Journal ArticleDOI
Confinement-induced phase transitions in simple liquids.
Jacob Klein,Eugenia Kumacheva +1 more
TLDR
The liquid-to-solid transition of a simple model liquid confined between two surfaces was studied as a function of surface separation and the rigidity of the confined films increased reversibly by at least seven orders of magnitude.Abstract:
The liquid-to-solid transition of a simple model liquid confined between two surfaces was studied as a function of surface separation. From large surface separations (more than 1000 angstroms) down to a separation corresponding to seven molecular layers, the confined films displayed a liquid-like shear viscosity. When the surface separation was further decreased by a single molecular spacing, the films underwent an abrupt, reversible transition to a solid. At the transition, the rigidity of the confined films (quantified in terms of an "effective viscosity") increased reversibly by at least seven orders of magnitude.read more
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Journal ArticleDOI
Segmental and chain dynamics of polymers: from the bulk to the confined state
TL;DR: In this paper, the molecular dynamics of oligomeric poly(propylene glycol) (PPG) melts of different molecular weights confined to nanoporous glasses (pore sizes 2.5, 5.0, 7.5 and 20 nm).
Journal ArticleDOI
Methane Sorption in Nanoporous Metal−Organic Frameworks and First-Order Phase Transition of Confined Methane
Hui Wu,Wei Zhou,Taner Yildirim +2 more
Abstract: Nanoporous metal−organic frameworks (MOFs) are promising materials for methane sorption and storage. Using neutron powder diffraction, we have directly determined the methane sorption sites in two prototypical MOF materials: zeolitic imidazolate framework-8 (ZIF-8, Zn6(N2C4H5)12) and metal−organic framework-5 (MOF-5, Zn4O13(C8H4)3). The primary methane adsorption sites are associated with the organic linkers in ZIF-8 and the metal oxide clusters in MOF-5. Methane molecules on these primary sites possess well-defined orientations, implying relatively strong binding with the framework. With higher methane loading, extra methane molecules populate the secondary sites and are confined in the framework. The confined methanes are orientationally disordered and stabilized by the intermolecular interactions. Below 100 K a maximum of ∼18 and ∼24 methane molecules per formula unit can be stored in ZIF-8 and MOF-5, corresponding to ∼20 and ∼50 wt % storage capacities, respectively. An unusual reversible methane-indu...
Journal ArticleDOI
Nanohydrodynamics: The Intrinsic Flow Boundary Condition on Smooth Surfaces†
TL;DR: The impact of experimental errors and data analysis on the accuracy of slip length determination is demonstrated and the relative influence of hydrophobicity and liquid viscosity on boundary flow is compared by using water-glycerol mixtures with similar wetting properties.
Journal ArticleDOI
Electrofreezing of confined water
Ronen Zangi,Alan E. Mark +1 more
TL;DR: Results from molecular dynamics simulations of the freezing transition of TIP5P water molecules confined between two parallel plates under the influence of a homogeneous external electric field show a close similarity between the local structure of the liquid phase and the short-range order of the corresponding solid phase.
Book ChapterDOI
Imaging of Polymers Using Scanning Force Microscopy: From Superstructures to Individual Molecules
TL;DR: In this paper, the authors describe progress made in scanning force microscopy of polymers during the last five years including fundamental principles of SFM and recent developments in instrumentation relevant to polymer systems.
References
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Journal ArticleDOI
Surface energy and the contact of elastic solids
TL;DR: In this paper, the influence of surface energy on the contact between elastic solids is discussed and an analytical model for its effect upon the contact size and the force of adhesion between two lightly loaded spherical solid surfaces is presented.
Book
The friction and lubrication of solids
Frank Philip Bowden,David Tabor +1 more
TL;DR: Tabor and Bowden as mentioned in this paper reviewed the many advances made in this field during the past 36 years and outlined the achievements of Frank Philip Bowden, and reviewed the behavior of non-metals, especially elastomers; elastohydrodynamic lubrication; and the wear of sliding surfaces.
Journal ArticleDOI
Slow viscous motion of a sphere parallel to a plane wall—I Motion through a quiescent fluid
TL;DR: Asymptotic solutions of the Stokes equations are derived for both the translational and rotational motions of a sphere parallel to a plane wall bounding a semi-infinite, quiescent, viscous fluid in the limit where the gap width tends to zero as discussed by the authors.
Journal ArticleDOI
Physics of the Granular State
TL;DR: The generation of analogies between the physics found in a simple sandpile and that found in complicated microscopic systems, such as flux motion in superconductors or spin glasses, has prompted a number of new theories and to a new era of experimentation on granular systems.