Assessing Diffusion Relaxation of Interlayer Water in Clay Minerals Using a Minimalist Three-Parameter Model

2021 ◽  
Author(s):  
Martin H. Petersen ◽  
Nathan Vernet ◽  
Will P. Gates ◽  
Félix J. Villacorta ◽  
Seiko Ohira-Kawamura ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Interlayer Water ◽  
Diffusion Relaxation

scholarly journals Inelastic Neutron Scattering and Molecular Simulation of the Dynamics of Interlayer Water in Smectite Clay Minerals

2015 ◽  
Vol 119 (50) ◽  
pp. 28005-28019 ◽  
Author(s):  
Randall T. Cygan ◽  
Luke L. Daemen ◽  
Anastasia G. Ilgen ◽  
James L. Krumhansl ◽  
Tina M. Nenoff
Keyword(s):  
Neutron Scattering ◽  
Clay Minerals ◽  
Molecular Simulation ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Interlayer Water ◽  
Smectite Clay

scholarly journals Surface Chemistry of Halloysite Nanotubes. As investigated by adsorption reactions and imaging analysis

2021 ◽  
Author(s):  
◽  
Nia B. Gray-Wannell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Chemistry ◽  
Clay Minerals ◽  
External Surface ◽  
Halloysite Nanotubes ◽  
Interlayer Water ◽  
Adsorption Sites ◽  
Transmission Electron ◽  
Microscopy Techniques

Interest in halloysite clay minerals has increased steadily over the last 20+ years, in part, due to their nanotubular shape and size, high aspect ratio and potential technological applications (Churchman et al., 2016). Throughout this thesis the surface chemistry of halloysite nanotubes is investigated by employing several analytical and advanced microscopy techniques to obtain a greater understanding of their internal and external surface features and surface adsorption reactions. This multifaceted analysis approach investigates a range of tubular halloysites of two morphologies, cylindrical and polygonal prismatic, where comparison of the two forms a framework for the presentation and discussion of the results. The results presented in Chapter 3 demonstrate the phosphate adsorption capacity of halloysite nanotubes is influenced by pH and maximum adsorptions of 1.3 mg/g and 0.5 mg/g were obtained for the cylindrical and polygonal prismatic morphologies respectively. Use of advanced microscopy techniques in Chapter 4 showed the external surface of the polygonal prismatic nanotubes have multiple steps and edges, which may act as additional adsorption sites, as has been shown for other clay minerals (Siretanu et al., 2016). In addition, use of cross-section transmission electron microscopy provided evidence of the link between the two morphologies, where the cylindrical nanotubes appear to be the template from which the larger polygonal prismatic nanotubes grow, as previously postulated by Hillier et al. (2016). In further novel work (Chapter 5), gold nanotags have been functionalised with a variety of anionic and neutral terminated linkers and used as nanoscale probes to study adsorption to the surface of halloysite nanotubes Here, transmission electron microscopy proved that the adsorption occurred primarily on the nanotube inner lumen and edges. The final technical chapter, Chapter 6, focuses on the structure and dynamics of interlayer water in halloysite through the use of neutron scattering techniques, where the initial results demonstrated that the interlayer water appears to move via both rotations and translations within the interlayer. The research presented ascertains that the surfaces of the halloysite nanotubes are more complex than often depicted for technological applications and that the specific tubular morphology is important in the functionality and behaviour of the nanotubes. This fundamental work contributes towards optimisation of halloysite nanotubes for technological applications.

Hydrated form of some clay minerals observed using a film sealed environmental cell

1978 ◽  
Vol 36 (1) ◽  
pp. 72-73
Author(s):  
N. Kohyama ◽  
K. Fukushima ◽  
A. Fukami
Keyword(s):  
Clay Minerals ◽  
Morphological Changes ◽  
Carbon Film ◽  
Electron Microscopic Observation ◽  
Adsorbed Water ◽  
Electron Microscopic ◽  
Hydrated Form ◽  
Thin Carbon ◽  
Environmental Cell ◽  
Thin Carbon Film

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

Colloidal systems in soils

1994 ◽  
Vol 52 ◽  
pp. 64-65
Author(s):  
J. Thieme ◽  
J. Niemeyer ◽  
P. Guttman
Keyword(s):  
Clay Minerals ◽  
Polymeric Materials ◽  
Spatial Arrangement ◽  
High Specific Surface Area ◽  
Turnover Rates ◽  
Colloidal Systems ◽  
Chemical Conditions ◽  
Aggregation Phenomena ◽  
Iron And Manganese ◽  
Soil Colloids

In soil science the fraction of colloids in soils is understood as particles with diameters smaller than 2μm. Clay minerals, aquoxides of iron and manganese, humic substances, and other polymeric materials are found in this fraction. The spatial arrangement (microstructure) is controlled by the substantial structure of the colloids, by the chemical composition of the soil solution, and by thesoil biota. This microstructure determines among other things the diffusive mass flow within the soils and as a result the availability of substances for chemical and microbiological reactions. The turnover of nutrients, the adsorption of toxicants and the weathering of soil clay minerals are examples of these surface mediated reactions. Due to their high specific surface area, the soil colloids are the most reactive species in this respect. Under the chemical conditions in soils, these minerals are associated in larger aggregates. The accessibility of reactive sites for these reactions on the surface of the colloids is reduced by this aggregation. To determine the turnover rates of chemicals within these aggregates it is highly desirable to visualize directly these aggregation phenomena.

In-Situ Observation of Clay Minerals Hydrated and Intercalated With Liquid Chemicals Using Film-Sealed Environmental Cell

1980 ◽  
Vol 38 ◽  
pp. 208-209 ◽  
Author(s):  
K. Fukushima ◽  
N. Kohyama ◽  
A. Fukami
Keyword(s):  
Carbon Film ◽  
Resolving Power ◽  
In Situ Observation ◽  
Interlayer Water ◽  
Saturated Water ◽  
Structure Changes ◽  
Environmental Cell ◽  
Gas Layer ◽  
20 Nm

A film-sealed high resolution environmental cell(E.C) for observing hydrated materials had been developed by us(l). Main specification of the E.C. is as follows: 1) Accelerated voltage; 100 kV. 2) Gas in the E.C.; saturated water vapour with carrier gas of 50 Torr. 3) Thickness of gas layer; 50 μm. 4) Sealing film; evaporated carbon film(20 nm thick) with plastic microgrid. 5) Resolving power; 1 nm. 6) Transmittance of electron beam; 60% at 100 kV. The E.C. had been successfully applied to the study of hydrated halloysite(2) (3). Kaolin minerals have no interlayer water and are basically non-expandable but form intercalation compounds with some specific chemicals such as hydrazine, formamide and etc. Because of these compounds being mostly changed in vacuum, we tried to reveal the structure changes between in wet air and in vacuum of kaolin minerals intercalated with hydrazine and of hydrated state of montmori1lonite using the E.C. developed by us.

Mineral nitrogen isotope signature in clay minerals formed under high ammonium environment conditions in sediment associated with ammonium-rich sediment-hosted hydrothermal system

2018 ◽  
Vol 52 (4) ◽  
pp. 317-333 ◽  
Author(s):  
Jaeguk Jo ◽  
Toshiro Yamanaka ◽  
Tomoki Kashimura ◽  
Yusuke Okunishi ◽  
Yoshihiro Kuwahara ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Hydrothermal System ◽  
Nitrogen Isotope ◽  
Mineral Nitrogen ◽  
Isotope Signature
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