Proof-of-concept information encryption was conducted using NDI-coPyMA and NDI-coAntMA with PAM loading of 7.20% and 5.20%, respectively. For handwriting patterns, 0.1 g mL -1 polymer solutions in toluene were prepared. Using a paintbrush dipped in the solutions, the English letters were hand-written on a glass substrate, followed by air-drying for 10 min. For patterns of numbers and the QR code, substrates with 0.6 mm-deep indentations were first designed and 3D-printed using a commercial resin (PlasClear, Asiga). One drop from the toluene solutions of the copolymers (20 mg mL -1 ) was cast into each design's indentation, followed by air-drying for 15 min. The substrates were then exposed to 365-nm UV for 30 min, and images were captured. Positive parameters increase the value of respective photophysical property (e.g., λem of polymer aggregates) and negative parameters decrease the value. H NMR was estimated from the corresponding ratio of areas under the peaks at 6.45-7.29 ppm (phenyl protons in polystyrene), at characteristic peaks of PAMs, and at 8.75 ppm (aromatic protons in NDI scaffold). Mn was calculated as follow: Mn,NMR = MW(NDI-diBr) + DPSt,NMR × MW(styrene) + DPPAM,NMR × MW(PAM). c Ratio between St and PAM based on the estimated DP from NMR. d Mn,GPC and Đ were determined by GPC, calibrated with poly(methyl methacrylate) standards. e λem and absolute photoluminescence quantum yield (Φ) were determined from polymer thin films using an absolute PLQY spectrometer. Average values of triplicate measurements on Φ and the corresponding standard deviations (in the brackets) are listed. f λem was determined from polymer aggregates (5 μM) in DMF/H2O (5/95, v/v) using a molecular fluorescence spectrometer. Fitting parameter χ and its standard deviation shown in bracket. Fluorescence lifetimes (τavg, t1, and t2) determined from polymer thin films using a Hamamatsu Quantaurus-Tau Fluorescence Lifetime Spectrometer. H NMR was calculated from the corresponding ratio of areas under the peaks at 6.45-7.29 ppm (phenyl protons in polymer repeating units) and at 8.75 ppm (aromatic protons in NDI scaffold). Number average molar mass (Mn) was calculated as follow: Mn,NMR = MW(NDI-diBr) + DPNMR × MW(monomer). b Mn,GPC and polydispersity index (Đ) were determined by GPC, calibrated with poly(methyl methacrylate) standards. c λem and absolute PLQY (Φ) were determined from polymer thin films using an absolute PLQY spectrometer. Average values of triplicate measurements on Φ and the corresponding standard deviations (in the brackets) are listed. d λem was determined from polymer aggregates (5 μM) in DMF/H2O (5/95, v/v) using a molecular fluorescence spectrometer. e Conversion of the end group transformation was determined by H NMR using the characteristic proton signals of polycyclic aromatic groups and NDI. f Conversions were low possibly due to low reactivity of FluoOH or AntOH. The TSCT emission peaks are not visible due to strong anthracene emission in polymer aggregates. h Calculation was difficult due to strong coupling.