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Auswahl der wissenschaftlichen Literatur zum Thema „Nano-clays“
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Zeitschriftenartikel zum Thema "Nano-clays"
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Kakiage, Masaki, Rie Takamatsu, Hiroki Uehara, Takeshi Yamanobe und Keizo Suzuki. „Nano-Platelet Structure of Clay Materials Observed by Atomic Force Microscope“. Key Engineering Materials 459 (Dezember 2010): 57–61. http://dx.doi.org/10.4028/www.scientific.net/kem.459.57.
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In this study, we investigated the nano-platelet structures of original and organically modified montmorillonite clays. Atomic force microscope observation gave accurate width and thickness of the nano-platelet clays. The organically modified clays could not be homogeneously dispersed even in organic solvent. Ultrasonication of the solution resulted in the destruction of the layered structure of the clays. In contrast, the supernatant solution before ultrasonication contained the mono-layered nano-platelets of the organically modified clays whose surface was rough in the angstrom level due to the adsorbed molecules.
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Saulick, Yunesh, und Sergio Lourenço. „Hydrophobisation of clays and nano silica for ground engineering“. E3S Web of Conferences 195 (2020): 03039. http://dx.doi.org/10.1051/e3sconf/202019503039.
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Altering the hydrophobicity of particles allows their use as functional construction materials in ground engineering (e.g. in barriers). This study examines the hydrophobisation of nano to micro particles by using two clays (kaolin and halloysite) and nano silica. To induce hydrophobicity, dimethyldichlorosilane (DMDCS) was used in concentrations varying from 0.25% to 20%. The sessile drop method was used to measure the contact angle (CA) of the particles. Kaolin was initially hydrophobic with a CA of 93 5◦ while the other two materials were hydrophilic. The addition of DMDCS to the materials increased CAs of all materials investigated. The maximum CAs recorded at 20% for the halloysite, kaolin and nano silica were respectively: 116 5◦, 143 3◦ and 144 6◦. The difference in CAs attained by the clays was attributed to their different structure. Scanning electron microscope-energy dispersive spectroscopy analysis showed increases in carbon content with only halloysite and nano silica after hydrophobisation. The results demonstrate that hydrophobising clays and nano silica can effectively improve their resistance to water infiltration.
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Voicu, Rodica Cristina, Mihai Gologanu, Catalin Tibeica, Mercedes Santiago-Calvo, María Asensio, Esteban Cañibano, Oana Nedelcu und Titus Sandu. „Prediction of Mechanical Properties of Nano-Clay-Based Biopolymeric Composites“. Nanomaterials 14, Nr. 17 (28.08.2024): 1403. http://dx.doi.org/10.3390/nano14171403.
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An understanding of the mechanical behavior of polymeric materials is crucial for making advancements in the applications and efficiency of nanocomposites, and encompasses their service life, load resistance, and overall reliability. The present study focused on the prediction of the mechanical behavior of biopolymeric nanocomposites with nano-clays as the nanoadditives, using a new modeling and simulation method based on Comsol Multiphysics software 6.1. This modeling considered the complex case of flake-shaped nano-clay additives that could form aggregates along the polymeric matrix, varying the nanoadditive thickness, and consequently affecting the resulting mechanical properties of the polymeric nanocomposite. The polymeric matrix investigated was biopolyamide 11 (BIOPA11). Several BIOPA11 samples reinforced with three different contents of nano-clays (0, 3, and 10 wt%), and with three different nano-clay dispersion grades (employing three different extrusion screw configurations) were obtained by the compounding extrusion process. The mechanical behavior of these samples was studied by the experimental tensile test. The experimental results indicate an enhancement of Young’s modulus as the nano-clay content was increased from 0 to 10 wt% for the same dispersion grades. In addition, the Young’s modulus value increased when the dispersion rate of the nano-clays was improved, showing the highest increase of around 93% for the nanocomposite with 10 wt% nano-clay. A comparison of the modeled mechanical properties and the experimental measurements values was performed to validate the modeling results. The simulated results fit well with the experimental values of Young’s modulus.
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Hong, Seok-In, und Jong-Whan Rhim. „Antimicrobial Activity of Organically Modified Nano-Clays“. Journal of Nanoscience and Nanotechnology 8, Nr. 11 (01.11.2008): 5818–24. http://dx.doi.org/10.1166/jnn.2008.248.
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Antimicrobial activity of three kinds of commercially available montmorillonite nano-clays including a naturally occurring one (Cloisite Na+) and two organically modified ones (Cloisite 20A and Cloisite 30B) against four representative pathogenic bacteria (two Gram-positive ones such as Staphylococcus aureus and Listeria monocytogenes, and two Gram-negative ones such as Salmonella typhimurium and E. coli O157:H7) was investigated. Antimicrobial activity was found to be dependent on the type of nano-clay and microorganisms tested. Among the nano-clays tested, Cloisite 30B showed the highest antibacterial activity followed by Cloisite 20A, however, the unmodified montmorillonite (Cloisite Na+) did not show any antibacterial activity. Especially, Cloisite 30B inactivated Gram-positive bacteria completely within an hour of incubation and inactivated Gram-negative bacteria by more than 2–3 log cycles after 8 hours incubation. SEM and TEM images of cell structure indicated that the organically modified nano-clay caused rupture of cell membrane and inactivation of the bacteria. This finding of antimicrobial activity of the organo-clay would open a new opportunity to develop polymer nanocomposites with additional functionality, i.e., antimicrobial function.
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Ahmed, H. R., und S. N. Abduljauwad. „Nano-level constitutive model for expansive clays“. Géotechnique 67, Nr. 3 (März 2017): 187–207. http://dx.doi.org/10.1680/jgeot.15.p.140.
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C. Staniford, Mark, Marina M. Lezhnina und Ulrich H. Kynast. „Phthalocyanine blue in aqueous solutions“. RSC Advances 5, Nr. 6 (2015): 3974–77. http://dx.doi.org/10.1039/c4ra11139g.
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Cortés, Guillermo R. Martín, Adriana A. Silva, Kleberson R. O. Pereira, Fabio José Esper, Lisiane N. L. Santana, Wildor Theodoro Hennies und Francisco Rolando Valenzuela-Díaz. „Technology Characterization of Organo-Clays Obtained from Bentonites of the State of Paraiba“. Materials Science Forum 660-661 (Oktober 2010): 1124–29. http://dx.doi.org/10.4028/www.scientific.net/msf.660-661.1124.
