Nanofibre nonwoven

Ding B et al (2004) Fabrication of blend biodegradable nanofibrous nonwoven mats via multi-jet electrospinning. Polymer 45(6) 1895-1902... 

Microdenier filament yams, 506 microfibre nonwoven, 43-4 electrospun nanofibre nonwoven web, 43... 

Cellulose acetate nanofibers reinforced with chopped polyaniline, PANI, nanoparticles were produced. PANI acts as a nucleating agent and increases the formation of crystallites. The overall degree of ciystalhzation is increased, leading to the increased number of dipoles in the nanofibrous nonwoven membranes. ... 

Cutting edge technologies include as nanofibre nonwoven filtration media and electret-charged media. These electrostatic effects directly increase the efficiency of capture of submicron particles, resulting in improved filtration performance. 

Fibres of fine diameter have been employed most successfully by the filtration industry. A number of in-house technologies have been in existence for some time however, these proprietary processes have not been available to those outside of the filtration industry. Nanofibre nonwovens are used to improve fine dust efficiencies, lower pressure drop, and capture dangerous materials, such as biological and chemical agents. 

The mechanical and attritional properties of nanofibre nonwovens are inherently low. This can result in issues during conversion into product, eg, a pleated filter, as the integrity of the nonwoven can be disrupted during manufacture. The in-use mechanical stresses and abrasion conditions should be carefully considered when designing a product. The nanofibres are commonly laid upon a relatively inexpensive nonwoven support layer, eg, a spunbond fabric. 

There are many existing and potential applications for nanofibre nonwovens. Some of these are given in Fig. 4.8 [34]. 

Nanofibre nonwovens focused on defence and security include applications such as chemical and biological protection, and composite reinforcement and sensors (optical, chemical, gas). Soldiers can be exposed in the battlefield to harmful chemicals and biological agents from explosives. Chemical and biological warfare agents, such as mustard gas, covalently bond with DNA or forms disulphide bonds with thiol groups, which leads to cell death or eventually to cancer [42]. Nanofibre developments are... 

The main requirements for chemical protective clothing include protection against liquid and vapour contaminants, resistance to rain, air permeability, tear strength, fabric weight, and durabihty. Nanofibre nonwovens offer the opportunity to offer high levels of chemical protection while maintaining high breathabUity [43]. 

Microfibers are fiequently used to enhance filtration efficiency of nonwoven fabrics, and nanofibrous nonwovens are frequently used in combination with membrane filtrations for the filtration of nanoscale particles. 

With consideration of the requirements of avoidance of fibre shedding in the filtration process, nonwoven fabrics made from continuous fibres such as melt blown, spun-bond, and hydroentangled nonwovens and electrospun/centrifugal spinning nanofibre nonwovens, as well as their composite combinations comprising both microfibres and nanofibres, are widely used in microfiltration as a water filtration media. They... 

Compared with microfibres, nonwovens with nanofibres were developed in smart polymer textiles such as shape memory polymer nonwovens, PCM nonwovens and colour change nonwovens. SMP electrospun micro- and nanofibre nonwoven structures have unique properties including quicker response to the external stimuli, larger recovery stress, quicker recovery rate and enhanced functionalities such as antibacterial and water vapour permeability. 

Zhuo H., Hu J. and S. Chen (2011), Study of water vapor permeability of shape memory polyurethane nanofibrous nonwovens. Textile Research Journal, 81(9) pp. 883-891. 

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