## 4 Conclusions  
A hydrophobic alumina hollow fiber with high performance in VMD is successfully prepared. The alumina hollow fiber membrane is fabricated using a method that combines phase-inversion and sintering. The as-sintered hollow fiber is hydrophobilized using fluoroalkylsiances, to obtain a hydrophobic hollow fiber. The hydrophobic hollow fiber prepared at 1400 \({}^{\circ}\)C has a thickness of 230 \(\upmu\)m, an average pore size of 220 nm, porosity of 55%, a contact angle of 137\({}^{\circ}\) and an LEP\({}_{\mathrm{w}}\) value of 2.5 bar. It exhibits a high permeate flux value of 60 Lm\({}^{-2}\)h\({}^{-1}\) which is twice as high compared to that prepared at 1500 \({}^{\circ}\)C, and a salt rejection of greater than 99.9% in VMD that uses 3.5 wt% NaCl aqueous solution at 70 \({}^{\circ}\)C at 0.03 bar. The permeate flux value of 60 Lm\({}^{-2}\)h\({}^{-1}\) is much greater than previously reported values using ceramic membranes. This hydrophobic alumina hollow fiber is suitable for use in seawater desalination. Checking the durability of the as-prepared hollow fiber over a longer duration will be the subject of future work.  
The authors would like to thank the Ministry of Science and Technology (MOST), Taiwan, for its financial support (Project numbers 104-2221-E-002-176-MY3, 105-2622-E-002-010-CC1 and 105-2923-E-002 -011-MY2) and acknowledge their gratitude for the collaboration project funding from the Industrial Technology Research Institute, Taiwan.  
[PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] conceived and designed the experiments; [PERSON] performed the experiments; [PERSON] and [PERSON] analyzed the data; [PERSON], [PERSON] and [PERSON] contributed reagents/materials/analysis tools; [PERSON] wrote the paper.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Configuration** & **Membrane** & **Membrane** & **NaCl Feed** & **Hot Side Temp (\({}^{\circ}\)C)** & **MD Permeate** & **Ref.** \\  & **Material** & **Morphology** & **Solution** & & **Flux (Lm\({}^{-2}\)h\({}^{-1}\))** & **Ref.** \\ \hline VMD & Si\({}_{3}\)N\({}_{4}\) & Hollow fiber & 4.0 wt\% & 60 \({}^{\circ}\)C (70 \({}^{\circ}\)C) [80 \({}^{\circ}\)C] & 14.6 (22.9) [27.5] & [30] \\ DCMD & Si\({}_{3}\)N\({}_{4}\) & Hollow fiber & 4.0 wt\% & 60 \({}^{\circ}\)C (70 \({}^{\circ}\)C) [80 \({}^{\circ}\)C] & 5.4 (75) [10.4] & [30] \\ VMD & Al\({}_{2}\)O\({}_{3}\) & Planar & 4.0 wt\% & 60 \({}^{\circ}\)C (70 \({}^{\circ}\)C) [80 \({}^{\circ}\)C] & 5.8 (7.9) [10.44] & [31] \\ DCMD & g-Salion & Hollow fiber & 4.0 wt\% & 60 \({}^{\circ}\)C (70 \({}^{\circ}\)C) [80 \({}^{\circ}\)C] & 3.8 (5.4) [6.7] & [31] \\ VMD & Al\({}_{2}\)O\({}_{3}\) & Hollow fiber & 4.0 wt\% & 60 \({}^{\circ}\)C (70 \({}^{\circ}\)C) [80 \({}^{\circ}\)C] & 19.0 (32.0) [42.9] & [32] \\ VMD & Zeolite/Al\({}_{2}\)O\({}_{3}\) & Tubular & 3.5 wt\% & 60 \({}^{\circ}\)C & 12.0 & [33] \\ DCMD & ZrO\({}_{2}\)/Ti & Tubular & 0.5 [M] & 75 \({}^{\circ}\)C (85 \({}^{\circ}\)C) [95 \({}^{\circ}\)C] & 1.7 (2.5) [3.8] & [34] \\ VMD & Si\({}_{3}\)N\({}_{4}\) & Hollow fiber & 4.0 wt\% & 50 \({}^{\circ}\)C (60 \({}^{\circ}\)C) [70 \({}^{\circ}\)C] & 9.6 (14.6) [22.2] & [35] \\ SGMD & Si\({}_{3}\)N\({}_{4}\) & Planar & 4.0 wt\% & 75 \({}^{\circ}\)C & 6.7 & [36] \\ VMD & Al\({}_{2}\)O\({}_{3}\) & Disk & 3.5 wt\% & 70 \({}^{\circ}\)C & 37.1 & [37] \\ DCMD & TiO\({}_{2}\) & Nanofiber & 3.5 wt\% & 60 \({}^{\circ}\)C (70 \({}^{\circ}\)C) [80 \({}^{\circ}\)C] & 7.1 (9.2) [11.9] & [38] \\ VMD & Al\({}_{2}\)O\({}_{3}\) & Hollow fiber & 3.5 wt\% & 50 \({}^{\circ}\)C (60 \({}^{\circ}\)C) [70 \({}^{\circ}\)C] & 35.0 (47.0) [60.0] & This work \\ \hline \hline \end{tabular}
\end{table}
Table 2: _Cont._  
Figure 7: A comparison between the MD permeate flux value obtained from this work and historical data, as a function of feed solution temperature.