Electrospun tree-like nanofiber membrane: Fabrication and applications for air and water treatments

Gaining an insight into the creatures generated by nature can provide an effective way to imitate nature and create new materials and structures. Plants are nature’s creation that cover the earth, which not only possess the most important process for sustainable life on earth via photosynthesis, but also have excellent water transport systems, through which underground water can be transported against gravity from the roots all the way up to the leaves. In this chapter, multiscaled tree-like nanofiber membranes (TLNMs) are prepared by tailoring the properties and processing parameters of polymer solutions via electrospinning. The effects of salt type, salt content, and processing parameters on the morphologies and properties of TLNMs are investigated. A possible mechanism for the formation of TLNMs is proposed by image analysis of the spin jet using a high-speed camera. TLNMs possess extremely small pore sizes, large specific surface areas, and excellent mechanical properties. Polyvinylidene fluoride (PVDF) TLNMs and PVDF-graft-poly(acrylic acid) TLNMs fabricated by electrospinning are also highlighted in this chapter. Electrospun TLNMs are promising materials for air/liquid filtration, catalysis, heavy metal ion adsorption, electrochemistry, and oil/water separation fields. This study opens a new way for the preparation of bionic specially shaped nanofibers using a one-step electrospinning method and broadens the application field of electrospun nanofibers.