Fabrication and characterization of corrugated microfiltration membranes


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Kimya Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: YİĞİT GENÇAL

Danışman: PINAR ZEYNEP ÇULFAZ EMECEN

Özet:

In this study, the effect of corrugations on the membrane fouling performances of polyethersulfone (PES) membranes was investigated. Membranes were prepared by non-solvent induced phase inversion method and they were characterized by scanning electron microscopy (SEM), pure water permeance (PWP) and fouling during Baker’s yeast (saccharomyces cerevisiae) filtration. Since, it is nearly impossible to create the skin-layer on the mold side of the membrane a symmetric morphology was sought. In order to achieve this, firstly, modifications were done on the phase separation conditions and casting solution recipe to get symmetric membrane morphology on flat membranes which were easier to fabricate. When 10 wt% PES, 60 wt% PEG 400, 5 wt% H2O and 25 wt% NMP solution was pre-coagulated in humid air for 10 minutes and fully coagulated in water, a symmetric morphology with connected pores of the average size 1.3 μm and no observable skin layer was obtained. 2 The chosen recipe was applied on corrugated mold with 50μm corrugation depth and width successfully. Moreover, in addition to 10 minutes humid air exposure, 5 minutes humid air also gave usable membranes with smaller pores (nearly 1μm) on the mold side and larger ones on the solution, non-solvent interface (nearly 1.8μm). The membranes with 15 minutes humid air exposure and same concentration also gave symmetric morphologies with 1.2μm average pore size. However, increase in humid air exposure increased shrinkage for the membranes. Even if the area enhancement was eliminated there has still been a nearly twofold increase in pure water permeabilities of corrugated membranes compared to flat ones. The difference between fouling performances of corrugated and flat membranes was negligibly small.