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The organo-clays have important industrial uses between others are: rheological additives for drilling fluids in oil bases, inks, glues, lubricants and cosmetics. At the moment and in a growing way, these materials are considered as important reinforcement fillers in the structuring of nano-composites clays/polymers. They are obtained by the smectite clay reaction with quaternary ammonium salts. In this work an organophillic clay sample prepared by a dry process at the PMT – EPUSP – Metallurgic and Materials Engineering Department of the Polytechnic School at the University of São Paulo, had been characterized basically by techniques of XRD, IR, Thermal Analysis, and by swell capacity of the clays in some oils and organic solvents.
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GARCÍA, SILVIA, PAULINA TREJO GARCIA, JOEL MERLOS ESPERICUETA und ILCE CASTILLO GALVAN. „NANOSILICA TO MODIFY THE CONSISTENCY OF HIGH COMPRESSIBLE LACUSTRINE CLAYS“. DYNA 97, Nr. 2 (01.03.2022): 145–49. http://dx.doi.org/10.6036/10358.
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Despite the incredible advances in the most innovative branch of materials science, the nanotechnology research on its application in the geotechnical field is still very limited. Since many minerals in soil and rocks are nanomaterials and their chemical reactions are at the nanoscale, there is a great potential for the use of this important technology in different geotechnical problems. In this study, the stabilization of a soft lacustrine clay using nano-SiO2 is investigated. Through the examination of the Atterberg Limits, as the simplest and most affordable indicators of the consistency of these highly compressible and plastic materials, it is shown that the addition of nanosilica to clay masses substantially modifies their compressibility and resistance as well as their drainage and absorption capacities. When nano-SiO2 is mixed these very plastic and high-water content clays, it transforms them into consistent masses (from very soft to firm). The results presented contribute to widen the knowledge about nano-substances and plastic soils revealing the effects on exceptional lacustrine clays.
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Shamim, Arslan, Sajjad Ahmad, Anwar Khitab, Waqas Anwar, Rao Arsalan Khushnood und Muhammad Usman. „Applications of Nano Technology in Civil Engineering“. International Journal of Strategic Engineering 1, Nr. 1 (Januar 2018): 48–64. http://dx.doi.org/10.4018/ijose.2018010104.
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This article presents the recent trends in the field of civil engineering with an emphasis on the applications of nano materials and their beneficial effects at nano scale. The role and utilization of nanoparticles such as nano silica, carbon nano tubes, graphene, nano clays, nano CaCO3, nano TiO2, etc., is sharply increasing with the passage of time for achieving high performance composites. These nano materials not only enhance the mechanical properties of the resulting composites but also produce multifunctional characteristics. In this review, the authors have highlighted the various types of nanomaterials being used in the field of civil engineering and the performance improvements achieved by their utilization. Besides the potential benefits of Nano materials, they may pose some health and environmental concerns. A brief discussion is also provided on this issue.
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Chivrac, Frédéric, Eric Pollet, Marc Schmutz und Luc Avérous. „Starch nano-biocomposites based on needle-like sepiolite clays“. Carbohydrate Polymers 80, Nr. 1 (März 2010): 145–53. http://dx.doi.org/10.1016/j.carbpol.2009.11.004.
Der volle Inhalt der QuelleDissertationen zum Thema "Nano-clays"
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Chivrac, Frédéric. „Nano-biocomposites : structured systems based on starch and clays“. Strasbourg, 2009. http://www.theses.fr/2009STRA6066.
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Les bioplastiques représentent une solution élégante aux problèmes environnementaux induit par l’utilisation de plastiques issus de ressources non renouvelables. Parmi les différents biopolymères pouvant être développés, l’amidon apparaît être une solution écologiquement viable puisque que ce matériau est directement produit lors de la phase de croissance de la plante et ensuite extrait. Néanmoins, s’il est possible de développer des matériaux plastiques à partir de cette matrice amylacée, de nombreuse faiblesses, telles que de faibles propriétés mécaniques et une forte sensibilité à l’eau, restent à solutionner. L’introduction et de charges nanométriques (nanocharges) de type argile (montmorillonite et sépiolite), en vue de produire des matériaux nano-biocomposites, vise à pallier à ces principales déficiences. L’analyse de l’influence de la nature de la surface de la nanocharge a clairement montré le rôle majeur de l’utilisation d’un comptabilisant à l’interface matrice/nanocharge, à savoir l'amidon cationique. Par ailleurs, le rôle du plastifiant sur la dispersion et les propriétés résultantes de ces nano-biocomposites a également été étudié. L’ensemble de ces travaux a révélé des nano-structures complexes, fortement influencées par la polarité des différents éléments constitutifs de ces matériaux nano-biocomposites, mais a également clairement éclairé la forte valeur ajoutée d’une telle démarche. Enfin, une étude plus fondamentale nous a permis de mieux décrire l’influence de ces nanocharges, en fonction de leur état de dispersion, sur le comportement mécanique macroscopique de ces matériauxBioplastics are a powerful strategy to answer to the environmental diseases induced by non-degradable plastics produced from non renewable resources. Since starch is inherently biodegradable and produced during the plant growth, it seems to be a suitable option to develop environmentally friendly materials. Nevertheless, even if bioplastics can be produced with this biomacromolecule, the resulting materials are very sensitive to water and have low mechanical properties. The dispersion of nanosized fillers (nanofillers), like clays (montmorillonite, sepiolite), to produce nano-biocomposite materials, is an interesting option to overcome these weaknesses. The influence of the nanofillers surface treatment has been studied and has highlighted the key role of this parameter on the resulting morphology. It has been demonstrated that the use of a clay compatibilizer, namely cationic starch, is required to have an optimal dispersion quality. Moreover, one part of this study has revealed the influence of the plasticizer on the nanofillers morphology. Thus, these analyses have shown complex morphologies, influenced by the polarity of the different components of the nano-biocomposites, but have also demonstrated the added value of such development. Finally, a more fundamental work allowed us a better understanding of the nanofiller influence, as a function of their dispersion state, on the macroscopic mechanical behaviour of these materials
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Aloui, Lobna. „Synthèse de nano-adsorbant à base d’argile, application à l’adsorption de métaux lourds et de chlorophénols“. Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0644/document.
