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Author Gupta, Abhishek Kumar ♦ Verma, Yogendra Lal ♦ Singh, Manish Pratap ♦ Singh, Rajendra Kumar
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword 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
Abstract 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.
ISSN 00224596
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-10-15
Publisher Place United States
Journal Journal of Solid State Chemistry
Volume Number 242
Part 1


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