• 한국응용과학기술학회지
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• 제28권2호
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• pp.146-151
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• 2011

In this study, by using oleic acid and polypropylene glycol, good natured antifoaming agent for suitable electronics process under the alkaline conditions were synthesized. For the synthesized mono and diesters, acid value, hydroxyl value was measured, and identified by FT-IR and $^1H-NMR$ spectroscopy. Surface properties such as surface tension, critical micelle concentration(cmc) for diluted aqueous solution was measured, and tested the antifoaming properties according to the difference of alkyl chain length, various concentration, temperature and pH. The surface tension of synthesized antifoaming agent, PPMO(Polypropylene glycol monooleate) was 24.3 dyne/cm, PPDO(Polypropylene glycol dioleate) was 23.7 dyne/cm. By increasing of the alkyl chain length, surface tension was decreased slightly, and showed good antifoaming properties at 0.06 wt% concentration and $50^{\circ}C$, pH 11. These synthesized compounds are expected to apply as a suitable antifoaming agents in the semiconductor and the PCB(Printed Circuit Board) manufacturing process.

• 해양환경안전학회지
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• 제25권1호
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• pp.81-88
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• 2019

본 연구는 실리콘계 소포제가 해양으로 배출되었을 때 소포제 내에 존재하는 주요 성분들이 해양 저서환경에 서식하는 생물에게 미치는 영향을 알아보기 위해 실리콘 및 알코올계 소포제에 대해 저서성단각류(Monocorophium acherusicum)와 발광박테리아(Vibrio fischeri)를 이용하여 해양생태독성실험을 수행하였고 실리콘계 소포제의 주요성분인 디메틸폴리실록산(PDMS)에 대한 수중생물 독성영향을 조사하였다. 실리콘 및 알코올계 소포제에 대한 발광박테리아와 저서성단각류를 이용한 독성실험결과, 실험생물별 독성영향은 발광박테리아가 저서성 단각류에 비해 알코올계 소포제에서 최대 9배 까지 민감한 독성영향을 보였으며 소포제 종류별 독성영향은 실리콘계 소포제가 알코올계 소포제에 비해 최대 400배 이상 높은 독성영향이 나타났다. 실리콘계 소포제의 주요성분인 PDMS가 수중생물에 미치는 영향을 조사한 결과, 식물플랑크톤, 무척추동물 및 어류에 대한 반수치사농도($LC_{50}$)및 반수영향농도($EC_{50}$)값은 $10{\sim}44,500{\mu}g/L$의 범위로 나타났다. 물질의 정성적인 특성을 나타내는 지표인 PBT(P: persistency, B: bioaccumulation, T: toxicity)특성을 PDMS에 적용한 결과, 지속성(P)과 생물농축성(B)의 특성을 가지는 것으로 나타나 PDMS가 해양으로 배출될 경우 생물농축 및 먹이사슬을 통한 상위 영양단계로 축적될 가능성이 존재하며 저서생물에게 부정적인 영향을 미칠 수 있을 것으로 나타났다. 본 연구결과로 향후 실제 해양으로 배출되는 다양한 소포제가 해양생태계에 미치는 영향조사시 소포제 내 주요성분을 고려한 보다 객관적이고 과학적인 위해성평가에 기초자료로 활용될 수 있을 것으로 기대된다.

• 대한화학회지
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• 제44권4호
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• pp.337-342
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• 2000

현재 한전의 화력발전소에서 사용되는 실리콘 오일계 소포제의 품질관리를위해 각종 실험을 실시한 결과 제조업체별로 다른 계면활성제 (예를 들면 유화제와증점제)를 사용하고 있어 가가의 소포제는 특징적인 물성을 나타냄을 확인할 수 있었다. 보다 간편하면서도 정확한 소포제의 품질관리를 위해 고안된본 실험은 소포제에 사용된 계면활성제의 종류나 양에 관계없이 소포제에 함유된 실리콘 오일의 정확한 함량을 측정하고자 시도하였다. 우선 매우 간단한 실험 기구로 행할수 있은 중량법이나 원심분리법을 사용하여 실리콘 오일의 함량을 구한 다음, FT-IR에 의한 분광법을 사용하여 비교${\cdot}$확인하였다. 원심분리법은 바탕실험과 실제 소포제에 대해 적용한 결과, 소포제 내의 실리콘 오일의 전량 회수되지 않으므로 오일 함량의 분석에는 좋은 방법이 될 수 없음을 확인하였다. 한편 일부 회사에서 제조된 소포제의 경우 이들 방법 사리에 상당한 차이를 나타내었다. 비교실험 결과, FT-IR에 의한 분광법이 적은 시료의 양으로 짧은 시간내에 손쉽게 분석이 가능하고 좋은 재현상을 나타내므로, 언급한 전처리 방법과 함께 사용할 경우 첨가된 계면활성제의 종류와 양에 관계없이 좋은 결과를 얻을 수 있다고 판단된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.501-504
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• 2005