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La pollution des eaux usées par les éléments métalliques présents à l’état de traces et les cholorophénols pose un problème majeur pour l’environnement et la santé humaine. Cette étude concerne la synthèse d’argiles organophiles et de zéolithes à partir d’argiles naturelles prélevées en Tunisie et leurs applications pour l’adsorption respectivement des chlorophénols et des cations métalliques (Pb2+, Cd2+).Sur le plan de la synthèse d’argiles organophiles, une argile de type smectitique a été modifiée en utilisant le tensio-actif HDTMA. Cette argile organophile a été utilisée pour l’adsorption du 3-chlorophénol et du 4-chlorophénol. L’étude des isothermes et de la calorimétrie d’adsorption ont prouvé l’efficacité de cette argile organophile pour l’adsorption des deux chlorophénols.Des zéolithes ont été préparées à partir d’une argile naturelle composée de kaolinite, d’illite et de quartz. Ces zéolithes ont été utilisées pour l’adsorption des éléments métalliques tels que la cadmium (Cd2+) et le plomb (Pb2+) . Les cinétiques et les isothermes d’adsorption de Cd2+ et Pb2+ sur les zéolithes synthétisées (CAN, ANA, mélange Faujasite (FAU), néphéline et quartz), une cancrinite naturelle, une zéolithe commerciale (FAU 13X) et l’argile de départ ont été étudiées à 25°C en utilisant la méthode des restes. Une étude calorimétrique a été faite pour mieux comprendre les phénomènes mis en jeu lors de l’adsorption. La cinétique d’adsorption est très rapide. Une meilleure affinité est obtenue pour les zéolithesThis study concerns the synthesis of zeolites and organophilic clays from clay and their applications for the adsorption of metallic elements (Pb2+, Cd2+) and chlorophenols.In terms of the synthesis of organophilic clays, a smectite clay was modified using the HDTMA surfactant. This organophilic clay was used for the adsorption of 3-chlorophenol and 4-chlorophenol. The study of isotherms and adsorption calorimetry have proved the effectiveness of this organophilic clay for the adsorption of the two chlorophenols.By hydrothermal high-pressure synthesis of zeolites, from natural clay composed of a fraction of kaolinite, illite and quartz, two types of zeolites were synthesized with good purity, a cancrinite (CAN) type zeolite and the other analcime (ANA) type; other type of zeolite was synthesized such as faujasite 13X but the purity and reproducibility was limited.These three types of zeolite (CAN, ANA and FAU 13X) were tested for the adsorption of Pb (II) and Cd (II). A better affinity of the zeolites synthesized than the starting clay with respect to the two metallic cations (Pb (II) and Cd (II)). The study of the adsorption kinetics of Pb (II) and Cd (II) showed rapid adsorption of the two metallic cations studied on the different types of zeolites. The results proved that the synthesized zeolites were a very promising materials for the adsorption and removal of heavy metals in water
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Hassan, Nejad Mehdi [Verfasser], und Manfred [Akademischer Betreuer] Wagner. „Improving the Mechanical Properties of Polysaccharide Derivatives through Melt Compounding with Nano-Clays / Mehdi Hassan Nejad. Betreuer: Manfred Wagner“. Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2011. http://d-nb.info/1014756820/34.
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AbdelSater, Mohammad. „Microscopic view of hydrogen adsorption in size-variant nano-clay materials“. Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASP168.
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L'hydrogène est le combustible sans carbone par excellence, car sa combustion n'émet que de l'eau. Actuellement, le principal obstacle à un déploiement massif des technologies utilisant l'hydrogène à des fins énergétiques est son stockage. Les technologies basées sur l’adsorption de H₂ figurent parmi les plus explorées. Mais peu de recherches ont été menées sur les argiles pour le stockage d'hydrogène, alors que la découverte récente de fortes teneurs en hydrogène dans des roches riches en argile montre leur potentiel à cet égard. L'objectif de la présente étude est d'examiner, au niveau microscopique, les mécanismes d'adsorption de H₂ sur des smectites trioctaédriques synthétiques 2:1 de dimensions nanométriques, spécifiquement la Laponite et son précurseur, la pré-Laponite. À partir des isothermes d'adsorption d'hydrogène, nous avons observé que la pré-Laponite présente une capacité de sorption de H₂ plus élevée que la Laponite à 40K et 77K à 1 bar. La première partie de la thèse se concentre sur la caractérisation des échantillons synthétisés. L'ICP-AES a montré que la Laponite et la pré-Laponite partagent une formule moléculaire identique, tandis que la diffraction des rayons X a révélé une structure atomique similaire mais que la pré-Laponite présente un ordre à longue portée plus réduit. La spectroscopie IR indique un ordre local identique dans les deux matériaux. La spectroscopie d'absorption des rayons X réalisée aux seuils K du Si et du Mg corrobore cette conclusion. La RMN du silicium à l'état solide apporte des informations supplémentaires, révélant trois environnements distincts pour le silicium dans les deux échantillons, les variations des intensités intégrées des signaux correspondants indiquant avec des rapport bord-volume différents dans les deux matériaux. Les isothermes d'adsorption d'azote ont également mis en évidence des différences dans les propriétés texturales : la pré-Laponite présente à la fois de la microporosité et de la macroporosité, tandis que la Laponite est principalement microporeuse avec des contributions mésoporeuses. La seconde partie de la thèse concerne l'adsorption de H₂. Les isothermes d'adsorption à 40 K ont été fittées avec des contributions de type Langmuir et Freundlich. Des simulations Monte-Carlo en Grand Canonique ont permis de déduire que le modèle de Langmuir, représentant les sites de liaison les plus forts avec saturation en monocouche, décrit l'adsorption au sein de l'interfeuillet, tandis que le modèle de Freundlich prend en compte l'adsorption sur la surface externe. Des expériences de diffusion inélastique des neutrons ont été menées pour sonder la transition rotationnelle para-à-ortho de H₂, dont l’énergie est très dépendante de l’environnement de la molécule. À 40 K, trois sites d'adsorption ont été identifiés dans la pré-Laponite. Le premier pourrait correspondre à un site de dissociation de l’hydrogène et les deux autres sont des sites de physi-sorption dans l’espace interfeuillet. La dépendance en pression d’hydrogène de l'intensité du pic 001 dans les diagrammes de diffraction des neutrons de la Laponite et de la pré-Laponite révèle que l’hydrogène intercalé forme une monocouche dense. La diffusion des neutrons à grands angles, combinée à des simulations atomistiques, a été utilisée pour sonder la structuration du D₂ (utilisé à la place de H₂ pour améliorer le rapport signal/bruit) dans l’interfeuillet. Ce travail de thèse contribue à une plus grande compréhension des mécanismes d'adsorption de H₂ dans des matériaux