1：Experimental Design and Method Selection:

The study involved the fabrication of PVA/Na2ZnO2 nanocomposite films via aqueous solution casting to achieve fluorescent down-conversion. Methods included hydrothermal synthesis of nanofillers, solution casting for film formation, and various characterizations (FTIR, XRD, UV-visible spectroscopy, fluorescence spectroscopy, DSC, TG, contact angle measurements) to assess optical, thermal, and surface properties.

2：Sample Selection and Data Sources:

Samples were PVA films with varying weight fractions (0.5, 1.0, 2.0, and 4.0 wt%) of nanostructured sodium zincate (Na2ZnO2). Data were obtained from laboratory experiments using synthesized materials.

3：5, 0, 0, and 0 wt%) of nanostructured sodium zincate (Na2ZnO2). Data were obtained from laboratory experiments using synthesized materials. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Materials included sodium nitrate (NaNO3), zinc nitrate hexahydrate (Zn(NO3)2·6H2O), hexamethylenetetramine (HMTA), poly(vinyl alcohol) (PVA, Mol. Wt. 85,000–124,000, 86.0–89.0% hydrolyzed), and distilled water. Equipment included pressure vessels, mechanical shearing devices, ultrasonicator (Frequency 40 kHz), glass molds, FTIR spectrometer, XRD diffractometer, UV-visible spectrophotometer, fluorescence spectrometer, DSC analyzer, TG analyzer, and contact angle goniometer.

4：0–0% hydrolyzed), and distilled water. Equipment included pressure vessels, mechanical shearing devices, ultrasonicator (Frequency 40 kHz), glass molds, FTIR spectrometer, XRD diffractometer, UV-visible spectrophotometer, fluorescence spectrometer, DSC analyzer, TG analyzer, and contact angle goniometer. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Sodium zincate nanofillers were synthesized hydrothermally by dissolving stoichiometric amounts of precursors in water, homogenizing at 80°C, heating in a pressure vessel at 95°C for 3 hours, washing, drying, and annealing at 600°C in oxygen. PVA/Na2ZnO2 suspensions were prepared by dissolving PVA in water, adding Na2ZnO2, homogenizing mechanically and ultrasonically, then solution casting into films and drying at ambient temperatures. Characterizations were performed as per standard protocols.

5：Data Analysis Methods:

Data were analyzed using techniques such as Tauc plot for band gap calculation, spectral analysis for Stokes shift determination, and thermal analysis for stability assessment. Software tools were not specified.