Electrospun PAN Nanofibers Research Articles

Preparation and In-Vitro Assessment of Hierarchal Organized Antibacterial Breath Mask Based on Polyacrylonitrile/Silver (PAN/AgNPs) Nanofiber.

In this report, we designed and synthesized polyacrylonitrile/silver (PAN/AgNPs) nanofibers via an in-situ method to obtain a washable with high-dispersed silver nanoparticles membrane to form the hierarchically organized antibacterial mask to prevent the two-way effect of bacteria from person to environment and environment to person. For this objective, the electrospun PAN nanofibers were stabilized via the heating method. Different amounts of AgNPs were loaded into the PAN nanofibers by using silver nitrate and sodium hydroxide solutions. The basic results showed that AgNPs was homogenously loaded in PAN nanofiber matrixes. Furthermore, the release profile based on two-stage release theory showed that when the negligible amount of AgNPs was loaded into the nanofibers, the release significantly decreased, whereas antibacterial activity increased. The greatest potential antibacterial activity of the lowest amount of AgNPs showed controllable AgNPs release from PAN nanofibers that has a direct relationship with the washability and could promote the application of the produced product.

Core-shell structured carbon nanofibers yarn@polypyrrole@graphene for high performance all-solid-state fiber supercapacitors

Carbon nanofibers yarns (CNY) have been prepared by carbonizing twisted electrospun PAN nanofibers, which can be used as the electrode of fiber-shaped all-solid-state supercapacitor after depositing conductive polymer of polypyrrole (PPy) and reduced graphene oxide (rGO) on their surface to form a core-shell structure (CNY@PPy@rGO). The flexible and binder-free fiber supercapacitors with PVA/H3PO4 gel electrolyte have a high specific capacitance (92.57 F/g, 80.46 F/cm3, 836.87 mF/cm2, and 111.46 mF/cm of CM, CV, CA, and CL, respectively, at the scan rate of 2 mV/s) thanks to the core-shell structure and synergistic effects of three conponents. It also shows high cycling performance with 86% capacitance retention after 10000 cycles with excellent flexibility and stability at different bending angles.

Flexible all-solid-state supercapacitors based on freestanding, binder-free carbon nanofibers@polypyrrole@graphene film

A freestanding, binder-free carbon nanofibers@polypyrrole@reduced graphene oxide (CNFs@PPy@rGO) core-double-shell supercapacitor electrode is prepared by carbonization of electrospun PAN nanofibers network follow by the electrochemical deposition of PPy and then reduced graphene oxide layer coating. The flexible all-solid-state supercapacitor based on the CNFs@PPy@rGO core-double-shell electrode with PVA/H3PO4 gel electrolyte demonstrates a highest specific capacitance of 188 F/g at the scan rate of 2 mV/s and good cycling stability. Due to the synergistic effect of three materials, the newly designed composite electrode shows the highest specific capacitance of 336.2 F/g at the scan rate of 2 mV/s, which increases by 10% than that of CNFs@PPy electrode (302.7 F/g) at the same scan rate in a three-electrode system. Furthermore, it shows excellent cycling stability performance with 98% capacitance retention after 2500 cycles, which is better than that of CNFs@PPy electrode (90%).

Immobilization of Ag3PO4 nanoparticles on electrospun PAN nanofibers via surface oximation: Bifunctional composite membrane with enhanced photocatalytic and antimicrobial activities

Abstract Ag 3 PO 4 /PAN composite nanofibers have been fabricated by simple and low cost electrospinning technique followed by surface modification of PAN nanofibers with amidoxime ( C(CN 2 ) NOH) groups to utilize as anchoring sites for Ag + ions through coordinate bonding. Subsequently, the coordinated Ag + ions were allowed to react with PO 4 3− ions in order to form Ag 3 PO 4 /PAN composite nanofibers. Thus obtained composites were characterized by FESEM, XRD, TEM, FTIR, XPS and UV–vis. Experimental results revealed that composite nanofibers prepared by reacting ( C(CN 2 ) NOH) functionalized PAN nanofibers with 0.02 M solutions of AgNO 3 and Na 2 HPO 4 have higher efficiency towards the photodegradation and bactericidal activities under visible light.