argileux en feuillets, mettant en lumière la capacité de sorption améliorée de la pré-Laponite, et il montre comment les isothermes d'adsorption et les techniques de diffusion des neutrons se complètent mutuellementHydrogen is the carbon-free fuel par excellence because its combustion emits only water. At present, the limiting point to a massive deployment of technologies using hydrogen for energy purposes is its storage. Technologies based on sorption are among the most thoroughly explored. Little research has been done on clays for hydrogen storage, while the recent discovery of high hydrogen contents in clay-rich rocks shows their potential for it. The aim of the present study is to investigate, at the microscopic level, H₂ adsorption mechanisms on synthetic 2:1 trioctahedral smectites of nanometric dimensions, specifically Laponite, and its precursor, pre-Laponite. Starting with the hydrogen adsorption isotherms, we observed that pre-Laponite exhibits a higher H₂ sorption capacity than Laponite at 40K and 77K at 1bar. The first part of the thesis focuses on the characterization of synthesized samples. ICP-AES showed that Laponite and pre-Laponite share a similar molecular formula, while X-ray scattering revealed similar structure and that pre-Laponite exhibits reduced long-range order. IR spectroscopy points towards similar local order in both materials. X-ray absorption near-edge spectroscopy performed at the Si and Mg K-edges supports this conclusion.. ²⁹Si solid-state NMR provided additional insights, revealing three distinct silicon environments in both samples, with variations in signal area that correlate with differences in the edge-to-volume ratio between the two materials. Nitrogen adsorption isotherms further highlighted differences in textural properties: pre-Laponite exhibits a composite pore structure with both microporosity and macroporosity, whereas Laponite is primarily microporous with mesoporous contributions. The second part of the thesis concerns H₂ adsorption. The adsorption isotherms at 40 K were fitted with Langmuir and Freundlich contributions. Grand-Canonical Monte-Carlo simulations allowed one to infer that the Langmuir model, accounting for the strongest binding sites with monolayer saturation, describes adsorption within the interlayer, while the Freundlich model accounts for adsorption at the external surface. Inelastic neutron scattering experiments were undertaken to probe the para-to-ortho rotational transition of H₂, the energy of which is highly sensitive to its environment. At 40K, three adsorption sites were identified in pre-Laponite. The first could correspond to a hydrogen dissociation site, while the other two are physiosorption sites in the interlayer space. The pressure dependence of the 001-peak intensity in the neutron diffraction diagrams of Laponite and pre-Laponite reveals that interlayer H₂ forms a dense phase. Wide-angle neutron scattering, combined with atomistic simulations, was used to probe the structuration of D₂ (used in place of H₂ for improved signal-to-noise ratio) within this interlayer region. This thesis work contributes to a deeper understanding of H₂ adsorption mechanisms in layered clay materials, particularly highlighting the enhanced sorption capacity of pre-Laponite, and demonstrates how adsorption isotherms and neutron scattering techniques complement each other
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Huang, Jie-Ting, und 黃婕婷. „Evaluation of micro/nano clays on cytotoxicity and acute toxicity of mice“. Thesis, 2016. http://ndltd.ncl.edu.tw/handle/88347554822681914089.
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碩士國立中興大學
動物科學系所
104
Clay is an abundant and inexpensive inorganic mineral. As nano clays show unique physicochemical properties, it has been applied in a variety of fields. The novel physical properties of nano clays draw serious concerns by the public for its biosafety when applied to the organisms, and thus it is critical to evaluate its toxicity. The purpose of this study was to evaluate the cytotoxicity and acute toxicity of micro/nano clays (TB, TBB1, TBI1) and nanosilcate platelets (NSP) in mice. In vitro morphological observations showed that high doses at 500 μg/mL micro/nano clays resulted in cell growth arrest and 100 μg/mL micro/nano clays slightly caused cell apoptosis, but had no significant effect on necrosis. ROS scavenger (N-MPG and PDTC), NADPH oxidase inhibitor (DPI and Apo) and endocytosis inhibitor (Cyto D) were used to investigate the mechanisms of cell apoptosis induced by micro/nano clays. 300 μM N-MPG treatment significantly rescued cell apoptosis induced by NSP, and 2 mM PDTC treatment also significantly ameliorated cell apoptosis by TB or NSP. 10 µM DPI and 30 µM Apo also slightly ameliorated apoptosis by TB, TBB1 and TBI1, but had no effect on apoptosis induced by NSP. Treatment of Cyto D at 1 µg/mL significantly rescued cell apoptosis induced by micro/nano clays or NSP. Both DPI and Cyto D treatment significantly suppressed ROS generation induced by micro/nano clays or NSP, but Apo treatment exacerbated ROS production. Analysis of LDH release suggested that micro/nano clays and NSP could damage cell membranes and lead to a slightly higher LDH activity. TB, TBI1 and NSP had no significant effect on cellular GSH content, but TBB1 significantly reduced GSH content. Neither micro/nano clays nor NSP exerted an effect on SOD activity. Micro/nano clays and NSP at 100 μg/mL significantly caused mitochondrial damage leading to membrane potential loss and treatment of N-MPG failed to rescue the mitochondrial membrane potential loss by micro/nano clays, but NSP add N-MPG or Cyto D treatment significantly rescued the mitochondrial membrane potential loss. Treatment of DPI significantly suppressed caspase-6 activity induced by NSP. Furthermore, treatment of zVAD.fmk, a caspase inhibitor, ameliorated cell apoptosis and necrosis induced by NSP. N-MPG and PDTC treatment failed to affect HSP70 expression by NSP. N-MPG, DPI or Cyto D exerted no effect on gelsolin expression and JNK activation induced by NSP. In acute toxicity of mice with daily oral administration of micro/nano clays for 14 days, body weight and feed intake and histopathology were not different between micro/nano clay treated and control groups. Micronucleus analysis suggested that there was no significant micronucleus formation in the erythrocytes induced by micro/nano clays at various concentrations. Results from the acute toxicity study suggested that micro/nano clays have a lethal dose (LD50) greater than 4 g/kg body weight and further tests suggested that micro/nano clays of LD50 is greater than 4 g/kg body weight for male and female B6 mice. In conclusion, results from this study suggested that micro/nano clays showed slight cytoxicity, but had no significant acute toxicity and genotoxicity in living animals.
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Yang, Hsing-Chung, und 楊行中. „The Study of Preparation and Properties of the NanocompositesFoams and Films based on PU and Nano-clays“. Thesis, 2004. http://ndltd.ncl.edu.tw/handle/36429773613312697612.
