Figure 2.

Fluorescence Behavior of CA/oPD-CPDs

(A–C) PL spectra with different excitation wavelengths of CA/oPD-CPDs and corresponding excitation-emission matrix in (A) pH 2, (B) pH 7, and (C) pH 12 aqueous solutions with either HCl or NaOH.

(D) The PL spectra of CA/oPD-CPDs excited with 380 nm at different pH values.

(E) Emission-pH matrix of the same concentration CA/oPD-CPDs aqueous solution with different pH.

(F) Digital photos of CA/oPD-CPDs in pH 2, pH 7, and pH 12 aqueous solutions with either HCl or NaOH.

(G and H) Composites of cellulose and CA/oPD-CPDs under natural light and UV light. (G) Composites with urea and LiOH. (H) The stiff and brighter part of the composites after removing extra urea and LiOH.

(I) Hand drawing obtained from CA/oPD-CPDs in HCl solution and FM in neutral solution.

See also Tables S2 and S3 and Figures S6–S9.