scholarly journals Silacrown Ethers-Clay Intercalation Materials: Application in Potentiometric Sensors for Detection of Alkali-Ions

2018 ◽  
Vol 91 (4) ◽  
pp. 608-616 ◽  
Author(s):  
Eduardo Ruiz-Hitzky ◽  
Almudena Gómez-Avilés ◽  
Margarita Darder ◽  
Pilar Aranda
Keyword(s):  
Potentiometric Sensors ◽  
Alkali Ions ◽  
Clay Intercalation ◽  
Intercalation Materials

Elemental mass loss in silicate minerals during x-ray analysis

1990 ◽  
Vol 48 (4) ◽  
pp. 804-805
Author(s):  
P.E. Champness ◽  
R.W. Devenish
Keyword(s):  
Mass Loss ◽  
Current Density ◽  
Damage Mechanism ◽  
Beam Current ◽  
Single Chain ◽  
Plagioclase Feldspar ◽  
X Ray ◽  
Alkali Ions ◽  
Structural Order ◽  
Sheet Silicate

It has long been recognised that silicates can suffer extensive beam damage in electron-beam instruments. The predominant damage mechanism is radiolysis. For instance, damage in quartz, SiO2, results in loss of structural order without mass loss whereas feldspars (framework silicates containing Ca, Na, K) suffer loss of structural order with accompanying mass loss. In the latter case, the alkali ions, particularly Na, are found to migrate away from the area of the beam. The aim of the present study was to investigate the loss of various elements from the common silicate structures during electron irradiation at 100 kV over a range of current densities of 104 - 109 A m−2. (The current density is defined in terms of 50% of total current in the FWHM probe). The silicates so far ivestigated are:- olivine [(Mg, Fe)SiO4], a structure that has isolated Si-O tetrahedra, garnet [(Mg, Ca, Fe)3Al2Si3AO12 another silicate with isolated tetrahedra, pyroxene [-Ca(Mg, Fe)Si2O6 a single-chain silicate; mica [margarite, -Ca2Al4Si4Al4O2O(OH)4], a sheet silicate, and plagioclase feldspar [-NaCaAl3Si5O16]. Ion- thinned samples of each mineral were examined in a VG Microscopes UHV HB501 field- emission STEM. The beam current used was typically - 0.5 nA and the current density was varied by defocussing the electron probe. Energy-dispersive X-ray spectra were collected every 10 seconds for a total of 200 seconds using a Link Systems windowless detector. The thickness of the samples in the area of analysis was normally 50-150 nm.

Upconversion Luminescence of MgSc2O4: Er3+/Yb3+ Nanocrystals Co-doped Alkali Ions

2020 ◽  
Vol 41 (11) ◽  
pp. 1351-1357
Author(s):  
Mei-juan YUANG ◽  
◽  
Jing LI ◽  
Hui-lian QIN ◽  
Ya-ru PENG ◽  
...  
Keyword(s):  
Upconversion Luminescence ◽  
Alkali Ions ◽  
Co Doped

Design of Potentiometric Sensors Based on Interaction of Cyclodextrins with the Enantiomer of Interest

2015 ◽  
Vol 9 (4) ◽  
pp. 250-255
Author(s):  
Raluca-Ioana Staden ◽  
Rahel Bokretsion ◽  
Jacobus van Staden ◽  
Hassan Aboul-Enein
Keyword(s):  
Potentiometric Sensors

Atomistic Mechanism of Passivation of Halide Vacancies in Lead Halide Perovskites by Alkali Ions

2021 ◽  
Vol 33 (4) ◽  
pp. 1285-1292
Author(s):  
Wei Li ◽  
Juan Zhan ◽  
Xiaorui Liu ◽  
Jianfeng Tang ◽  
Wan-Jian Yin ◽  
...  
Keyword(s):  
Alkali Ions ◽  
Halide Perovskites ◽  
Lead Halide

scholarly journals Potentiometric Sensors with Ion-Exchange Donnan Exclusion Membranes

2013 ◽  
Vol 85 (13) ◽  
pp. 6208-6212 ◽  
Author(s):  
Ewa Grygolowicz-Pawlak ◽  
Gastón A. Crespo ◽  
Majid Ghahraman Afshar ◽  
Günter Mistlberger ◽  
Eric Bakker
Keyword(s):  
Ion Exchange ◽  
Potentiometric Sensors

scholarly journals Electrochemical concentration of alkali ions in activated pores of electrochemically pretreated glassy carbon fibers.

1989 ◽  
Vol 5 (5) ◽  
pp. 613-614 ◽  
Author(s):  
Tsutomu NAGAOKA ◽  
Yoshihisa UCHIDA ◽  
Kotaro OGURA
Keyword(s):  
Carbon Fibers ◽  
Glassy Carbon ◽  
Alkali Ions
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