Post Processing Strategies for the Enhancement of Mechanical Properties of ENMs (Electrospun Nanofibrous Membranes): A Review

Abstract

Electrospinning is a versatile technique which results in the formation of a fine web of fibers. The mechanical properties of electrospun fibers depend on the choice of solution constituents, processing parameters, environmental conditions, and collector design. Once electrospun, the fibrous web has little mechanical integrity and needs post fabrication treatments for enhancing its mechanical properties. The treatment strategies include both the chemical and physical techniques. The effect of these post fabrication treatments on the properties of electrospun membranes can be assessed through either conducting tests on extracted single fiber specimens or macro scale testing on membrane specimens. The latter scenario is more common in the literature due to its simplicity and low cost. In this review, a detailed literature survey of post fabrication strength enhancement strategies adopted for electrospun membranes has been presented. For optimum effect, enhancement strategies have to be implemented without significant loss to fiber morphology even though fiber diameters, porosity, and pore tortuosity are usually affected. A discussion of these treatments on fiber crystallinity, diameters, and mechanical properties has also been produced. The choice of a particular post fabrication strength enhancement strategy is dictated by the application area intended for the membrane system and permissible changes to the initial fibrous morphology.

Electrospun Silk Fibroin/Polylactic-co-glycolic Acid/Black Phosphorus Nanosheets Nanofibrous Membrane with Photothermal Therapy Potential for Cancer

“…Appropriate mechanical properties of electrospun membrane are necessary for its application [ 44 , 45 ]. Therefore, the effect of the BP@SF on the mechanical properties of the electrospun membrane were investigated, using a tensile testing machine ( Figure 4 c).…”

Application of Electrospun Nonwoven Fibers in Air Filters

“…However, with some postprocessing, such as crosslinking, post-fabrication drawing and stretching, solvent welding, heat treatment or annealing, etc. [34], the mechanical properties can be effectively altered to fit the requirements. Large surface-to-volume ratio, ability to tailor pore's structure, pore interconnectivity, tunable morphology, and large dust-holding capacity are some of the advantages of electrospun fibers for air filter application [26,27].…”

“…However, with some postprocessing, such as crosslinking, post-fabrication drawing and stretching, solvent welding, heat treatment or annealing, etc. [34], the mechanical properties can be effectively altered to fit the requirements.…”

Electrospun Medicated Nanofibers for Wound Healing: Review

“…When the liquid jet stretches over a certain distance, it enters the bending and whiplash stage. With the solvent volatilization, the jet is stretched to micrometers or even tens of nanometers, finally solidified and deposited on the collector to form nanofiber [ 65 , 66 ]. On the basis of this principle, the electrospinning process can be adjusted by system parameters (polymer type, molecular weight, viscosity, conductivity of the solution, surface tension), process parameters (voltage, flow rate, receiving distance) and environmental parameters (humidity, temperature) to change the morphology and size of nanofibers [ 67 , 68 ].…”