Comparative Study of Organoclays with Ionic Surfactant

2014 ◽  
Vol 798-799 ◽  
pp. 9-14 ◽  
Author(s):  
B.M.A. de Brito ◽  
Juliana Melo Cartaxo ◽  
Julliana Marques Rocha Costa ◽  
Heber Carlos Ferreira ◽  
Gelmires Araújo Neves

The clays of the smectite group, mainly montmorillonite, are widely used in the production of organoclays due to the small dimensions of the crystals, high cation exchange capacity (CEC), and swelling capacity in water, which lead to a rapid and efficient intercalation of organic compounds used in the synthesis. In this context, this research was intended to make a comparative study of clays organofilized with ionic surfactants through their respective CEC. We selected four samples of bentonites, namely Chocolate (Boa Vista, PB), Brasgel (industrial), Dark Bentonite (Pedra Lavrada, PB) and M400 Bentonite (industrial). The natural samples were characterized through XRD, EDX, TA and GA, and the organofilized ones through XRD. The characterization tests showed that the samples are composed of clay minerals of the smectite group, the CEC values ​​were insignificant changes when comparing the values ​​of natural and activated clays with sodium carbonate. And the levels indicated by the CEC for the ionic surfactant Praepagem HY proved insufficient to transform the organophilic clays, as the nominees for the ionic surfactant Praepagem WB led to adequate results regarding the incorporation of the surfactant in the clay fraction of the studied samples.

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Nenad Tomašić ◽  
Štefica Kampić ◽  
Iva Cindrić ◽  
Kristina Pikelj ◽  
Mavro Lučić ◽  
...  

AbstractThe adsorption properties in terms of cation exchange capacity and their relation to the soil and sediment constituents (clay minerals, Fe-, Mn-, and Al-oxyhydroxides, organic matter) were investigated in loess, soil-loess transition zone, and soil at four loess-soil sections in North-Western Croatia. Cation exchange capacity of the bulk samples, the samples after oxalate extraction of Fe, Mn and Al, and after removal of organic matter, as well as of the separated clay fraction, was determined using copper ethylenediamine. Cation exchange capacity (pH∼7) of the bulk samples ranges from 5 to 12 cmolc/kg in soil, from 7 to 15 cmolc/kg in the soil-loess transition zone, and from 12 to 20 cmolc/kg in loess. Generally, CEC values increase with depth. Oxalate extraction of Fe, Mn, and Al, and removal of organic matter cause a CEC decrease of 3–38% and 8–55%, respectively, proving a considerable influence of these constituents to the bulk CEC values. In the separated clay fraction (<2 μm) CEC values are up to several times higher relative to those in the bulk samples. The measured CEC values of the bulk samples generally correspond to the clay mineral content identified. Also, a slight increase in muscovite/illite content with depth and the vermiculite occurrence in the loess horizon are concomitant with the CEC increase in deeper horizons, irrespective of the sample pretreatment.


Clay Minerals ◽  
2012 ◽  
Vol 47 (4) ◽  
pp. 499-511 ◽  
Author(s):  
A. Mbaye ◽  
C. A. K. Diop ◽  
B. Rhouta ◽  
J. M. Brendle ◽  
F. Senocq ◽  
...  

AbstractThere is interest in exploiting and developing natural resources, particularly deposits of natural clays. Senegal has several clay mineral deposits for which chemical and mineralogical compositions have been little studied. Some of these natural materials are nowadays used in pottery and ceramics. To extend applications, a better basic knowledge is required and, for this objective, the raw clay and separated <2 μm clay fraction from Keur Saër (Senegal) were subjected to chemical and mineralogical studies. Several techniques including X-ray diffraction (XRD), thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), N2 adsorption-desorption isotherms, cation exchange capacity (CEC) measurements and solid state nuclear magnetic resonance (NMR) have been used to characterize the material. It was found that the raw clay and the separated clay fraction consist of a mineral mixture in which kaolinite is the main component. 29Si and 27Al MAS-NMR spectra show the presence of silicon atoms linked to three other silicon atoms via an oxygen atom and six coordinated Al atoms. Significant increases in the specific surface area and cation exchange capacity were observed on purification, reaching a maximum of about 73.2 m2g–1 and 9.5 meq/100 g for the separated fine clay fraction while the values for the raw material were around 28.9 m2g–1 and 7.3 meq/100 g.


Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody

Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.


Clay Minerals ◽  
1966 ◽  
Vol 6 (4) ◽  
pp. 341-344 ◽  
Author(s):  
W. E. Worrall ◽  
A. E. Cooper

AbstractA white-burning, highly-plastic clay from Jamaica, containing mainly disordered kaolinite, was examined recently. It was unusual in that it was practically free from fine mica, and therefore could be purified readily by standard sedimentation techniques.The cation exchange capacity was abnormally high, and the purified clay mineral, on analysis and calculation of the ionic composition, was found to be deficient in aluminium, but contained magnesium and iron.The results confirmed the view, previously expressed, that disorder in kaolinites is associated with a high cation exchange capacity and a substituted lattice.


2013 ◽  
Vol 3 (3) ◽  
pp. 179-183 ◽  

In order to study the erodibility characteristics of some calcareous soils from Central Greece, the instability of aggregates of 2.0-4.7 mm in water was studied. Soil loss experiments were also conducted in the laboratory using a rain simulator where soil loss was measured and the soils’ attitude was studied under the conditions of simulated rainfall. It was found that the instability of aggregates is negatively correlated with cation exchange capacity and the total specific surface of soils. Also the calcium carbonate content affects positively the aggregates instability. The process which seems to control dominantly the time that runoff occurs and the runoff and soil loss quantity, is the creation of surface seals with raindrop impact due to large calcium carbonate quantities that are met in the clay fraction.


2015 ◽  
Vol 820 ◽  
pp. 30-35
Author(s):  
C.D. Silva ◽  
J.M.R. Figueiredo ◽  
I.D.S. Pereira ◽  
J.M. Cartaxo ◽  
G.A. Neves ◽  
...  

Bentonite clays, after treated with surfactants, are called organofilic clays. The objective of this work is the development of organofilic clays, using ionic surfactants, based on a variety of smectite from Cubati, PB, for application in organic media. The following materials were used: Superior Gray bentonite clay from the town of Cubati, PB, Brazil, and the ionic surfactants Praepagen WB® and Praepagen HY®. The clay was characterized with basis on the granulometric analysis by laser diffraction (AG), chemical composition by X-ray fluorescence (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TG) and thermal differential (DTA). The clay was processed and then turned into sodic and later into organofilic clays. The results prove that there was intercalation of the ionic surfactant into the clay fraction, and that the process variables did not affect the organofilization process, but the surfactant type has influence on the process.


2019 ◽  
Vol 7 (19) ◽  
pp. 16410-16418 ◽  
Author(s):  
Gyanendra Kharel ◽  
Oumar Sacko ◽  
Xu Feng ◽  
John R. Morris ◽  
Claire L. Phillips ◽  
...  

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