표고 재배 중 톱밥 배지의 물리적 성질과 목재 화학성분 변화

이종신,강석구,양승민,김진경 한국균학회 2022 韓國菌學會誌 Vol.50 No.4

In this study, the physical properties of the medium and changes in the wood chemical composition of the sawdust were investigated during the cultivation of oak mushroom sawdust bags, and the following results were obtained. After inoculation, the weight of the medium decreased during the incubation period. It is determined that this is not due to evaporation of moisture containing the medium or decomposition of sawdust, but to decomposition of rice bran, a low molecular substance added to the medium. It was confirmed that the moisture content of the medium was steadily increased during incubation, and it was estimated that the organic substrates such as rice brane in the medium was decomposed by mycelium, and water, one of the decomposition products of organic substrates, caused an increase in the moisture content of the medium. Along with the increase in the harvest of oak mushrooms, the proportion of organic substances such as holocellulose and lignin, the main components of the wood cell wall of sawdust, steadily decreased. In particular, the degradation characteristics of the wood cell wall component of shiitake, which is a white rot fungi, were confirmed by higher lignin reduction rate than that of holocellulose. On the other hand, ash, which is an inorganic material, increased with an increase in the number of mushroom harvests. The increase in the amount of ash in the medium may have been due to the decrease in the organic matter content such as holocellulose and lignin.

Sodium Hydroxide-urea 수용액을 이용하여 제조한 셀룰로오스계 에어로겔의 특성

김은지 ( Eun Ji Kim ),권구중 ( Gu Joong Kwon ),김대영 ( Dae Young Kim ) 한국목재공학회 2013 목재공학 Vol.41 No.4

Sodium hydroxide-urea 수용액을 이용한 다공성 셀룰로오스계 에어로겔은 용해, 겔화, 재생, 유기용매 치환과 동결건조과정에 의해 제조되었다. 에어로겔의 구조적 특성과 다공성은 주사전자현미경과 질소흡착장치를 이용하여 분석하였다. 그 결과, 용해펄프는 완전히 용해되었지만, 여과지와 홀로셀룰로오스는 원심분리과정에서 수용액에 용해된 부분과 용해되지 않은 부분으로 구분되었다. 용해펄프 에어로겔의 표면은 다공성 공극, 내부는 그물모양의 망목상 구조가 관찰되었다. 여과지와 홀로셀룰로오스 에어로겔은 표면이 압축된 다공성 네트워크 형태였고, 내부는 open-pore 구조의 나노피브릴 네트워크로 구성되었다. 홀로셀룰로오스 에어로겔에서 수용액에 용해되지 않는 형태의 섬유들이 관찰되었다. 용해펄프로부터 만들어진 에어로겔의 비표면적은 260∼326 ㎡/g 범위였고, 농도 증가와 함께 감소하였다. 그러나 여과지 에어로겔의 비표면적(198∼418 ㎡/g)은 농도 증가와 함께 증가하였다. 홀로셀룰로오스 에어로겔은 2% 농도에서는 137 ㎡/g로 농도의 증가와 함께 증가하여 4% 농도에서 401 ㎡/g로 최댓값을 보여주었고, 5% 농도에서 감소하였다. The highly porous cellulosic aerogels were prepared by freeze-drying method using sodium hydroxide-urea aqueous solution in the process of dissolution, gelation, regeneration and organic solvent substitution. The structural characteristics of porous aerogel were analyzed using scanning electron microscopy and nitrogen adsorption apparatus. As a result, the dissolving pulp was completely dissolved, but filter papers and holocellulose were divided into two layers (dissolved and undissolved parts) in the process of centrifugation. The structure of aerogel from dissolved pulp showed porous pores in the surface and net-shaped network in the inner part. Aerogels from filter paper and holocellulose had the condensed porous network surface and the open-pore nano-fibril network inner structure. Undissolved form of fibers was observed in the aqueous solution of aerogel from holocellulose. The BET value (SBET) of aerogel from dissolved pulp was ranged in 260∼326 ㎡/g, and it was decreased with the increase of concentration. Whereas, the SBET value of aerogel from filter paper (198∼418 ㎡/g) was increased with the increase of concentration. The SBET value of aerogel from holocellulose were 137 ㎡/g at 2% (w/w) of cellulose, and it was increased to maximum 401 ㎡/g at 4% (w/w) of cellulose. Then, it was decreased at 5% (w/w) of cellulose.

