Tianjin Polytechnic University

Qinglin Huang

Changfa Xiao

Jian Zhao

Shulin An

Hailiang Liu

Chun Wang

Mingxing Chen

Junqiang Hao

Zitao Wang

Xiao Hu

Zhongqing Miao

The present invention discloses a hydrophobic-oleophilic and hollow fiber composite membrane and preparing method thereof. A preparing method includes preparing hollow tubular braids by two-dimensional braided technique using polyester filaments, wherein the hollow tubular braids are used as the reinforcements. The method further includes mixing polyvinylidene fluoride, hydrophobic pore-forming agent, and the rest of solvent to prepare a casting solution of surface separation layer. The method further includes pre-treatment processing of the reinforcements; and coating the casting solution of surface separation layer on the outer surface of the processed reinforcements through a spinning spinneret to form a primary membrane. The reinforcements are replaced by the primary after post-processing, and repeating the coating process.

Hydrophobic-oleophilic hollow fiber composite membrane and preparing method thereof

A hollow tubular oil absorbing material includes: a core formed by a spring, and an outer shell formed by a flat sponge wrapped at the spring; wherein the flat sponge is fixed at both ends of the spring; the flat sponge fully covers all the spring or is sealed at a first end; a connecting tube is connected at a second end of the spring for communicating with a vacuum pump; a graphene oxide layer is coated at the outer sponge. The graphene oxide layer on the flat sponge of hollow tubular oil absorbing material is formed by immersion and coating under negative pressure. Further the reduction of graphene oxide is performed with hydrazine hydrate steam and followed by washing and drying. Finally, a hollow tubular oil absorbing material with a spring core and an outer grapheme-coated sponge structure is obtained, which can be applied to continuous oil-water separation.

Hollow tubular oil absorbing material and preparing 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

A preparation method of a perfluorinated polymer hollow fiber membrane comprises: evenly mixing a first mixture that is mixed by a perfluorinated polymer, PS, a polymer additive, and a composite pore-forming agent; evenly mixing a second mixture that is mixed by the first mixture and an organic liquid; under 300&#xb0; C.-350&#xb0; C., processing the second mixture with a melt to spin by a twin-screw extruder; extruding a hollow fiber by a hollow fiber spinneret; dipping the hollow fiber membrane into deionized water for 48 hours; putting the hollow fiber membrane aired into a concentrated sulfuric acid to process with a sulfonation; washing the hollow fiber membrane by deionized water; and drying the hollow fiber membrane; in such a manner that the hydrophilic perfluorinated polymer hollow fiber membrane is obtained.

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Tianjin, China

Qinglin Huang