Activated carbon nanofiber produced from electrospun PAN nanofiber as a solid phase extraction sorbent for the preconcentration of organophosphorus pesticides

ABSTRACT Activated carbon nanofibers (CNFs) were derived from electrospun nanofibers with subsequent heat treatment. They were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The applicability of activated CNFs for preconcentration and determination of organophosphorus pesticides (OPPs) was investigated by high-performance liquid chromatography with diode array detector (HPLC-DAD). Some important parameters influencing the extraction efficiency, such as amount of sorbent, pH, flow rate and amount of salt, were investigated by response surface method (RSM). The obtained results showed that this analytical method will be useful for the analysis of OPPs in tap water with high precision and accuracy.

Iron oxide nanoparticle-immobilized PAN nanofibers: synthesis and adsorption studies

Iron oxide nanoparticles grown on the surface of an electrospun PAN nanofiber membrane can be used as a next generation nanoadsorbent for effective removal of CR dye.

Comparative Study of the Electrospun PAN Nanofiber Reinforced with CNT and CNF: Effect on Morphology, Thermal Stability and Electro-Conductivity Properties

Reinforced electrospun PAN nanofibers with carbon nanotubes and carbon nanofibers were produced via electrospinning techniques. The spinning was carried out in a ratio of 6 and 10 wt % of CNT and CNF to PAN slurry respectively. The applied voltage was 10.0 kV and the spuns had undergone three stages of thermal treatments, namely, stabilization, carbonization, and graphitization. The studies indicated that the nanofiber diameter, thermal stability and electric conductivity properties of the PAN electrospun were greatly affected by the ratio of the nanoparticles. The morphological study revealed that the fiber diameters of the PAN/CNT electrospun were between 0.62 to 0.70 mm, and the PAN/CNF fiber diameters were between 1.03 to 1.20 mm respectively. For the thermal stability study, it was observed that the thermal degradation of the PAN polymer had increased as the CNT and CNF ratios increased. The electro-conductivity study also revealed that addition of CNT had increased the conductivity of the PAN polymer until 5.4 x 10-4 Scm-1 besides PAN/CNF increased the electrical resistivity of PAN from 2.49 x 10-5 to 1690.2 Ω cm-1 respectively.

Preparation and Characterization of the Amidoxime-Modified Polyacrylonitrile (PAN-Amidoxime) Nanofibre Composite

In this research, a kind of nonwoven composite used for the absorption of heavy mental ions has been made. The composite was made of two layers of ES thermal bonded nonwovens as the protective layers and the PAN-amidoxime nanofibers which are prepared through the modification of electrospun PAN nanofibers as the interlayer. The composition was achieved by the ultrasonic bonding method. After the composition the PAN nanofibers were modified by grafting the amidoxime group to PAN. The results of FT-IR spectra and FE-SEM indicated that nitrile groups in PAN were partly converted into amidoxime groups and there were no serious cracks on the surface of PAN-amidoxime nanofibers. The results show that the amidoxime groups have been proved to be grafted to the PAN nanofibers with the percent grafting of 81.6%.

Enhancing thermal and ionic conductivities of electrospun PAN and PMMA nanofibers by graphene nanoflake additions for battery-separator applications

Enhancing thermal and ionic conductivities of electrospun PAN and PMMA nanofibers by graphene nanoflake additions for battery-separator applications

A one-pot synthesis of a highly dispersed palladium/polypyrrole/polyacrylonitrile nanofiber membrane and its recyclable catalysis in hydrogen generation from ammonia borane

A palladium/polypyrrole/polyacrylonitrile (Pd/PPy/PAN) composite nanofiber membrane was synthesized by a one-pot redox polymerization process between pyrrole monomers and Na2PdCl4 in the presence of electrospun PAN nanofibers.

