Khaleel Samraa R, Ibrahim Salah S, Criscuoli Alessandra, Figoli Alberto, Lawal Dahiru U, Alsalhy Qusay F
Membrane Technology Research Unit, Chemical Engineering Department, University of Technology-Iraq, Alsinaa Street 52, Baghdad 10066, Iraq.
Institute on Membrane Technology (CNR-ITM), Via P. Bucci 17/C, 87036 Rende, CS, Italy.
Membranes (Basel). 2025 Apr 1;15(4):104. doi: 10.3390/membranes15040104.
Vacuum membrane distillation (VMD) is a promising process for water desalination. However, it suffers some obstacles, such as fouling and wetting, due to the inadequate hydrophobicity of the membrane and high vacuum pressure on the permeate side. Therefore, improving surface hydrophobicity and roughness is important. In this study, the effect of 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (PFTES) on the morphology and performance of CNM/PAC/PVDF membranes at various concentrations was investigated for the first time. Membrane characteristics such as FTIR, XRD, FE-SEM, EDX, contact angle, and hydrophobicity before and after modification were analyzed and tested using VMD for water desalination. The results showed that the membrane coated with 1 wt.% PFTES had a higher permeate flux and lower rejection than the membranes coated with the 2 wt.% PFTES. The 2 wt.% PFTES enhanced the contact angle to 117° and increased the salt rejection above 99.9%, with the permeate flux set to 23.2 L/m·h and at a 35 g/L NaCl feed solution, 65 °C feed temperature, a 0.6 L/min feed flow rate, and 21 kPa (abs) vacuum pressure. This means that 2 wt.% PFTES-coated PVDF membranes exhibited slightly lower permeate flux with higher hydrophobicity, salt rejection, and stability over long-term operation. These outstanding results indicate the potential of the novel CNM/PAC/PVDF/PFTES membranes for saline water desalination. Moreover, this study presents useful guidance for the enhancement of membrane structures and physical properties in the field of saline water desalination using porous CNM/PAC/PVDF/PFTES membranes.
真空膜蒸馏（VMD）是一种很有前景的海水淡化工艺。然而，由于膜的疏水性不足以及渗透侧的高真空压力，它存在一些障碍，如污垢和润湿问题。因此，提高表面疏水性和粗糙度很重要。在本研究中，首次研究了不同浓度的1H,1H,2H,2H-全氟癸基三乙氧基硅烷（PFTES）对CNM/PAC/PVDF膜形态和性能的影响。使用VMD进行海水淡化分析和测试了改性前后膜的FTIR、XRD、FE-SEM、EDX、接触角和疏水性等特性。结果表明，涂覆1 wt.% PFTES的膜比涂覆2 wt.% PFTES的膜具有更高的渗透通量和更低的截留率。在35 g/L NaCl进料溶液、65 °C进料温度、0.6 L/min进料流速和21 kPa（绝对）真空压力下，2 wt.% PFTES使接触角增大到117°，并使脱盐率提高到99.9%以上，渗透通量设定为23.2 L/m·h。这意味着涂覆2 wt.% PFTES的PVDF膜在长期运行中表现出略低的渗透通量，但具有更高的疏水性、脱盐率和稳定性。这些出色的结果表明新型CNM/PAC/PVDF/PFTES膜在海水淡化方面的潜力。此外，本研究为使用多孔CNM/PAC/PVDF/PFTES膜进行海水淡化领域中膜结构和物理性能的增强提供了有用的指导。
