Direct observation of anisotropic growth of water films on minerals driven by defects and surface tension

Knowledge of the occurrences of water films on minerals is critical for global biogeochemical and atmospheric processes, including element cycling and ice nucleation. The underlying mechanisms controlling water film growth are, however, misunderstood. Using infrared nanospectroscopy, amplitude-modulated atomic force microscopy, and molecular simulations, we show how water films grow from water vapor on hydrophilic mineral nanoparticles. We imaged films with up to four water layers that grow anisotropically over a single face. Growth usually begins from the near edges of a face where defects preferentially capture water vapor. Thicker films produced by condensation cooling completely engulf nanoparticles and form thicker menisci over defects. The high surface tension of water smooths film surfaces and produces films of inhomogeneous thickness. Nanoscale topography and film surface energy thereby control anisotropic distributions and thicknesses of water films on hydrophilic mineral nanoparticles.

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Radical-surface interactions during film deposition: A sticky situation?

Pure and Applied Chemistry ◽

10.1351/pac200678061187 ◽

2006 ◽

Vol 78 (6) ◽

pp. 1187-1202 ◽

Cited By ~ 24

Author(s):

Dongping Liu ◽

Ina T. Martin ◽

Jie Zhou ◽

Ellen R. Fisher

Keyword(s):

Film Growth ◽

High Surface ◽

Film Surface ◽

Chemical Vapor ◽

Electronic Configuration ◽

Surface Reactivity ◽

Film Deposition ◽

Electron Configuration ◽

Plasma Parameters ◽

Temperature Plasma

Our imaging of radicals interacting with surfaces (IRIS) method was used to investigate radical-surface reactions during low-temperature plasma-enhanced chemical vapor deposition (PECVD) processes. Special emphasis was placed on the analysis of surface reactivities for CH, SiH, CN, NH, NH2, CF2, and SiCl2 radicals during film growth. The effects of plasma parameters, such as radio frequency (rf) power and gas composition, substrate temperature, and substrate bias on radical-surface reactivity were analyzed. Different radicals exhibit different behavior at the surface of a depositing film. Specifically, CH, SiH, and CN are "sticky", with high surface reactivities. In contrast, other species such as NH, CF2, and SiCl2 do not stick to the surface of growing films and, in some cases are actually generated at the surface of the depositing film. Different plasma systems and parameters can have an effect on the stickiness of some of these species. Our IRIS measurements indicate a molecule's surface sticking probability may also be related to the molecule's electronic configuration and stability, with the most reactive species being molecules with a doublet electron configuration. In contrast, the singlet species examined here tend to be generated at the surface during film deposition. Our results also indicate that when a molecule scatters with greater than 100 % probability, it is likely to be strongly affected by energetic ion bombardment of the film surface.

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New Design for a Differentially Pumped Hydration Chamber for a Siemens IA

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006427x ◽

1971 ◽

Vol 29 ◽

pp. 44-45

Author(s):

R. C. Moretz ◽

G. G. Hausner ◽

D. F. Parsons

Keyword(s):

Electron Microscopy ◽

Water Vapor ◽

Electron Diffraction ◽

Water Vapor Pressure ◽

Biological Materials ◽

Thin Membrane ◽

Reliable System ◽

System A ◽

Water Films ◽

Aperture Opening

Electron microscopy and diffraction of biological materials in the hydrated state requires the construction of a chamber in which the water vapor pressure can be maintained at saturation for a given specimen temperature, while minimally affecting the normal vacuum of the remainder of the microscope column. Initial studies with chambers closed by thin membrane windows showed that at the film thicknesses required for electron diffraction at 100 KV the window failure rate was too high to give a reliable system. A single stage, differentially pumped specimen hydration chamber was constructed, consisting of two apertures (70-100μ), which eliminated the necessity of thin membrane windows. This system was used to obtain electron diffraction and electron microscopy of water droplets and thin water films. However, a period of dehydration occurred during initial pumping of the microscope column. Although rehydration occurred within five minutes, biological materials were irreversibly damaged. Another limitation of this system was that the specimen grid was clamped between the apertures, thus limiting the yield of view to the aperture opening.