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博士中原大學
化學研究所
92
The aim of the present work is to prepare nanocomposites of PU/Clay foam and films by adding nanosized clays into polymer matrix and study their characteristics. The content of this work is divided into two parts. In the first part, hydrophilic clay pk805, pk802, pk811, pk812 were modified with quaternary ammonium salts of dilaury (dimethylammonium bromide [CH3(CH2)11]2N(CH3)2Br (LD) and caprolactone CH2(CH2)5CO O (CPL) , obtaining five corresponding organophilic clays clay11, clay12, clay22, clay51, and clay52. The X-Ray diffraction result showed that the modification was dependent on the structure of the modifier. By using LD modifier, the nanolayer of silicate d-spacing was increased to 2.44nm from its original value of 1.13nm (Clay51), but, in the case of using CPL modifier the d-spacing only increased from 1.13nm to 1.44nm (Clay52). The five as-prepared organophiic clays (clay11, clay12, clay22, clay51, clay52), with the ratio of 1 wt% or 3 wt% or 5 wt% increment were separately dispersed into the PU polymer matrix to form the corresponding PU/Clay nanocomposite foams. X-ray diffraction(XRD), scanning electron microscopy(SEM), Fourier transform infrared spectrometer(FT-IR), density, hardness, isothermal conductivity, limit oxygen index(LOI), differential scanning calorimetric(DSC), thermal gravemetric analysis(TGA) and tensile testing measurements were performed to characterize the physical properties of the as-prepared nanocomposites of PU/Clay foams. The results indicated that the density of the nanocomposite PU/clay foam was increased with the amount of clay content, but the hardness was decreased due to the intercalation. The FT-IR spectra showed that only simple intercalations with no bonding formation was revealed between clay in the polymer matrix. From the mechanical studies, it was found that the modulus, elongation and the tensile strength were decreased as the clay content increased. This suggested that the intercalation of layer silicates disrupted the network structure of the PU foam. The thermal analyses and thermal conductivity measurements showed that the heat-resistance and thermal conductivity were elevated with the increase of clay content. The LOI values and the char yields formed were also increased with increasing of the clay in the burning state. Implying that the dispersion of nanoclays in the polymer matrix obviously increased the anti-fire properties of the PU polymer composite foams prepared. In the second part, the principle purpose is that the montmorillonite clay was modified with two different quaternary ammonium salts, dilauryldimethylammonium bromide [CH3(CH2)11]2(CH3)2NBr (LD) and 4,4’-diaminodiphenyl methane H2NC6H4CH2C6H4NH2 (AP), to form the corresponding organophilic clays, LDM and APM. Two series of PU/clay nanocompositie materials were then prepared by the reaction of appropriate amounts of PPG, TDI and 1,4 butandiol, followed by addition of the modified clays. The X-ray diffraction patterns and transmission electron micrographs of the nanocomposites revealed that the modified clay galleries were exfoliated or intercalated in the polyurethane matrix. In comparison with the corresponding pristine PU, it was found that the PU/clay nanocomposites showed higher glass transition temperature and thermal stability due to the presence of the dispersed nanolayers of the organophilic clay in the PU matrix. The LOI measurements indicated that the flame retardancy of the PU was also enhanced by dispersion of the organophilic clays. Using the Tafel method, the results of the electrochemical measurements, corrosion potential, polarization resistance and corrosion current, showed that all the PU nanocomposites with low clay loading in the form of coating on stainless steel disk (SSD) exhibited better corrosion protection over the pristine PU. The SSD coated with the composite containing 2 wt% of APM clay showed the lowest corrosion rate, which was one order lower than that of the SSD coated with the pristine PU.
Bücher zum Thema "Nano-clays"
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name, No. Chemo-mechanical coupling in clays: From nano-scale to engineering applications: proceedings of the Workshop on Chemo-Mechanical Coupling in Clays: from Nano-Scale to Engineeering Applications, Maratea, Italy, 28-30 June 2001. Lisse: Balkema, 2001.
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C, Di Maio, Hueckel Tomasz und Loret B, Hrsg. Chemo-mechanical coupling in clays: From nano-scale to engineering applications : proceedings of the Workshop on Chemo-Mechanical Coupling in Clays : from Nano-Scale to Engineering Applications, Maratea, Italy, 28-30 June 2001. Lisse [Netherlands]: Balkema, 2002.
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Chemo-Mechanical Coupling in Clays: From Nano-scale to Engineering Applications. Routledge, 2018. http://dx.doi.org/10.1201/9781315139289.
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DiMaio, C. Chemo-Mechanical Coupling in Clays : from Nano-Scale to Engineering Applications: Proceedings of the Workshop, Maratea, 38-30 June 2001. CRC Press LLC, 2018.
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DiMaio, C. Chemo-Mechanical Coupling in Clays : from Nano-Scale to Engineering Applications: Proceedings of the Workshop, Maratea, 38-30 June 2001. CRC Press LLC, 2018.
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DiMaio, C. Chemo-Mechanical Coupling in Clays : from Nano-Scale to Engineering Applications: Proceedings of the Workshop, Maratea, 38-30 June 2001. CRC Press LLC, 2018.
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DiMaio, C. Chemo-Mechanical Coupling in Clays : from Nano-Scale to Engineering Applications: Proceedings of the Workshop, Maratea, 38-30 June 2001. CRC Press LLC, 2018.
Den vollen Inhalt der Quelle findenBuchteile zum Thema "Nano-clays"
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Raji, Marya, Elmokhtar Essassi, Hamid Essabir, Denis Rodrigue, Abou el kacem Qaiss und Rachid Bouhfid. „Properties of Nano-composites Based on Different Clays and Polyamide 6/Acrylonitrile Butadiene Styrene Blends“. In Bio-based Polymers and Nanocomposites, 107–28. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-05825-8_6.
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Kasaai, Mohammad Reza. „Nano-sized Clays, Graphene, and Inorganic Oxides as Fillers of Nanocomposites for Their Mechanical and Barrier Properties Improvement: A Global View“. In Handbook of Nanofillers, 1–14. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-3516-1_149-1.
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Bergaya, Faïza, Maguy Jaber und Jean-François Lambert. „Clays and Clay Minerals as Layered Nanofillers for (Bio)Polymers“. In Environmental Silicate Nano-Biocomposites, 41–75. London: Springer London, 2012. http://dx.doi.org/10.1007/978-1-4471-4108-2_3.
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Kiran Zhade, Shanti, Syam Kumar Chokka, V. Suresh Babu und K. V. Sai Srinadh. „A Review on Mechanical Properties of Epoxy-Glass Composites Reinforced With Nanoclay“. In Epoxy-Based Composites [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.102159.
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Polymer nanocomposites are currently one of the most rapidly growing families of materials, and they are finding use in a wide range of industrial applications, including aerospace and defense. The broad usage of composites is because of their consolidated mechanical properties. Glass fiber reinforced epoxy composites are available for the last few decades. The idea of adding nano clay into it has emerged in the late first decade of this century. This study is aimed at reporting the effects of the addition of nano clay into GFRP on its mechanical properties. The new composite formed is epoxy-glass composites reinforced with nano clay (EGCN). Nano clay has a crystal structure that facilitates the formation of intercalated and exfoliated mixture with liquid epoxy during mixing which results in good dispersion of Nano clay thereby resulting in improved mechanical properties compared to GFRP. The work done by several researchers in this area and the results obtained are reported in this article. The improved mechanisms of failures were discussed with the addition of nano clays.
