• 한국환경과학회지
• /
• 제27권12호
• /
• pp.1215-1226
• /
• 2018

In this study, PAN-SZ (polyacrylonitrile scoria zeolite) beads were prepared by immobilizing Na-A zeolite (SZ-A) synthesized from Jeju volcanic rocks (scoria) on the polymer PAN. FT-IR and TGA analysis results confirmed that the SZ-A was immobilized in the PAN-SZ beads. SEM images showed that the PAN-SZ beads are a spherical shape with 2 mm diameter and exhibit a porous inner structure inside the bead. The most suitable mixing ratio of PAN to SZ-A as the adsorbent for removing Sr ions was PAN/SZ-A = 0.2 g/0.3 g. The adsorption kinetic data for Cu and Sr ions were fitted well with the pseudo-second-order model. The Cu and Sr ion uptakes followed a Langmuir isotherm model and the maximum adsorption capacities at $20^{\circ}C$ were 84.03 mg/g and 75.19 mg/g, respectively. The amount of Sr ion adsorbed by SZ-A on the PAN-SZ beads was about 160 mg/g, which was similar to that adsorbed by SZ-A powder. Thus, the PAN-SZ beads prepared in this study are considered to be effective adsorbents for removing metal ions in aqueous solutions.

• 대한화학회지
• /
• 제11권2호
• /
• pp.77-80
• /
• 1967

Radiolysis of polyacrylonitrile(PAN) has been studied. Parameters for crosslinking and scission induced by gamma-ray irradiation were obtained by means of sol-gel partitioning method. G-value of crosslinking in PAN ($\bar{M}n=6{\times}10^5$) was 0.038 and the gel dose 21.6 Mrad. The effects of irradiation on the thermal degradation rate in PAN was also studied. No appreciable changes in thermal degradation rate observed up to 81.8 Mrad of irradiation dose.

• 전기화학회지
• /
• 제3권3호
• /
• pp.169-172
• /
• 2000

Polyacrylonitrile (PAN) 고분자의 유기용매 함유능을 증대시키기 위하여 PAN을 수정한 새로운 polyacrylonitrile-co-bis[2-(2-methoxyethoxy)ethyl]itaconate (PANI로 약칭) 공중합체를 합성하였다. PAN과 PANI의 혼합 고분자에 ethylene carbonate (EC)와 dimethyl carbonate (DMC)의 혼합유기용매, $LiClO_4$ 염을 혼합한 젤 고분자 전해질을 제조하였다. 상온에서의 이온전도도는 25PAN +10PANl +50EC/DMC+$15LiClO_4$ 조성의 전해질에서 $2\times10^{-3}\; Scm^{-1}$로 가장 높은 값을 나타내었다. 이는 PANI의 혼합으로 인하여 유기용매 영역의 결정질 성분이 줄어들고, 따라서 전하운반자의 수가 증가하기 때문인 것으로 분석하였다. PANI를 고분자 기질로 적당량 첨가하면, PAN만을 단용으로 사용한 젤-전해질에 비해 기계적 강도가 감소하는 단점이 있기는 하지만, 이온전도성, 열적 특성, 용매와의 혼화성, 전기화학적 안정성, 리튬 전극과의 계면 안정성 등 거의 모든 면에서 성능이 개선되는 것으로 나타났다.

• 대한화학회지
• /
• 제11권2호
• /
• pp.70-76
• /
• 1967

Structural changes attending polyacrylonitrile(PAN) upon heating and treating with nucleophilic reagents have been studied for some time and a few authors have studied on the thermal degradation, particularly on the characterization of degradation products in PAN. It is the purpose of this paper to report the kinetic study on the thermal degradation above $250^{\circ}C$ and make some suggestions as to the degradation process and mechanism in PAN. The degradation process in PAN is considered that three reactions are combined in two steps. Random chain scission accompanying the naphthylidine-type ring formation is the first step and the degradation of naphthylidine-type ring occurred as the next step. The reactions in the first step are competitive so that the maximum weight loss on pyrolysis of PAN, under such a condition that the degradation of naphthylidine-type ring is negligible, is depended on the relative reaction rate of these two competitive reactions.

• Macromolecular Research
• /
• 제15권7호
• /
• pp.605-609
• /
• 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.

