# Three-Dimensional-Printed Polymeric Cores for Methane Hydrate Enhanced Growth
## 3 Results
### Methane Hydrate Growth with 3D-Printed Cores  
The observed nucleation events and further methane hydrate growth parameters are summarized in Table 3 and Figures 4-9. It should be noted right away that a detailed study of nucleation was not carried out at this stage. Only the sites of the hydrate growth onset were identified in a few cases. In the presented photographs (Figures 4-9) and videos (see Supplementary; Videos S1-S9), the time is counted almost from when the hydrate crystallization center appears.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Sample** & **Porosity (\%)** & **Effective Porosity** & **Effective Porosity** & **Total Model** & **Equivalent Pore** \\  & & **(\%)** & **Volume (mm\({}^{3}\))** & **Volume (mm\({}^{3}\))** & **Diameter (mm)** \\ \hline Digital model & 19.6 & 19.6 & 556.1 & 2835.0 & 1.2 \(\pm\) 0.7 \\ PLA & 20.9 & 19.4 & 497.6 & 2569.7 & 1.0 \(\pm\) 0.6 \\ PLA\({}^{*}\) & 20.4 & 18.8 & 426.5 & 2262.1 & 2.0 \(\pm\) 1.2 \\ ABS & 20.4 & 18.4 & 500.2 & 2717.9 & 1.0 \(\pm\) 0.5 \\ PolyFlex & 16.3 & 7.0 & 167.0 & 2385.9 & 1.3 \(\pm\) 0.6 \\ UltraX & 20.4 & 17.1 & 429.9 & 2515.9 & 1.0 \(\pm\) 0.5 \\ ePC & 20.0 & 18.5 & 455.4 & 2464.5 & 1.4 \(\pm\) 0.8 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Characteristics of the printed samples.  
Figure 4: Methane hydrate formation from 3 mL of deionized water without insertion; blue arrow indicates the hydrate onset site.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multirow{2}{*}{\
\begin{tabular}{c} **Water** \\ **Volume** \\ **(mL)** \\ \end{tabular} } & \multirow{2}{*}{\(\mathbf{T}\) (\({}^{\circ}\)**C)**} & **Initial \(\mathbf{P}\)** & **Final \(\mathbf{P}\)** &
\begin{tabular}{c} **Water-to-** \\ **Hydrate** \\ **Conversion (\%)** \\ \end{tabular} & \multirow{2}{*}{\(\Delta\)S (\%)1  & \multirow{2}{*}{\(\Delta\)S (\%)1  } \\ \hline No & 3 & 1 & 9.20 & 9.14 & 4.1 & – \\ insertion & 5 & 1 & 9.02 & 8.89 & 4.9 & – \\  & 2 & 1 & 8.72 & 7.63 & 100.6 2 & – \\ PLA & 5 & 1 & 8.98 & 7.65 & 42.7 & 21 \\  & 3 & 1 & 9.25 & 9.16 & 5.6 & – \\ PLA* & 2 & 1 & 9.25 & 9.19 & 5.9 & – \\ ABS & 2 & 1 & 9.20 & 8.51 & 65.2 & – \\  & 2 (r1) 3  & 1 & 9.10 & 8.45 & 61.3 & – \\  & 5 & 1 & 8.99 & 8.04 & 30.7 & –56 \\  & 5 (r1) & 1 & 8.88 & 8.52 & 11.8 5 & \(-\)56 \\  & 5 (r2) 4  & 1 & 8.88 & 7.95 & 29.9 & –56 \\ PolyFlex & 2 & 1 & 9.25 & 9.17 & 7.2 & – \\ UltraX & 2 & 1 & 9.28 & 8.73 & 52.9 & –60 \\ ePC & 2 & 1 & 9.17 & 8.55 & 59.3 & – \\  & 5 & 1 & 9.18 & 8.31 & 28.8 & –59 \\ \hline \hline \end{tabular}
\end{table}
Table 3: List of experiment parameters.  
Figure 5: Methane hydrate formation from 3 mL of deionized water with PLA* after 12 h since hydrate onset (**a**) and 2 mL of deionized water with PLA (**b**) insertions; blue arrow indicates the hydrate onset site.  
Figure 6: Methane hydrate formation from 2 mL of deionized water with PolyFlex insertion; the blue arrow indicates the hydrate onset site; the lower right photo shows the system’s appearance after 12 h since the hydrate onset.  
Figure 8: Methane hydrate formation from 2 mL of deionized water with ePC insertion; the blue arrow indicates the hydrate onset site; the right photo shows the system’s appearance after 12 h since the hydrate onset.  
Figure 7: Methane hydrate formation from 2 mL of deionized water with UltraX insertion; the blue arrow indicates the hydrate onset site; the lower right photo shows the system’s appearance after 12 h since the hydrate onset.