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Real-Time Viscosity and Mass Density Sensors Requiring Microliter Sample Volume Based on Nanomechanical Resonators

Bircher, Benjamin A. and Dümpelmann, Luc and Renggli, Kasper and Lang, Hans Peter and Gerber, Christoph and Bruns, Nico and Braun, Thomas. (2013) Real-Time Viscosity and Mass Density Sensors Requiring Microliter Sample Volume Based on Nanomechanical Resonators. Analytical Chemistry, 85 (18). pp. 8676-8683.

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Official URL: http://edoc.unibas.ch/dok/A6212053

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Abstract

A microcantilever based method for fluid viscosity and mass d. measurements with high temporal resoln. and microliter sample consumption is presented. Nanomech. cantilever vibration is driven by photothermal excitation and detected by an optical beam deflection system using two laser beams of different wavelengths. The theor. framework relating cantilever response to the viscosity and mass d. of the surrounding fluid was extended to consider higher flexural modes vibrating at high Reynolds nos. The performance of the developed sensor and extended theory was validated over a viscosity range of 1-20 mPa·s and a corresponding mass d. range of 998-1176 kg/m3 using ref. fluids. Sepg. sample plugs from the carrier fluid by a two-phase configuration in combination with a microfluidic flow cell, allowed samples of 5 μL to be sequentially measured under continuous flow, opening the method to fast and reliable screening applications. To demonstrate the study of dynamic processes, the viscosity and mass d. changes occurring during the free radical polymn. of acrylamide were monitored and compared to published data. Shear-thinning was obsd. in the viscosity data at higher flexural modes, which vibrate at elevated frequencies. Rheokinetic models allowed the monomer-to-polymer conversion to be tracked in spite of the shear-thinning behavior, and could be applied to study the kinetics of unknown processes. [on SciFinder(R)]
Faculties and Departments:05 Faculty of Science > Departement Chemie > Chemie
05 Faculty of Science > Departement Chemie > Chemie > Makromolekulare Chemie (Meier)
UniBasel Contributors:Bruns, Nico and Dümpelmann, Luc and Renggli, Kasper and Lang, Hans Peter and Gerber, Christoph and Braun, Thomas and Bircher, Benjamin
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:American Chemical Society
ISSN:0003-2700
Note:Publication type according to Uni Basel Research Database: Journal article
Language:English
Identification Number:
Last Modified:24 Aug 2017 12:29
Deposited On:31 Jan 2014 09:49

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