Green Clay Research Articles

Radiation shielding and spectroscopic features of replacement materials: Reusing of agricultural and industrial wastes

Environmental pollution increases due to the large amounts of waste production and raw material consumption depending on the increasing population. Agricultural and industrial wastes which are some of the sources of the pollution need to be reuse to reduce the negative impact on the environment and also contribute positive effect to the economy. In this context, industrial wastes such as clay types (red and green) and agricultural wastes such as egg shell, walnut shell and banana shell were used to prepare materials which can be used as replacement materials for construction industry. Radiation attenuation parameters (mass attenuation coefficients, effective atomic number, linear attenuation coefficients, mean free path, half-value layer, exposure and energy absorption build up factors, fast neutron removal cross-section) were acquired by Phy-X/PSD code. Spectroscopic techniques (XRD, EPR, SEM-EDS) were performed for the structural analysis. The existence of calcite main phase peaks (≈29.7) as well as SiO2 (≈20° and 26°) and cellulose phases (≈16° and 34.7°) were observed by XRD. Mn+2 sextet lines with five weak doublets attributed to the forbidden transition lines of Mn+2 and a singlet with a g value of ≈2.00 and linewidth of ≈10 G were recorded by EPR. Among the samples, it was found that K1 (Red clay (20%)-eggshell waste (60%)-Bayburt stone waste (20%)), K3 (Red clay (60%)-eggshell waste (20%)-Bayburt stone waste (20%)), C3 (Red clay (60%)-eggshell waste (20%)-walnut shell waste (20%)) and Z3 (Green clay (60%)-egg shell waste (20%)-Bayburt stone waste (20%)) have the highest shielding potentials. All samples examined with good protection performances can be used as substitute materials instead of cement or aggregate for the aim of reusing the wastes and supporting the environmental and economic benefits.

Low Speed Impact of an Elastic Ball with Tapes and Clay Court

The study aims to investigate the normal and oblique impact of an elastic sphere (tennis ball) on a granular surface (clay) and two different plastic tape lines. In this research, we model the impact force with a mathematical elastoplastic force model, and a differential approach is used. The model is applied for an impact with granular material (green clay) and plastic surfaces (line tapes). We investigated the normal and oblique impact dynamics of a sphere (tennis ball). The impact duration is divided into two phases: compression with an elastoplastic force and restitution with an elastic force. The laboratory experiments in various configurations are recorded with a high frame-per-second camera and analyzed using image processing methods. The mathematical model for the impact with rebounds is verified with the experimental set-up for the considered surfaces. The viscoelastic and elastic forces agree well with the experimental data. The impact parameters of the granular surface and plastic tapes are compared. The ANOVA test suggests robust statistical significance in the coefficient of restitution between granular surfaces and plastic tapes. Our force model for impact performs well, and the impact responses of the sphere on the granular surface and the plastic line tapes are significantly different.

Berthierine authigenesis as grain pseudomorph? A new insight from the early Maastrichtian Kallankurichchi Formation, India

This study presents detailed sedimentological, geochemical, and mineralogical evidence of green clay formation at the basal part of the early Maastrichtian Kallankurichchi Formation, Cauvery Basin, India. Immediately overlying a basal scree conglomerate, the highly fossiliferous Kallankurichchi Formation hosted a ∼ 3.5 m thick dark grey limestone containing abundant green clay minerals formed by the alteration of metastable framework grains. Abundant fresh to partially palagonitized sideromelane glass and occasional preservation of gas bubble structures in green clays strongly suggest a volcaniclastic source. Petrographic observations manifested primary occurrences of the green grain pseudomorphs mimicking the shape of the precursor volcanic grains. The X-Ray Diffraction analysis of the randomly oriented bulk sample and oriented, smear-mounted green clay separates identified the berthierine by the strong ∼7 Å basal spacing. The mineral chemical data of the berthierine grain pseudomorphs recorded substantial compositional variation from Mg-, Si- and Al-rich core and Fe-rich rim, characterizing the maturation of berthierine from volcaniclastic substrate through ‘proto’-berthierine. Tiny berthierine flakes (1–5 μm long) grew vertically from the mineral grain boundary and feldspar cleavages, suggesting its authigenic origin. Contemporaneous tectonic events, marked by abundant slide planes, suggested continuous sagging of the basin, causing oxygen-depleted bottom water conditions. The unusual appearance of berthierine as grain pseudomorphs, rarely reported from the rock record, revealed the dissolution of metastable volcaniclastic grains in a slightly acidic, oxygen-depleted depositional environment as the primary mechanism of authigenesis. The early diagenetic calcite cementation ceased the berthierine formation, preventing compaction and transformation.