This paper discusses the development of drying shrinkage reducing type superplasticizer(DSRS) by varying dosage of polycarboxylic based superplasticizer, liquid type expansive admixture and antifoaming agent. Adequate mixture proportion of each admixture is fixed at 0.3$\%$ of superplasticizer, 0.15$\%$ of liquidtype expansive admixture and 0.0005$\%$ of antifoaming agent to insure the improvement in drying shrinkage as well as comparable to the slump and air content of conventional concrete. With this mixture proportion, compressive strength of concrete using DSRS is comparable to that of conventional concrete. The use of DSRS studied by the authors has a favorable effect on reducing drying shrinkage due to the effect of water content and expansion by expansive admixture.

• 펄프종이기술
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• 제32권3호
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• pp.25-31
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• 2000

It is required to use substantial amount of wet strength resin for producing multi-functional mulch papers since these paper products shold maintain its strength properties when they exposed to outdoor weather for several months. While producing mulch papers it is usual to observe significant amount of foam at white water silo. Thus it is imperative to use defoaming or antifoaming agents. In this study diverse defoaming and antifoaming agents have been tested for their effective-ness in eliminating foams that produced. It was shown that combined use of a silicone type defoamer and a fatty acid type anti-foaming agent was msot effective in eliminating foams. These chemicals were used in trial production of mulch papers and their influence on paper-making wet end system was examined including one pass retention cationic demand con-ductivity pH etc. It was found that the defoaming agents were very effective for removing foams in trial production. Tensile strengths of the mulch papers produced were significantly greater than commericial mulch papers produced in Japan.

• 대한토목학회논문집
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• 제26권3A호
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• pp.547-553
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• 2006

안료가 칼라콘크리트의 성질에 미치는 영향을 알아보기 위해 산화철이 주성분인 적색, 황색 및 흑색 안료와 동 프탈로시아닌을 착색성분으로 하는 청색과 녹색 안료 5종류를 사용하여 모르타르와 콘크리트 실험을 실시하였다. 안료의 종류 및 첨가율에 따라 모르타르 및 콘크리트의 품질특성이 차이가 있었다. 적색, 황색 및 흑색 안료를 첨가한 콘크리트의 응결시간은 다소 빨라지고 압축강도는 약간 증가하는 경향이었으며, 슬럼프 및 공기량은 거의 같거나 감소하였다. 반면, 청색 및 녹색 안료를 첨가한 경우 계면활성제의 공기연행에 의해 콘크리트의 압축강도가 크게 저하하였으며, 슬럼프 및 공기량은 크게 증가하였다. 이들 청색 및 녹색 안료를 첨가한 콘크리트에 소포제를 첨가함으로써 콘크리트의 압축강도가 크게 개선되어 안료를 첨가하지 않은 콘크리트와 비슷한 강도발현이 나타났다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.40-44
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• 2003

Soil-borne infectious disease including Pythium aphanidermatum and Rhizoctonia solani causes severe damage to plants, such as cucumber. This soil-borne infectious disease was not controlled effectively by chemical pesticide. Since these diseases spread through the soil, chemical agents are usually ineffective. Instead, biological control, including antagonistic microbe can be used as a preferred control method. An efficient method was developed to select an antagonistic strain to be used as a biological control agent strain. In this new method, surface tension reduction potential of an isolate was included in the ‘decision factor’ in addition to the other factors, such as growth rate, and pathogen inhibition rate. Considering these 3 decision factors by a statistical method, an isolate from soil was selected and was identified as Bacillus sp. GB16. In the pot test, this strain showed the best performance among the isolated strains. The lowest disease incidence rate and fastest seed growth was observed when Bacillus sp. GB16 was used. Therefore this strain was considered as plant growth promoting rhizobacteria (PGPR). The action of surface tension reducing component was deduced as the enhancement of wetting, spreading, and residing of antagonistic strain in the rhizosphere. This result showed that new selection method was significantly effective in selecting the best antagonistic strain for biological control of soil-borne infectious plant pathogen. The antifungal substances against P. aphanidermatum and R. solani were partially purified from the culture filtrates of Bacillus sp. GB16. In this study, lipopeptide possessing antifungal activity was isolated from Bacillus sp. GB16 cultures by various purification procedures and was identified as a surfactin-like lipopeptide based on the Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), high performance liquid chromatography mass spectroscopy (HPLC-MS), and quadrupole time-of-flight (Q-TOF) ESI-MS/MS data. The lipopeptide, named GB16-BS, completely inhibited the growth of Pythium aphanidermatum, Rhizoctonia solani, Penicillium sp., and Botrytis cineria at concentrations of 10 and 50 mg/L, respectively. A novel method to prevent the foaming and to provide oxygen was developed. During the production of surface active agent, such as lipopeptide (surfactin), large amount of foam was produced by aeration. This resulted in the carryover of cells to the outside of the fermentor, which leads to the significant loss of cells. Instead of using cell-toxic antifoaming agents, low amount of hydrogen peroxide was added. Catalase produced by cells converted hydrogen peroxide into oxygen and water. Also addition of corn oil as an oxygen vector as well as antifoaming agent was attempted. In addition, Ca-stearate, a metal soap, was added to enhance the antifoam activity of com oil. These methods could prevent the foaming significantly and maintained high dissolved oxygen in spite of lower aeration and agitation. Using these methods, high cell density, could be achieved with increased lipopeptide productivity. In conclusion to produce an effective biological control agent for soil-borne infectious disease, following strategies were attempted i) effective screening of antagonist by including surface tension as an important decision factor ii) identification of antifungal compound produced from the isolated strain iii) novel oxygenation by $H_2O_2-catalase$ with vegetable oil for antifungal lipopeptide production.

