Nano-nets Membranes Fabrication And Filtration Properties With Double Syringe Needles Electrospinning

In this dissertation, the electro-spinning process of PA6/66 with nano-spider web fiber membrane(NSFM) by a double-needle electrospinning were discussed. Composite membrane was made by the NSFM and conductive fabric,the influence of the coverage rate of the nano-nets of the NSFM on the air permeability and air filtering effect was studied.Then, the effect of the pore size distribution and water filtration properties of the NSFM with different coverage rate of the nano-nets was analyzed.The main conclusions of this study were as follows:Investigation on the technique of the electrospinning process with NSFM: The effects of the mass fraction of Ca Cl2, voltage, humidity and other parameters for coverage of nano-nets and fiber morphology were studied. The results showed that when the mass fraction of the Ca Cl2 powder in the electrospinning solution was 2%, the spinning voltage was 20 k V, and the ambient humidity was 40%, the coverage rate of the nano-nets in the NSFM was the highest and the form was best.Air filtering properties for NSFM/conductive fabric composite membranes: The influence of areal density and the coverage rate of the nano-nets on the composite membrane on air permeability and air filtering effect was studied. The results showed that:With the increase of the coverage rate of the nano-nets and the areal density,the decreased of the air permeability of the composite membranes. When the areal density of composite membranes was same,with the increase of the coverage rate of the nano-nets,the increased of the filtration efficiency and pressure drop. But comprehensive filter indicator that the quality factor had improved to some extent, nano-spider web fiber which the diameter of only 20 nm will help to improve air filtration performance of the fiber membrane. When the coverage rate of the nano-nets was same, with the increase of the air density, the quality factor of the composite membranes was reduced after the first raised.Structure and filtration properties of dye for the NSFM: The influence of coverage rate of the nano-nets of NSFM on pore size distribution、the contact angle and filtration properties of dye was studied. The results showed that:With the increase of the coverage rate of the nano-nets, the reduced of the pore size and the concentrated in pore size distribution. The influence of the coverage rate of the nano-nets on the contract angle was limited. The filtration flux decreased a little with the increasing of the coverage rate of the nano-nets, while the retention of dye of NSFM increased apparently, from 94.4% up to 96.8%. Therefore, the NSFM was made by the this study has some application prospect in dye waste water treatment.