کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10411146 | 894549 | 2005 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Use of self-assembled monolayers, metal ions and smectic liquid crystals to detect organophosphonates
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Use of self-assembled monolayers, metal ions and smectic liquid crystals to detect organophosphonates Use of self-assembled monolayers, metal ions and smectic liquid crystals to detect organophosphonates](/preview/png/10411146.png)
چکیده انگلیسی
Smectic liquid crystals form stable, micrometer-thick films when deposited onto the surfaces of solids. In this paper, we report that orientational transitions of thin films of the smectic liquid crystal (LC), 4â²-octyl-4-biphenyl-carbonitrile (8CB) supported on surfaces presenting copper ions can be exploited to detect the presence of organophosphonate compounds at parts-per-billion (ppb) levels in gas phases. The orientational transition of the 8CB is driven by the competitive binding of the nitrile groups of 8CB and dimethyl methyl phosphonate (DMMP) for the surface-immobilized copper ions. Because the orientational transition of the LC can be observed by using a polarizing film and the naked eye, this detection scheme does not require complex instrumentation to transduce the signal. The film of LC responds to 10Â ppbv of DMMP and the initial response time is approximately 20Â s. The system is also demonstrated to exhibit molecular specificity. The LC does not respond to gaseous streams containing 1% of the saturated vapor concentrations of ethanol (770Â ppm), hexane (1990Â ppm) and acetone (3020Â ppm) and 75% relative humidity of water.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Sensors and Actuators B: Chemical - Volume 104, Issue 1, 3 January 2005, Pages 50-56
Journal: Sensors and Actuators B: Chemical - Volume 104, Issue 1, 3 January 2005, Pages 50-56
نویسندگان
Kun-Lin Yang, Katie Cadwell, Nicholas L. Abbott,