Polisülfon Membranlarının Mikroyapı ve Performansı Üzerine Bir Gözenek Oluşturucu Olarak Polivinilpirolidonun Rolü

Abstract

Bu çalışmada, gözenek oluşturucu olarak polivinilpirrolidonun (PVP), polisülfon (PSF) membran performansı üzerindeki etkisi incelenmiştir. XRD spektrumları, artan PVP miktarı ile kristalin fazdan amorf faza geçişinin gerçekleştiğini ortaya koydu. SEM sonuçları, membranlardaki makro boşlukların şekli ve boyutunun, polimer çözeltisindeki artan PVP miktarı ile değiştiğini gösterdi. Saf PSF ve ağırlıkça % 5 PVP ilave edilmiş PSF membranı için Tg değerleri sırasıyla 189 °C ve 182 °C olarak ölçülmüştür. Membranların performansı, Saf Su Akışı (SSA) ölçümleri kullanılarak belirlendi. Membranların SSA'sı PSF polimer çözeltisinde PVP miktarının (ağırlıkça %0'dan %10'a) artmasıyla 36.76 L m -2 s -1 'dan 86.80 L m -2 s -1 'e yükselmiştir. SSA ve PVP içeriği arasındaki ilişki artan termodinamik kararsızlık ve kinetik engel ile açıklanmıştır.

Tailoring of Narrow Pores, Pore Size Distribution and Structural Details in Asymmetric Nanofiltration Membranes via Polyvinyl-pyrrolidone Additive

“…This is due to the dope's thermodynamic instability in reaction with the non-solvent (water) that will increase due to the inclusion of PVP. Additionally, as the number of additives increases, the dope solution will be more resistant to deform, obstructing component dispersion during the membrane making process [12]. During the process, the polyvinyl-pyrrolidone is considered to be dissolved in coagulation media.…”

“…The inclusion of polyvinyl-pyrrolidone into dope solution can accelerate the generation of macro-voids in membranes, leading to a higher pure water flux [12,14]. Low molecular weight (M w ) polyvinyl-pyrrolidone generates tiny pores and is simply leached from membranes.…”

Assessment on Performance-properties of Asymmetric Nanofiltration Membranes from Polyethersulfone/n-Methyl-2-pyrrolidone/water Blends with Poly(vinyl pyrrolidone) as Additive

“…The occurrence of macrovoids was associated with the instantaneous demixing mechanism as PVP addition increased the dope's thermodynamic instability in reaction with the non-solvent water. Moreover, the viscosity of the dope solution increased with the amount of the additives, which hindered the diffusions among the components in the phase inversion process (kinetic effect) [27].…”

“…Besides the formation of micropores, it has been generally accepted that the porosity increased and the macrovoids formation disappeared as PVP was added to casting solution [28]. The addition of PVP additives into dope solution can promote the formation of macrovoids in the membranes and pure water flux was thus increased [27,29].…”

Carbon nanotubes and silver nanoparticles modification of PVDF membranes for improved seawater desalination in direct contact membrane distillation

“…As per ternary diagrams, reduced affinity of polymer to the solvent increases demixing rate (Alibakhshi et al, 2019). The decrease in LEP and contact angle from M1 to M2 was attributed to the addition of PVP, largely due to its high polarity and water solubility (Rawat et al, 2014), causing a rise in the thermodynamic instability of the polymer solution during casting (Eren and Güney, 2019). Consequently, an instantaneous demixing of the solvent and non-solvent occurred, leading to the formation of large macropores (Figure 3).…”