표면 활성화된 폐 EPDM 분말의 물성과 냄새 성분 분석 연구

최종만 ( J. Choi ),김섭 ( S. Kim ),정경호 ( K. Chung ),정진수 ( J. Chung ),유태욱 ( T. Yoo ),양준호 ( J. Yang ) 한국고무학회 2007 엘라스토머 및 콤포지트 Vol.42 No.4

본 연구에서는 웨더스트립 공정스크랩인 폐 EPDM을 재활용하기 위해 고온전단분쇄기를 이용하여 표면활성화 된 EPDM 분말을 제조하여 이의 물성과 냄새성분분석에 관한 연구를 수행하였다. 본 연구에서 사용되어진 폐 EPDM은 solid, sponge, solid+sponge, solid+metal형으로서 입도분석과 SEM을 통해 입자크기와 입도 분포도를 조사하였고, 가교제를 첨가하여 활성화 된 분말표면의 재가교 여부를 조사하였다. Solid형의 경우 가장 좁은 입도 분포도와 작은 입자크기, 상대적으로 높은 인장 물성을 나타내었다. 화학적 표면 탈황을 유도하기 위해 표면 활성화제를 첨가한 결과 표면활성화제의 첨가량이 증가할수록 효율적인 탈황이 유도되었다. TPE제조를 위해 폴리올레핀과의 블렌드 시 활성화된 EPDM 분말의 동적가황 가능성을 확인하기 위하여 가교제를 첨가하여 반응을 진행한 결과 황을 첨가할 경우 가교반응이 진행되지 않았고, DCP(dicumyl peroxide)의 경우 6 phr이 첨가되었을 때 효율적인 표면 가교반응 및 최적의 인장 물성을 나타내었다. 화학적 표면 활성화를 유도한 폐 EPDM 분말의 경우 표면활성화제의 첨가로 인해 냄새가 발생되는데, 이를 제거하기 위하여 수분흡착 공정과 rose oil 첨가 공정을 진행하였으며 GC/MS를 통해 냄새 성분을 분석하였다. In this study, the EPDM powder which was surface activated by high temperature and shear pulverization process was prepared and the mechanical properties and odor material analysis were investigated. Analysis for particle size and size distribution of waste of the EPDM powder has been performed. The waste EPDMs used in this study were 4 types of solid, sponge, solid+sponge, and solid+metal. According to the results, the solid type showed the smallest particle size among the 4 types of EPDM powder. Effective surface devulcanization of EPDM powder could be obtained by the addition of the reclaiming agent. The dicumyl peroxide was considered as the best crosslink agent for dynamic vulcanization when the surface activated EPDM powder was blended with polyolefin in order to make TPE. Also, the optimum amounts of DCP was 6 phr in terms of surface crosslink reaction and mechanical properties of EPDM powder. The processes of water adsorption and rose oil addition were employed to remove the odor of EPDM powder caused by reclaiming agent. The GC/MS was used to analyze the odor compounds.

Photoresponsive Carbohydrate-based Surface Active Agents: Automatic Vertical Alignment of Liquid Crystal

박서희,정광운 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

For the fabrication of remote-controllable optical devices, we synthesized a photo-functionalized surfactant (abbreviated as CHA_n). CHA_n molecules contain both carbohydrate and azobenzene groups for the vertical alignment (VA) layer of nematic (N) liquid crystal (LC). It also contains the cellobiosyl polar head group for inducing the automatic 2D monolayer on the solid substrates. In case of CHA₁, it creates sufficient space in the self-assembled monolayer structure. The N-LC molecules can crawl into the space of the surfactant and form a VA layer. Because the CHA₃ molecules make a more dense monolayer structure on the substrates, the N-LC form the planar alignment (PA) layer. The N-LC alignments can be reversibly transformed between VA and PA by UV-Vis light. This work was supported by the MOTIE/KDRC 10051334, BK21 Plus program, and Mid-Career Researcher Program (2016R1A2B2011041).