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Modern Biodegradable Plastics—Processing and Properties Part II

Materials ◽

10.3390/ma14102523 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2523

Author(s):

Janusz W. Sikora ◽

Łukasz Majewski ◽

Andrzej Puszka

Keyword(s):

Water Vapor ◽

Rotational Speed ◽

Corn Starch ◽

Potato Starch ◽

Reference Sample ◽

Film Surface ◽

Barrier Properties ◽

Processing Parameters ◽

Biodegradable Plastics ◽

Film Blowing

Four different plastics were tested: potato starch based plastic (TPS-P)–BIOPLAST GF 106/02; corn starch based plastic (TPS-C)–BioComp BF 01HP; polylactic acid (polylactide) plastic (PLA)—BioComp BF 7210 and low density polyethylene, trade name Malen E FABS 23-D022; as a petrochemical reference sample. Using the blown film extrusion method and various screw rotational speeds, films were obtained and tested, as a result of which the following were determined: breaking stress, strain at break, static and dynamic friction coefficient of film in longitudinal and transverse direction, puncture resistance and strain at break, color, brightness and gloss of film, surface roughness, barrier properties and microstructure. The biodegradable plastics tested are characterized by comparable or even better mechanical strength than petrochemical polyethylene for the range of film blowing processing parameters used here. The effect of the screw rotational speed on the mechanical characteristics of the films obtained was also demonstrated. With the increase in the screw rotational speed, the decrease of barrier properties was also observed. No correlation between roughness and permeability of gases and water vapor was shown. It was indicated that biodegradable plastics might be competitive for conventional petrochemical materials used in film blowing niche applications where cost, recyclability, optical and water vapor barrier properties are not critical.

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Atomic Layer Deposition of Chalcogenides for Next-Generation Phase Change Memory

Journal of Materials Chemistry C ◽

10.1039/d1tc00186h ◽

2021 ◽

Author(s):

Yoon Kyeung Lee ◽

Chanyoung Yoo ◽

Woohyun Kim ◽

Jeongwoo Jeon ◽

Cheol Seong Hwang

Keyword(s):

Thin Film ◽

Atomic Layer Deposition ◽

Film Growth ◽

Phase Change Memory ◽

Film Surface ◽

Atomic Layer ◽

Thin Film Growth ◽

Growth Technique ◽

Layer Deposition ◽

Change Memory

Atomic layer deposition (ALD) is a thin film growth technique that uses self-limiting, sequential reactions localized at the growing film surface. It guarantees exceptional conformality on high-aspect-ratio structures and controllability...

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Tracing surfactant transformation from cellular release to insertion into an air-liquid interface

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00342.2003 ◽

2004 ◽

Vol 286 (5) ◽

pp. L1009-L1015 ◽

Cited By ~ 34

Author(s):

T. Haller ◽

P. Dietl ◽

H. Stockner ◽

M. Frick ◽

N. Mair ◽

...

Keyword(s):

Surface Tension ◽

Cultured Cells ◽

High Surface ◽

Lamellar Body ◽

Liquid Interface ◽

Alveolar Type ◽

Tensile Forces ◽

Modify Surface ◽

Fluorescence Imaging Microscopy ◽

Air Liquid Interface

Pulmonary surfactant is secreted by alveolar type II cells as lipid-rich, densely packed lamellar body-like particles (LBPs). The particulate nature of released LBPs might be the result of structural and/or thermodynamic forces. Thus mechanisms must exist that promote their transformation into functional units. To further define these mechanisms, we developed methods to follow LBPs from their release by cultured cells to insertion in an air-liquid interface. When released, LBPs underwent structural transformation, but did not disperse, and typically preserved a spherical appearance for days. Nevertheless, they were able to modify surface tension and exhibited high surface activity when measured with a capillary surfactometer. When LBPs inserted in an air-liquid interface were analyzed by fluorescence imaging microscopy, they showed remarkable structural transformations. These events were instantaneous but came to a halt when the interface was already occupied by previously transformed material or when surface tension was already low. These results suggest that the driving force for LBP transformation is determined by cohesive and tensile forces acting on these particles. They further suggest that transformation of LBPs is a self-regulated interfacial process that most likely does not require structural intermediates or enzymatic activation.

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Thin-film-induced morphological instabilities over calcite surfaces

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2015.0031 ◽

2015 ◽

Vol 471 (2176) ◽

pp. 20150031 ◽

Cited By ~ 5

Author(s):

R. Vesipa ◽

C. Camporeale ◽

L. Ridolfi

Keyword(s):

Morphological Evolution ◽

Water Film ◽

Environmental Parameters ◽

Climatic Conditions ◽

Point Of View ◽

Theoretical Point ◽

Carbon Dioxide Transport ◽

Physical Mechanisms ◽

Water Films ◽

Dissolved Ions

Precipitation of calcium carbonate from water films generates fascinating calcite morphologies that have attracted scientific interest over past centuries. Nowadays, speleothems are no longer known only for their beauty but they are also recognized to be precious records of past climatic conditions, and research aims to unveil and understand the mechanisms responsible for their morphological evolution. In this paper, we focus on crenulations, a widely observed ripple-like instability of the the calcite–water interface that develops orthogonally to the film flow. We expand a previous work providing new insights about the chemical and physical mechanisms that drive the formation of crenulations. In particular, we demonstrate the marginal role played by carbon dioxide transport in generating crenulation patterns, which are indeed induced by the hydrodynamic response of the free surface of the water film. Furthermore, we investigate the role of different environmental parameters, such as temperature, concentration of dissolved ions and wall slope. We also assess the convective/absolute nature of the crenulation instability. Finally, the possibility of using crenulation wavelength as a proxy of past flows is briefly discussed from a theoretical point of view.

