• Macromolecular Research
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• v.15 no.7
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• pp.605-609
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• 2007

The molecular interactions of polyacrylonitrile (PAN) and cellulose acetate (CA) were investigated thoroughly via dilute solution viscometry in dimethylformamide (DMF) as a common solvent at $30^{\circ}C$. The intrinsic viscosities and viscometric interaction parameters were experimentally determined for both binary (polymer/dimethylformamide) and ternary (PAN/CA/dimethylformamide) systems. As all investigated PAN/CA ternaries evidenced negative viscometric interaction parameter values $({\Delta}b\;&{\Delta}k<0)$, the existence of repulsive intermolecular interactions was deduced, and PAN/CA blends were assigned as immiscible. Moreover, the results of microscopy photograph analysis indicated that pure PAN film evidences a homophasic structure, and the size of the phase domain increases gradually with increases in CA. In DSC analysis, it was determined that the glass transition temperature of the blend film increased slightly with increases in the CA content of the blend film.

• Fibers and Polymers
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• v.5 no.3
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• pp.198-203
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• 2004

Composite films were prepared by casting the solution of polyacrylonitrile (PAN) and single wall nanotube (SWNT) in DMF subsequent to sonication. The SWNTs in the films are well dispersed as ropes with 20-30 nm thickness. Moreover, AFM surface image of the composite film displays an interwoven fibrous structure of nanotubes which may give rise to conductive passways and lead to high conductivity. The polarized Raman spectroscopy is an ideal characterization technique for identification and the orientation study of SWNT. The well-defined G-peak intensity at 1580 $cm^{-1}$shows a dependency on the draw ratio under cross-Nicol. The degree of nanotube orientation in the drawn film was measurable from the sine curve obtained by rotating the drawn film on the plane of cross-Nicol of polarized Raman microscope. The threshold loading of SWNT for electrical conductivity in PAN is found to be lower than 1 wt% in the composite film. The electrical conductivity of the SWNT/PAN composite film decreased with increasing of draw ratio due to the collapse of the interwoven fibrous network of the nanotubes with uniaxial orientation.

• Journal of the Korean Electrochemical Society
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• v.3 no.3
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• pp.169-172
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• 2000

A new gel polymer electrolyte based on the modified polyacrylonitrile (PAN), polyacrylonitrile-co-bis[2-(2-methoxyethoxy)ethyl]itaconate (abbreviated as PANI) copolymer was synthesized in expectation of enhanced trapping ability of liquid electrolytes. PAN and PANI blend was complexed with organic solvents, ethylene carbonate (EC) and dimethyl carbonate (DMC), and $LiClO_4$ salt. The highest room temperature conductivity of $2\times10^{-3}\;Scm^{-1}$ was found for a film of 25PAN+10PANl+50EC/DMC+$15LiClO_4$. The solvent-rich crystalline part decreases due to the blending of PANI and therefore number of charge carriers increases giving higher ionic conductivity. The addition of PAM as a host polymer in the PAN-based gels has beneficial effects such as higher ionic conductivity, better thermal characteristics, better miscibility with solvent, wider electrochemical stability, and better interfacial stability with lithium electrode, though it exhibits slightly less mechanical rigidity.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.106-110
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• 2023

Lignin is compatible with various polymeric materials and useful as a carbon precursor. In this work, carbon monolith films were produced from polyacrylonitrile (PAN)@lignin precursor films by a controlled carbonization cycle. In addition, their morphological features, electrical properties, and adsorption behavior were analyzed and compared with those of carbonized PAN films. The successful formation of PAN@lignin precursor was confirmed by Fourier-transform infrared (FT-IR) spectroscopy. SEM was used to examine the morphology of precursor and carbonized films, revealing that both precursor and carbonized films retained structural stability following carbonization. A trace of lignin in the carbonized films was also found. The pore structure of the carbonized PAN@lignin film was measured using the BET method, indicating the formation of fairly uniform pores. The electrical properties were also analyzed to obtain the Ohmic relation, which demonstrated that the electrical signal was influenced by incoming materials. Finally, the carbonized PAN@lignin films were useful as adsorbents to remove metal ions. This study provides important information for future initiatives in relevant research fields.

• Fibers and Polymers
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• v.6 no.2
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• pp.108-112
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• 2005

Nanocomposite films were prepared by casting the solution of polyacrylonitrile (PAN) and single wall nanotube (SWNT) in nitric acid subsequent to sonication. Even though SWNT shows good dispersion visually, the reinforcing effect was not satisfactory. The G-band Raman spectra of the drawn film clearly demonstrated that SWNTs in the film are well-oriented along the drawing axis of the film. The electrical resistivity of the film prepared using nitric acid was lower than that of the film using DMF. Thus, nitric acid is presumably more effective in dispersing nanotubes than DMF.

