1：Experimental Design and Method Selection:

The study employs a bottom-up approach involving the synthesis of a maleic acid-capped diacetylene monomer (PCDA-EDMA), self-assembly in aqueous media with an organic base (TMG), and UV-induced topochemical polymerization to form polydiacetylene (PDA) nanosheets. The design leverages amphiphilicity, hydrogen bonding, π-π stacking, and electrostatic interactions for monolayer formation.

2：Sample Selection and Data Sources:

The primary material is PCDA-EDMA synthesized from precursors like PCDA, EDEA, and maleic anhydride. Organic bases such as TMG, triethylamine, and pyridine are tested for their templating effects. Samples include aqueous dispersions of nanosheets, films made by vacuum filtration, and inkjet-printed patterns.

3：List of Experimental Equipment and Materials:

Key instruments include a Bruker AVANCE III NMR spectrometer, JEOL JEM2011 TEM, Zeiss Ultra 55 FE-SEM, Bruker Multimode 8 AFM, Olympus IX83-Cell^TIRF fluorescence microscope, SSRF beamline BL16B for SAXS, Bruker D8 ADVANCE XRD, Thermofisher Nicolet 6700 FT-IR, Perkin-Elmer Lambda UV-vis spectrometer, HORIBA JobinYvon XploRA Raman spectrometer, Shimadzu RF-5301 spectrofluorometer, and a commercial inkjet printer (HP Deskjet 1112). Materials include PCDA, HOBT, EDCI, EDEA, maleic anhydride, TMG, and others from Sigma-Aldrich, TCI, and Sinopharm.

4：2). Materials include PCDA, HOBT, EDCI, EDEA, maleic anhydride, TMG, and others from Sigma-Aldrich, TCI, and Sinopharm. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Synthesis involves stepwise reactions to produce PCDA-EDMA. Nanosheet preparation: Dissolve PCDA-EDMA in DMSO, add to water with TMG, sonicate, refrigerate, then UV irradiate for polymerization. Dialyze to purify. For films, vacuum filter nanosheet dispersion. For inkjet printing, load nanosheet ink into a printer cartridge and print on substrates. Characterization techniques include TEM, SEM, AFM, fluorescence microscopy, SAXS, XRD, FT-IR, UV-vis, Raman spectroscopy, and fluorescence spectroscopy.

5：Data Analysis Methods:

SAXS data analyzed using NIST Igor packages with a two-layer lamellar model. UV-vis and Raman spectra used to monitor colorimetric transitions and structural changes. Statistical analysis of thickness and size from AFM and microscopy images.