining the optical part for the generation of IP and AFM. A possible mechanism explaining different responses on the irradiation of amorphous polymers is discussed in the frame of a theoretical model proposed by Saphiannikova et al. (J. Phys. Chem. B 113, 5032-5045 (2009)).
KW  - azobenzene
KW  - surface relief grating
KW  - light-induced mass transport
KW  - interference pattern
KW  - nano-object motion
Y1  - 2015
U6  - https://doi.org/10.1002/jsid.306
SN  - 1071-0922
SN  - 1938-3657
VL  - 23
IS  - 4
SP  - 154
EP  - 162
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -