A novel series of hard-soft-hard triblock azo-copolymers (TBCs) composed of poly(2-[2-(4-cyano-azobenzene-4-oxy)ethylene-oxy]ethyl methacrylate) (PCEAMA), poly(methyl methacrylate) (PMMA) and poly(p-dodecylphenyl-N-acrylamide) (PDOPAM) were synthesized by employing reversible addition-fragmentation chain transfer polymerization. Chemical structures and molecular weights were characterized by H-1 nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). Thermal behavior, mesophase, photochemistry and morphology were investigated using differential scanning calorimetry (DSC), optical polarizing microscopy (OPM), ultraviolet-visible spectrophotometry (UV-vis), atomic force microscopy (AFM) and grazing-incidence small-angle X-ray scattering (GISAXS). Kinetic studies confirmed characteristic of controlled/living radical polymerization with low polydispersities (1.40). TBCs manifested both endothermic and exothermic transition peaks assigned to smectic to nematic, nematic to smectic, and smectic-A to smectic-C phases. TBCs having hight azo fractions of 39 and 34wt % revealed textures of smectic phase whereas TBC possessing 30wt % of azo content exhibited poor texture, suggesting nematic phase. Regarding TBC with low azo ratio (25wt %), neither mesophase texture was found. All TBCs showed photoresponsive behavior under UV-vis irradiation or thermal relaxation. TBC-1 with PCAEMA (39wt %), PMMA (40wt %) and PDOPAM (21wt %) generated a mixture of cylinder and lamellar nanostructures compared to TBC-2 and TBC-3 which formed lamellae. However, TBC-4 having the highest PDOPAM fraction (50wt %) produced hexagonal cylindrical nanostructure. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1617-1629