Forward osmosis (FO) has attracted research attention as the energy-effective water separation process. For a FO process, it is important to prevent leakage of a solute of the DS. As a low-leakage solute, a branched thermo-responsive oligomer, pentaerythritol-oligo(ethylene oxide)_m-b-(butylene oxide)_n oligomers (PEBs), had been reported. In this study, the relationship between the chemical structure and the permeability of the PEBs through a FO membrane had been investigated in detail. For the detailed investigation, the mole fraction of each component having different absolute molecular weights in the PEBs was determined by the MALDI/TOF-MS, then the permeabilities of the components through the FO membrane were independently quantified. As the result, for the PEBs with low absolute molecular weight, the permeability of the PEBs was strongly affected by the molecular weight of the PEBs. On the other hand, for the PEBs with high absolute molecular weight, it was confirmed that the permeability of the PEBs was affected by the hydrophobicity of the PEBs. Conclusively, it was indicated that not only the molecular weight but also the affinity between the PEBs and the FO membrane is important for the reverse solute flux.

正向渗透（FO）作为一种节能的水分离过程引起了研究的关注。对于 FO 过程，重要的是防止 DS 的溶质泄漏。作为一种低泄漏溶质，一种支链热响应低聚物，季戊四醇-低聚（环氧乙烷）_m - b -（环氧丁烷）_n低聚物（PEBs），已被报道。在本研究中，详细研究了 PEB 通过 FO 膜的化学结构和渗透性之间的关系。为了详细研究，PEB 中具有不同绝对分子量的每种组分的摩尔分数通过 MALDI/TOF-MS 测定，然后独立量化组分通过 FO 膜的渗透率。结果，对于具有低绝对分子量的PEBs，PEBs的渗透性受PEBs分子量的强烈影响。另一方面，对于高绝对分子量的PEBs，证实了PEBs的渗透性受PEBs疏水性的影响。最终，