나노실리카와 TEOS가 함유된 친수성 코팅액의 태양광 유리팬널에 미치는 표면 특성 연구

이 수(Soo Lee),김승혜(Seung Hye Kim),황 헌(Heon Hwang) 한국유화학회 2017 한국응용과학기술학회지 Vol.34 No.1

태양광 발전의 효율을 높이기 위한 실란 커플링제와 나노 무기산화물을 첨가한 계면활성제를 이용한 친수성 코팅액을 제조하여 태양광 모듈의 유리 표면에 도포하여 김서림 방지(antifogging) 및 내오염성(antifouling)을 부여하였다. 1% 친수성 코팅액에 나노 무기산화물인 LudoxⓇ를 첨가한 경우 LudoxⓇ의 농도에 관계없이 초친수성과 우수한 antifogging 효과를 나타내었다. 그러나 유리에 대한 antifouling 효과는 LudoxⓇ를 10% 이상 첨가하였을 때부터 발현되었다. 또한, pH 4에서 가수분해한 TEOS를 첨가한 코팅액의 경우 TEOS를 0.7% 첨가한 경우 steam test 결과 antifogging 효과를 유지하였으며, 코팅한 유리 표면을 젖은 킴와이프로 100회 문지른 후에도 pollution test 결과 antifouling 효과를 유지하였다. 또한, AFM을 이용하여 표면 거칠기(Rq)를 확인한 결과 TEOS를 너무 많이 첨가하면 가장 높은 표면 거칠기 값을 보였으며 코팅된 표면의 상태도 매우 불규칙하였다. TEOS가 0.7% 첨가된 경우 비교적 높은 표면 거칠기 값과 안정된 표면 상태를 나타내었다. 결론적으로 김서림 방지 특성만을 위하여는 나노 무기산화물인 LudoxⓇ는 필요없으나, antifouling의 효과를 나타내기 위해서는 최소 10%의 LudoxⓇ가 첨가되어야 하며, 우수한 내구성을 나타내기 위해서는 0.7%의 TEOS를 첨가해야 한다. A hydrophilic coating solution was prepared by adding a silane coupling agent and a nano-inorganic oxide in aqueous surfactant solution to increase the efficiency of photovoltaic power generation due to the introduction of antifogging and antifouling properties on the glass surface of the solar cell module. Addition of LudoxⓇ, a nano-inorganic oxide, to 1% hydrophilic coating solution showed improved hydrophilicity and excellent antifogging effect regardless of LudoxⓇ concentration. However, the antifouling effect on the glass surface was showed only when Ludox was added more than 10%. In the case of addition of 0.7% of hydrolyzed TEOS at pH 4, the antifogging effect was maintained as a result of the steam test as well as the antifouling effect even after the coated glass surface was rubbed 100 times with a wet Kimwipe. In addition, from the surface roughness (Rq) calculated using AFM data, the higher surface roughness with irregular surface shape was obtained with the higher concentration of TEOS. The addition of 0.7% of TEOS showed relatively high surface roughness and well organized surface condition which can help to improve transmittance of light. In conclusion, LudoxⓇ is not required only for the antifogging property. However, at least 10% of Ludox should be added to show antifouling effect and 0.7% of TEOS should be added for good durability.