홀로셀룰로오스 에어로겔의 특성

권구중 ( Gu Joong Kwon ),김대영 ( Dae Young Kim ),김남훈 ( Nam Hun Kim ) 한국목재공학회 2010 목재공학 Vol.38 No.3

본 연구는 홀로셀룰로오스를 이용하여 제조한 에어로겔과 에어로겔의 열적특성 및 다공성에 대해서 검토하였다. 홀로셀룰로오스는 alkali hydroxide-urea 용액으로 용해 및 겔화시켜 동결건조로 에어로겔을 제조하였다. 홀로셀룰로오스 에어로겔은 그물모양 또는 스폰지와 같은 다공성구조로 이루어졌다. 밀도는 0.04 g/cm3이었고, 비표면적은 145.3 m2/g이었다. 에어로겔의 열분해는 210∼350°C의 온도범위에서 일어났으나, 저속의 승온조건일수록 열분해가 보다 낮은 온도에서 일어났다. 홀로셀룰로오스 에어로겔은 승온조건이 저속일수록 micro pore체적이 증가하였다. 홀로셀룰로오스 에어로겔 탄화물의 비표면적은 0.5°C/min의 승온조건이 656.7 m2/g로 가장 높았다. 탄화물들은 에어로겔의 구조가 열에 의해 섬유의 배열이 변형되어 불규칙적 구조로 변화된 것이 주사전자현미경에 의해 관찰되었다. This study was carried out to investigate the characterization of aerogel made by holocellulose, the thermal properties of the aerogel, and its shapes and porous structures. The aerogel was made by holocellulose through the gelation in alkali hydroxide-urea solution and freeze drying processes. Holocellulose aerogel had porous structure such as net or sponge. The density of holocellulose aerogel was 0.04 g/cm3, and the specific surface area 145.3 m2/g. Although thermal degradation occurred in the range of 210∼350°C, significant thermal degradation occurred at low temperature with low heating rate, Micropore volume was sharply increased with low heating rate. Holocellulose aerogel char obtained by carbonization with 900°C and 0.5°C/min. heating rate had the highest surface area, 656.7 m2/g. The deformed and irregular structures of holocellulose aerogel chars due to the thermal degradation were observed in SEM.

Adsorption Capacity of Lead on Holocellulose Aerogels Synthesized from an Alkali Hydroxide - Urea Solution

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.

LiBr 수용액으로 용해시켜 제조한 거대억새 홀로셀룰로오스 용해 및 재생 필름특성

양지욱,권구중,황교정,황원중,황재현,김대영 한국펄프·종이공학회 2015 펄프.종이기술 Vol.38 No.1

In this study, dissolution characteristics of 60% LiBr aqueous solution for Miscanthus sinensis holocellulose in accordance with heating time and characteristics of regenerated films were analyzed. Miscanthus sinensis holocellulose was made by peracetic acid method. During the dissolution of 60% LiBr solution for the holocellulose, the dissolution was started from the tip of the cellulose fiber after about 7 minutes, and proceeded as it swollen like a balloon. A lot of Si was identified by analyzing hollocellulose regenerated film through SEM/EDS. Cross section of regenerated film as dissolution time till 40 minutes of dissolution showed multilayered structure and fiber orientation. But after 40 minutes, multilayered structure and fiber orientation was not observed. The crystal structure of the holecellulose was transformed cellulose I into cellulose II. Therefore, dissolution for 20 minutes with 60% LiBr solution in the condition of 190℃ hot plate was shown as an optimum condition to manufacture the holocellulose regenerated film.

Simultaneous and rapid production of AgNPs and AgNPs decorated holocellulose nanofibrills by microwave irradiation

( Rajkumar Bandi ),한송이,박찬우,박지수,이은아,( Azelia Wulan Cindradewi ),권구중,이승환 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

A novel green method offering the simultaneous production of silver nanoparticles (AgNPs) and AgNPs decorated holocellulose nanofibrills (AgNPs/HCNF) is reported here. This method is rapid (60 sec) and devoid of additional reducing agent. Synthetic conditions were optimized using UV-vis spectroscopy. Morphological features and crystal structure of as obtained nanomaterials were unveiled by transmission electron microscopy (TEM) and powder X-ray diffraction (XRD) techniques. Surface chemical composition was studied by X-ray photoelectron spectroscopy (XPS) and Fourier Transform infrared (FT-IR) spectroscopy. Mechanistic studies revealed the crucial role of hemicellulose in the reduction and stabilization of AgNPs.

LiBr 수용액으로 용해시켜 제조한 거대억새 홀로셀룰로오스 용해 및 재생 필름특성

양지욱(Ji-Wook Yang),권구중(Gu-Joong Kwon),황교정(Kyo-Jung Hwang),황원중(Won-Jung Hwang),황재현(Jae-Hyun Hwang),김대영(Dae-Young Kim) 한국펄프·종이공학회 2015 펄프.종이기술 Vol.47 No.6

In this study, dissolution characteristics of 60% LiBr aqueous solution for Miscanthus sinensis holocellulose in accordance with heating time and characteristics of regenerated films were analyzed. Miscanthus sinensis holocellulose was made by peracetic acid method. During the dissolution of 60% LiBr solution for the holocellulose, the dissolution was started from the tip of the cellulose fiber after about 7 minutes, and proceeded as it swollen like a balloon. A lot of Si was identified by analyzing hollocellulose regenerated film through SEM/EDS. Cross section of regenerated film as dissolution time till 40 minutes of dissolution showed multilayered structure and fiber orientation. But after 40 minutes, multilayered structure and fiber orientation was not observed. The crystal structure of the holecellulose was transformed cellulose I into cellulose II. Therefore, dissolution for 20 minutes with 60% LiBr solution in the condition of 190℃ hot plate was shown as an optimum condition to manufacture the holocellulose regenerated film.

