Effect of take‐up speed on polyvinylidene fluoride hollow fiber membrane in a thermally induced phase separation process

Abstract

The porous polyvinylidene fluoride hollow fiber membranes were prepared via the thermally induced phase separation process using mixed diluent. The effects of take-up speed on the structure of membranes were investigated by scanning electron microscopy, differential scanning calorimetry, and wide-angle X-ray diffraction. The membrane properties were measured in terms of the pure water flux, porosity, and mechanical properties. The results showed that the cross-sectional structure of membrane had an obvious change and presented a uniform structure when TS increased to 72 m min À1 , whereas the membrane made from TS <41 m min À presented an interconnected aggregation structure. However, the change of surface structure of all membranes was hardly observed. In addition, the strength and elongation of breakage of membrane increased obviously with the increase of TS, whereas the pure water flux and porosity changed slightly.

Fabrication and characterization of hydroxylated and carboxylated multiwalled carbon nanotube/polyethersulfone (PES) nanocomposite hollow fiber membranes

“…In the current work we explore the fabrication and improved mechanical properties of extruded hollow fiber ultrafiltration membranes composed of PES-CNTs. Desalination 359 (2015) [123][124][125][126][127][128][129][130][131][132][133][134][135][136][137][138][139][140] In hollow fiber fabrication, commonly used polymers for ultrafiltration include polyethersulfone (PES) [9,[13][14][15][16], polyvinylidene fluoride (PVDF) [8,17], polyacrylonitrile (PAN) [18], and polysulfone (PS) [19][20][21]; solvents [5,22] include N-N-dimethylformamide (DMF) and 1-methyl-2-pyrrolidone (NMP); and the most common additives [5,14,[23][24][25] are polyvinylpyrrolidone (PVP), and polyethylenegylcol (PEG). The hollow fiber spinning process depends on several parameters, including air gap length [26,27], dope solution viscosity [28], dope extrusion rate [29][30][31], coagulation bath temperature and composition [15,32], take-up speed [33], and bore and outer fluid type [20].…”

Fabrication of a biconnected structure PVB porous heddle via thermally induced phase separation

“…Good connection of aggregations without obvious orientation leads to higher strength and elongation of breakage. 41 Therefore, increase of the take-up speed in the experimental range will be favorable to the enhancement of the strength.…”

Advances in water treatment by microfiltration, ultrafiltration, and nanofiltration

“…Commonly used polymeric membrane materials are cellulose acetate (Chou & Yang, 2005;Saljoughi, Amirilargani, & Mohammadi, 2010), polyvinylidene fluoride (PVDF) (Han, Xu, Yu, Wei, & Cao, 2010;Li, Liu, Xiao, Ma, & Zhao, 2012), polyacrylonitrile (PAN), polypropylene (PP), polyethersulfone (PES) (Chen, Li, Han, Xu, & Yu, 2010;Loh, Wang, Shi, & Fane, 2011;Xu, L€ u, Zhen, Ku, & Yi, 2008), and polysulfone (PS) (Ohya, Shiki, & Kawakami, 2009;Rugbani, 2009). A good polymer material should resist thermal and chemical attack and have good mechanical strength and the ability to form flat-sheet or hollow-fiber configurations easily.…”