Preparation And Application Of Monolithic Electrospun Nanofibrous Membrane

Electrospinning technology makes use of high voltage to stretch macromolecular jet and process it into nanofibers, which is a simply technique that provides a direct approach to continuous 1 dimension nanofibers with controllable diameter and morphology. And electrospun nanofibers of polymer with high surface area, remarkable porosity and good mechanical strength are widely used in biomedicine, energy, environment, etc. This paper, based on electrospinning technology, reported that we successfully fabricated the ZIF-8/PAN hybrid nanofibrous membrane which was applied in heavy metal treatment and solved the problem of low capacity of heavy metal removal with electrospun nanofibrous membrane. At the same time, it's reported that a high tempreture-resistant nanofibrous membrane with a novel electrospinning precursor poly (phthalazione ether nitrile ketone) (PPENK) was found in this paper. The detailed contents are presented as follow:The ZIF-8/PAN hybrid nanofibrous membrane was fabricated by modification of proous electrospun PAN with alkali solution and then in situ loading some ZIF-8 nanoparticles on PAN nanofibers. The hybrid membrane was uesd in heavy metal treatment and performed a good removal capacity. It was found that two-layer membrane with one-hour hydrolysis time and 0.3 wt.% Poly(sodium 4-styrenesulfonate) was optimum hybrid membrane for heavy metal removal by changing the conditions of membrane-making. The optimum hybrid membrane showed a high removal efficiency of 99.5% and a huge permeation flux of 2.61 x 104 Lm-2 h-1 MPa-1. Besides, the capacity of heavy metal removal improves distinctly about 3 times while comparing the membrane before with after loading ZIF-8 nanoparticles. That is, it is an effective way to solve the problem of low capacity of heavy metal removal with electrospun membrane.Electrospun nanofibrous membrane with the advantages of high surface area and porosity was widely used in many fields. However, it's seldom to find the report about high temperature-resistant electrospun membrane for the absence of precursor with spinnability and superior thermal stability simultaneously. This work studied the spinnability of a novel thermostable resin PPENK through changing concentrations of PPENK solution, and successfully prepared some electrospun PPENK nanofibrous membrane. The morphology and structure of electrospun PPENK nanofibers were characterized by scanning electron microscope (SEM) and fourier transform infrared spectrophotometer (FTIR). Then differential scanning calorimetry(DSC), thermogravimetric analyzer (TG) were applied to detect electrospun PPENK membrane. The results indicated that electrospun PPENK membrane possess high glass transition temperature (285?) and thermal decomposition temperature (500?). The electrospun PPENK nanofibrous can form a mesh-structure after cross-link reaction by curing at high temperature of 290?. And the mechanical strength of electrospun PPENK membrane after curing is 6 times larger than before. With high thermal stability and superior mechanical strength, electrospun PPENK nanofibrous membrane can be a promising candidate in membrane applications specially asking for high temperature and pressure environment.