Physico-chemical properties of Russian natural aluminosilicates for purification of aqueous environment

The paper analyses and compares the physico-chemical properties of aluminosilicate green clay and bentonite and diatomite from the Russian deposits. The research determines specific surface area and the morphological features of aluminosilicates, their pore sizes, and pore distribution by volume. The surface of the green clay includes silicon and aluminum oxides, montmorillonite, kaolinite, impurities of pyrite, saponite, micas, and hydrosludes. It also contains a lot of rounded particles with a diameter of 1-2 μm. According to the research, adsorption isotherms for mesoporous green clay samples belong to type IV; the samples of bentonite and diatomite (Middle Volga regions of Russia) belong to type II. They characterize the monolayer-multilayer concentration of solution components on macroporous bodies. Also the research revealed a sufficiently high amount of adsorbate (31 ml • g-1) to cover the surface of diatomite (Ulyanovsk region, Russia) with a monomolecular layer. The source minerals of diatomite are montmorillonite and muscovite. The study of adsorption and desorption branches for a bentonite sample (Samara region, Russia) indicates the processes asymmetry. Hence, we compared the ability to adsorb iron (II) and lead ions from aqueous systems using green clay extracted in different years (2017 and 2023).

Bed bug control with various dusts: Efficacy comparison between silicon dioxide, diatomaceous earth, and Sommières earth.

Bed bugs are considered a major public health problem in industrialized countries. Usually, bed bug infestations are managed using a combination of physical and chemical methods. In recent years, new strategies for bed bug control have emerged, particularly the use of dusts like diatomaceous earth and silicon dioxide. However, in Europe, the use of silicon dioxide is restricted to professional, while diatomaceous earth can be harmful to the lungs. This study aimed to assess bed bug mortality rates associated with Sommières earth, green clay, talc, and sodium bicarbonate compared to silicon dioxide and diatomaceous earth from a pest management company, diatomaceous earth for litter conditioner, and diatomaceous earth from a supermarket. We tested permanent exposure, short exposure, horizontal transfer and repellent effect on two bed bug colonies. Sommières earth demonstrated efficacy ranging from 75% to 100% in permanent and short exposures, similar to the efficacy of diatomaceous earth from the pest management company. On the contrary, diatomaceous earth for litter conditioner and diatomaceous earth from a supermarket, green clay, talc, and sodium bicarbonate were found to be ineffective. This study demonstrates, for the first time, the efficacy of Sommières earth against bed bugs, but also highlights the variability in efficacy of diatomaceous earths on bed bugs depending on their quality.

Middle Pleistocene to Holocene estuarine and aeolian deposits at L’Amélie (Médoc peninsula, Southwest France).