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Noor, Nairah, Asima Shah, Adil Gani, Zanoor Ul Ashraf und F. A. Masoodi. „Nanomaterials in Food Packaging“. In Applications of Nanomaterials in Agriculture, Food Science, and Medicine, 270–87. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-5563-7.ch015.
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Nano-materials hold great promise regarding their application in the food industry due to their size-dependent properties, high surface area, longer retention, easy absorption, and unique optical properties. The role of nanomaterials have been extended for increasing the stability and bioavailability of nutrients, encapsulation of flavors, bioactives, enhancing the physical and mechanical properties of food packaging (nanocomposites), pesticide and growth hormone delivery, antimicrobial agents to boost preservation of foodstuffs, detection of foodborne pathogens, biodegradable nano-sensors for monitoring of temperature and moisture, etc. There are various types of nanomaterials like nanoparticles, nano-emulsions, and nano-clays which are synthesized by several methods to be used in the food industry. However, there is some food safety concerns associated with these nanomaterials when used in food systems. It is, therefore, very necessary to formulate and develop some method for the detection of nanomaterials, in particular when used in-vivo.
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„9. Ionic Transport in Nano-Porous Clays with Consideration of Electrostatic Effects“. In Pore Scale Geochemical Processes, 287–330. De Gruyter, 2015. http://dx.doi.org/10.1515/9781501502071-009.
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Jain, P. „In-situ Composite Formation by Polymerization on the Hectorite or other Clay Materials“. In Materials Research Foundations, 1–23. Materials Research Forum LLC, 2022. http://dx.doi.org/10.21741/9781644902035-1.
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Clays are the naturally existing mineral having layered structures with at least one dimension in the nano-range that are economical and environment friendly. There exist two types of nanoclays, anionic and cationic, depending on the surface charge layered. Nanoclays have wide application in different areas for improving physical properties like heat resistance, mechanical strength and anticorrosion quality of the polymer matrix. Clay and its composite have promising applications including tissue engineering, petroleum, drug delivery, food packaging and enzyme immobilization. Due to their superior properties like flame retardancy, non-toxic, magnetic properties and large surface areas; hectorites and their composite are of great interest. The primary focus of this chapter is Composite Formation by in-situ polymerization of hectorite/clay materials and its application in different areas.
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Singh, Prashant, Bhavana Tomar, Tirunima Patle, Sneh Singh Parihar, Shiv Singh Tomar und Dayashankar Singh Singh. „Nanotechnology Solutions for Sustainable Pest and Disease Control for Sustainable Agriculture and Food Security“. In Advances in Environmental Engineering and Green Technologies, 193–215. IGI Global, 2024. http://dx.doi.org/10.4018/979-8-3693-1890-4.ch010.
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Each year, a significant portion of crops, ranging from 20% to 40%, succumb to plant pests and pathogens, resulting in substantial agricultural losses. Traditional methods of managing plant diseases heavily rely on the application of toxic pesticides, posing potential hazards to both human health and the environment. Nanotechnology presents a promising avenue for addressing these challenges by offering various advantages over conventional pesticides. These include mitigating toxicity, enhancing shelf-life, and improving the solubility of pesticides that are poorly water-soluble, thereby potentially yielding positive environmental outcomes. This review delves into two primary approaches for leveraging nanoparticles in plant disease management: employing nanoparticles independently as protective agents or utilizing them as carriers, often termed as 'magic bullets,' for delivering a range of substances such as herbicides, insecticides, fungicides, fertilizers, and RNA-interference molecules or genes directly to specific cellular organelles within plants. Nanoparticles encapsulate active compounds with high stability and biodegradability, shielding them from degradation by external factors or the host plant itself. Moreover, they minimize inadvertent dispersion into the soil, consequently reducing the need for multiple active compounds in plant treatments and thereby lowering environmental impacts. Additionally, nanoparticles can be functionalized with biomolecules like antibodies or aptamers to ensure target selectivity and specificity. Despite these benefits, there remain certain challenges associated with the use of nano devices for plant protection. Foremost among these is the insufficient research on the potential toxicity of certain nanomaterials, such as nano silver and nano gold, to plants, animals, and ecosystems. Accumulation of nanomaterials in plant and animal tissues could potentially enter the food chain, necessitating rigorous safety assessments and consumer education efforts. Nonetheless, the adoption of non-toxic materials, such as starch, chitin, or nano clays, as alternatives to metals, can mitigate such risks.
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Deka, Rinki, und Mukul Kalita. „NANOTECHNOLOGY IN AGRICULTURE“. In Futuristic Trends in Chemical Material Sciences & Nano Technology Volume 3 Book 21, 105–15. Iterative International Publishers, Selfypage Developers Pvt Ltd, 2024. http://dx.doi.org/10.58532/v3becs21p6ch3.
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Nanoparticles are not a recent occurrence in nature; they can be found in nature in the form of minerals, clays, bacterial byproducts etc. Apart from various perspectives of nanotechnology, it plays a crucial role in agriculture. Conventionally, chemical fertilizers, herbicides, pesticides etc. are heavily applied in agriculture to sustain production, which have major adverse effects on the environment including human health. Again, as a result of pest infestation, microbial attacks, natural catastrophes, low-quality soil, and unavailability of nutrients, a third or so of crops are cultivated traditionally which suffer harmful effect. Abiotic stresses like stress caused by salinity and drought, and flood stress are major concerned issues including critical issues like the increasing continuous food demands due to expanding global population. All of these issues cannot be mitigated by using the conventional procedures. Consequently, there is a pressing need to look for better options. Nanotechnology’s use in this context has the potential to revolutionise agriculture’s transition to sustainable practises. Using a range of nanoparticle-based approaches, including nano-sized pesticides, herbicides, fungicides, fertilisers, sensors, etc., it has been thoroughly studied how to preserve plant health and soil. Although nanoparticles have been effectively applied to plants as fertilizers or to promote plant development, little is understood about the mechanism by which nanoparticles migrate across the cell walls. This chapter summarises current efforts to implement cutting-edge nanotechnology in agriculture in diverse directions including socio-economic issue, challenges, which may make it easier to meet the rising need for sustainable food production.
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Ahmed, F. R. „Halloysite-Starch based Nano-Composites and Applications“. In Advanced Applications of Micro and Nano Clay, 152–71. Materials Research Forum LLC, 2022. http://dx.doi.org/10.21741/9781644901915-7.