• Tribology and Lubricants
• /
• 제25권3호
• /
• pp.176-181
• /
• 2009

Aminated polyacrylonitrile as the new organic disperse phases of the anhydrous ER fluid has been synthesized and ER effect of the suspension composed of aminated polyacrylonitrile in silicone oil investigated. The suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the suspension exhibited the dependence with a factor equals to 1.6 power on theelectric field. The current density and the conductivity of the of aminated polyacrylonitrile suspension increase with the electric field intensity and moreover the conductivity of the suspension is about 8 order of magnitude higher than that of the silicone oil. On the basis of the the results, aminated polyacrylonitrile suspension showed the ER flow behavior upon application of the electric field due to the polarizability of the branched amine polar group of the aminated polyacrylonitrile particles.

• 한국환경과학회지
• /
• 제25권12호
• /
• pp.1613-1622
• /
• 2016

Zeolite (FZ), prepared from fly ash, was immobilized with polyacrylonitrile (PAN) to fabricate PAN/FZ beads. The prepared PAN/FZ beads were characterized by scanning electron microscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The optimum ratio to prepare PAN/FZ beads was 0.3 g of PAN to 0.3 g of FZ. The diameter of the prepared PAN/FZ beads was about 3 mm. Sr and Cu ion adsorption experiments were conducted with PAN/FZ beads. A pseudo-second-order model fit the kinetic data for Sr and Cu ion adsorption by PAN/FZ beads well. The equilibrium data fitted well with the Langmuir isotherm model, and the maximum adsorption capacities were 96.5 mg/g and 74.6 mg/g for the Sr and Cu ions, respectively. Additionally, the values of thermodynamic parameters such as Gibbs free energy (${\Delta}G^o$), enthalpy (${\Delta}H^o$) and entropy (${\Delta}S^o$) were determined. The positive values of ${\Delta}H^o$ revealed the endothermic nature of the adsorption process and the negative values of ${\Delta}G^o$ were indicative of the spontaneity of the adsorption process.

• 한국세라믹학회지
• /
• 제43권4호
• /
• pp.203-206
• /
• 2006

Polyacrylonitrile (PAN) nanofibers, which are pH-sensitive and exhibit soft actuation as a linear actuator and artificial muscles, were prepared by electrospinning to investigate the effect of viscosity on the morphology of PAN fibers. Experimental results revealed that higher viscosity is critical for the formation of unbeaded nanofibers because surface tension is almost constant throughout the experiment. Uniform, smooth, and continuous fibers with diameters of about 700 nm were achieved for the 10 wt% PAN fibers at a flow rate of 0.5 mL/h and an electric field of 0.875 kV/cm.

• 한국재료학회지
• /
• 제17권5호
• /
• pp.278-282
• /
• 2007

Polyacrylonitrile nanofibers were fabricated by co-electrospinning technique and were characterized using scanning electron microscopy(SEM). We have evaluated systematically the effects of the important processing parameters affected on the morphology of the formed fibers; voltage, solution concentration and tip to collector distance. PAN nanofibers of about 200 nm${\sim}$2500 nm in diameter were well fabricated at the polymer concentration of 7.5 wt%${\sim}$15 wt%. It has been found that the average diameter of PAN nanofibers increased with increasing the concentration of PAN solution due to the reduction of whipping and splitting for the high viscosity solution. we also found an evidence that the applied voltage is strongly correlated with the distribution of nanofibers and the uniformed size of nanofibers were obtained at electrostatic value of 1 kV/cm.

• 멤브레인
• /
• 제29권3호
• /
• pp.123-129
• /
• 2019

가속화되는 산업화로 인해 중금속 이온의 침출이 환경문제로 떠오르고 있다. 수질 정화를 위한 몇 가지 방법 중 기능성 고분자 섬유를 이용한 흡착은 효율적이며 경제적이라는 장점이 있다. 특히, 폴리아크릴로나이트릴(polyacrylonitrile, PAN)은 금속 이온을 흡착할 수 있는 작용기가 많아 관심을 끌고 있다. PAN은 쉽게 전기방사를 통해 고분자 나노 섬유화될 수 있으며 높은 표면적을 가질 수 있다. 본 총설에서 다룰 복합 PAN 섬유는 폐수 처리를 위한 또 다른 유형의 고분자이다.