Membrane fouling is an inevitable process but could be mitigated by understanding its fouling mechanism. In this work, organic fouling phenomena of direct contact membrane distillation (DCMD) on membrane with different surface properties were examined under high salinity and elevated temperature conditions. Membranes with different surface energies and pore structures showed different fouling phenomenon by the hydrophilic/amphiphilic polymer. Surface energy studies showed that molecular interaction between the organic solutes and Polytetrafluoroethylene (PTFE) membrane were strong enough to form the segregated or films like structure on the membrane. On the other hand, the weaker interactions between the Polyvinylidene fluoride (PVDF) membrane induced aggregated/precipitated form of foulants. The flux declination trend is very much depending on the characteristic of the foulants. The aggregated foulants could easily precipitate on the membrane surface to produce loose fouling layer that reduced the flux. However, the smaller precipitate could block the pores and gave significant flux declination. The effort to make the surface become more hydrophilic could reduce the fouling propensity of bovine serum albumin, however the hydrophilic PVDF layer was susceptible to higher wetting potential at elevated temperature. Increasing the surface hydrophobicity could alleviate the molecular interactions but its potential to interact via hydrophobic interactions could be an unwanted phenomenon. Therefore, studying the surface energy as well as pore structure of membrane is crucial to understand the organic fouling behaviour of DCMD at elevated temperature.

膜结垢是不可避免的过程，但可以通过了解其结垢机理来减轻。在这项工作中，在高盐度和高温条件下，研究了具有不同表面性质的膜上直接接触膜蒸馏（DCMD）的有机结垢现象。具有不同表面能和孔结构的膜被亲水/两亲聚合物显示出不同的结垢现象。表面能研究表明，有机溶质与聚四氟乙烯（PTFE）膜之间的分子相互作用足够强，可以在膜上形成偏析或膜状结构。另一方面，聚偏二氟乙烯（PVDF）膜之间的相互作用较弱，导致聚集/沉淀形式的污垢。磁通量的下降趋势在很大程度上取决于污垢物的特性。聚集的污垢很容易沉淀在膜表面上，从而形成疏松的污垢层，从而降低了通量。但是，较小的沉淀物可能会阻塞孔并导致明显的磁通偏斜。使表面变得更亲水的努力可以降低牛血清白蛋白的结垢倾向，但是亲水的PVDF层在升高的温度下易于具有较高的润湿潜能。增加表面疏水性可以减轻分子相互作用，但是其通过疏水性相互作用的潜力可能是不希望的现象。因此，