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Halloysite is a novel mineral belonging to the kaolinite family of clays. It consists of largely cylindrical particles in the size range of few hundred to few micrometers in length. The negatively charged Si-O-Si functional groups at the surface and positively charged Al2(OH)4 at the luminal side offer unique chemistry to this clay mineral. Biopolymers such as starch are considered biodegradable and non-toxic in nature. But their higher water permeability, poor mechanical strength, and rigid characteristics limit their applications in many fields. Halloysite and starch hybrid materials or composites have been demonstrated to improve on these properties and at the same time remain natural. They have a wide variety of applications such as tissue engineering, drug delivery and food packaging materials. Besides this, they have also been used as catalyst and flame retardant materials.
Konferenzberichte zum Thema "Nano-clays"
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Abdo, Jamil, und Hamed Al-Sharji. „Effect of Nano-Clays on the Lubricity of Drilling Fluids“. In ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/detc2016-59368.
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In this study, nano-sepiolite (NSP) was synthesized, dispersed and used as a replacement for regular additives in water-based drilling fluids to enhance its lubricity. Due to its structure and morphology the suspended sepiolite nanoparticles is expected to enhance the stability against segmentation along with better thermal, mechanical and electrical properties. The morphology of the nano-modified drilling fluids and the dispersion of the nano-sepiolite are characterized using XRD and SEM. The influences of various sizes and compositions of the NSP on the stability of drilling fluids on HTHP conditions are investigated. Results revealed that the drilling fluids lubricity and the drillstring axial force transfer were significantly improved by using NSP in the base drilling fluids. The investigations showed that the lubricity and rheological properties of the nano-modified drilling fluids depend on the size and composition of the NSP additive. The studies were performed on normal and HTHP conditions.
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Brochard, L., T. Honorio, M. Vandamme, I. Stefanou, S. Ghabezloo und M. Bornert. „A Possible Nano-Scale Origin of the Surprising Thermal Expansion of Clays“. In Sixth Biot Conference on Poromechanics. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784480779.077.
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Koo, Joseph, S. Lao, Jason Lee, Chris Lam, Jinyong Lee, Tess Moon, Louis Pilato und Gerry Wissler. „Performance of Clays, Carbon Nanofibers, Multi-Walled Carbon Nanotubes, and Nano-Alumina in Polyamide 11 Nanocomposites“. In 51st AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference
18th AIAA/ASME/AHS Adaptive Structures Conference
12th. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2010. http://dx.doi.org/10.2514/6.2010-2565.
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Abduljauwad, Sahel N., und Habib-ur-Rehman Ahmed. „Use of Nano-Level Constitutive Model to Predict the Volume Change Behavior of the Treated Expansive Clays“. In IFCEE 2018. Reston, VA: American Society of Civil Engineers, 2018. http://dx.doi.org/10.1061/9780784481585.015.
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„Effects of Physiochemical Properties of Nano-Clays on the Removal of Heavy Metals from Acid Mine Drainage“. In Nov. 16-17, 2020 Johannesburg (SA). Eminent Association of Pioneers, 2020. http://dx.doi.org/10.17758/eares10.eap1120256.
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Patel, Hasmukh, und Gadam Myratgeldiyev. „Anisotropic Nano-Platelets to Develop Gel Strength at High Temperature in Aqueous Fluids“. In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205955-ms.
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Abstract Aqueous fluids also refer as water-based drilling muds (WBMs) have considered as the most favorable WBMs, owing to their inherent advantages such as economically viability and environmentally benign characteristics. The major problems WBMs encountered is thinning of drilling fluids while drilling under high pressure high temperature. The detrimental rheological properties of WBMs under HPHT result into pipe sticking, low rate of penetration of the drill bit and requirement of high torque for drilling operations. The hydrophilic clays have been employed as viscosifiers in WBMs to maintain the rheological properties, albeit, their viscosifying characteristics have hindered in the presence of ionic species in the aqueous system at high temperature. These shortcomings can be tackled by developing an additive that can exhibit neutral surface changes and ability to undergo gelation at higher temperature. We have developed an additive functionalized with polar groups on anisotropic nano-platelets (LMS) through sol-gel technique. Spectroscopic and crystallographic characterization of LMS have proved the formation of layered structures with covalently linked polar functionalities. The viscoelastic studies were conducted on aqueous dispersion of these nano-platelets at different temperature, which revealed an unprecedented phenomenon -increase in gel strength at higher temperature, a key property required for ideal WBMs. LMS nano-platelet has shown formation of network structure in aqueous medium to boost storage modulus of the fluid. This additive can overcome the demerits associated with natural hydrophilic layered silicates and improve the rheological properties under challenging well conditions.
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Aluvihara, Suresh, C. S. Kalpage, P. W. S. K. Bandaranayake, W. M. A. T. Bandara und Ciprian Chelaru. „Investigations and Analysis of Earth Materials towards the Developments in Some Advanced Chemical and Catalytic Uses“. In The 9th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2022. http://dx.doi.org/10.24264/icams-2022.i.3.
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Earth materials are some sort of valuable resources with some multiples uses in some of industrial purposes and they are obtaining some economical values based upon the demand and the abundance. According to the most of research and experiments that relevant with the characteristics of solid earth materials, mainly there were obtained and disclosed some various outstanding physic-chemical characteristics of a large number of earth materials including the applications of material processing, nano-materials, composite materials and hard materials. In the existing research there were expected to characterize some selected clay varieties, a dolomite variety and a feldspar variety which are available in Sri Lanka towards the developments especially in some advanced chemical and catalytic applications. The X-ray fluorescence (XRF) spectroscopic analysis and Scanning electron microscopic (SEM) analysis were done for all of selected materials. The X-ray diffraction (XRD) analysis was done for three different selected clays and the Fourier transforms infrared (FT-IR) spectroscopic analysis was done for three different clay types and for a dolomite variety. According to the obtained results for the research, there were found the presence of at least 75% of Fe as the major element in each of clay with some other trace metallic elements such as K, Ti, Ca, Ba and Zr in such clays, kaolinite, montmorillonite and some of Fe minerals namely as muscovite and glauconite in such clays with quartz as a non-clayey mineral. There were found some higher amount of calcite in the selected dolomite with a trace amount of K and also there were found some higher K and Ca amounts presence in the selected feldspar rocks. When comparing the obtained results with past research out comes and modifications of materials, it seems that these materials will be much useful in the industrial applications such as the catalytic activities, waste water treatment applications in the removal of heavy metals due to the adsorption capacity, ion exchanging materials to remove unnecessary ions from waste water and in the removal of hardness from waste water due to the adsorption capacity of dolomite.