• Polymer(Korea)
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• v.39 no.3
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• pp.394-402
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• 2015

Modification of polyacrylonitrile (PAN) films by using hydroxylamine (HA) and hydrazine to produce hydroxyl and amine groups, respectively, and to introduce cross-linking of PAN polymers was studied. Modified PAN films obtained by HA and/or hydrazine treatment including a successive or a simultaneous process were analyzed by the degree of conversion, water and N,N'-dimethylformamide (DMF) swelling ratio, FTIR spectra, atom content, and thermal analysis data. PAN films reacted with HA showed increased hydrophilicity and low dimensional stability in water. Hydrazine treatment gave PAN films high dimensional stability of low DMF swelling. Although the DMF swelling ratio of the modified PAN films was dramatically decreased by the successive treatment of hydrazine and HA, the introduction of the hydrophilic functional groups was limited due to the cross-linking. Simultaneous treatment of HA and hydrazine was the most effective method to increase hydrophilicity of PAN films with a high dimensional stability.

• Journal of Sensor Science and Technology
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• v.17 no.4
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• pp.281-288
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• 2008

Polyacrylonitrile(PAN)/metal oxide(MO) nanocomposite mats with a thickness of 0.12 mm were electrospun by adding 0 to 10 wt% of MO nanoparticles ($Fe_2O_3$, ZnO, $SnO_2$, $Sb_2O_3-SnO_2$) into PAN. Pt electrode was patterned on $Al_2O_3$ substrate by DC sputtering and then the PAN(/MO) mats on the Pt patterned $Al_2O_3$ were electrically wired to investigate the $CO_2$ gas sensing properties. As the MO content rose, the fiber diameter decreased due to the presence of lumps caused by the presence of MOs in the fiber. The PAN/2% ZnO mat revealed a faster response time of 93 s and a relatively short recovery of 54 s with a ${\Delta}R$ of 0.031 M${\Omega}$ at a $CO_2$ concentration of 200 ppm. The difference in sensitivity was not observed significantly for the PAN/MO fiber mats in the $CO_2$ concentration range of 100 to 500 ppm. It can be concluded that an appropriate amount of MO nanoparticles in the PAN backbone leads to improvement of the $CO_2$ gas sensing properties.

• Polymer(Korea)
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• v.35 no.5
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• pp.472-477
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• 2011

To study the effects of the acid group of functionalized MWNT (multiwalled carbon nanotube) on the thermal and mechanical properties of polyacrylonitrile(PAN) nanofibers, acid ($H_2SO_4/HNO_3$) treated MWNT (O-MWNT) were further functionalized by diazonium salt reaction with 5-aminoisophthalic acid (IPA). Compared to O-MWNT, IPA-MWNT with isophthalic acid group showed a better dispersion stability in polar solvents and IPA-MWNT/PAN composite film displayed lower heat of reaction (${\Delta}H$) than that of homo PAN when stabilized under air atmosphere. The continuous electrospun fibers were prepared using a conductive water bath. PAN fibers containing 1 wt% of IPA-MWNT showed an increase of tensile strength by 100% and tensile modulus by 240% compared to the PAN fibers without IPA-MWNT.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.307.2-307.2
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• 2016

In this study, we synthesized Au nanoparticles (AuNPs) in polyacrylonitrile (PAN) thin films using a simple annealing process in the solid phase. The synthetic conditions were systematically controlled and optimized by varying the concentration of the Au salt solution and the annealing temperature. X-ray photoelectron spectroscopy (XPS) confirmed their chemical state, and transmission electron microscopy (TEM) verified the successful synthesis, size, and density of AuNPs. Au nanoparticles were generated from the thermal decomposition of the Au salt and stabilized during the cyclization of the PAN matrix. For actual device applications, previous synthetic techniques have required the synthesis of AuNPs in a liquid phase and an additional process to form the thin film layer, such as spin-coating, dip-coating, Langmuir-Blodgett, or high vacuum deposition. In contrast, our one-step synthesis could produce gold nanoparticles from the Au salt contained in a solid matrix with an easy heat treatment. The PAN:AuNPs composite was used as the charge trap layer of an organic nano-floating gate memory (ONFGM). The memory devices exhibited a high on/off ratio (over $10^6$), large hysteresis windows (76.7 V), and a stable endurance performance (>3000 cycles), indicating that our stabilized PAN:AuNPs composite film is a potential charge trap medium for next generation organic nano-floating gate memory transistors.

• Textile Coloration and Finishing
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• v.2 no.2
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• pp.7-13
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• 1990

The polyacrylonitrile (PAN)/polypyrrole (PPy) composite films have been prepaxed by exposing the PAN films containing oxidizing agent such as ferric chloride or cupric chloride to pyrrole vapor. The formation of PPy in PAN was confirmed by means of IR spectroscopy and scanning electron microscopy and the X-ray differaction study showed the amorphous structure of PPy. The breaking strength of PAN/PPy composite films was 3-5 times lower but the breaking elongation of them was 4-5 times higher than that of PAN film.