Moisture Condensation Behavior of Hierarchically Carbon Nanotube-Grafted Carbon Nanofibers

Hierarchical micro/nanosurfaces with nanoscale roughness on microscale uneven substrates have been the subject of much recent research interest because of phenomena such as superhydrophobicity. However, an understanding of the effect of the difference in the scale of the hierarchical entities, i.e., nanoscale roughness on microscale uneven substrates as opposed to nanoscale roughness on (a larger) nanoscale uneven surface, is still lacking. In this study, we investigated the effect of the difference in scale between the nano- and microscale features. We fabricated carbon nanotube-grafted carbon nanofibers (CNFs) by dispersing a catalyst precursor in poly (acrylonitrile) (PAN) solution, electrospinning the PAN/catalyst precursor solution, carbonization of electrospun PAN nanofibers, and direct growth of carbon nanotubes (CNTs) on the CNFs. We investigated the relationships between the catalyst concentrations, the size of catalyst nanoparticles on CNFs, and the sizes of CNFs and CNTs. Interestingly, the hydrophobic behavior of micro/nano and nano/nano hierarchical surfaces with water droplets was similar; however a significant difference in the water condensation behavior was observed. Water condensed into smaller droplets on the nano/nano hierarchical surface, causing it to dry much faster.

A Novel Methanol Sensor Based on Gas-Penetration Through a Porous Polypyrrole-Coated Polyacrylonitrile Nanofiber Mat

In this work, we propose a novel chemoresistive gas sensor operated under a vertical analyte flow passing through a permeable sensing membrane. Such a configuration is different from the use of a planar sensor implemented under a conventional horizontal flow. A highly porous core-shell polyacrylonitrile-polypyrrole (PAN@PPy) nanofiber mat was prepared as the sensing element via electrospinning and two-step vapor-phase polymerization (VPP). Various analysis methods such as SEM, TEM, FT-IR and XPS measurements were employed in order to characterize structural features of the porous sensing mat. These analyses confirmed that very thin (ca. 10 nm) conductive PPy sheath layers were deposited by VPP on electrospun PAN nanofibers with an average diameter of 258 nm. Preliminary results revealed that the gas penetration-type PAN@PPy sensor had a higher sensor response and shorter detection and recovery times upon exposure to methanol analyte when compared with a conventional horizontal flow sensor due to efficient and fast analyte transfer into the sensing layer.

Role of elasticity in control of diameter of electrospun PAN nanofibers

A series of poly(acrylonitrile-co-methylacrylate) copolymers (PAN) with varying molecular weight were synthesized by radical copolymerization using α-α′-azobisisobutyronitrile (AIBN) as initiator. These copolymers were dissolved at different concentrations in DMF and electrospun at Minimum electrospinning voltage (MEV) to correlate electrical energy required to perform the mechanical work during the spinning of the fibers. The diameters of the resultant fibers were correlated with the Berry number and average number of entanglements per chain of the spinning solution. It was observed that number of entanglements per chain, which represents the capacity of the polymer system to store elastic energy, could correlate well with the ultimate diameter of the fiber. Interestingly, the diameters of the nanofibers were found to increase linearly with increase in number of entanglements per chain with two distinct regions having transition of the slope at number of entanglement value of 3.5.

SnO2@TiO2 double-shell nanotubes for a lithium ion battery anode with excellent high rate cyclability

SnO2@TiO2 double-shell nanotubes have been facilely synthesized by atomic layer deposition (ALD) using electrospun PAN nanofibers as templates. The double-shell nanotubes exhibited excellent high rate cyclability for lithium ion batteries. The retention of hollow structures during cycling was demonstrated.

TiO2 nanoparticles immobilized on polyacrylonitrile nanofibers mats: a flexible and recyclable photocatalyst for phenol degradation

TiO2/polyacrylonitrile (TiO2/PAN) hybrid nanofibers with small TiO2 nanoparticles well-immobilized on the electrospun PAN nanofibers have been successfully fabricated by means of a combination of an electrospinning technique and a hydrothermal process. The as-fabricated hybrid nanofibers were characterized by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and Brunauer–Emmett–Teller analysis. The results revealed that the TiO2/PAN hybrid nanofibers possessed a large surface area as well as being flexible in nature. Such hybrid nanofibers materials have exhibited outstanding performance for the photocatalytic degradation of phenol under UV light irradation. And, by adjusting the operating parameters during the photocatalytic process, the results further showed that the photoreactor pattern, initial pH value and concentration of phenol solution had important influence on phenol degradation. What's more, repeating the experiments five times indicated that the catalyst is stable and recyclable.

