Role of reduced precursor and solvolytic reagent molar ratio on preparation and properties of ionogel

Journal Article · Sat Oct 15 04:00:00 EDT 2016 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2016.07.008· OSTI ID:22658025

Gupta, Abhishek Kumar; Verma, Yogendra Lal ^[1]; Singh, Manish Pratap ^[1]

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1. Ionic Liquid and Solid State Ionics Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221005 (India)

In the present study, ionogels have been synthesized by immobilizing IL (1-ethyl-3-methylimidazolium tetrafluoroborate) in silica gel matrices using non-aqueous route. In this process, tetraethyl orho-silane (TEOS) as a precursor to silicon dioxide and formic acid as a solvolytic gelating reagent in reduced molar ratio 1:4 were used. We find that reduced molar concentration of formic acid results the formation of ionogels having less number of closed pores (totally isolated from their neighbours), larger density and stable monolithic form. TEM and SEM measurements are used to visualize the morphology of sample and closed pores present in the sample. N{sub 2}-sorption measurement is used to measure the pore parameters of the silica matrices which shows the mesoporous structure. DSC and TGA results show the change in phase transition temperature and thermal stability of IL upon confinement in silica matrices. Moreover, ionic conductivity of bulk and confined IL is measured using impedance spectroscopy and it has been found that it increases with increasing the temperature as well as concentration of IL in ionogels. Apart from these characterization techniques, ionogels have been characterized using FTIR and fluorescence spectroscopy which exhibit the change in vibrational frequencies and fluorescence behaviour of confined IL. - Highlights: • Synthesis of stable ionogel using non-hydrolytic route with reduced precursor and solvolytic reagent molar ratio. • Ionogels are free from entrapped residual reaction product. • The ionogels synthesized with higher amount of ionic liquids show bulk liquid like electrical behaviour.

• OSTI ID: 22658025
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: Part 1 Vol. 242; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
EXPERIMENTAL DATA
FLUORESCENCE SPECTROSCOPY
FLUOROBORATES
FORMIC ACID
FOURIER TRANSFORMATION
IMIDAZOLES
INFRARED SPECTRA
IONIC CONDUCTIVITY
MOLTEN SALTS
PHASE TRANSFORMATIONS
PRECURSOR
SCANNING ELECTRON MICROSCOPY
SILICA GEL
SILICON OXIDES
SYNTHESIS
THERMAL GRAVIMETRIC ANALYSIS
TRANSITION TEMPERATURE