Enhancing hydrophobicity through polydimethylsiloxane-blended poly(vinylidene fluoride-co-hexafluoropropylene) electrospun membranes: A well-designed approach

With the growing environmental concerns over the use of chemicals and nanomaterials to achieve membrane hydrophobicity, polydimethylsiloxane (PDMS) has emerged as a sustainable and eco-conscious alternative. Introducing PDMS into the doping solution to be used for electrospinning is a simple yet highly efficient means of augmenting the hydrophobicity of the electrospun membrane. Nevertheless, to achieve stable nanofibers and an appropriate structure as a membrane when using PDMS introduction, it is imperative to regulate the polymer concentration. In the present investigation, we explored modifications in the physicochemical characteristics of the membrane, specifically changes in hydrophobicity, upon the addition of PDMS to a 15 % poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) solution. Increasing the amount of PDMS was found to introduce more CH₃ groups to the membrane's surface, but it also had the side effect of enlarging the fiber diameter. Thus, the maximum contact angle improved to 148° with the addition of 10 % PDMS. However, the membrane distillation system using the membrane that included 5 % PDMS exhibited the most stable performance, as it sustained continuous operation for more than 170 h and effectively prevented membrane wetting.