文献类型：期刊文献

英文题名：Measurement of temperature-dependent diffusion coefficients using a confocal Raman microscope with microfluidic chips considering laser-induced heating effect

作者：Lin, Ying[1];Yu, Xinhai[1];Wang, Zhenyu[2];Tu, Shan-Tung[1];Wang, Zhengdong[1]

机构：[1]E China Univ Sci & Technol, Key Lab Pressurized Syst & Safety, Minist Educ, Sch Mech & Power Engn, Shanghai 200237, Peoples R China;[2]Peking Univ, Sch Software & Microelect, Wuxi Integrated Micro&Nano Syst Engn Ctr, Wuxi 214121, Peoples R China

年份：2010

卷号：667

期号：1-2

起止页码：103

外文期刊名：ANALYTICA CHIMICA ACTA

收录：;EI(收录号：20102112949032);WOS:【SCI-EXPANDED(收录号:WOS:000278152500013)】；

基金：This study was financially supported by the China Natural Science Foundation (Contract No. 20606011) and the Swedish Research Links Programme by the Swedish Research Council (VR).

语种：英文

外文关键词：Temperature-dependent diffusion coefficient; Raman microscope; Microfluidic chip; Laser-induced heating

摘要：Conventional methods for measuring diffusion coefficients (D) are complex and time consuming. This study presents a method for the continuous measurement of temperature-dependent diffusion coefficients using a confocal Raman microscope with microfluidic chips. Concentration information was collected by a Raman microscope to extract D values. An isothermal diffusion process at various temperatures was ensured by coupling the silicon-based microfluidic chip with an isothermal plate. In the simple silicon/glass chip, the heating effect induced by a Raman laser was observed to contribute to abnormally high D values. To eliminate the heating effect, a 200 nm-thick aluminum (Al) reflection film was used to coat the channel bottom. The Al film substantially reduced absorption of laser power, thus ensuring precise D values in excellent agreement with literature data. Other potential methods to eliminate the heating effect were also evaluated by computational fluid dynamics (CFD) simulations and were found impractical for implementation. Consequently, this method for the continuous measurement of temperature-dependent diffusion coefficients is proven to be accurate, efficient, and reliable. (C) 2010 Elsevier B.V. All rights reserved.