The chronostratigraphy of Pleistocene and Holocene coastal deposits in the Médoc Peninsula (southwest France) was revised during preventive archaeology work carried out prior to the restoration of the riprap protecting L'Amélie seaside resort. This study revealed that the Pleistocene deposits were more complex than initially expected. At the base, they comprise subtidal to supratidal estuarine units (“Argiles du Gurp”: laminated silts, green clay, sandy peat with tree stumps) related to the high sea level of Marine Isotopic Stage (MIS) 11 (Holsteinian). These deposits were incised by a fluvial/deltaic channel at the end of the interglacial, then covered by aeolian sands dating back to MIS 10. The whole area is covered unconformably by gravelly sand colluvium. Holocene aeolian deposits fill a small valley cut into the Pleistocene deposits and indicate the arrival of the coastal dune massif in the area during the late Antiquity. An overview of the results obtained in Médoc shows successive bodies of estuarine deposits indicating a gradual northward migration of the Gironde estuary. Only a few high marine levels are recorded (MIS 1, MIS 9, MIS 11, Gelasian, Piacenzian), presumably both because the sea level reached was similar to or higher than the Holocene level and because the deposits were preserved from erosion during the periods of valley incision.

Applying Decision Analysis and System Dynamics Community Governance in the Evaluation of Juvenile Delinquency Prevention Strategies

Abstract From the perspective of juvenile delinquency prevention theory, this paper explores the current situation of juvenile delinquency in rural areas of W County and the mechanism of relevant functional departments in local community governance based on the questionnaire survey method. Then, six juvenile delinquency prevention service programs are selected as the object of evaluation research, and the intelligent decision analysis system of system dynamics is used as the tool of evaluation research to evaluate the six juvenile delinquency prevention programs systematically and comprehensively. The following conclusions were obtained after the analysis. The crime rate of rural youths in County W is as high as 15.8%, with a wide range of crimes. 81.6% of the relevant departments in community governance did not establish rural juvenile records, and about 13% of the departments did not conduct crime prevention training. The Green Clay People Juvenile Crime Prevention Program, which uses social connection theory as a strategy, has an evaluation value of 0.242, and the completion rate of the agreed service indicators specified in the contract is more than 100%. The overall evaluation of the six programs was 87% satisfied. Therefore, the intelligent decision analysis system in this paper has been well applied in the evaluation of juvenile crime prevention strategies, with the progress and development of society, and will occupy an important position in the future for a considerable time.

Flora of cretaceous low mountains of South-Western Hissar Ridge

List of creataceuos flora of Southern-Western Hissar district belonging to Bactrian subprovince of Mountainous Middle Asiatic (Afghan-Turkestan) botanical geographic with 491 species from 250 genera and 49 families of vascular plants province is given. Analysis of florogenitic hypothesis of this florocenotype is also given. We confirmed ideas of R. V. Kamelin (1979) about genesis of this relic subtropical-mediterranean type of vegetation, appeared in paleogen-neogen on the base of relic xeropphytic and partly Mediterranean floras. Flora of gypsaceous low mountains seems to be rather poor and isolated from red cretaceous and green clays presents relic shard of tropical-subtropic afro-arabian flora. First complex is presented by such genera as Plocama Aiton, Molucella, Camptoloma Benth., Rorida J. F.Gmel. having distribution from Canary Islands, Western and Eastern Africa and Sokotra Island to Khorassan and Southern Pamir-Alay. Second complex of gypsaceous mountains presented by autochthonous neogen afghan-pamir-alayan endemic species of genera Spryginia Popov, Bolbosaponaria Bondar., Gypsophila L.

Clay Therapy in Wound Healing: A Brief Review of the Literature

Clay is ubiquitous, and its hydrous phyllosilicate properties have promoted its use as a traditional wound healing agent in many cultures. Various types of natural clay have been utilized for skin diseases and wound treatments. Therefore, we aimed to study natural and synthetic clay minerals and summarize their applicability in medical settings. A review of prospective studies published since 2008 examining the properties of different forms of natural clay minerals and their therapeutic benefits in wound care was conducted. Studies were obtained using the databases of Google Scholar, PubMed, Web of Science, and HINARI (Health Inter-Network Access to Research Initiative) and searching related journals. The primary outcomes were assessed qualitatively and were categorized by the type of natural clay used. The included papers studied five available types of clay: Chamliyal clay, French green clay, Oregon Mineral Technologies blue clay, Kisameet clay, and various synthetic clays. The studies found how these forms of clay together demonstrate anti-inflammatory and antibacterial properties while promoting fibroblast regeneration and circulation while remaining biocompatible. Clay-based materials may be a potential alternative for conventional dressings for wound healing in resource-limited settings. This review opens doors to expanding clay-based therapies for wound healing.

