| Hollow fiber membrane is widely used in the field of membrane separation and wastewater treatment because of its unique hollow structure and self-support.The filling density and arrangement of hollow fiber membrane have a significant impact on the application of the membrane.The wound or woven hollow fiber membrane module can make the fluid flow on the membrane surface unstable,to reduce the membrane pollution.For woven hollow fiber membrane,membrane materials are usually required to have good flexibility and strength.Ultra high molecular weight polyethylene（UHMWPE）is an engineering material with high strength and high modulus.It is the preferred material for obtaining weavability hollow fiber membrane.In this study,using mineral oil as diluent,UHMWPE hollow fiber membrane and UHMWPE hybrid hollow fiber membrane with Si O2 were prepared by thermally induced phase separation（TIPS）and stretching method.Firstly,the effects of spinning winding speed and Si O2 content on the structure and properties of UHMWPE membranes were studied.The membranes were characterized by scanning electron microscopy（SEM）,X-ray diffraction（XRD）,infrared spectroscopy（FTTR）,porosity,flux,and contact angle.The results showed that the inner part of the membrane was loose and uniform network structure,and the surface was dense.With the increase of winding speed,the internal structure of the membrane became closer.The porosity and the dimensional stability increased.The gas flux first increased and then decreased.With the increase of Si O2 content,the crystallinity,the internal network structure,and the hydrophobicity of hybrid membrane increased.The membrane flux increased.Then,the weavability of UHMWPE hollow fiber membrane was studied.The effects of different spinning winding speed,Si O2 content and different materials on the weavability of the membrane were discussed by strength and flexibility tests.The results showed that the UHMWPE membrane had good strength,elongation at break and flexibility.Although the spinning winding speed and hybrid ratio affected the properties of the membrane,the UHMWPE membrane still had good strength,elongation at break and flexibility.Compared with other polytetrafluoroethylene,polyvinylidene fluoride,polyethersulfone and polyvinyl chloride hollow fiber membranes,the UHMWPE membrane had obvious advantages in weavability.Finally,the influence of knitting on UHMWPE hollow fiber membrane was explored through the tests of membrane mechanical properties,contact angle and flux.The results showed that the gas flux decreased with the increase of weaving length.Knitting might compress the membrane pore structure and destroy the microporous structure,but weaving would not damage the overall membrane structure.Knitting had no significant effect on the mechanical properties and contact angle of the membrane.Compared with water flux before knitting,the water flux after knitting of knitting slice were decreased.The knitting slice itself had a certain coarse filtration effect,and the hollow fiber membrane also had the separation function.It could realize multistage filtration in the process of sewage treatment.The coarse filtration of knitting slice could effectively separate large particle suspended solids from sewage by using by the gap of purl knitting structure.At the same time,the hollow fiber membrane had the function of microfiltration,which could effectively separate micro-particle,and was expected to realize the multistage filtration of hollow fiber membrane knitting slice. |
PDF Full Text Request