Structural Evolution and Formation Mechanism of the Soft Colloidal Arrays in the Core of PAAm Nanofibers by Electrospun Packing

Abstract

Electrospinning provides a facile and versatile method for generating nanofibers from a large variety of starting materials, including polymers, ceramic, composites, and micro-/nanocolloids. In particular, incorporating functional nanoparticles (NPs) with polymeric materials endows the electrospun fibers/sheets with novel or better performance. This work evaluates the spinnability of polyacrylamide (PAAm) solution containing thermoresponsive poly(N-isopropylacrylamide-co-tert-butyl acrylate) microgel nanospheres (PNTs) prepared by colloid electrospinning. In the presence of a suitable weight ratio (1:4) of PAAm and PNTs, the in-fiber arrangements of PNTs-electrospun fibers will evolve into chain-like arrays and beads-on-string structures by confining of PAAm nanofibers, and then the free amide groups of PAAm can bind amide moieties on the surfaces of PNTs, resulting in the assembling of PNTs in the cores of PAAm fibers. The present work serves as a reference in the fabrication of novel thermoresponsive hybrid fibers involving functional nanospheres via electrospun packing. The prepared nanofibers with chain-like and thermoresponsive colloid arrays in the cores are expected to have potential application in various fields.

Polymer mechanochemistry: from single molecule to bulk material

“…The thermoresponsive PNIPAm show obvious turbidity and changes in the transmittance of visible light at the phase separation state. 78 The resulting turbid phenomenon, caused by the newly formed PNIPAm phase separation, implies that force-triggered polymer strand scission induces rapid radical polymerization within the gel material (Fig. 5c).…”

Robust Multiscale-Oriented Thermoresponsive Fibrous Hydrogels with Rapid Self-Recovery and Ultrafast Response Underwater

“…The newly synthesized P­(N/A) demonstrates a pronounced thermoresponsivity with a lower critical solution temperature (LCST) at around T = 28.2 °C. The LCST of P­(N/A) is obviously lower than that of homopolymer PNIPAm ( T = 32 °C), which is due to the incorporation of hydrophobic BP moieties. , To assure the continuous spinning ability of the fibers, the linear copolymer P­(N/A) was dissolved in the organic solvent DMF in this research.…”

“…The LCST of P(N/A) is obviously lower than that of homopolymer PNIPAm (T = 32 °C), which is due to the incorporation of hydrophobic BP moieties. 12,25 To assure the continuous spinning ability of the fibers, the linear copolymer P(N/A) was dissolved in the organic solvent DMF in this research.…”

“…Electrospinning provides a versatile and more direct approach for generating interconnected porous hydrogels with well-controllable morphology and chemical composition. − Nonwoven-like micro/nanofibrous structures with large surface area to volume prepared by electrospinning are highly desired for a responsive hydrogel to achieve an ultrafast response. In addition, the multiscale-oriented structure of electrospun fibrous hydrogels mimics a lot of natural biomaterials .…”

Review on Fabrication of Structurally Colored Fibers by Electrospinning

“…In terms of the electrospinning technique, with the advantages of easy access to the adjustment of morphology of nanofibres and fast continuous preparation process [16], various kinds of electrospun nanofiber assemblies with desired properties could be prepared for myriad specific applications [17]. Unlike the dip-coating method [18], the electrospun nanofibers could be prepared without adhesion between the substrate and coating layer.…”