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1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU)의 탈불화를 이용한 PVDF와 PTFE로부터 메조포러스 탄소의 합성
손인식,황버들,전상은 대한금속·재료학회 2021 대한금속·재료학회지 Vol.59 No.5
Porous carbon has found commercial applications as a filter material based on the sorption ability of its pores. The pore size and surface properties of the carbon can be varied depending on the type of particles to be filtered. Here, mesoporous carbon was induced through the pyrolysis of polyvinylidene fluoride (PVDF) to fabricate a porous material for microparticle filtration. Because removal of the constituent fluorine at elevated temperature leaves small-sized micropores, the PVDF precursor mainly generates micropores during pyrolysis. To suppress the micropore evolution mechanism, the PVDF precursor was defluorinated before the heat treatment using 1,8-Diazabicyclo[5.4.0]undec-7-ene(DBU) and then pyrolyzed. The suppressed evolution of the micropores during carbon synthesis leads to a lower specific surface area, suggesting low adsorption capacity. The polytetrafluoroethylene (PTFE) was mixed with the PVDF precursor to induce mesoporosity. The PVDF precursor mixed with the PTFE enhanced the surface area since the PTFE could be removed, leaving mesopores after pyrolysis. The effect of the defluorination process on the porosity was investigated by varying the ratio of DBU to vinylidene fluoride unit (1, 5, 10, 20) in the precursor solution. With higher DBU content in the precursor, the micropore evolution was reduced with a lower specific surface area. The porous carbons synthesized from the precursor with a high DBU amount (DBU/vinylidene fluoride unit = 5, 10, 20) were almost entirely composed of mesopores. In addition, the higher DBU content reduced the hydrophilicity of the synthesized carbon. In summary, to separate and absorb relatively large impurities, the mesoporous carbon should be synthesized using a mixture of PVDF and PTFE precursor with an appropriate amount of DBU for a higher specific surface area.
孫仁植 釜山工業大學校 1982 論文集 Vol.23 No.2
相關係數가 0.7以上의 것이 20個項이였으며, 0.9 以上의 良好한 相關性이 4個項으로, 그들의 回掃直線式은 BOD=2.3(Cl-)-7.8(大淵川), 濁度=1.2(BOD)+46.7(大淵川), DOD=3.2(COD)-21(龍湖川), SS=1.5(COD)-5.1(寶水川)로 밝혀졌다. There can be found 20 item being 0.7 interrelationship and 4 excellent item being 0.9 interrelationship as the result of test. Thus the equation of regression curve couldbe expressed as the following formula. BOD=2.3(Cl-)-73.8 Turbidity=1.2(BOD)+46.7 BOD=3.2(COD)-21 SS=1.5(COD)-5.1