• 제목/요약/키워드: chemical analysis

검색결과 12,546건 처리시간 0.044초

Temperature-dependent studies on catalytic hydrosilation of polyalkylsiloxane using NMR

  • Sul, Hyewon;Lee, Tae Hee;Lim, Eunsoo;Rho, Yecheol;Kim, Chong-Hyeak;Kim, Jeongkwon
    • 분석과학
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    • 제30권4호
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    • pp.213-219
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    • 2017

  • Polyalkylsiloxane has been spotlighted in pressure-sensitive adhesive (PSA) application due to excellent physical properties and good biocompatibility. Thermal behaviour of polyalkylsiloxane mixtures, such as thermal stability and heat flow, were studied using TG-DTA during catalytic hydrosilation. To understand reaction kinetics of cross-linking, catalytic hydrosilation of polyalkylsiloxane was monitored using variable temperature nuclear magnetic resonance (VT-NMR) as increased temperature. The formation of cross-linking bond $Si-CH_2-CH_2-Si$ was directly observed using distortionless enhanced by polarization transfer (DEPT) technique. Successfully polyalkylsiloxane PSA samples exhibited excellent adhesion properties by cross-linking reaction.

  • https://doi.org/10.5806/AST.2017.30.4.213 인용 PDF KSCI

Analysis of Chemical Warfare Agents in Water Using Single-Drop Microextraction

  • Park, Yang-Gi;Kim, Sung-Ki;Choi, Ki-Hwan;Son, Byung-Hoon;Park, Ju-Sub;Kang, Hong-Ku
    • Bulletin of the Korean Chemical Society
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    • 제30권1호
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    • pp.49-52
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    • 2009

  • Single-drop microextraction (SDME) is an extraction methodology where the drop plays an essential role as extracts. It was evaluated for the GC-MS determination of nerve agents, one class of the chemical warfare agents (CWAs). Since these nerve agents are highly toxic, it is important to detect the nerve agents in the environmental samples. Several affecting factors including extraction solvents, stirring rate, extraction time, and amounts of salt were optimized. The limit of detections (LODs) were 0.1 - 10 ng/mL and the relative standard deviations (RSDs%, n=5) were in the range of 6.3% to 9.0% for four nerve agents. Without pretreatment of the environmental samples, 5-103 fold enrichments and 48-100% recovery were accomplished. These results demonstrated the feasibility of this method for on-site and off-site analysis of water sample collected from suspicious CWAs site.

  • https://doi.org/10.5012/bkcs.2009.30.1.049 인용 PDF KSCI