## 3 Results and Discussion
### Activation Energies of Diffusion
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Substance**} & **Molecular** & **Molecular** & **Temperature** & **Activation** & **Pre-Exponential** & \multirow{2}{*}{**Method**} \\  & **Volume** & **Weight** & **Range** & **Energy** & **Factor D\({}_{0}\)** & \\ \hline  & **(Å3)** & **(g/mol)** & (\({}^{\circ}\)C)** & **(kJ/mol)** & **(cm2/s)** & \\ \hline Ethyl acetate & 90.6 & \(88.1\) & 75–100 & 111.4 & \(2.4\times 10^{7}\) & Desorption, below Tg \\ Ethyl acetate & 90.6 & \(88.1\) & 100–115 & 169.3 & \(3.1\times 10^{15}\) & Desorption, above Tg \\ Chlorobenzene & 97.6 & 112.6 & 75–100 & 152.2 & \(2.6\times 10^{12}\) & Desorption, below Tg \\ Chlorobenzene & 97.6 & 112.6 & 100–115 & 218.1 & \(5.1\times 10^{21}\) & Desorption, above Tg \\ Toluene & 100.6 & 92.1 & 75–100 & 162.8 & \(6.7\times 10^{13}\) & Desorption, below Tg \\ Toluene & 100.6 & 92.1 & 100–115 & 224.4 & \(3.2\times 10^{22}\) & Desorption, above Tg \\ Styrene & 111.8 & 104.2 & 75–100 & 169.2 & \(3.7\times 10^{14}\) & Desorption, below Tg \\ Styrene & 111.8 & 104.2 & 100–115 & 239.3 & \(6.9\times 10^{23}\) & Desorption, above Tg \\ \(n\)-Octane & 146.6 & 114.2 & 80–100 & 288.5 & \(1.0\times 10^{31}\) & Desorption, below Tg \\ \(n\)-Octane & 146.6 & 114.2 & 100–110 & 236.8 & \(6.7\times 10^{23}\) & Desorption, above Tg \\ Phenyl cyclohexane & 174.0 & 160.3 & 80–100 & 367.4 & \(1.2\times 10^{10}\) & Desorption, below Tg \\ Phenyl cyclohexane & 174.0 & 160.3 & 100–115 & 367.7 & \(1.8\times 10^{40}\) & Desorption, above Tg \\ Benzophenone & 174.4 & 182.2 & 80–100 & 297.0 & \(3.4\times 10^{30}\) & Desorption, below Tg \\ Benzophenone & 174.4 & 182.2 & 100–115 & 246.3 & \(3.9\times 10^{23}\) & Desorption, above Tg \\ \(n\)-Dodecane & 213.8 & 170.3 & 80–100 & 318.7 & \(1.4\times 10^{34}\) & Desorption, below Tg \\ \(n\)-Dodecane & 213.8 & 170.3 & 100–115 & 233.0 & \(1.4\times 10^{36}\) & Desorption, above Tg \\ \(n\)-Tetradecane & 247.3 & 198.4 & 80–100 & 538.4 & \(2.1\times 10^{64}\) & Desorption, below Tg \\ \(n\)-Tetradecane & 247.3 & 198.4 & 100–110 & 376.1 & \(5.1\times 10^{41}\) & Desorption, above Tg \\ \(n\)-Hexadecane & 281.0 & 226.5 & 80–100 & 567.2 & \(9.3\times 10^{67}\) & Desorption, below Tg \\ \(n\)-Hexadecane & 281.0 & 226.5 & 100–110 & 407.6 & \(6.3\times 10^{45}\) & Desorption, above Tg \\ \(n\)-Octadecane & 314.6 & 254.5 & 100–110 & 472.8 & \(3.7\times 10^{54}\) & Desorption, above Tg \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Activation energies of diffusion \(\mathrm{E_{A}}\) and pre-exponential factors \(\mathrm{D_{0}}\) for HIPS. For \(n\)-alkanes and styrene diffusion, coefficients are available below and above the glass transition temperature T\({}_{\rm g}\) of 100 \({}^{\circ}\)C (Figure 3a). The results show that the diffusion behavior of GPPS and HIPS changes slightly at the glass transition temperature T\({}_{\rm g}\) (Figure 3a,b). The activation energies of diffusion E\({}_{\rm A}\) are lower above T\({}_{\rm g}\) compared to the values below T\({}_{\rm g}\), which results in a lower slope of the Arrhenius plot above T\({}_{\rm g}\). The change in the diffusion behavior is more significant for larger molecules compared to smaller molecules. Relatively small sized molecules like styrene and \(n\)-octane show only a slight change in the diffusion behavior whereas \(n\)-octadecane shows a significant change of the diffusion behavior at the glass transition temperature. In the case of GPPS sheet 2, only one temperature was determined above T\({}_{\rm g}\) (Figure 3c). The results indicate that that for larger molecules like phenyl cyclohexane and benzophenone, the activation energy of diffusion E\({}_{\rm A}\) is also lower above T\({}_{\rm g}\) compared to the slopes below T\({}_{\rm g}\), which is in agreement with the results of the \(n\)-alkane spiked sheet. However, due to the fact that only one temperature is available, these findings are on a weak basis.