## 2 Materials and Material Production
### Nanocellulose (Binder + Humectant)  
Equation (1), which shows the reaction of NO\({}_{x}\) with CaCO\({}_{3}\), indicates that moisture (H\({}_{2}\)O) is an intrinsic part of the mechanism. This occurs because the reaction is an ionic bond exchange of CO\({}_{3}\)\({}^{2-}\) for nitrite/nitrate 2(NO\({}_{2}\)\({}^{-}\)/2 NO\({}_{3}\)\({}^{-}\)), and anionic group exchange between the salts requires they dissociate in aqueous medium. A supply of moisture within the immediate molecular environment is needed to support the CaCO\({}_{3}\)-NO\({}_{x}\) interaction. To guarantee the presence of moisture, it must be absorbed from the surrounding air. Materials that absorb moisture in this way are termed hygroscopic, and if they also dissolved in the absorbed moisture, then they are termed deliquescent. This need can be met by a humectant material that absorbs and stores moisture in excess of its own matrix dispersion. Such a \begin{table}
\begin{tabular}{c c c} \hline \multicolumn{2}{c}{**Volume Defined Particle Size Distribution Data Measured by Light Scattering**} \\ \hline
**Particle Size 1** & **Before Sonication (\(\upmu\)m)** & **After Sonication (\(\upmu\)m)** \\ \hline \(d_{10}\) (vol) 2 & 3.33 & 1.12 \\ \hline \(d_{50}\) (vol) & 4.61 & 1.41 \\ \hline \(d_{90}\) (vol) & 6.05 & 1.77 \\ \hline \end{tabular} \({}^{1}\) Particle size determined by laser light diffraction in dilute aqueous suspension (Malvern Mastersizer, Malvern Instruments, Malvern, UK). 2 For particles of identical material and optical densities, the n/o size distribution was identical to the w/w size distribution.  
\end{table} 
Table 4: Particle size upper limits in the fractions contained in the \(<\) 10 v/v%, \(<\) 50 v/v% (median), and \(<\) 90 v/v% regions before and after ultrasonication in water. \begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**Sample**} & **Specific Surface** & **Total Pore Volume,** & **Mesopore** & **Micropore Volume** & **Pore Diameter from Alpha S-Plot, \(d_{w}\)** \\  & **Area, SSA** & **Vust** & **Volume, \(V_{\text{meso}}\)** & \(V_{\text{mico}}\)** & **Alpha S-Plot, \(d_{w}\)** \\  & **(m\({}^{2}\)g-1)** & **(cm\({}^{3}\)g-1)** & **(cm\({}^{3}\)g-1)** & **(cm\({}^{3}\)g-1)** & **(mm)** \\ \hline CaCO\({}_{3}\) (GCC) & 5.05 & 0.0192 & 0.0184 & 0.0023 & 20.9 \\ \hline \end{tabular}
\end{table} 
Table 5: BET (Brunauer-Teller-Emmett) and BJH (Barrett, Joyner, and Halenda) N\({}_{2}\) specific surface area data and meso and micropore volume. material is conveniently sourced from the same feed material used as the substrate (cellulose fibres) [18] and produced in the form of micro nano-fibrilated cellulose (MNFC), which is readily derived either by high shear homogenising under high pressure extrusion or by micro-grinding, as shown in Figure 7, from either virgin or multi-recycled fibres [19]. Using over-recycled fibre, which is intrinsically weak, enables less energy input to be consumed to form the fine fibrillar material needed. To reduce energy consumption further, sodium sulphite (Na2 SO3)2 was added, following the report of [PERSON] et al. [20], which effectively reduced the number of passes through the laboratory mass collider from 10 to 7. In addition, the bleaching effect of sulphite facilitated further de-inking of the newsprint fibres. To aid removal of excess sulphite and reduce the number of ink particles, the product was repeatedly washed with water. The disintegrated pulp suspension was fed through a feeding neck into the mass collider, where it passed between a static and a rotating abrasive grinding stone rotating at a speed of about 1500 min-1 (rpm) with a motor frequency setting of 560 MHz. The fibrillation occurs under the hydrodynamic pressure, mechanical grinding, and shearing forces generated by the grinding stones, which result in the breakdown of the macroscopic plant fibre walls and the release of nanometre-thick strands of nanofibrils branching from the parent fibre wall.