The Behavior of Rare Earth Elements during Green Clay Authigenesis on the Congo Continental Shelf

Clay mineral authigenesis at continental margins plays an important role in global marine element cycles. However, despite being increasingly used as tracers for both modern and past oceanographic conditions, the behavior of the rare earth elements (REEs) and their isotopes during marine clay authigenesis still remains poorly known. In this study, we report on a detailed geochemical investigation of glauconite from the West African continental shelf, near the mouth of the Congo River. Elemental, neodymium, and hafnium isotope analyses were conducted on both acid leachate and separated clay-size fractions of glauconite pellets, in order to investigate the behavior of REE during the formation of authigenic clays. Our data indicate that kaolinite dissolution and subsequent Fe-bearing clay authigenesis act as a net source of REEs to seawater. We show that enhanced glauconitization, as inferred from increasing Fe and K contents, is accompanied by significant decoupling of the REE toward markedly LREE-enriched shale-normalized patterns in neoformed clay separates. Using both Nd and Hf isotopes and SEM observations, we rule out any seawater influence and argue that this shift primarily reflects the progressively overwhelming presence of insoluble nanocrystals of detrital LREE-rich phosphates, which are known to occur in close association with kaolinite in tropical soils. Due to their marked insolubility in surface environments, such nanocrystals can be preserved during kaolinite dissolution and subsequently incorporated into the aggregates of authigenic green clays forming the peloids. Most strikingly, we show that the combined influence of net REE loss (due to kaolinite dissolution) and decoupling (due to subsequent entrapment of inherited LREE-bearing accessory phases into neoformed clay minerals) is accompanied by preferential release of a dissolved REE fraction characterized by seawater-like distribution patterns. These findings reinforce the emerging view that clay mineral dissolution and authigenesis at continental margins possibly play a major role in marine REE cycling.

Polymeric Patches Based on Chitosan/Green Clay Composites and Hazelnut Shell Extract as Bio-Sustainable Medication for Wounds.

Hazelnut shells, the main waste deriving from hazelnut processing, represent an interesting source of active molecules useful in pharmaceutics, although they have not yet been examined in depth. A hydrosoluble extract (hazelnut shell extract, HSE) was prepared by the maceration method using a hydroalcoholic solution and used as the active ingredient of patches (prepared by casting method) consisting of composites of highly deacetylated chitosan and green clay. In vitro studies showed that the formulation containing HSE is able to stimulate keratinocyte growth, which is useful for healing purposes, and to inhibit the growth of S. aureus (Log CFU/mL 0.95 vs. 8.85 of the control after 48 h); this bacterium is often responsible for wound infections and is difficult to treat by conventional antibiotics due to its antibiotic resistance. The produced patches showed suitable tensile properties that are necessary to withstand mechanical stress during both the removal from the packaging and application. The obtained results suggest that the developed patch could be a suitable product to treat wounds.

Plastic behaviour of clay materials for the manufacture of fast-drying red ceramics