퇴적층 남조류 휴면세포의 생리적-분자생물학적 연구를 위한 Ludox 처리법

김건희,유경은,호혜인,박채홍,김현진,황순진 한국하천호수학회 2023 생태와 환경 Vol.56 No.1

Cyanobacterial resting cells, such as akinetes, are important seed cells for cyanobacteria’s early development and bloom. Due to their importance, various methods have been attempted to isolate resting cells present in the sediment. Ludox is a solution mainly used for cell separation in marine sediments, but finding an accurate method for use in freshwater is difficult. This study compared the two most commonly used Ludox methods (direct sediment treatment and sediment distilled water suspension treatment). Furthermore, we proposed a highly efficient method for isolating cyanobacterial resting cells and eDNA amplification from freshwater sediments. Most of the resting cells found in the sediment were akinete to the Nostocale and were similar to those of Dolichospermum, Cylindrospermum, and Aphanizomenon. Twenty times more akinetes were found in the conical tube column using the sediment that had no treatment than in the sample treated by suspending the sediment in distilled water. Akinete separated through Ludox were mainly spread over the upper and lower layers in the column rather than concentrated at a specific depth in the column layer. The mibC, Geo, and 16S rDNA genes were successfully amplified using the sediment directly in the sample. However, the amplification products of all genes were not found in the sample in which the sediment was suspended in distilled water. Therefore, 5 g to 10 g of sediment is used without pretreatment when isolating cyanobacterial resting cells from freshwater sediment. Cell isolation and gene amplification efficiency are high when four times the volume of Ludox is added. The Ludox treatment method presented in this study isolates cyanobacterial resting cells in freshwater sediment, and the same efficiency may not appear in other biotas. Therefore, to apply Ludox to the separation of other biotas, it is necessary to conduct a pre-experiment to determine the sediment pretreatment method and the water layer where the target organism exists.

유해남조류 발생 잠재성 분석을 위한 eDNA 기반의 퇴적물 전처리 방법: 밀도 구배 원심분리법(Ludox method)

유경은,호혜인,김현진,김건희,황순진 한국하천호수학회 2023 생태와 환경 Vol.56 No.1

Environmental DNA (eDNA) can exist in both intracellular and extracellular forms in natural ecosystems. When targeting harmful cyanobacteria, extracellular eDNA indicates the presence of traces of cyanobacteria, while intracellular eDNA indicates the potential for cyanobacteria to occur. However, identifying the “actual” potential for harmful cyanobacteria to occur is difficult using the existing sediment eDNA analysis method, which uses silica beads and cannot distinguish between these two forms of eDNA. This study analyzes the applicability of a density gradient centrifugation method (Ludox method) that can selectively analyze intracellular eDNA in sediment to overcome the limitations of conventional sediment eDNA analysis. PCR was used to amplify the extracted eDNA based on the two different methods, and the relative amount of gene amplification was compared using electrophoresis and Image J application. While the conventional bead beating method uses sediment as it is to extract eDNA, it is unknown whether the mic gene amplified from eDNA exists in the cyanobacterial cell or only outside of the cell. However, since the Ludox method concentrates the intracellular eDNA of the sediment through filtration and density gradient, only the mic gene present in the cyanobacteria cells could be amplified. Furthermore, the bead beating method can analyze up to 1 g of sediment at a time, whereas the Ludox method can analyze 5 g to 30 g at a time. This gram of sediments makes it possible to search for even a small amount of mic gene that cannot be searched by conventional bead beating method. In this study, the Ludox method secured sufficient intracellular gene concentration and clearly distinguished intracellular and extracellular eDNA, enabling more accurate and detailed potential analysis. By using the Ludox method for environmental RNA expression and next-generation sequencing (NGS) of harmful cyanobacteria in the sediment, it will be possible to analyze the potential more realistically.

중형저서동물에서 효율적인 DNA 추출 방법 비교 연구

이승한 ( Seung Han Lee ),백진욱 ( Jin Wook Back ),이원철 ( Won Choel Lee ) 한국환경생물학회 2011 환경생물 : 환경생물학회지 Vol.29 No.3

The efficiency of mtCOI amplication after DNA extraction of benthic harpacticoid Tigriopus japonicus s.l. was tested under different conditions depending on fixative (99% Ethanol, or 4% Formalin) and additional chemicals (Ludox or Rose Bengal). Each experimental group by the fixative was subdivided into four groups, respectively: 1) Control (fixative only), 2) processed with Ludox HS40, 3) processed with Rose Bengal, and 4) processed with both Ludox HS40 and Rose Bengal. For the 99% ethanol fixed sample, overall success rate of amplification by PCR was 96% or above, while for the 4% formalin fixed one, success rate was much lower than those of ethanol fixed: 1) Control: 27%, 2) Ludox HS40: 3%, 3) Rose Bengal: 7%, and 4) Ludox HS40 and Rose Bengal: 3%. As a result present study verify that 99% ethanol is a proper fixative for DNA extraction in meiofauna organisms.

Effect of different amorphous silica mixing ratios on grain-boundaries of MFI membranes and separation performance

오연정,이평수 한국공업화학회 2022 한국공업화학회 연구논문 초록집 Vol.2022 No.1