• 자원리싸이클링
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• 제15권2호
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• pp.18-23
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• 2006

일관제철소 제강공정의 전로 조업시 발생하는 슬래그 폼은 전로 외부로 슬래그가 용출되는 현상으로써 용강의 실수율 저하와 설비이상을 초래할 수 있다. 이러한 슬래그 폼을 억제시킬 수 있는 다양한 진정제가 사용중에 있는데, 본 보고에서는 제지산업에서 발생하는 폐기물인 제지슬러지를 이용하여 슬래그 폼 진정제를 제조하였고 그 효과를 확인하였다. $CaO-SiO_2-FeO$계 슬래그 물성이 폼 발생에 미치는 영향을 모사 실험을 통해 관찰한 결과, 슬래그 염기도 및 슬래그중(FeO)농도가 증가할수록 슬래그 표면장력 증가와 슬래그중($SiO_2$) 활량의 저하로 인해 폼 지수(${\Sigma}$)는 감소하였다. 알루미늄 드로스, 코크스, 쌀겨 및 제지슬러지 등 4가지 종류의 슬래그 진정제를 실제 공정에 적용하여 슬래그 폼 진정효과를 관찰한 결과, 알루미늄 드로스가 슬래그 폼 진정효과가 가장 우수하였고 제지슬러지를 이용해 제조한 진정제도 우수한 효과를 나타내었다.

• 한국세라믹학회지
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• 제46권1호
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• pp.47-52
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• 2009

Lime paint surpassing others in execution efficiency, anti-bacterial, anti-mold and small quantity emission of VOCs(Volatile Organic Compounds) characteristics was developed using a limestone as raw materials. The lime paint prepared by mixing slaked lime($37{\sim}40\;wt%$), PVA:EVA(9 wt%:1 wt%), talc(23 wt%), $TiO_2$(14 wt%), zeolite (3 wt%), antifoaming agent(5 wt%), wetting agent (5 wt%) was indicated over 99.8% of anti-bacterial and anti-mold characteristics. Also, the environment-friendly function of the lime paint was confirmed by detection of small amount of TVOCs($0.01\;mg/m^2h$) and formaldehyde($0.008\;mg/m^2h$). Execution efficiency, economy-and environment-friendly characteristics of this lime paint can make up for defects of established paints. And, it also presents the advantage of a limestone as high value added materials.

• 한국농공학회논문집
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• 제49권2호
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• pp.37-46
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• 2007

The service life of agricultural concrete structures is designed in about 30 to 100 years, but actual service lift is estimated in an average 18 years. Therefore, as the service life of the agricultural concrete structures increases, necessity of repair by aging from various environment condition exposure increases. This study was to determinate the optimum mix proportion of latex modified repair mortar and to improve the durability performance of agricultural concrete structures. The physical and mechanical tests of latex modified repair mortar were performed. Tests of flow, compressive strength, flexural strength and bond strength tests were conducted. Test results show that the optimum nex proportion of latex modified repair mortar, when used in 5% latex volume fraction (weight of cement), 1.5% antifoaming agent (weight of latex), 0.2% PVA fiber volume fraction, 1:2 (binder-sand ratio), 10% silica fume replacement ratio (weight of cement), could result in best performance for the repair of agricultural concrete structures.