Tianjin Polytechnic University

Chun Wang

Changfa Xiao

Mingxing Chen

Shulin An

Qinglin Huang

Hailiang Liu

Jingjing Yan

Xiaoyu Hu

A homogeneous fiber reinforced PVDF hollow fiber membrane and a preparation method thereof are provided. The membrane includes a hollow tubular reinforcement made of PVDF fibers and a polymer separation layer made of PVDF casting solution; wherein the polymer separation layer casting solution comprises 4-25% PVDF resin, 5-20% pore-forming agent, 0-3% inorganic particles and 52-91% solvent according to mass fraction. The preparation method includes steps of: (1) preparing a hollow tubular reinforcement made of PVDF fibers; (2) preparing a PVDF polymer separation layer casting solution; and (3) obtaining the homogeneous fiber reinforced PVDF hollow fiber membrane.

Homogeneous fiber reinforced PVDF hollow fiber membrane and preparation method thereof

A method for preparing a homogeneous braid-reinforced (HMR) PPTA hollow fiber membrane combines PPTA hollow tubular braids with PPTA surface separation layer. The method includes following steps of: (1) preparing the PPTA hollow tubular braids, wherein the PPTA hollow tubular braids which are made from PPTA filament yarns are woven by a two-dimensional braided method, the outer diameter of the PPTA tubular braids is 1-2 mm; (2) preparing the PPTA casting solution as the surface separation layer, wherein the 1-3 wt % PPTA resin, 0-2 wt % inorganic particles and 10-20 wt % pore-forming agents are mixed into 75-89% inorganic acid solvent, stirred for 1-3 hours at 70&#xb0; C.-90&#xb0; C. to form homogeneous and transparent casting solution; and (3) preparing reinforced PPTA hollow fiber membrane, wherein the casting solution as the surface separation layer is evenly coated on the surfaces of the PPTA hollow tubular braids through spinneret, and they are immersed in a coagulation bath for solidified formation.

Method for preparing homogeneous braid-reinforced PPTA hollow fiber membrane

A method for preparing an aromatic polyamide porous hollow fiber membrane firstly premixes PPTA resin, solvent, composite pore-forming agents and inorganic particles in a stirring vessel to form casting solution, secondly injects the casting solution into a double-screw extruder to be fully dissolved under the effect of shear force and enters a spinneret via a metering pump. The PPTA hollow fiber membranes are prepared by the dry-wet spinning method, which solves the problems that hard pore-forming and low porosity in the preparation process of PPTA porous membrane. Utilization of the double-screw extruder is capable of greatly shortening the dissolved time and the deaeration time. Meanwhile the increase of PPTA in casting solution also improves mechanical properties of the PPTA membrane. The addition of the inorganic particles improves mechanical toughness and enhance pure water flux, hydrophilia and rejection rate.

Method for preparing aromatic polyamide porous hollow fiber membrane

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Tianjin, China

Chun Wang