Estimation of Thermal Expansion Coefficients of 1-Butyl-3-methylimidazolium Hexafluorophosphate + Poly(ethylene glycol) from Density Data in the Temperature Range (313.15–363.15 K)

Gautam, Pavan Kumar; Saroj, Rama Shankar; Gautam, Ravindra Kumar; Pandey, J. D.

doi:10.1007/s40009-014-0306-8

Cited by 2 publications

(1 citation statement)

References 29 publications

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“…The thermal sensitivities of the PEG-DA microcantilever in these two temperature ranges are 2 orders of magnitude higher than that of the silicon microcantilever used for comparison. Such huge decrease in the resonance frequency of the PEG-DA microcantilever upon heating is mainly attributed to the decrease in its Young’s modulus since the effect of thermal expansion of the PEG-DA microcantilever on the resonance frequency change is less than 5% upon heating from room temperature to 100 °C based on the thermal expansion coefficient of ∼600 ppm/K for PEG with similar molecular weight (MW 400) found in literatures. − Upon further heating, the resonance frequency of the PEG-DA microcantilever keeps decreasing until ∼120 °C, and then it becomes insensitive to heating (see Supporting Information Figure S1). Therefore, the temperature of ∼120 °C is thought to be another phase transition of the PEG-DA MW 250.…”

Section: Results and Discussionmentioning

confidence: 73%

Standoff Mechanical Resonance Spectroscopy Based on Infrared-Sensitive Hydrogel Microcantilevers

Chae

Khan

Song³

et al. 2016

Anal. Chem.

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This paper reports a highly sensitive and selective remote chemical sensing platform for surface-adsorbed trace chemicals by using infrared (IR)-sensitive hydrogel microcantilevers. Poly(ethylene glycol) diacrylate (PEG-DA) hydrogel microcantilevers are fabricated by ultraviolet (UV) curing of PEG-DA prepolymer introduced into a poly(dimethylsiloxane) mold. The resonance frequency of a PEG-DA microcantilever exhibits high thermal sensitivity due to IR irradiation/absorption. When a tunable IR laser beam is reflected off a surface coated with target chemical onto a PEG-DA microcantilever, the resonance frequency of the cantilever shifts in proportion to the chemical nature of the target molecules. Dynamic responses of the PEG-DA microcantilever can be obtained in a range of IR wavelengths using a tunable quantum cascade laser that can form the basis for the standoff mechanical resonance spectroscopy (SMRS). Using this SMRS technique, we have selectively detected three compounds, dimethyl methyl phosphonate (DMMP), cyclotrimethylene trinitramine (RDX), and pentaerythritol tetranitrate (PETN), located 4 m away from the PEG-DA microcantilever detector. The experimentally measured limit of detection for PETN trace using the PEG-DA microcantilever was 40 ng/cm. Overall, the PEG-DA microcantilever is a promising candidate for further exploration and optimization of standoff detection methods.

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Section: Results and Discussionmentioning

confidence: 73%