Influence of medium structure on the physicochemical properties of aging colloidal dispersions investigated using the synthetic clay Laponite®

Soft Matter ◽

10.1039/d1sm00987g ◽

2021 ◽

Author(s):

Chandeshwar Misra ◽

Venketesh Thrithamara Ranganathan ◽

Ranjini Bandyopadhyay

Keyword(s):

Physicochemical Properties ◽

Electrostatic Interactions ◽

Physical Aging ◽

Colloidal Dispersions ◽

Aqueous Dispersions ◽

Synthetic Clay

Physical aging in colloidal dispersions manifests as a reduction in kinetic freedom of the colloids. In aqueous dispersions of charged clay colloids, the role of interparticle electrostatic interactions in determining...

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Characteristics Of The Structure Formation Of Gypsum Binder Modified With Zinc Hydrosilicates

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2020.02.40-46 ◽

2020 ◽

pp. 40-46

Keyword(s):

Synergistic Effect ◽

Physicochemical Properties ◽

Structure Formation ◽

Silicic Acid ◽

Chemical Properties ◽

Crystal Formation ◽

Ability To Act ◽

Chemical Factors ◽

Sorption Characteristics

The authors' methodic for assessing the role of chemical and physic-chemical factors during the structure formation of gypsum stone is presented in the article. The methodic is also makes it possible to reveal the synergistic effect and to determine the ranges of variation of controls factors that ensure maximum values of such effect. The effect of a micro-sized modifier based on zinc hydro-silicates on the structure formation of building gypsum is analyzed and corresponding dependencies are found. It is shown that effects of influence of modifier on the properties of gypsum compositions are determined by chemical properties of modifier. Among the mentioned properties are sorption characteristics (which depend on the amount of silicic acid and its state) and physicochemical properties - the ability to act as a substrate during crystal formation. The proposed method can also be extended to other binding substances and materials. This article contributes to the understanding of the processes that occur during the structure formation of composites, which will make it possible to control the structure formation in the future, obtaining materials with a given set of properties.

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Electrostatic interactions in cytochrome c. The role of interactions between residues 13 and 90 and residues 79 and 47 in stabilizing the heme crevice structure.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)86087-8 ◽

1980 ◽

Vol 255 (4) ◽

pp. 1689-1697

Author(s):

N. Osheroff ◽

D. Borden ◽

W.H. Koppenol ◽

E. Margoliash

Keyword(s):

Cytochrome C ◽

Electrostatic Interactions

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The Role of H2C2O4 and Na2CO3 as Precipitating Agents on The Physichochemical Properties and Photocatalytic Activity of Bismuth Oxide

Open Chemistry ◽

10.1515/chem-2020-0013 ◽

2020 ◽

Vol 18 (1) ◽

pp. 129-137

Author(s):

Yayuk Astuti ◽

Rizka Andianingrum ◽

Abdul Haris ◽

Adi Darmawan ◽

Keyword(s):

Photocatalytic Activity ◽

Methyl Orange ◽

Physicochemical Properties ◽

Bismuth Oxide ◽

Rate Constants ◽

Degradation Rate ◽

Precipitation Method ◽

Methyl Orange Degradation ◽

Methyl Orange Dye

AbstractSynthesis of bismuth oxide synthesis through the precipitation method using H2C2O4 and Na2CO3 precipitating agents, identification of physicochemical properties and its photocatalysis activity for methyl orange degradation were conducted. The bismuth oxide synthesis was undertaken by dissolving Bi(NO3)3.5H2O in HNO3, then added precipitating agents to form precipitate. The results showed that bismuth oxide produced by H2C2O4 precipitating agent was a yellow powder containing a mixture of α-Bi2O3 (monoclinic) and β-Bi2O3 (tetragonal), porous with size of 28-85 μm. Meanwhile, the use of Na2CO3 as precipitating agent resulted in bismuth oxide consisting of α-Bi2O3 and β-Bi2O3 and Bi2O4, irregular shape without pore being 40-115 μm in size. Bismuth oxide synthesized with H2C2O4 precipitating agent showed higher photocatalytic activity compared to bismuth oxide synthesized using Na2CO3 on degrading methyl orange dye with degradation rate constants of 2.35x10-5 s-1 for H2C2O4 and 1.81x10-5 s-1 for Na2CO3.

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