## 3 Results and Discussion
### Thermal Properties  
Figure 6 displays the Differential Scanning Calorimetry (DSC) curves for (a) composite gypsum boards GB/OD@CCF and (b) composite cement boards CB/OD@CCF with varying percentages of OD@CCF content. Figure S1 displays the respective curves for pure octadecane. The melting (Tm) and solidification (Ts) temperatures, along with their corresponding enthalpies (\(\Delta\)Hm and \(\Delta\)Hs), are presented in Table S1. Analysis indicates that for both gypsum and cement boards, the melting temperature of octadecane falls within the range of 26.4-28.3 \({}^{\circ}\)C, while the solidification temperature ranges from 22.7 to 24.5 \({}^{\circ}\)C. Furthermore, the melting enthalpy rises progressively from the lowest to the highest OD@CCF loading, as expected (increasing from 6.3 J/g to 22.5 J/g for gypsum  
Figure 5: Images from X-ray computed microtomography (micro-CT) of GB reference board (**a**) and GB/OD@CCF composite boards containing 10% (**b**), 20% (**c**), and 30% (**d**) OD@CCF. boards and from 6.0 J/g to 14.8 J/g for cement boards). Conversely, the solidification enthalpy decreases from \(-5.2\) J/g to \(-22.0\) J/g for gypsum boards and from \(-8.3\) J/g to \(-13.5\) J/g for cement boards. These findings are plotted in Figure 7.  
The results from thermal conductivity (k) and specific heat capacity (Cp) measurements for the reference gypsum and cement boards and their composites GB/OD@CCF and CB/OD@CCF are presented in Table S2. Moreover, Figure 8 depicts the graphical correlation between thermal conductivity and specific heat capacity with increasing percentages of OD@CCF additive. The data analysis reveals noticeable variations in these parameters corresponding to the incremental increase in additive content. Specifically, a positive correlation is evident, indicating an improvement in both thermal conductivity and specific heat capacity with higher additive content. This positive correlation is interpreted as the OD@CCF component making a positive contribution to the heat transfer capabilities within the composite gypsum and cement boards. The data suggest that as the percentage of OD@CCF additive increases, there is a concurrent enhancement in both thermal conductivity and specific heat capacity, highlighting the positive influence of the additive on the heat transfer properties of the composite material. This improvement can be attributed to two main factors. Firstly, carbon foam contributes to an overall en  
Figure 6: DSC curves of (a) GB/OD@CCF and (b) CB/OD@CCF with various % OD@CCF. Figure 7: Variations in AHM and AHs values of composite boards GB and CB at different percentages of OD@CCF content. hancement in the thermal conductivity of the composites. Secondly, the well-dispersed and inter-connected carbon foam particles within the gypsum or cement matrix create additional channels for heat transfer [34]. Similar findings are reported in the literature. For instance, in our previous work [22], the incorporation of activated carbon/RT18 HC in gypsum boards increased the thermal conductivity and specific heat capacity from 0.33 W/(m\(\cdot\)K) and 1455 (J/Kg\(\cdot\)K) to 0.53 and 1833 (J/Kg\(\cdot\)K), respectively, for a 30% w.t. additive. [PERSON] et al. [35] noticed that diatomic/paraffin incorporation into gypsum boards reinforced with 1% carbon fibers resulted in an increment of thermal conductivity from 0.86 to 0.93 W/(m\(\cdot\)K). In addition, according to the same team, expanded graphite/paraffin gypsum-based composites with 20% w.t. additive increased the thermal conductivity from 0.742 W/(m\(\cdot\)K) to 1.137 W/(m\(\cdot\)K) [23]. Concerning cement composite boards, in our case, the thermal conductivity values are measured in the range of 0.06-0.08 W/(m\(\cdot\)K), which are in agreement with the literature for perlite concrete thermal conductivity properties (0.07-0.08 W/(m\(\cdot\)K)) [36], showing a \(\sim\)33% increment for 30% additive.