AbstractFast drying (~60 min) is useful for optimizing production processes by increasing productivity and reducing costs and environmental impacts, especially in red ceramic industries in Brazil. However, suitable clays are necessary and, currently, studies focused on the plastic behaviour of clays with compositions suitable for extrusion, especially for fast drying, are scarce. Therefore, in this study, three different clays from the same mineral deposit were studied for producing clay-based structural products via fast drying. The clays were characterized according to their chemical, mineralogical and thermal properties, particle size, cation-exchange capacity, specific surface area and open pore volume distribution. Ten formulations were developed using a simplex-centroid mixture design of experiments and their plasticity index (PI) values were determined. The response surfaces of the formulations were evaluated according to their PI, while the formation characteristics were determined according to their extrusion workability factor values. Formulations F5 (50.0 wt.% yellow clay and 50.0 wt.% green clay) and F8 (66.6 wt.% yellow clay, 16.7 wt.% grey clay and 16.7 wt.% green clay; PI = 15.5–16.6%) displayed optimal extrusion properties, followed by formulations F7 (33.3 wt.% yellow clay, 33.3 wt.% grey clay and 33.3 wt.% green clay) and F10 (16.7 wt.% yellow clay, 16.7 wt.% grey clay and 66.6 wt.% green clay; PI = 13.8–14.2%), which are within acceptable extrusion index values. Thus, the chosen formulations have significant potential for use in the manufacture of fast-drying red ceramics.

Microstructure of Brownish and Blackish Color on Bizen Stoneware Fired in a Firewood Kiln and Reproduction of Brownish Color

Bizen stoneware is produced by firing shaped green clay in a firewood kiln at around 1200°C. The brownish and blackish colors that appear on the stoneware surface in a firewood kiln do not appear on stoneware heated in an electric furnace. The brownish color was found to be caused by the formation of single crystalline, branched, dendritic, Al-substituted ε-Fe2O3 particles. Composite particles consisting of Al-substituted ε-Fe2O3 and Fe-substituted spinel solid solution also formed on the stoneware surface. In this study, we successfully prepared brownish samples that were similar in color to Bizen stoneware by annealing at 1200°C for 2 h in air after heating Bizen clay pellets with K2CO3 at 1230°C under a 10 vol% CO and 90 vol% Ar gas mixture in an electric furnace instead of firing in a firewood kiln. Dendritic hematite particles also formed on the reproduced samples. The blackish color on Bizen stoneware fired in a firewood kiln was caused by the formation of augite [(Ca,Mg,Fe)2Si2O6], which was produced by a reaction between the Bizen clay and firewood ash.

Muttalip green clay and its ultraviolet and infrared absorption and reflection

AbstractThe search for sufficiently high-quality clays for use in the tile industry represents a significant challenge. This study aimed to prepare Muttalip green clay tiles with flexural strengths adhering to the TS EN 1304:2016 standard. Muttalip green clay was subjected to sieving, vacuum pressed, dried and then baked to obtain galette tiles. The tiles were analysed subsequently using optical techniques, including X-ray diffraction, X-ray fluorescence spectrometry and field-emission scanning electron microscopy. The influence of various firing temperatures (900, 950 and 1000°C) on the flexural strength of the tiles was also investigated. The tiles obtained at 950°C exhibited a maximum flexural strength of 153.91 kg cm–2. Fourier-transform infrared spectroscopy revealed that the tiles reflect ultraviolet A radiation and absorb infrared radiation. Muttalip green clay is a suitable material for preparing tiles for roofing applications.

Structural Study of Nano-Clay and Its Effectiveness in Radiation Protection against X-rays.

With the increasing applications of nuclear technology, radiation protection has become very important especially for the environment and the personnel close to radiation sources. Natural clays can be used potentially for shielding the X-ray radiations. In this study, the correlation between structural parameters and radiation shielding performance of natural clay extracted from Algerian Sahara (Adrar, Reggan, and Timimoune) was investigated. Phase composition and structural parameters (lattice parameters, average crystallite size, and microstrain) were determined by the Rietveld refinements of X-ray diffraction patterns in the frame of HighScore Plus software. The obtained results showed that the studied clays are nanocrystalline (nano-clay) since the calculated crystallite size was ≈3 nm for the feldspar phase. FTIR spectra confirmed the presence of all phases already detected by XRD analysis besides Biotite (around the band at 3558 cm−1). The remaining bands corresponded to absorbed and adsorbed water (3432 cm−1 and 1629 cm−1, respectively) and atmospheric CO2 (2356 cm−1). The shielding properties (mass absorption coefficient—µ/ρ and radiative attenuation rate—RA) for (green-yellow, green, and red) clays of Adrar, (red, white, and white-red) clays of Reggan, and red clay of Timimoune at same energy level were examined. The results of clay samples were compared with each other. The obtained results indicated that the green clay of Adrar exhibited the superior radiation shielding, i.e., 99.8% and 243.4 cm2/g for radiative attenuation rate and mass absorption coefficient, respectively.