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Awad, Walid, Amal Esawi und Adham Ramadan. „Fabrication and Properties of Nylon-6/Layered Silicate Nanocomposites by Melt Blending“. In ASME 2008 2nd Multifunctional Nanocomposites and Nanomaterials International Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/mn2008-47039.
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Polymer/clay nanocomposites currently attract immense interest from both research and industrial communities. By dispersing at the molecular level a tiny amount of clay within a polymeric matrix, a wide range of properties can be significantly improved. The efficiency of the clay (layered silicate) in improving the properties of the polymer materials is primarily determined by the degree of its dispersion in the polymer matrix. To promote the molecular and stable dispersion of the clay layers, the clays should be organically-modified with onium salts. In this work, nylon-6 nanocomposites based on two types of commercial organoclays were prepared by melt blending via single-screw extrusion. The good dispersion of clay in the nylon-6 nanocomposites was confirmed by X-ray diffraction and transmission electron microscopy. The influence of the dispersed nano-clay fillers on the thermal and mechanical properties of the resulting nanocomposites was characterized using thermogravimetric analysis and nanoindentation.
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Zayas, I. C., J. Meegoda, O. Kolawole, S. Pinkert und D. Zhang. „Study on High-Pressure Treatment of Unconventional Reservoirs with Water-Based Fluids“. In 57th U.S. Rock Mechanics/Geomechanics Symposium. ARMA, 2023. http://dx.doi.org/10.56952/arma-2023-0542.
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ABSTRACT Shales are tight rocks with ultra-low porosity and often contain hydrocarbons (oil and gas). Both the United States and Israel have abundant shale formations containing oil and gas. The majority of shale hydrocarbon production in the United States takes place in Permian basin, Texas, whereas the largest kerogen shale deposits in Israel occur in the Negev area. For the recovery of oil and gas, shale formations are hydraulically fractured by injecting water-based fluids under high pressure. To transition away from fossil fuel use and address atmospheric greenhouse gas levels, sequestration of carbon dioxide (CO2) and hydrogen (H2) storage is now proposed in depleted tight hydrocarbon formations, such as shales. Shales are composed largely of clays and silts, bound by carbonates to form ultra-tight matrices, and containing interconnected nano- to micro- to macro-voids with total porosities of 1-6%. The introduction of fracturing fluids and, potentially, other fluids for storage purposes (e.g., CO2 and H2) may cause changes to the ultra-tight shale matrix, as formations had previously been isolated for millions of years. These changes have been linked to reduced production of oil and gas and may affect possible storage of CO2 and H2. The interaction between artificially introduced fluids and shale formations, leading to softened shale, is attributed to the interlayer expansion of clays and the dissolution of cementing carbonates. This study seeks to investigate of the effects of interaction between various fluids and unconventional reservoir rock at high temperature and pressure for geo-storage implications. Shale-fluid interactions will be quantified through the lens of mineralogical, pore network, and mechanical property changes. of CO2 and H2. INTRODUCTION Shale formations have ultra-low porosity and permeability, and when shales contain hydrocarbons, are considered unconventional reservoirs. Large shale gas reserves are popularly located in China, United States, and Argentina; with 31.6, 17.6, and 22.7 trillion cubic meters of reserve, respectively (U.S. Energy Information Administration, 2015). Horizontal drilling and hydraulic fracturing are major methods of extracting the hydrocarbons trapped in these tight formations (Speight, 2020). Once both a vertical and horizontal well is drilled into the reservoir formation, high-pressure fluid is injected at a designed rate. The fluid, often a water-based brine, also contain proppants chosen to withstand the rock closure pressure as fractures propagate out perpendicular to the horizontal well. These new fractures increase the connectivity of formation pores and allow for the hydrocarbons stored within them to be recovered. Depleted unconventional oil and gas reservoirs therefore offer potential uses for nuclear and wastewater disposal, hydrogen storage, and carbon sequestration, due to their existing wells and fracture networks, and otherwise low porosity.
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Wang, Zichao, Wendi Zhang, Changhong Wu, Shunyao Song und Xuewei Liu. „A Novel Clay Control and Conductivity Approach in Water Sensitive Tight Oil Reservoirs in China During Proppant Fracturing“. In Middle East Oil, Gas and Geosciences Show. SPE, 2023. http://dx.doi.org/10.2118/213490-ms.
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Abstract Unconventional oil formations require high fracture contact with reservoir to enhance productivity. These target reservoirs have significantly tight characteristics with low permeability and nano porosity, that show adverse water sensitivity and proppant embedment. Clay swelling and dispersion due to water sensitive clay minerals in the producing formation can substantially reduce rock permeability and proppant embedment in high clay minerals reduce retained conductivity resulting in reduced well productivity. The effects of water based fracturing fluids in water sensitive formations have been extensively investigated which led to development of different types of clay stabilizers based on type of clays, bottomhole temperature, and clay protection time. A novel clay stabilization liquid additive has been successfully introduced for permanent frac face clay protection, while an SMA (surface modified agent) additive was used for proppant pack protection. The frac strategy is to enhance propped fracture productivity and fracture conductivity while protecting the fracture face, instead of using high slickwater volumes to create shear fractures. Crosslinked fluid was utilized to control the fluid leak-off into formation and increase proppant delivery capacity. The new permanent clay control additive is a cationic polymer with ultra-low molecular weight and is compatible with borate and zirconium crosslinkers. A new concentrated clay control additive prepad was used during the treatment which reduced pad leakoff damage. The conductivity enhancer SMA with nano coating was used on the proppant pack to mitigate embedment damage and increase the proppant pack conductivity. Designing and optimizing a particular type of clay stabilizer requires identifying the types of clay minerals present in the formation and their relative concentrations. For the formation in this study, clay fraction was 9∼11% with over 75% illite/smectite mixing layer. Core flood testing provides the most authoritative data upon which to base recommendations and results showed regained perm at +75%. Accordingly, a special clay stabilizer concentration was chosen to be used in the fracturing fluid. Based on reservoir closure stress and the conductivity test results, an SMA treatment concentration was chosen. Then fracture density and cluster spacing was optimized using geological data in a 3D frac model with log interpretation profiles. The productivity of fracturing treatments performed using this innovative approach resulted in negative skin factors and production ratios that exceeded expectations in water-sensitive and high clay content reservoirs. This paper provides a novel approach and frac strategy on the water sensitive and soft rock formations. Lab testing and field implementation of this novel approach on proppant fracture treatments are detailed in this paper. Post treatment pressure matching was conducted to predict the final fracture geometry and then analysis was performed using the created fracture geometry and actual flowback data to further validate the incremental production increase after the treatment.