Effects of Wound Dressing with Thiophanate-Methyl Paste on Compartmentalization of Pruning Wounds

이규화,이경준 한국산림과학회 2010 한국산림과학회지 Vol.99 No.2

This study was conducted to examine the effects of wound dressing with thiophanate-methyl paste on the compartmentalization of pruning wounds in Acer palmatum. A total of thirty field-grown trees were used for three different treatments, such as no dressing, dressing once right after pruning cut, and dressing twice, one more dressing treatment one year after initial dressing. Wound closure rate (WCR) and discolored/wound area ratio (D/W ratio) two years after treatment were measured. Variations of extractives, holocellulose and lignin at the treated branch unions were also examined. The WCR of no dressing treatment of 70.9% was significantly lower than those of the two dressing treatments (85.4% and 82.7%, respectively), while the difference between dressing once and twice was not significant. The D/W ratio of no dressing treatment (39.3%) was significantly higher than those of the two dressing treatments (around 30%). Generally, at the branch core of the treated union, contents of extractives and lignin were higher and holocellulose contents were lower than the branch core of the union with living branch. Among the branch core of treated union, no dressing treatment showed a relatively lower holocellulose (63.5%), and relatively higher extractives (2.8%) and lignin (26.6%) than dressing once (66.2%, 1.7%, 26.1%, respectively).

Effects of Wound Dressing with Thiophanate-Methyl Paste on Compartmentalization of Pruning Wounds

Lee, Kyu-Hwa,Lee, Kyung-Joon Korean Society of Forest Science 2010 한국산림과학회지 Vol.99 No.2

This study was conducted to examine the effects of wound dressing with thiophanate-methyl paste on the compartmentalization of pruning wounds in Acer palmatum. A total of thirty field-grown trees were used for three different treatments, such as no dressing, dressing once right after pruning cut, and dressing twice, one more dressing treatment one year after initial dressing. Wound closure rate (WCR) and discolored/wound area ratio (D/W ratio) two years after treatment were measured. Variations of extractives, holocellulose and lignin at the treated branch unions were also examined. The WCR of no dressing treatment of 70.9% was significantly lower than those of the two dressing treatments (85.4% and 82.7%, respectively), while the difference between dressing once and twice was not significant. The D/W ratio of no dressing treatment (39.3%) was significantly higher than those of the two dressing treatments (around 30%). Generally, at the branch core of the treated union, contents of extractives and lignin were higher and holocellulose contents were lower than the branch core of the union with living branch. Among the branch core of treated union, no dressing treatment showed a relatively lower holocellulose (63.5%), and relatively higher extractives (2.8%) and lignin (26.6%) than dressing once (66.2%, 1.7%, 26.1%, respectively).

白色腐朽菌에 依한 현사시나무材의 化學組成分變化에 관한 硏究

金銀姬,金思翼,吳正壽 동국대학교 생명자원과학대학 연습림 1993 연습림논문집 Vol.- No.3

Numbers of various fungi have been shown to degrade lignin at least partially. Fungi with the capacity to remove lignin from wood are of interest in bioconversion process such as biomechanical pulping, biobleaching, treatment of lignin­derived wastes and conversion of lignocellulosics into feed and food. This study was carried out to investigate the extent of lignin biodegradation of hybrid poplar(P. alba×P. grandulosa) during decay process by white rot fungus, Phanerochaete chrysosporium. Hybrid poplar wood block was rotted for 20, 40, 60, 80 days by white rot­fungus, Phanerochaete chrysosporium, and the change in weight loss, alkali solubility, ethanol―benzen extractives, Klason lignin and holocellulose were estimated for each treatment. Wood weight loss after decaying 20, 40, 60, 80 days were 1.98%, 4.36%, 10.19%, 12.25%, respectively. Decaying was proceeded rather fast after 40 days. Lignin, holocellulose and extractives of organic solvent were decreased, but extractives of hot water, alkali were increased. After 80days, Klason lignin and holocellulose content decreased from 21.4% to 14.74%, 83.15% and 64.47% respectively. Tendency of extractives content of hot water, dilute alkali was increased with the increase in the extent of wood decay but extractives content of organic solvent was decreased from 5.17% to 4.11%.