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PEG(Polyethylene glycol)처리에 의한 국내산 주요 소경재의 치수 안정화에 관한 연구
권구중,김남훈 한국목재공학회 2002 목재공학 Vol.30 No.1
PEG처리에 의한 국내산 주요 소경재 다섯 수종(소나무,. 잣나무, 일본잎갈나무, 신갈나무, 굴참나무)의 치수안정성을 조사하고, 목재내의 PEG분포를 X선회절법에 의해 검토하였다. 그 결과 공시수종 모두 PEG 30%의 수용액에서 좋은 치수안정 효과를 보여주었다. 또한 PEG농도 증가에 따라 PEG처리 목재의 중량증가율과 벌킹효과가 증가하였는데 침엽수재가 활엽수재에 비해 그 정도가 크게 나타났다. X선회절 결과, 잣나무는 만재와 조재 모두 2θ= 19°와 2θ= 23° 부근에서 PEG 결정유래의 피크가 출현하였으나, 신갈나무는 공권부와 공권외부에서 목재 셀룰로오스결정 이외의 PEG결정 유래의 피크가 나타나지 않았다. 이러한 X선회절 결과는 잣나무재내에 신갈나무재보다 더 많은 양의 PEG가 존재하는 것을 의미하는 것으로서 치수안정성이 큰 이유를 설명해 주는 증거의 하나로 생각되었다. This study was carried out to investigate the dimensional stability of three softwoods (Pinus densiflora S. et Z., Pinus koraiensis S. et Z., Larix kaempferi C_ARR.) and two hardwoods(Quercus mongolica F., Quercus variabilis B_L.) treated with polyethylene glycol(PEG). Existence of PEG in wood was examined by an X-ray diffraction method. Shrinkage of the sample woods decreased with increasing concentration of PEG. The dimensional stability of five species had improved highly in thirty percent solutions of PEG with molecular weight 1000∼4000, and the dimension of PEG-treated softwoods was more stable than that of PEG-treated hardwoods. Weight gain and bulking effect of the woods treated with PEG increased with increasing concentration of PEG. X-ray diffractograms of Pinus koraiensis wood treated with PEG showed two peaks derived from PEG crystal at 2θ= 19°and 2θ= 23°. However, the diffractograms of Quercus mongolica wood did not present any peaks caused by PEG crystal. From the result of X-ray diffraction, it was revealed that the content of PEG in Pinus koraiensis wood was higher than that in Quercus mongolica wood.
권구중,권성민,김남훈 한국목재공학회 2003 목재공학 Vol.31 No.4
본 연구에서는 국내산 소경재의 보다 효율적인 이용을 위하여 PEG처리한 활엽수재의 환공재 4수종(신갈나무, 굴참나무, 물푸레나무, 오동나무)과 산공재 4수종(산벚나무, 물박달나무, 층층나무, 은사시나무)에 대한 치수안정성을 평가하였다. 수축률은 공시수종 모두 PEG처리에 의해 감소하는 효과가 있었고, 산공재가 환공재보다 낮았다. 중량증가율은 PEG농도의 증가에 따라 증가되었고, 산공재가 환공재보다 다소 높은 증가율을 보여주었다. 벌킹효과는 PEG농도의 증가에 따라 증가하였지만, 분자량이 클수록 감소하였고, 산공재가 환공재보다 벌킹효과가 높게 나타났다. 결론적으로, 산공재가 환공재보다 높은 치수안정성을 보여주었다. 따라서 PEG처리재의 치수안정효과는 목재의 구조(도관의 분포상태 및 타이로시스 존재유무)와 밀도에 크게 영향받는 것으로 생각되었다. This study was carried out to investigate the dimensional stability of wood treated with PEG for better utilization of domestic small-diameter logs. Four species of ring-porous wood(Quercus mongolica F_(ISCH), Quercus variabilis B-(LUME), Fraxinus rbynchopbhlla H_(ANCE), Paulownia coreana U_(YEKI),) and fore species of diffuse-porous wood(Prunus sargentii R-(EHDER), Betjal davurica P_(ALL), Populus tomentiglandulosa T. L_(EE), cornus controversa H_(EMSLEY)) were used for this experiment. The shrinkage of wood decreased with increasing the concentration of PEG. The shrinkage of diffuse- porous woods was lower than that of ring-porous woods. The weight gain increased in proportional to the PEG concentration. Diffuse-porous woods showed a little higher weight gain than ring-porous woods. Bulking effect also increased with increasing the PEG concentration, but was in inverse proportional to the molecular weight of PEG. Diffuse-porous woods showed higher bulking effect than ring-porous woods. Consequently, diffuse-porous woods showed better dimensional stability than ring porous woods. It was considered that dimensional stability was affected by characteristics of wood such as vessel and tylosis, and density.
