Photoinduced optical anisotropy in azobenzene methacrylate block copolymers: Influence of molecular weight and irradiation conditions

Molecular-level interactions of an azopolymer and poly(dodecylmethacrylate) in mixed Langmuir and Langmuir–Blodgett films for optical storage

“…The lines are drawn to guide the eye. [4,10,24,35], copolymers [5,10,17,36,37] and blends [38,39] with the advantage of a relatively small writing time. The comparison of the two mixtures indicated that 41% molar fraction of azopolymer are sufficient for the photoinduced birefringence, with an optimized writing process using 1.4 mW of laser power.…”

“…Its kinetics depends on whether the azobenzenes are chemically bonded onto the polymer backbones [6]. Photo-orientation depends on several factors, such as the free volume for the chromophores and the spacer between the azo groups, the main chain structure of the polymer [7][8][9][10], the light intensity, and the film thickness [11,12].…”

“…In this context, highly organized, oriented films can be produced with the Langmuir-Blodgett (LB) technique [10,13], particularly when advantage can be taken of molecular engineering approaches. The latter may be important to obtain stable Langmuir films amenable to transfer onto solid supports, as is the case of mixtures of polymers and amphiphiles.…”

Effect of Molecular Structure and Thermal Treatment on Photo‐optical Properties of Photochromic Azobenzene‐containing Polymer Films

“…In most cases, these groups are oriented perpendicularly to the polarization plane of the incident light. [5][6][7][8][9][10][11][12][13][14][15][16] The origin of this phenomenon is explained by the process of selective excitation and E-Z-E isomerization cycles of the chromophores oriented predominately along the polarization plane. After many cycles of excitationrelaxation and isomerization accompanied by a rotational diffusion, the assembly of chromophores becomes oriented in the direction perpendicular to the polarization plane.…”

“…Despite the large number of publications devoted to the study of photo-orientation phenomena, [5][6][7][8][9][10][11][12][13][14][15][16] the relationship between the molecular structure and photoorientation kinetics, as well as the values of photoinduced dichroism, is still not completely clear. Another important topic for future research in this field is related to the investigation of the effect of the thermal treatment of samples on the kinetics of photo-orientation.…”