## 2 Results and Discussion
### Antimicrobial Activity Analysis  
As shown in Figure 6a,b, the diameter of the inhibition zone increased as the amount of TTO increased. Furthermore, the anti-bacterial rate was proportional to the TTO amount. The inhibition zone of the TTO microspheres was smaller than that of TTO due to the fact that TTO microspheres generally serve as an inhibitor and have further been reported to slow down the release of terpineol (2016), 1,8-cineole, and other substances ([PERSON] et al., 2016). Although the inhibition zone of the TTO microspheres is small, the diameter does not differ to a significant extent. As shown in Figure 6c, the slope \(K\) of TTO was 7.3333, and the \(K\) of TTO microspheres was 6.3333. As the slope of the two was relatively close and the probability value \(P\) = 0.534 was higher than the critical statistical value (\(P\) = 0.05) by covariance analysis, with a low TTO amount, the anti-bacterial effect of the two was not significantly different. With a larger TTO amount, the TTO anti-bacterial effect improved. However, as shown in Figure 6b, the anti-bacterial effect of the TTO microspheres was still significant, even at low TTO amounts. In order to further study the sustained release properties of TTO and TTO microspheres, both materials were released at different time points as part of this anti-bacterial experiment. The corresponding results are shown in Figure 7a,b. After a release time of 36 h, the inhibition zone of TTO changed from about 30.2 mm to 15.9 mm. However, the inhibition zone of the TTO microspheres was only reduced from 28.4 mm to 23.8 mm. Figure 7(b\({}_{2}\)-b\({}_{4}\)) shows little change in the inhibition zone, indicating that the anti-bacterial effect of TTO microspheres was better than that of TTO. In order to further understand the relationship between the anti-bacterial rate and the release time, the corresponding fitting curve is shown in Figure 7c. The slope \(K\) of the TTO was \(-\)0.4167, while that of the TTO microspheres was \(-\)0.1574. This latter finding shows that the anti-bacterial effect of the TTO rapidly decreased upon increasing the release time. As the \(P\) = 0.034 was lower than the critical statistical value (\(P\) = 0.05), the anti-bacterial effect of the two was significantly different. Both intersect at 13 h, indicating that the anti-bacterial effects of the two materials are the same at this time. However, after 13 h, the anti-bacterial effect of the TTO microspheres was better than that of TTO. This finding demonstrated that TTO microspheres were able to continuously release TTO and continuously inhibit the growth of _E. coli._ \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Kinetic Model** & **Zero-Order** & **First-Order** & **Higuchi** & **Korsmeyer-Peppas** \\ \hline
**Sample** & & \(\mathbf{r^{2}}\) & & & \(\mathbf{n}\) \\ \hline m\({}_{\text{St}}\):m\({}_{\text{BMA}}\) = 2:8 & 0.7599 & 0.8863 & 0.9288 & 0.9733 & 0.3418 \\ m\({}_{\text{St}}\):m\({}_{\text{BMA}}\) = 4:6 & 0.7365 & 0.8963 & 0.9221 & 0.9759 & 0.4446 \\ m\({}_{\text{St}}\):m\({}_{\text{BMA}}\) = 6:4 & 0.7094 & 0.8487 & 0.9018 & 0.9718 & 0.4191 \\ m\({}_{\text{St}}\):m\({}_{\text{BMA}}\) = 8:2 & 0.8049 & 0.8687 & 0.9567 & 0.9937 & 0.3275 \\ m\({}_{\text{St}}\):m\({}_{\text{BMA}}\) = 10:0 & 0.8782 & 0.9383 & 0.9844 & 0.9886 & 0.4005 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Fitting results for release curves at various monomer ratios. Figure 6: _Cont._Figure 6: (a) Inhibition zones of TTO at various dosages 20 \(\mu\)L (**a1**), 30 \(\mu\)L (**a2**), 40 \(\mu\)L (**a3**), and 50 \(\mu\)L (**a4**) for 24 h; (b) inhibition zones of TTO microspheres at various dosages 20 \(\mu\)L (**b1**), 30 \(\mu\)L (**b2**), 40 \(\mu\)L (**b3**), and 50 \(\mu\)L (**b4**) for 24 h; and (c) anti-bacterial rate of TTO and TTO microspheres at various dosages.