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Studies on synthetic-polymer plates with high surface energy. IV. Determination of critical surface tension with aqueous solutions of salts

Journal of Applied Polymer Science ◽

10.1002/app.1982.070270836 ◽

1982 ◽

Vol 27 (8) ◽

pp. 3161-3169

Author(s):

Norio Kaneko ◽

Yasuji Ohtsuka

Keyword(s):

Surface Tension ◽

Surface Energy ◽

Aqueous Solutions ◽

High Surface ◽

Synthetic Polymer ◽

Critical Surface ◽

Critical Surface Tension ◽

High Surface Energy

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Effect of hydraulic and mechanical characteristics of sediment layers on water film formation in submarine landslides

Progress in Earth and Planetary Science ◽

10.1186/s40645-020-00375-7 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Shogo Kawakita ◽

Daisuke Asahina ◽

Takato Takemura ◽

Hinako Hosono ◽

Keiji Kitajima

Keyword(s):

Tensile Strength ◽

Pore Pressure ◽

Mechanical Characteristics ◽

Film Formation ◽

Mass Movement ◽

Water Film ◽

Submarine Landslides ◽

Overburden Pressure ◽

Water Films ◽

Sediment Layers

Abstract Through two lab-scale experiments, we investigated the hydraulic and mechanical characteristics of sediment layers during water film formation, induced by elevated pore pressure—considered one of the triggers of submarine landslides. These involved (1) sandbox experiments to prove the effect of water films on mass movement in low slope gradients and (2) experiments to observe the effect of the tensile strength of semi-consolidated sediment layers on water film formation. Portland cement was used to mimic the degree of sediment cementation. We observed a clear relationship between the amount of cement and pore pressure during water film formation; pressure evolution and sediment deformation demonstrated the hydraulic and mechanical characteristics. Based on the results of these experiments, conditions of the sediment layers during water film formation are discussed in terms of pore pressure, permeability, tensile strength, overburden pressure, and tectonic stresses. The results indicate that the tensile strength of the sediment interface provides critical information on the lower limit of the water film formation depth, which is related to the scale of potential submarine landslides.

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Suppression of the Kapitza instability in confined falling liquid films

Journal of Fluid Mechanics ◽

10.1017/jfm.2018.902 ◽

2018 ◽

Vol 860 ◽

pp. 608-639 ◽

Cited By ~ 7

Author(s):

Gianluca Lavalle ◽

Yiqin Li ◽

Sophie Mergui ◽

Nicolas Grenier ◽

Georg F. Dietze

Keyword(s):

Linear Stability ◽

Pressure Difference ◽

Film Surface ◽

Water Film ◽

Narrow Channel ◽

Liquid Films ◽

Interfacial Instability ◽

Critical Conditions ◽

Driving Mechanism ◽

Strong Confinement

We revisit the linear stability of a falling liquid film flowing through an inclined narrow channel in interaction with a gas phase. We focus on a particular region of parameter space, small inclination and very strong confinement, where we have found the gas to strongly stabilize the film, up to the point of fully suppressing the long-wave interfacial instability attributed to Kapitza (Zh. Eksp. Teor. Fiz., vol. 18 (1), 1948, pp. 3–28). The stabilization occurs both when the gas is merely subject to an aerostatic pressure difference, i.e. when the pressure difference balances the weight of the gas column, and when it flows counter-currently. In the latter case, the degree of stabilization increases with the gas velocity. Our investigation is based on a numerical solution of the Orr–Sommerfeld temporal linear stability problem as well as stability experiments that clearly confirm the observed effect. We quantify the degree of stabilization by comparing the linear stability threshold with its passive-gas limit, and perform a parametric study, varying the relative confinement, the Reynolds number, the inclination angle and the Kapitza number. For example, we find a 30 % reduction of the cutoff wavenumber of the instability for a water film in contact with air, flowing through a channel inclined at $3^{\circ }$ and of height 2.8 times the film thickness. We also identify the critical conditions for the full suppression of the instability in terms of the governing parameters. The stabilization is caused by the strong confinement of the gas, which produces perturbations of the adverse interfacial tangential shear stress that are shifted by half a wavelength with respect to the wavy film surface. This tends to reduce flow-rate variations within the film, thus attenuating the inertia-based driving mechanism of the Kapitza instability.

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