HRTEM evidences of Tajo Basin mineralogical complexity: Crystal chemistry and genetic relationship

In this study, a new genetic interpretation of the Mg-bentonite deposits from the Tajo Basin is given through a high-resolution transmission electron microscopy study. These bentonites, belonging to the Green Clays and Pink Clays lithostratigraphic units, are afforded by the sum of processes occurring during the weathering of parent rocks and the evolution of the materials by the transformation of phyllosilicates in the sedimentary environment. The primary phyllosilicates progressively change their microstructure and crystal chemistry, resulting in very complex clay minerals assemblages. The Green Clays are relatively enriched in Al, Fe, and K, whereas Pink Clays are enriched in Mg and Si, corresponding to almost pure trioctahedral smectites. Although the point analysis of the particles showed a continuous compositional variation that evidences their genetical relationship, they were statistically classified in groups that represented the evolution from the primary phyllosilicates (dioctahedral and trioctahedral micas and chlorites) to the final products comprise very low-charge saponite and scarce sepiolite. The intermediate steps in this transformation included the following: 1) particles of structural formulas with an excess of octahedral cations that were interpreted as hydroxy-interlayer minerals and 2) random mixed-layers of illite/smectite progressively poorer in illitic component as the more evolved particles. Green Clays correspond to the state of transformation to smectites where partially transformed detrital components were still predominant, corresponding to more proximal facies, whereas Pink Clays represented most evolved stages in the mineral transformation. The alternation of Green and Pink Clay levels was related to climatic changes with alternation of wetter and drier periods.

Characterization of the High Swelling Green Clay in the Vicinity of Amman Area

Introduction: Jordan is awarded huge areas in the north and western part of the country in which brown and green clay is dominant. This research focuses on the problems and behaviour of the green clay only. The main problem of the green clay is its high swelling pressure which is the main cause of excessive settlement and wall cracks in buildings, especially during the wet season. Methods: This study aims to investigate the engineering properties and behaviour of the green clay deposits in the Amman area, which will serve as a guide for both geotechnical and structural engineers when preparing the foundation design. Results: Based on the consolidation test, the investigated green clay showed high swelling pressure of 3.11 kg/cm2, liquid limit (LL) of 73%, plasticity index (PI) of 40%, the shrinkage limit (SL) of 12%, and liquidity index (LI) of 0.125. The moisture content at saturation is 35.14%, while the natural moisture content is 28%, dry density is 1407 kg/m3, cohesion (C) is 0.20 kg/cm2 and unconfined compressive strength is 1.05 kg/cm2. The XRD results of the clay size fraction have confirmed the presence of the expansive clay mineral smectite as the essential clay mineral together with kaolinite. Results provide a general understanding of the behaviour and properties of the green clay, and the regression analysis showed good correlations between the liquid limit and initial moisture content with the compression index and also between the initial void ratios with the swelling index. Conclusion: Changes in the volume are due to the unsaturation level of clay when provided with initial water content.

Studying and Utilizing Traditional Technologies: Microstructure and Formation Mechanism of ε-Fe2O3 on Traditional Japanese Bizen Stoneware.

