Role of the nature of the chemical bond and the dispersion in the formation of powder materials

1988 ◽  
Vol 27 (8) ◽  
pp. 627-633 ◽  
Author(s):  
R. A. Andrievskii
Keyword(s):  
Chemical Bond ◽  
Powder Materials

scholarly journals Leading Interaction Components in the Structure and Reactivity of Noble Gases Compounds

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2367
Author(s):  
Francesca Nunzi ◽  
Giacomo Pannacci ◽  
Francesco Tarantelli ◽  
Leonardo Belpassi ◽  
David Cappelletti ◽  
...  
Keyword(s):  
Chemical Bond ◽  
Theoretical Approach ◽  
Noble Gases ◽  
Halogen Bond ◽  
Noble Gas ◽  
Anomalous Behavior ◽  
Type Interaction ◽  
Long Life ◽  
Weak Chemical

The nature, strength, range and role of the bonds in adducts of noble gas atoms with both neutral and ionic partners have been investigated by exploiting a fine-tuned integrated phenomenological–theoretical approach. The identification of the leading interaction components in the noble gases adducts and their modeling allows the encompassing of the transitions from pure noncovalent to covalent bound aggregates and to rationalize the anomalous behavior (deviations from noncovalent type interaction) pointed out in peculiar cases. Selected adducts affected by a weak chemical bond, as those promoting the formation of the intermolecular halogen bond, are also properly rationalized. The behavior of noble gas atoms excited in their long-life metastable states, showing a strongly enhanced reactivity, has been also enclosed in the present investigation.

scholarly journals Understanding the role of phase in chemical bond breaking with coincidence angular streaking

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
J. Wu ◽  
M. Magrakvelidze ◽  
L.P.H. Schmidt ◽  
M. Kunitski ◽  
T. Pfeifer ◽  
...  
Keyword(s):  
Chemical Bond ◽  
Bond Breaking

scholarly journals The Development of a New Phosphogypsum-Based Construction Material: A Study of the Physicochemical, Mechanical and Thermal Characteristics

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7369
Author(s):  
Hela Garbaya ◽  
Abderraouf Jraba ◽  
Mohamed Amine Khadimallah ◽  
Elimame Elaloui
Keyword(s):  
Construction Material ◽  
Thermal Analyses ◽  
Thermal Characteristics ◽  
Specific Area ◽  
Powder Materials ◽  
Water Pump ◽  
Degree Of Hydration ◽  
Close Proximity ◽  
Structural Characterizations

Phosphogypsum (PG) is a waste (or by-product) of the production of phosphoric acid, a basic constituent in the manufacturing of modern fertilizers. The annual production of phosphogypsum in Tunisia is currently estimated to be 10 million tons. Its storage in slag in close proximity to production plants generates pollution problems; however, valorization may be a solution. The present paper proposes a simple process for the valorization of this by-product into a construction material. Several physicochemical characterizations are used to prove the characteristics of samples. The chemical composition shows that PG is a gypsum compound with several impurities. The morphological analyses show that the powder materials are mesoporous with a lower specific area. The structural characterizations show that these solids play the role of a water pump as the degree of hydration changes from 2 to 0 and vice versa, depending on the temperature. Mechanical and thermal analyses show that the prepared formulation is brittle and insulating, which presents opportunities for it to be used as a decoration material.

scholarly journals The Role of Powder Materials in Defense, Energy, and Security Systems

JOM ◽  
2014 ◽  
Vol 66 (6) ◽  
pp. 998-999
Author(s):  
Fernand D. S. Marquis
Keyword(s):  
Powder Materials ◽  
Security Systems

scholarly journals ADSORPTION AS A BASIS OF PROTECTIVE ACTION OF FILTERS-ADSORBER

2018 ◽  
Vol 1 (2) ◽  
pp. 59-63
Author(s):  
V Kovalenko ◽  
A Borysova ◽  
I Pliuta ◽  
R Likhnovsky
Keyword(s):  
Adsorption Isotherm ◽  
Chemical Bond ◽  
Metal Ion ◽  
Protective Action ◽  
Chemical Substance ◽  
Hazardous Chemical ◽  
Action Time ◽  
Bet Theory

This article analyzes the regulatory documents on determination of protective action time of gas filters and FILTERS-ADSORBER, which are designed for individual and collective protection. The current absence of a current regulatory document in Ukraine is indicated according to which protective action time of filters is determined, adds relevance in the implementation of the method of determining this filter characteristic. The theoretical aspects of effect of absorbing capacity of filters are highlighted, the fundamental principles of adsorption are linked with the time of protective action time of filters against hazardous chemicals. The process of adsorption on the surface and formation of sorption layers in case of polymolecular adsorption is schematically shown, as described by the BET theory. It is indicated that protective action time on the direct depends on particular case of adsorption - chemisorption. The types of adsorption isotherms are considered, they are characterized and the Langmuir and BET equations are given. The protective action of filter as a phenomena of chemisorption on the surface of sorbent is described by the Langmuir isotherm, in particular, parts I and II. When determining protective action time the monomolecular adsorption of hazardous chemical substance occurs with formation of a chemical bond with the surface. The chemical bond is formed from the impregnated catalyst due to the redistribution of electrons. Solutions of metal salts are used as a catalyst, and the metal ion itself acts as an active center during the process of chemisorption. The role of adsorption kinetics in the implementation of sanitary cleaning of gas from the pollutant in the practical plane is considered. The possibility of calculating the amount of a chemical that a sorbent can absorb is shown by constructing an adsorption isotherm of a standard substance and a pollutant adsorption working line. Adsorption isotherm was captured for adsorbent from FG-130 FPK 95 filter on KELVIN 1042 sorptometr.

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