Reactive electrospinning

Ji Y et al (2006) Dual-syringe reactive electrospinning of cross-linked hyaluronic acid hydrogel nanofibers for tissue engineering applications. Macromol Biosci 6( 10) 811—817... 

Controlled increase in the surface area of isolated chitins and chitosans certainly results in more convenient chemical and biochemical reactivity. Likewise, controlled porosity is a means for optimizing the growth of human or animal cells within scaffolds. The mechanical disassembly of animal chitins under controlled conditions represents an important step forward in the exploitation of nanochitins and nanochitosans. Along with supercritical carbon dioxide drying, mechanical disassembly exhibits practical advantages over electrospinning. 

Ye, R Xu, Z.K. Wu, J. Innocent, C. Seta, P. Nanofibrous membranes containing reactive gronps Electrospinning from poly(acrylonitrile-co-maleic acid) for lipase immobilization. Macromolecules 2006, 39 (3), 1041-1045. 

In a more recent work, MWNTs have been incorporated into surface-modified, reactive P(St-co-GMA) nanofibres by electrospinning. Then resulting nanofibres have been functionalised with epoxide groups and added to the epoxy matrix producing reinforced epoxy resins. The polymer composites have demonstrated over a 20% increase in flexural modulus, when compared with neat epoxy, despite a very low composite fibre weight fraction (at approximately 0.2% by a single-layer fibrous mat). The increase is attributed to the combined effect of the well-dispersed MWNTs and the surface chemistry of the electrospun fibres that enabled an effective cross-linking between the polymer matrix and the nanofibres. 

Theron, J.P., Knoetze, J.H., Sanderson, R.D., Hunter, R., Mequanint, K., Franz, T. et al (2010) Modification, crosslinking and reactive electrospinning of a thermoplastic medical polyurethane for vascular graft applications. Acta Biomater., 6 (7), 2434-2447. 

The hybrid electrospun fibers that are most widely fabricated by the sol-gel approach and described in the literature are based either on a silica or titania inorganic phase. The composition of the sol to be electrospun is commonly defined by following the established knowledge of sol-gel processes. First of all, it is well known that silicon alkoxide precursors are much less reactive than their titanium counterparts, due to the higher electronegative character of Si compared with Ti, which makes the former less susceptible to nucleophilic attack during hydrolysis. From a practical point of view, the remarkably different reactivity of Si and Ti alkoxide precursors entails the use of different formulations in the phase of sol preparation for electrospinning. 

The electrospinning of a reactive sol that changes its properties during time is a major problem when a reasonable amount of electrospun fibers must be produced. In addition, the factors that are known to influence the sol-gel process (such as... 

The sol-gel approach coupled with dual-syringe reactive electrospinning was used by Poologasundarampillai et al. [165] to enrich PLLA-Si02 fibers with Ca " ions. To this aim they used a Ca alkoxide precursor. It is so reactive with water that, in order to avoid CaO precipitation, the authors used a modified electrospinning... 

Figure 16.1 Polyurethane composites of nano-HA (a) and (b), commercially available MasterGraft (MG) (c), and bioglass fabricated via electrospinning (a), foaming (b) and (d), and in situ reactive liqnid molding (c).

Electrospinning can be defined as a technique used to produce nanofibers from a reservoir of reactive precursor species expelled through a nozzle, the tip of which is held at high voltage, the fibers being collected on a grounded plate. [2]... 

Kim, S. H., S.-H. Kim, S. Nair, and E. Moore (2005). Reactive electrospinning of cross-linked poly(2-hydroxyethyl methacrylate) nanofibers and elastic properties of individual hydrogel nanofibers in aqueous solutions. Macromolecules 38(9) 3719-3723. 

Ye, R, Z.-K. Xu, J. Wu, C. Innocent, and P. Seta (2006). Nanofibrous membranes containing reactive groups electrospinning from poly(acrylonitrile-c >-maleic acid) for lipase immobilization. Macromolecules 39(3) 1041-1045. 

Xu X. Nanofibers, and apparatus and methods for fabricating nanofibers by reactive electrospinning, US Patent 2007/0018361. 2007. 

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