Surface free energy of a soil clay fraction in relation to aggregate stability

Clay Minerals ◽  
1993 ◽  
Vol 28 (1) ◽  
pp. 145-148
Author(s):  
B. Jańczuk ◽  
G. Józefaciuk ◽  
M. Hajnos ◽  
T. Bialopiotrowicz ◽  
A. Kliszcz
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Clay Fraction ◽  
Aggregate Stability ◽  
Soil Aggregate ◽  
Free Energies ◽  
Soil Aggregate Stability ◽  
Soil Clay ◽  
Energy Components

When studying surface free energies of clays in relation to clay composition, we calculated that in some instances the aggregate stability should be higher for Na- then for Ca-forms. This raised the question as to whether the results obtained with the surface free energy approach are reliable for estimation of soil aggregate stability. The aim of the present work was to measure the surface free energy components and attractive forces for a clay calculated from measurements of the contact angle of glycerol, diiodomethane and cis-decalin and to compare them with results of penetrometrical measurements.

Determination of the galena surface free energy components from contact angle measurements

1992 ◽  
Vol 31 (3) ◽  
pp. 235-241 ◽  
Author(s):  
Bronisław Jańczuk ◽  
Wiesław Wójcik ◽  
Anna Zdziennicka ◽  
Fernando González-Caballero
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Energy Components

The surface free energy components of homoion1c bentonite from contact angle measurements

1990 ◽  
Vol 26 (3-4) ◽  
pp. 375-394 ◽  
Author(s):  
B. Jańczuk ◽  
E. Chibowski ◽  
T. Białopiotrowicz ◽  
M. Hajnos ◽  
J. Stawiński
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Energy Components

scholarly journals Surface Testing of Dental Biomaterials—Determination of Contact Angle and Surface Free Energy

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2716
Author(s):  
Aneta Liber-Kneć ◽  
Sylwia Łagan
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Sessile Drop ◽  
Dental Materials ◽  
Free Energy Calculations ◽  
Critical Surface ◽  
Free Energies ◽  
Acrylic Resins

The key goal of this study was to characterize surface properties of chosen dental materials on the base on the contact angle measurements and surface free energy calculations. Tested materials were incubated in the simulated oral environment and drinks to estimate an influence of conditions similar to those in the oral cavity on wetting and energetic state of the surface. Types of materials were as follows: denture acrylic resins, composite and PET-G dental retainer to compare basic materials used in a prosthetics, restorative dentistry and orthodontics. The sessile drop method was used to measure the contact angle with the use of several liquids. Values of the surface free energies were estimated based on the Owens–Wendt, van Oss–Chaudhury–Good and Zisman’s methods. The research showed that surface wetting depends on the material composition and storage conditions. The most significance changes of CA were observed for acrylic resins (84.7° ± 3.8° to 65.5° ± 3.5°) and composites (58.8° ± 4.1° to 49.1° ± 5.7°) stored in orange juice, and for retainers (81.9° ± 1.8° to 99.6° ± 4.5°) incubated in the saline solution. An analysis of the critical surface energy showed that acrylic materials are in the zone of good adhesion (values above 40 mJ/m2), while BIS-GMA composites are in the zone of poor adhesion (values below 30 mJ/m2). Study of the surface energy of different dental materials may contribute to the development of the thermodynamic model of bacterial adhesion, based on the surface free energies, and accelerate the investigation of biomaterial interaction in the biological environment.

Molecular orientation of liquid aliphatic hydrocarbons on the surface and at the interface with water

1989 ◽  
Vol 54 (12) ◽  
pp. 3171-3186 ◽  
Author(s):  
Jan Kloubek
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Molecular Orientation ◽  
Phase Changes ◽  
Aliphatic Hydrocarbons ◽  
Water Molecules ◽  
Free Energies ◽  
Dispersion Component ◽  
System Water ◽  
Orientation Of Molecules

The validity of the Fowkes theory for the interaction of dispersion forces at interfaces was inspected for the system water-aliphatic hydrocarbons with 5 to 16 C atoms. The obtained results lead to the conclusion that the hydrocarbon molecules cannot lie in a parallel position or be randomly arranged on the surface but that orientation of molecules increases there the ration of CH3 to CH2 groups with respect to that in the bulk. This ratio is changed at the interface with water so that the surface free energy of the hydrocarbon, γH, rises to a higher value, γ’H, which is effective in the interaction with water molecules. Not only the orientation of molecules depends on the adjoining phase and on the temperature but also the density of hydrocarbons on the surface of the liquid phase changes. It is lower than in the bulk and at the interface with water. Moreover, the volume occupied by the CH3 group increases on the surface more than that of the CH2 group. The dispersion component of the surface free energy of water, γdW = 19.09 mJ/m2, the non-dispersion component, γnW = 53.66 mJ/m2, and the surface free energies of the CH2 and CH3 groups, γ(CH2) = 32.94 mJ/m2 and γ(CH3) = 15.87 mJ/m2, were determined at 20 °C. The dependence of these values on the temperature in the range 15-40 °C was also evaluated.

Dynamics of soil aggregate stability as induced by potassium in a soil-plant system

2021 ◽  
pp. 1-9
Author(s):  
Surachet Aramrak ◽  
Natthapol Chittamart ◽  
Worachart Wisawapipat ◽  
Wutthida Rattanapichai ◽  
Mutchima Phun-Iam ◽  
...  
Keyword(s):  
Aggregate Stability ◽  
Soil Aggregate ◽  
Soil Aggregate Stability ◽  
Plant System

scholarly journals Dynamics of Soil Organic Carbon and Labile Carbon Fractions in Soil Aggregates Affected by Different Tillage Managements

2021 ◽  
Vol 13 (3) ◽  
pp. 1541
Author(s):  
Xiaolin Shen ◽  
Lili Wang ◽  
Qichen Yang ◽  
Weiming Xiu ◽  
Gang Li ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Soil Aggregate ◽  
No Tillage ◽  
Labile Carbon ◽  
Carbon Fractions ◽  
Soil Aggregate Stability ◽  
Positive Effects

Our study aimed to provide a scientific basis for an appropriate tillage management of wheat-maize rotation system, which is beneficial to the sustainable development of agriculture in the fluvo-aquic soil areas in China. Four tillage treatments were investigated after maize harvest, including rotary tillage with straw returning (RT), deep ploughing with straw returning (DP), subsoiling with straw returning (SS), and no tillage with straw mulching (NT). We evaluated soil organic carbon (SOC), dissolved organic carbon (DOC), permanganate oxidizable carbon (POXC), microbial biomass carbon (MBC), and particulate organic carbon (POC) in bulk soil and soil aggregates with five particle sizes (>5 mm, 5–2 mm, 2–1 mm, 1–0.25 mm, and <0.25 mm) under different tillage managements. Results showed that compared with RT treatment, NT treatment not only increased soil aggregate stability, but also enhanced SOC, DOC, and POC contents, especially those in large size macroaggregates. DP treatment also showed positive effects on soil aggregate stability and labile carbon fractions (DOC and POXC). Consequently, we suggest that no tillage or deep ploughing, rather than rotary tillage, could be better tillage management considering carbon storage. Meanwhile, we implied that mass fractal dimension (Dm) and POXC could be effective indicators of soil quality, as affected by tillage managements.

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