Simplistic surface active agents mediated morphological tweaking of CdS thin films for photoelectrochemical solar cell performance

Vanalakar, S.A.,Suryawanshi, M.P.,Mali, S.S.,Moholkar, A.V.,Kim, J.Y.,Patil, P.S.,Kim, J.H. Elsevier 2014 Current Applied Physics Vol.14 No.12

This study reports on the formation of cadmium sulfide (CdS) nanostructures with controlled morphology synthesized via a simple chemical route in surface active agent environment. The effect of organic surface active agents (surfactants) as sodium dodecyl sulfate (SDS), polyethylene glycol (PEG) and cetyltrimethylammonium bromide (CTAB) on structural, morphological, optical and photoelectrochemical properties of CdS thin films have been studied. Our results reveal that the organic surfactants play key roles in tweaking the surface morphology. A compact spongy ball like morphology was observed for the CdS samples grown without organic surfactants. The cauliflower's with nanopetals from the CTAB, whereas crowded star fish like morphology is observed in PEG-mediated growth. Water hyacinth like morphology is tweaked using SDS. Considering the importance of these nanostructures, the growth mechanism has been discussed in details. Additionally, the samples are photoelectrochemically (PEC) active and having a compact surface with a nanoporous structure twig helps in improved photoelectrochemical performance compared to that of CdS deposits from surfactant free solution. This is a simplistic way to tune the morphology using surfactants, which can be applied to other energy conversion applications.

Simplistic surface active agents mediated morphological tweaking of CdS thin films for photoelectrochemical solar cell performance

S.A. Vanalakar,M.P. Suryawanshi,S.S. Mali,A.V. Moholkar,J.Y.Kim,P.S. Patil,김진혁 한국물리학회 2014 Current Applied Physics Vol.14 No.12

This study reports on the formation of cadmium sulfide (CdS) nanostructures with controlled morphology synthesized via a simple chemical route in surface active agent environment. The effect of organic surface active agents (surfactants) as sodium dodecyl sulfate (SDS), polyethylene glycol (PEG) and cetyltrimethylammonium bromide (CTAB) on structural, morphological, optical and photoelectrochemical properties of CdS thin films have been studied. Our results reveal that the organic surfactants play key roles in tweaking the surface morphology. A compact spongy ball like morphology was observed for the CdS samples grown without organic surfactants. The cauliflower's with nanopetals from the CTAB, whereas crowded star fish like morphology is observed in PEG-mediated growth. Water hyacinth like morphology is tweaked using SDS. Considering the importance of these nanostructures, the growth mechanism has been discussed in details. Additionally, the samples are photoelectrochemically (PEC) active and having a compact surface with a nanoporous structure twig helps in improved photoelectrochemical performance compared to that of CdS deposits from surfactant free solution. This is a simplistic way to tune the morphology using surfactants, which can be applied to other energy conversion applications.

Comparative Evaluation on the Type of Surface Active Agents for Cold Recycled Asphalt Mixture

Juyeol, Ryu,Yeong-Min, Kim,Hyun-Joon, Choi 한국도로학회 2018 한국도로학회 학술대회 발표논문 초록집 Vol.2018 No.05

Since the first development of asphalt emulsion in 1920, the asphalt emulsions have been in existence for almost 100 years. The advantages of asphalt emulsion compared to hot asphalt and cut back binders are related to the low application temperature, compatibility with other water-based binders like rubber latex and cement, and lowsolvent content. Surface active agents(surfactants), also known as emulsifiers or emulsifying agents, are needed to provide the stability required over time. The type of asphalt emulsion is largely divided into two for the mixture which acts as a binder by mixing with the aggregate and for the bonding strength between asphalt pavement layers. The cold recycled asphalt mixture is affected the binding strength between asphalt and aggregate, depending on the properties of the asphalt binder as well as the emulsifier properties. Four kinds of emulsifiers(alkyl amines, ligine amine, fatty amine, alkyl amido polyamines) were used to make emulsified asphalt, and their basic properties (storage stability, cement mixing test, penetration, etc.) and aggregate film separation were measured. As a result, the penetration of the asphalt emulsion made by the type of alkyl amido polyamines emulsifier was measured to be about 10.4% higher, and the stripping of the bitumen-aggregate film was also lower about 21%. This is because polyamine has two or more primary amino groups –NH2 forms a strong binding force.

