Application of the Partial Charge Model to the Aqueous Chemistry of Silica and Silicates

1997 ◽  
pp. 273-334 ◽  
Author(s):  
Marc Henry
Keyword(s):  
Partial Charge ◽  
Aqueous Chemistry ◽  
Charge Model ◽  
Partial Charge Model

Electronegativity-Based Computation of 29Si Chemical Shifts

1992 ◽  
Vol 271 ◽  
Author(s):  
Henry. M ◽  
Gerardin. C ◽  
Taulelle. F
Keyword(s):  
Chemical Shifts ◽  
Sol Gel ◽  
Partial Charge ◽  
Detailed Structure ◽  
Mean Excitation Energy ◽  
Charge Model ◽  
Partial Charges ◽  
Nuclear Shielding ◽  
Partial Charge Model ◽  
The Mean

ABSTRACTThe Partial Charge Model has been modified to take into account the detailed structure of any molecular sol-gel precursors or inorganic solid networks. Starting from these structure-dependent partial charges, the classical theory of nuclear shielding is applied to compute the electronic cloud compacity <r-3>p, the population unbalance Pu and also the mean excitation energy ΔE. With these three parameters it is possible to explain the chemical shifts variations, spanning from +40 down to -140 ppm, of more than 50 precursors. Depending on the ligands, the well-known upside-down U-curves for series SiXnY4-n (n=0‥4) can be ascribed either to the population unbalance term Pu or to a competition between the two other terms <r-3>p and ΔE.

An effective partial charge model for bulk and surface properties of cubic ZrO2, Y2O3 and yttrium-stabilised zirconia

2019 ◽  
Vol 21 (46) ◽  
pp. 25635-25648
Author(s):  
Thomas S. Hofer ◽  
Franziska M. Kilchert ◽  
Bagas A. Tanjung
Keyword(s):  
Surface Properties ◽  
Partial Charge ◽  
Interaction Potentials ◽  
Charge Model ◽  
Partial Charges ◽  
Partial Charge Model

Novel interaction potentials using effective partial charges are derived, leading to a superior description of bulk and surface properties.

Complexation of Zr(IV) Precursors in Aqueous Solutions

1992 ◽  
Vol 271 ◽  
Author(s):  
J. Livage ◽  
M. Chatry ◽  
M. Henry ◽  
F. Taulelle
Keyword(s):  
Aqueous Solutions ◽  
Sol Gel ◽  
Chemical Species ◽  
Ionic Species ◽  
Whole Process ◽  
Charge Model ◽  
Partial Charge Model ◽  
Sol Gel Synthesis ◽  
Inorganic Precursors

ABSTRACTThe sol-gel synthesis of metal oxides can be performed via the hydroxylation and condensation of metal cations in aqueous solutions. The complexation of these ionic species by anions leads to the chemical modification of inorganic precursors at a molecular level. The whole process of hydrolysis and condensation can then be modified allowing a chemical control of the morphology, the structure and even the chemical composition of the resulting powder.The role of anions during the formation of condensed phases from inorganic precursors in aqueous solutions has to be taken into account. The complexing ability of these anions is described in the frame of the Partial Charge Model as a function of pH and the mean electronegativity of anionie and cationic chemical species. Experimental evidence for the complexation of zirconyl species in aqueous solutions will be given using multinuclear NMR of anions.

Utilization of electrical charges in the pores of tofu waste for hydrogen production in water

2020 ◽  
pp. 124-135
Author(s):  
I. N. G. Wardana ◽  
N. Willy Satrio
Keyword(s):  
Magnetic Field ◽  
Hydrogen Production ◽  
Sodium Bicarbonate ◽  
Positive Charge ◽  
Electrical Energy ◽  
Hydrogen Sensor ◽  
Water Molecules ◽  
Partial Charge ◽  
Delocalized Electron ◽  
Water Hydrogen

Tofu is main food in Indonesia and its waste generally pollutes the waters. This study aims to change the waste into energy by utilizing the electric charge in the pores of tofu waste to produce hydrogen in water. The tofu pore is negatively charged and the surface surrounding the pore has a positive charge. The positive and negative electric charges stretch water molecules that have a partial charge. With the addition of a 12V electrical energy during electrolysis, water breaks down into hydrogen. The test was conducted on pre-treated tofu waste suspension using oxalic acid. The hydrogen concentration was measured by a MQ-8 hydrogen sensor. The result shows that the addition of turmeric together with sodium bicarbonate to tofu waste in water, hydrogen production increased more than four times. This is due to the fact that magnetic field generated by delocalized electron in aromatic ring in turmeric energizes all electrons in the pores of tofu waste, in the sodium bicarbonate, and in water that boosts hydrogen production. At the same time the stronger partial charge in natrium bicarbonate shields the hydrogen proton from strong attraction of tofu pores. These two combined effect are very powerful for larger hydrogen production in water by tofu waste.

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