Synthesis and Characterization of Conductive Core-Shell Polyacrylonitrile-Polypyrrole Nanofibers

Nonwoven polyacrylonitrile-polypyrrole (PAN-PPy) core-shell nanofiber mats were prepared through the growth of PPy layers on electrospun PAN nanofibers via a two-step vapor-phase polymerization, i.e., the wet-coating of ferric tosylate (FeTos) oxidants on PAN nanofibers followed by exposure to pyrrole monomers in the gas phase. Under the conditions ([FeTos] = 10 wt%, reaction time = 15 min, temperature = 15 degrees C), the PPy polymerization procedure led to both a uniform coating over the PAN surface with an average thickness of 18 nm and cross-linkages among the nanofibers without a noticeable change in the highly porous nanofibrous structures. The oxidant concentration and polymerization time were found to be key parameters for achieving a good nanostructured core-shell fiber mat. FT-IR, XPS, XRD and conductivity measurements confirmed the synthesis of Tos-doped PPy with some degree of crystallinity and a high conductivity.

Characterization of Polyacrylonitrile Based Carbon Nanofiber Mats via Electron Beam Processing

The aim of this study was to evaluate the ability of electron beam irradiation to drive stabilization reactions within PAN nanofiber mats to obtain carbon nanofiber mats. PAN nanofiber mats with fiber diameters of 300-400 nm were prepared via an electrospinning method. Electrospun PAN nanofiber mats were stabilized by electron beam irradiation with various doses up to 5,000 kGy. Using the irradiation-stabilized PAN nanofiber mats, carbon nanofibers were obtained by pyrolysis in a tube furnace for 1 h at 1,000 degrees C under an N2 atmosphere. FT-IR analysis indicated that the transformation of C[triple bond]N groups to C==N groups was accelerated by electron beam stabilization. The thermal behavior of the PAN nanofiber mats was studied using DSC and TGA. DSC thermograms showed that the peak temperatures of the exothermic reactions were found to decrease with increasing electron beam irradiation doses. Irradiation-stabilized PAN nanofiber mats were not observed to dramatically decrease in weight between 290 degrees C and 320 degrees C, an observation presumed to be related to cyclization. The char yields of PAN were found to increase with increasing irradiation doses.

Ag-Coated PAN Nanofibers Prepared by Poly(dopamine)-Assisted Electroless Plating

Silver-coated PAN nanofibers have been prepared by a facile method that combined the electrospinning technique and electroless plating method. Dopamine was used to functionalize the surface of electrospun PAN nanofibers to form the chemisorption sites in order to assist electroless plating of silver. SEM and ATR-FITR results indicated that poly(dopamine) has been successfully deposited on the surface of PAN nanofibers. XRD and SEM results also showed that face-centred cubic (fcc) crystal Ag nanoparticles with uniform size were well coated on the surface of electrospun PAN fibers.

PHOTOCATALYTIC OXIDATION OF VOLATILE ORGANIC COMPOUNDS OVER ELECTROSPUN ACTIVATED TIO2/CARBON NANOFIBER COMPOSITE

In this study, TiO 2/ PAN -based fibers were prepared by electrospinning a composite solution containing both the desirable contents of TiO 2 and a 10 wt. % PAN polymer solution dissolved in N , N -dimethylformamide. The TiO 2 loaded electrospun PAN nanofibers were then carbonized at 1000 °C in N 2 atmosphere furnace after stabilization at 230 °C in air. Then CNF / TiO 2 nanofibers were oxidized at 450 °C in air. The morphology and structure of the TiO 2-embeded carbon nanofibers were investigated by SEM and Raman spectroscopy. Specific surface area was determined using BET equation from N 2 adsorption analysis. Photocatalytic tests were conducted in a UV illuminated set-up specialized for the filters using ethanol vapor. The results have shown that ethanol vapor was efficiently degraded on TiO 2/ CNF composite nanofiber mat under UV illumination. The aim of this study was to further investigate the feasibility of TiO 2/ ACF for practical indoor air purification.

Surface Modification of Electrospun PAN Nanofibers and Its Application for Adsorption of Lead Ions

Surface Modification of Electrospun PAN Nanofibers and Its Application for Adsorption of Lead Ions