## 3 Results and Discussion
At 23 \({}^{\circ}\)C, the maximum force applied to the top of the microcapsule before breaking it was 13.2 \(\upmu\)N, while at 60 \({}^{\circ}\)C, this force was 5.3 \(\upmu\)N. In the light of these results, the force value diminished 60% from room temperature to 60 \({}^{\circ}\)C.  
Figure 4: Mechanical testing of the elastic-plastic region by AFM of the MPCM composed by PMMA:tetracosane (1:3) microcapsule at 60 \({}^{\circ}\)C: (**a**) no contact, blue continuous line; (**b**) plastic penetration; (**c**) deformation of the sample; and (**d**) retraction of the AFM probe, red discontinuous line. Figure 5: Mechanical testing of the elastic-plastic region by AFM of the MPCM composed by PS:tetracosane (1:3) microcapsule at 23 \({}^{\circ}\)C: (**a**) no contact, continuous line; (**b**) plastic penetration; (**c**) deformation of the sample; and (**d**) retraction of the AFM probe, discontinuous line. Accordingly, for an encapsulation ratio of 1:3, PS has a better mechanical performance as a shell than PMMA, because the \(E\) value only decreases by 27% (as opposed to by 96% of PMMA) when increasing the temperature from 23 \({}^{\circ}\)C to 60 \({}^{\circ}\)C. However, no significant differences between using PS and PMMA shells were found in terms of the force needed to break the MPCMs with change in temperature from 23 \({}^{\circ}\)C to 60 \({}^{\circ}\)C (PS and PMMA displaying decrease of 60% and 64%, respectively). Beyond the previous study comparing MPCM with different shells and same core, the mechanical response of two samples based on the encapsulation ratio was also evaluated. In this case, given the superior performance of PS, two samples using polystyrene (PS) as a shell and tetracosane as the core PCM, with encapsulation mass ratios of 1:3 (results shown above) and 1:1 were compared mechanically. This was performed using the same methodology and equipment as described for the previous measurements. Histograms for the \(E\) results of PS and tetracosane with a mass ratio of 1:1 are shown in Figure 7. At 23 \({}^{\circ}\)C, a value of 0.9 GPa was obtained (Figure 7a), and at 60 \({}^{\circ}\)C this value decreased to 0.1 GPa (Figure 7b). A reduction in the \(E\) value by around 87% is achieved by increasing the temperature to 60 \({}^{\circ}\)C. Comparing this value reduction with the 1:3 MPCM encapsulation mass ratio, it can be seen that it is much better to use a ratio of 1:3, because the value only decreases by 27%. Figure 6: Mechanical testing of the elastic-plastic region by AFM of the MPCM composed by PS:tetracosane (1:3) microcapsule at 60 \({}^{\circ}\)C: (**a**) no contact, continuous line; (**b**) plastic penetration; (**c**) deformation of the sample; and (**d**) retraction of the AFM probe, discontinuous line. Figure 3.0 Results for PS and tetracosane for 1:1 encapsulation mass ratio: (**a**) 3D image tested; (**b**) [PERSON]’s modulus results at 23 \({}^{\circ}\)C; (**c**) [PERSON]’s modulus results at 60 \({}^{\circ}\)C.  
To sum up, Table 1 shows a summary of the results, where it is important to highlight that, for the comparison study between encapsulation ratio 1:3 and 1:1 in PS:tetracosane, the higher \(E\) value takes place in the 1:3 encapsulation mass ratio. Hence, in terms of mechanical properties, the best combination core/sell/encapsulation mass ratio is PS/tetracosane/1:3. Moreover, the thermal properties for the 1:3 ratio are also better, as the PCM content increases.