Thermally responsive behaviour of the electrical resistance of electrospun P(NIPAm-co-NMA)/Ag composite nanofibers

Abstract

Thermally responsive copolymer P(NIPAm-co-NMA) was prepared via a radical copolymerization and spun into nanofibers using electrospinning. After thermal crosslinking, the electrospun fibers were modified using KH590 and silver nanoparticles were introduced onto the fiber surface using a chemical plating method.The electrical resistance of the composite fibers containing 65.5% of silver at different temperatures was investigated and it was found that the resistance dropped by $60% as the temperature increased from 42 C to 46 C, which is consistent with the solubility transition of PNIPAm with the change of temperature as revealed by differential scanning calorimetry (DSC) measurement.

Synthetic stimuli-responsive ‘smart’ fibers

“…After surface modification of the fibers with 3-mercaptopropyltrimethoxysilane (KH590), the silver nanoparticles were chemically plated onto the fibers [41]. It was then possible to use the lower critical solution temperature (LCST) of PNIPAAm as a temperature switch to induce a 60% change in the electrical resistance of the composite fiber [41]. Further research is being carried out to develop the LCST of these temperature sensitive sensors so that they may be able to operate at biologically relevant temperatures.…”

“…PNIPAAm electrospun fibers have been investigated for their utility as temperature sensors [41]. N-methylolacrylamide (NMA) and N-isopropyl acrylamide (NIA) monomers have been copolymerized and then thermally crosslinked via condensation of the hydroxyl group from the NMA monomer [41].…”

“…N-methylolacrylamide (NMA) and N-isopropyl acrylamide (NIA) monomers have been copolymerized and then thermally crosslinked via condensation of the hydroxyl group from the NMA monomer [41]. After surface modification of the fibers with 3-mercaptopropyltrimethoxysilane (KH590), the silver nanoparticles were chemically plated onto the fibers [41]. It was then possible to use the lower critical solution temperature (LCST) of PNIPAAm as a temperature switch to induce a 60% change in the electrical resistance of the composite fiber [41].…”

“…N-methylolacrylamide (NMA) and N-isopropyl acrylamide (NIA) monomers have been copolymerized and then thermally crosslinked via condensation of the hydroxyl group from the NMA monomer [41]. After surface modification of the fibers with 3-mercaptopropyltrimethoxysilane (KH590), the silver nanoparticles were chemically plated onto the fibers [41].…”

Aqueous-based electrospun P(NIPAAm-co-AAc)/RSF medicated fibrous mats for dual temperature- and pH-responsive drug controlled release

“…For example, NIPAAm had to be copolymerized with crosslinkable monomers (NMA) to achieve water-insoluble electrospun bers by a heat induced chemical crosslinking. 36 For P(NIPAAm-co-AAc) copolymer, because it contains a small number of carboxyl groups in the macromolecules structure, chemical crosslinking can be achieved by bioconjugation reaction between carboxyl groups and amino groups with the assistance of crosslinking agent. Commonly crosslinking agents are glutaraldehyde, genipin, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), etc., among them, the EDC is higher the crosslinking efficiency when it combined with n-hydroxysuccinimide (NHS).…”