염화아연(ZnCl<sub>2</sub>) 부활법에 의해 제조한 목재 활성탄의 특성
권구중,권성민,김남훈,Kwon, Gu-Joong,Kwon, Sung-Min,Kim, Nam-Hun 강원대학교 산림과학연구소 2007 Journal of Forest Science Vol.23 No.1
본 연구는 염화아연을 이용한 화학약품 부활법으로 잣나무재 활성탄을 제조하기 위해 원료에 대한 화학약품부활제 비율의 영향을 검토하였다. 염화아연과 혼합한 목분은 질소분위기에서 상온에서 $600^{\circ}C$까지 1시간 열처리하여 중량변화를 측정하였다. 이 처리과정에 있어 활성탄 내부에 다양한 공극크기 분포와 표면특성이 확인되었다. 즉, 최대 BET 표면적과 총 공극체적은 목분에 대하여 염화아연의 비율이 5배인 경우였으며, 각각 그 값은 $1468m^2/g$와 1.74 cc/g이었다. 결론적으로 활성탄 제조시 화학약품부활제의 비율에 의해 활성탄의 특성이 뚜렷하게 차이가 나타나는 것이 확인되었다. The effect of ratio between chemical activating agent and raw material in the preparation of activated carbons from wood has been studied. Pinus koraiensis wood and zinc chloride ($ZnCl_2$) were used for materials in this study. Mixtures of wood and zinc chloride were heated under nitrogen flow in the temperature ranging from room-temperature to $600^{\circ}C$ for 1 hr using thermogravimetric technique. During heat treatment, activated carbons with various pore size and specific surface properties were obtained. The maximum BET surface area and total pore volume were $1468m^2/g$ and 1.74 cc/g, respectively, at the mixture ratio of 1 (wood powder) to 5 ($ZnCl_2$). It can be concluded that the differences in the properties of the activated carbons were related significantly with the ratio of chemical activating regent.
권구중,김대영,김은지,강주현 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.4
This study investigated adsorption characteristics of lead on bead-type holocellulose aerogels synthesized from wood fiber by using an alkali hydroxide - urea solution. The synthesized holocellulose aerogels were classified into two groups for comparison according to the source of the precursor hydrogel, a dissolved upper layer and a precipitated bottom layer of hydrogel solution, formed during the synthesis procedure. As the equilibrium concentration of lead in the solution was increased, the amount of lead adsorbed on the holocellulose aerogel increased, eventually reaching a maximum. As the pH was increased, the adsorption capacity of lead also increased. The adsorption rate rapidly increased during the earlier 10 min period and then asymptotically approached equilibrium. However, as the lead concentration in the water was increased, the time required for achieving equilibrium also increased due probably to the dynamic exchange of lead molecules during the adsorption process. The lead adsorbed to the aerogels was visually identified by using Scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) analyses. This study suggests that the holocellulose aerogel can be potentially used in many water treatment applications targeting heavy - metal, including lead, removal.
권구중,김대영,강규영 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.10
Pretreatment of cellulose at below 300 ℃ prior to the carbonization at 1200 ℃ was studied for the production of high-yield biocarbons. Filter paper as the cellulosic raw material was pyrolyzed by heating schemes including 16-h isothermal step at 215-270 ℃ under nitrogen atmosphere, followed by fast heating up to 600 ℃ and finally to 1200 ℃. Cellulose degradation was completed in the 16-h holding isothermal step at above 250 ℃, and it was confirmed by the analyses of IR spectroscopy and X-ray diffraction. The yield of char was increased from 11% to 21% by pretreatment of cellulose after post-treatment at 600 ℃ or 1200 ℃. The BET surface area as the microporosity value was also significantly enhanced from 461 m<SUP>2</SUP>/g to 837 m<SUP>2</SUP>/g by straight heating of 10 ℃/min. It is considered that these results caused by slow heating and stabilizing effects by pretreatment of cellulose at the critical temperature for degradation.