Traditional Japanese Bizen stoneware is produced by firing a specific type of green clay in a wood-fired kiln at approximately 1200 °C. During this process, single crystalline branched dendrite-like particles of Al-substituted ε-Fe2O3 (ε-Fe1.7Al0.3O3) with widths and lengths of approximately 15 and 30 μm, respectively, are formed on the surface of the ceramic. Composite particles consisting of ε-Fe2O3 epitaxially connected to spinel structure compounds [comprising the Fe-substituted spinel (Mg,Fe)(Al,Fe)2O4 and γ-Fe2O3)] with lengths of approximately 3 μm are also generated. The present work clarified the crystallographic relationship between ε-Fe2O3 and the spinel structure compounds. In addition, brown-colored samples similar to Bizen pottery and with surface Al-substituted ε-Fe2O3 particles were prepared by heating clay with K2CO3 under a 10 vol % CO gas and 90 vol % Ar gas mixture using an electric furnace instead of a firewood kiln. Hence, a traditional method was adapted to achieve the industrial production of ε-Fe2O3 crystals.

Mass-suspension Polymerization Process as an Efficient Tool to Produce Polymer/Clay Nanocomposites

Background: This work presents the preparation and characterization of the polymeric nanocomposites based on methyl methacrylate (MMA), ethyl acrylate (EA), and natural and modified clays. The clays used to prepare the composite were natural green bentonite (GBC-N) and organophilic clays modified with ammonium quaternary salts: Praepagen (GCB-P), Dodigen (GCB-D) and Praepagen/Dodigen mixture 1:1 in weight (GCB-P/D). Objective: The experimental studies focused on the evaluation of the effect of clays (in nature and chemically modified) on the final quality of the polymeric nanocomposites containing around 3 wt%. of clay nanocharges in association with MMA to produce poly(methyl methacrylate)/clays, and MMA/EA to form poly(methyl methacrylate-co-ethyl acrylate)/clays. Methods: The poly(methyl methacrylate)/clay and poly(methyl methacrylate-co-ethyl acrylate)/- clay materials were synthesized through mass-suspension polymerization process. The natural and modified green bentonite clays were characterized by X-ray powder diffraction (XRD), infrared spectroscopy (IR), Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) analyses to understand its effect on the basal spacing, d001 (compared to the pure clay), as a result of cation exchange step, which also improved the thermal efficiency of the final nanocomposites. Results: The proper incorporation of MMA and MMA/EA monomers between the layers of natural and modified clays occurred through in situ mass-suspension polymerization, leading to a successful exfoliation of clay layers during the growth of the polymer chains. Conclusion: The IR, SEM, TGA and DSC analyses confirmed the improvement in the thermal property of the composites compared to polymers formed in the absence of clays. The experimental results are very promising, indicating that the experimental protocol based on the in situ formation of polymer nanocomposites by using sequential mass-suspension polymerization consisting of an interesting tool.

Mineralogical, thermal and rheological characterization of some Tunisian green commercial clays and possible application as peloids with thermal and sea waters

Many of therapeutic treatments in spas are concentrated on mud therapy. Clays are included in the formulation of thermal mud as vehicles of the mineral medicinal water. To be suitable for therapeutic use, some mineralogical, rheological and thermal properties should be respected in order to be topically applied. Our objective is to explore the suitability of three Tunisian commercial green clays traditionally used as facial and body masks by women in the region of Douiret (CD), Tozeur (CT) and Korbous (CK) in terms of their physicochemical structure chemical composition, heavy metals risk assessment, thermal properties, plasticity, rheology and their potential application as peloid with distilled and sodium chloride-rich sulfated thermal waters from hot spring in the region of hammam Lif and Korbous and sea waters. The mineralogy of samples (clay fraction and associated minerals) was determined by X-ray powder diffraction and FT-IR analysis, and the chemical composition was obtained by ICP. The main clay fraction of the samples was smectite and illite with significant amount of kaolinite. Regarding their mineralogical properties, the samples with a high amount of smectite fraction are more suitable for use in Tunisian spas and for the application as peloids. The thermal analyses of clay powders shows a specific heat value comparable to those use used in spas. Also the muds showed a low cooling rate which is necessary for therapeutic use. Rheological properties of peloids prove their thixotropic characteristics.