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< 전시-P-76 > TEMPO 산화 셀룰로오스의 PDDA/SiO<sub>2</sub> 혼합에 따른 특성 분석
황교정,권구중,양지욱,김성열,김대영 한국목재공학회 2018 한국목재공학회 학술발표논문집 Vol.2018 No.1
셀룰로오스 나노섬유는 기계적 강도, 분산성, 생분해성 등의 우수한 특성을 가지고 있어 이를 활용한 다양한 산업분야에서 활용하기 위한 연구가 활발하다. 현재, 셀룰로오스 나노섬유 제조에는 고결정성 셀룰로오스의 분산성이 우수한 TEMPO (2,2,6,6-tetramethyl piperidin-1-oxyl radical) 산화 반응 처리법을 많이 이용되고 있다. 이렇게 제조된 셀룰로오스 나노섬유는 분산액 형태로 다양한 수용성 폴리머와 블렌드 혼합 및 유기·무기계 안료와 복합화하여 쉬트 및 섬유화로 가능하여 고기능 포장재료, 투명 유기판부재, 고기능 섬유 등에 응용하여 새로운 고기능성 제품 개발이 기대되고 있다. 본 연구는 TEMPO 산화 셀룰로오스에 SiO<sub>2</sub>혼합시 가교제로서 양이온 고분자인 Polydiallyldimethylammonium chloride (PDDA) 첨가시 혼합비율이 셀룰로오스 나노섬유특성에 미치는 영향에 대해서 검토하였다. TEMPO산화 셀룰로오스에 SiO<sub>2</sub> 혼합시 가교제 역할을 하는 PDDA의 혼합비가 증가할수록 SiO<sub>2</sub>는 콜로이드 상태로 존재하는 것이 확인되었다. SEM /EDS 분석을 통해 TEMPO 산화 셀룰로오스에 PDDA/SiO<sub>2</sub> 의 혼합비율을 5 : 5로 해서 반응시킨 시료는 나노섬유의 표면이 매끄러운 형태였으며, 섬유에 실리카 결정들이 분포된 것으로 확인되었다. FT-IR 분석으로 TEMPO 산화 셀룰로오스에 PDDA와 SiO<sub>2</sub>의 존재를 확인하였다. 따라서 TEMPO산화 셀룰로오스와 SiO2 혼합에 PDDA의 혼합비율이 크게 영향을 주는 것으로 판단된다.
알칼리 용제를 이용하여 제조한 셀룰로오스 겔의 카드뮴 흡착특성
황교정,권구중,양지욱,황원중,황재현,김대영 한국펄프·종이공학회 2015 펄프.종이技術 Vol.38 No.1
This study was carried out to investigate the characterization of cadmium adsorption by cellulose hydrogel and aerogel. Hydrogel and aerogel were made from ashless pulp dissolved in alkali hydroxide-urea aqueous solution and manufactured in film and bead types. After regeneration of cellulose, hydrogel went through the process of substitution of organic solvent and freeze-dry in order to make aerogel. SEM was used to analyze the microstructure of hydrogel and aerogel. Experiment was conducted in various concentrations and pH conditions to find out the characteristic of cadmium adsorption. After that, EDS was used to identify existence and distribution of cadmium in hydrogel and aerogel. The result from comparisons of cadmium adsorption shows that bead type aerogel has the maximum cadmium adsorption and film type hydrogel has the minimum cadmium adsorption.
Characteristics of Cellulose-Microalgae Composite
황교정,권구종,양지욱,김성열,김대영 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.71 No.8
The composites were prepared in order of mixing the cellulose with the N. commune, dissolutionregeneration procedure by LiOH/Urea aqueous solution and freeze-drying. Before the freeze-drying, internal pores of the composites were substituted with an organic solvent. SEM analysis showed that the increase of N. commune results in blockage of cellulose network structure. Brunauer- Emmett-Teller (BET) surface area analysis showed the decrease of mesopore and macropore as the N. commune ratio increases, also the decrease of the specific surface area was shown. The composites appear to have different thermogravimetric analysis properties with the pure N. commune or cellulose itself. Fourier transform infrared spectroscopy (FT-IR) spectra of the composites have specific peaks of the cellulose and N. commune, and increase of N. commune ratio results broadening of peaks relevant to proteins, lipids, and fatty acids. The composites showed higher adsorptivity as the N. commune ratio increases. Especially, the adsorptivity was higher than active carbon before 120 minutes of adsorption. The composite is expected to be used for the situations which need urgent adsorption.
셀룰로오스 나노섬유(CNFs)로 제조된 에어필터의 공극 크기 조절을 위한 실리카 나노입자 도입 효과
황교정,박지수,이태주,권재경 한국펄프·종이공학회 2023 펄프.종이기술 Vol.55 No.1
CNF (Cellulose nanofiber) air filter incorporated with the inorganic nanoparticle (SiO2, silicon dioxide) was explored. Vacuum filtration process was applied to prepare the air filter and optimized through the analysis in morphology, appearance observation, and filtration time. The SiO2 nanoparticles were introduced to control the pore structure of the CNFs based filter. FT-IR (Fourier transform infrared spectroscopy) and EDS (Energy dispersive X-ray spectrometer) results showed that the SiO2 nanoparticles were effectively attached on the surface of CNFs. SEM (Scanning electron microscope) images showed that the inorganic nanoparticles formed the homogeneous pore structure in the CNF filter. Finally, the CNF air filter with SiO2 had a particle (PM2.5) removal efficiency of about 70%. Pore control of the aifilter by adding SiO2 improved PM2.5 removal performance of the air filter by approximately 20% compared to the CNF air filter without the inorganic nanoparticles. These results demonstrated that the introduction of the inorganic nanoparticles in an CNF filter preparation can be a good approach to enhance the filter performace and control their pore structure. .
Cellulase 활성 미생물 전처리에 따른 셀룰로오스 섬유의 특성 변화
황교정,박지수,전상진,오유진,이지은,이태주,권재경 한국펄프·종이공학회 2023 펄프.종이기술 Vol.55 No.2
This study evaluated the effects of microbial (Bacillus subtilis, Bacillus licheniformis) pretreatment and mechanical (ball mill) treatment on the nanofibrillation of cellulose. The optimal growth conditions were identified a B. subtilis (pH 6-8, 25℃ and 100 rpm) and B. licheniformis (pH 7, 35℃ and 150 rpm), respectively. As a result of evaluating microbial reducing sugar production from carboxymethyl cellulose, B. subtilis case showed similar trends at most experimental conditions (pH, temperature and rpm) except for pH 5. The maximum amount of reducing sugar by B. licheniformis was achieved at the culture conditions with pH 7, 35℃ and 150 rpm. There was no change in the crystalline structure of cellulose by ball mill and microbial treatment, but, XRD peaks intensity decreased. Cellulose nanofibers were observed after 6 hours ball mill treatment of alpha cellulose with/without the microbial pretreatment. When applying microbial pretreatment, the cellulose nanofibers produced by the ball mill had more longer in length than those without the pretreatment. .