염화아연(ZnCl₂) 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.

Effect of a surface active agent on performance of zinc/bromine redox flow batteries: Improvement in current efficiency and system stability

Yang, Jung Hoon,Yang, Hyeon Sun,Ra, Ho Won,Shim, Joonmok,Jeon, Jae-Deok Elsevier 2015 Journal of Power Sources Vol.275 No.-

<P><B>Abstract</B></P> <P>A sustained decrease in current efficiency (CE) is a commonly observed phenomenon in a zinc/bromine redox flow battery. To circumvent this problem, that is, to improve the CE and system stability of the redox flow battery, a surface active agent (SAA), polyoxyethylene (20) sorbitan monolaurate, is introduced as an additive. To investigate the effect of this SAA on the cell performance, polarization testing is performed and the electrode surface is observed after 32 cycles of charge–discharge testing. Adding the SAA facilitates catholyte mixing, leading to an effective reduction of bromine during discharging.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The effect of Polysorbate 20 on Zn/Br RFB performance was investigated. </LI> <LI> The surfactant prevented uneven dissolution of Zn during discharge. </LI> <LI> Current efficiency decrease with cycle number was improved with Polysorbate 20. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Physicochemical properties, cytotoxicity and penetration into dentinal tubules of sodium hypochlorite with and without surfactants

Coaguila-Llerena Hernán,Barbieri Isadora,Tanomaru-Filho Mário,Leonardo Renato de Toledo,Ramos Ana Paula,Faria Gisele 대한치과보존학회 2020 Restorative Dentistry & Endodontics Vol.45 No.4

Objectives: The aim of this study was to assess the physicochemical properties, cytotoxicity and penetration into dentinal tubules of ChlorCid™ Surf (3% sodium hypochlorite [NaOCl] with surfactant) in comparison to ChlorCid™ (3% NaOCl without surfactant). Materials and Methods: The physicochemical properties evaluated were pH, surface tension, free available chlorine (FAC) and contact angle. Cytotoxicity was evaluated in L929 fibroblasts exposed to the solutions by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and neutral red assays. Assessment of penetration into dentinal tubules was performed by staining single-rooted permanent human teeth with crystal violet (n = 9), which were irrigated with the solutions and analyzed in cervical, middle and apical segments. Data were analyzed by one-way analysis of variance (ANOVA) and Tukey's post-test, 2-way ANOVA and Bonferroni's post-test or t-test (α = 0.05). Results: ChlorCid™ Surf and ChlorCid™ FAC values were close to those indicated by the manufacturer. ChlorCid™ Surf showed lower surface tension and contact angle on dentin, and higher pH than ChlorCid™ (p < 0.05). The penetration of ChlorCid™ Surf was higher in cervical and middle segments, compared with ChlorCid™ (p < 0.05). There was no difference in irrigant cytotoxicity (p > 0.05). Conclusions: ChlorCid™ Surf showed lower surface tension, lower contact angle on root canal dentin, higher penetration into dentinal tubules and more alkaline pH, compared with ChlorCid™. However, both solutions showed similar cytotoxicity and FAC content.

표면 개질 활성탄소섬유의 dimethyl methylphosphonate 흡착에 관한 연구

신한울,이기봉 한국공업화학회 2024 한국공업화학회 연구논문 초록집 Vol.2024 No.0

자기연마가공에서 계면활성제의 효과에 관한 연구

손병훈(B.H. Son),김태완(T.W. Kim),유만희(M.H. You),곽재섭(J.S. Kwak) 한국생산제조학회 2014 한국생산제조시스템학회 학술발표대회 논문집 Vol.2014 No.9(1)