Electrospining Machine: One-step fabrication of strengthened breathable composite nanofiber membranes by electrospinning/electrospraying for highly waterproof application

In this paper, a "one-step" technology based on electrospinning machine and electrostatic spraying was developed to prepare a high-performance waterproof and breathable composite nanofiber membrane. By using thermoplastic polyurethane (TPU) as the matrix material, combining polyvinyl butyral (PVB) and short-chain perfluoroalkyl hydrophobic agent (PT60) to construct a multifunctional coating, the membrane achieved high hydrostatic pressure (73.7 kPa), good water vapor permeability (6.88 kg/m²·d) and excellent mechanical properties (tensile strength 25.72 MPa). This method is industrially scalable and can meet the performance requirements of different fields, such as protective clothing and Electrospun Nanofbers materials, by adjusting the material ratio and process parameters. The Nanofiber Membrane has excellent durability (wear resistance and cleaning resistance) and environmental protection, providing new ideas for the research and development of environmentally friendly high-performance Nanofiber Membrane materials.

Method

The study proposed a "one-step" process combining electrospinning and electrostatic spraying technology to prepare enhanced waterproof and breathable composite nanofibers WBMs composed of hydrophobic thermoplastic polyurethane (TPU) nanofibers and polyvinyl butyral (PVB) containing short fluoroalkyl hydrophobic agents. This method integrates the fiber structure control advantages of electrospinning and the functional coating capabilities of electrostatic spraying, providing a simple and efficient Nanofiber Membrane preparation strategy suitable for industrial production and multi-scenario applications.

Research highlights

One-step electrospinning/spraying combined technology:

The electrospinning and electrostatic spraying technologies are integrated to prepare the nanofiber skeleton by electrospinning and form the functional coating by spraying, completing the preparation of the composite membrane in one step. This method is simple and easy to operate, supports large-area membrane production, and is suitable for industrial promotion. 

Environmentally friendly material selection:

Materials such as hydrophobic thermoplastic polyurethane (TPU) and polyvinyl butyral (PVB) used in the study are environmentally friendly; The introduction of short-chain perfluoroalkyl hydrophobic agents reduces the use of environmentally harmful long-chain chemicals, which meets the current demand for environmentally friendly and sustainable materials.

Excellent comprehensive performance:

The prepared nanofibrous membrane exhibited excellent comprehensive properties, including high water contact angle (136.8°) and high hydrostatic pressure (73.7 kPa), high water vapor permeability (6.88 kg/m2.d), high tensile strength (25.72 MPa) and large elongation at break (217%).

Durability and Liquid Repellency: 

The nanofiber membranes showed good durability and were able to resist ultrasonic cleaning and abrasion, which makes them suitable for long-term use and applications in harsh environments. The membranes also have good water and oil repellency, which is critical for waterproof and breathable applications.

Customizable performance:

By adjusting the electrospinning and spraying parameters, the electrospinning machine can achieve flexible customization of membrane performance according to different needs. By adjusting the concentrations of PVB and PT60, the pore size, inter-fiber connectivity, and hydrophobicity of the membrane can be controlled; by changing the parameters of the electrospinning/spraying process, such as spinning solution flow rate, spraying solution volume, and fiber thickness, composite membranes with different hydrostatic pressure and air permeability properties can be produced.

Paper link：https://doi.org/10.1016/j.polymer.2023.126481