# Electrospinning of High-Performance Nanofibres: State of the Art and Insights into the Path Forward
## 4 Discussion
### Path Forward  
The electrospinning of high-performance polymers continues to be of interest as demand for lightweight porous materials with high strength, chemical resistance, and thermal resistance grows. This review has considered five high-performance polymers and assessed the current progress on the electrospinning of these polymers. For polymers that are difficult to dissolve, such as p-aramid and PBO, more research is needed on effective and efficient electrospinning processes, as well as the characterization and improvement of the nanofibre properties. The research on PBI is progressing but has been limited to characterization for specific applications [28; 32]. More general characterization will improve the general understanding of the effect of electrospinning properties on PBI formation, which will be helpful for any application. For PAI, the research has considered a range of production and electrospinning techniques, as well as some applications and scale-up techniques [20; 36]. Exploring the use of PAI nanofibres in composites through electrospinning or the addition of nanoparticles may be of interest to enhance the nanofibres' properties for specific applications. For m-aramid, there has been good coverage of the optimization of the electrospinning process, the improvement of nanofibre properties, and use in specific applications [9; 11; 45]. However, no research has considered the scale-up of m-aramid electrospinning. To move the production toward the market, this will be an important next step. Developing effective methods for the scale-up of electrospinning is a common challenge for the electrospinning of all types of polymers [55]. Needle-based electrospinning has a very low production rate, around 0.01-1 g/h, and is not suitable for mass production. Other techniques, such as multi-jet, multi-needle, and needleless electrospinning provide potential solutions to the issue of low production rates. Currently, only two studies of high-performance polymer electrospinning have considered alternative methods to single-needle electrospinningning [20; 28]. Although in theory, the principle for these methods is similar to single-needle electrospinning, the parameters of electrospinning must be adjusted to reduce electric field interference, manage changing solution viscosities, and determine different flow rates and electric field strengths that may effectively form fibres with these alternative electrospinning setups. The comparison of various high-production electrospinning methods to achieve the most efficient and precise electrospinningning process for high-performance fibres will be an important next step as electrospun high-performance nanofibres move toward the market. Furthermore, as scale-up and the industrial production of nanofibres are considered, the need for standardized characterization methods to assess nanofibrous membranes increases. These methods will help to ensure that scale-up electrospinningningprocesses are producing similar results to lab-based electrospinningning processes. Moreover, the standardized characterization will help to ease the adoption of nanofibrous materials into existing standards for various applications, as the nanofibrous membrane performance can be accurately compared to conventional materials that may be used for the same applications. The current stage of progress within the electrospinningning of high-performance nanofibres positions each polymer at a different level of development. At this stage, before any of the nanofibres reach mass market production, it is critical to compare the different types of high-performance nanofibres in order to find the best fit for each specific application. Generally, high-performance polymers are used for their high strength and thermal resistance. Since these are commonalities among all the nanofibres explored in this review, other factors such as the ease of electrospinningning and cost may be important considerations in the applications of the nanofibres.