## Materials and Methods
### Analytical Methods  
_Atomic force microscopy (CD particle size, TOBC dimension):_ AFM-topography imaging was performed with a Dimension Icon Scanning Probe Microscope (Bruker AXS, formerly Veeco, Champs sur Marne, France) equipped with a NanoScope V control station. An OTESPA cantilever was used in tapping mode at a resonance frequency of 299-301 kHz with a spring constant of 42 (12-103) N\(\cdot\)m\({}^{-1}\). The NanoScope 8.15R3 software package was used for data acquisition and the Gwyddion 2.40 software package for image processing. The fibril dimensions of TOBC were determined using an aliquot of a highly diluted dispersion (ca. 5 mg\(\cdot\)mL\({}^{-1}\)). The lengths of the fibers were measured directly as they appeared coplanar to the scan's plane while diameters were determined from the maximum height of cross sectional profiles. For diameters, every examined fiber was measured thrice over a distance of about 50-100 nm (depending on the appearance of the fiber sample). The different types of CDs were analyzed using highly diluted dispersions (4 \(\upmu\)g\(\cdot\)mL\({}^{-1}\)) prepared from the respective stock solutions.  
_Dynamic light scattering (DLS):_ Highly diluted dispersions (see above; 4 \(\upmu\)g\(\cdot\)mL\({}^{-1}\)) prepared from the respective stock solutions were analyzed in 20 runs each using a Zetasizer Nano ZS (Malvern Instruments, Worcestershire, UK) equipped with a quartz cell.  
_Field emission scanning electron microscopy (FEG-SEM):_ Surface and tearing edges of selected nanopaper sheets were imaged on a Zeiss Supra 55 VP (Oberkochen, Germany) using a 2 kV beam after being gold sputtered (Edwards S150B).  
_Fluorescence and UV/Vis spectroscopy:_ Fluorescence measurements were performed on a Hitachi F-700 spectrophotometer (Tokyo, Japan) at 310.15 K and 700 V acceleration voltage using a slit widths of 2.5 nm for both excitation and emission measurements. UV/Vis spectroscopy was performed on a Lambda 35 UV/vis instrument (PerkinElmer, Waltham, MA, USA) to determine the absorbance of dilution series of the different types of synthesized CDs.  
Quantum yields were determined as described elsewhere [35] using Equation (1) and quinine sulphate (QS) as a reference (standard, _st_) compound.  
\[\Phi(x)=\Phi(st)\times\frac{m(x)}{m(st)}\times\frac{\eta^{2}(x)}{\eta^{2}(st)} \tag{1}\]  
\(\Phi(x)\):quantum yield of the target sample; \(\Phi(st)\): quantum yield of QS (54%); _m(x), m(st)_ are the slopes of the respective linear regression curves describing the correlation between integrated fluorescence intensity and absorbance as estimated at an emission wavelength of 350 nm for five different QS (reference) and CD concentration levels. The latter were prepared from respective stock solutions in a way that absorbance values of 0.02, 0.04, 0.06, 0.08, and 0.1 were obtained. The terms \(\eta^{2}(x)\) and \(\eta^{2}(st)\) represent the squares of the refractive indices of sample (CD) and standard (QS), respectively. While the quantum yield \(\Phi(st)\) of quinine sulfate is 0.54 for a 0.1 M solution in H\({}_{2}\)SO\({}_{4}\), the refractive values of H\({}_{2}\)O and 0.1 M H\({}_{2}\)SO\({}_{4}\) are practically the same (\(\eta_{\text{H}_{2}\text{O}}\approx\eta_{\text{0.1 M H}_{2}\text{SO}_{4}}=1.33\)).  
_The impact of pH variation on photoluminescence intensity of CD dispersions_ was studied at an excitation wavelength of 350 nm which was considered a good compromise regarding the photoluminescence maxima of the different types of CDs. Aliquots of the stock solution uniform for each type of CD (50 \(\upmu\)L for GEA, e.g.,) were diluted in 4.95 mL of different aqueous media of varying pH to covering the pH range from 2 to 12 in increments of one.