Molecular Scale Behavior in Alternative Propellant-Based Inhaler Formulations

2006 ◽  
pp. 401-426
Keyword(s):  
Molecular Scale ◽  
Scale Behavior

scholarly journals Molecular-scale origins of wettability at petroleum–brine–carbonate interfaces

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Paul Fenter ◽  
Tianzhu Qin ◽  
Sang Soo Lee ◽  
Mohammed B. AlOtaibi ◽  
Subhash Ayirala ◽  
...  
Keyword(s):  
Interfacial Layer ◽  
Structural Changes ◽  
Interface Structure ◽  
Chemical Processes ◽  
Wetting Layer ◽  
Central Concept ◽  
Molecular Scale ◽  
Scale Behavior ◽  
Petroleum Oil ◽  
Parallel Measurements

AbstractWettability control of carbonates is a central concept for enhanced petroleum recovery, but a mechanistic understanding of the associated molecular-scale chemical processes remains unclear. We directly probe the interface of calcium carbonate (calcite) with natural petroleum oil, synthetic petroleum analogues, and aqueous brines to understand the molecular scale behavior at this interface. The calcite–petroleum interface structure is similar whether or not calcite was previously exposed to an aqueous brine, and is characterized by an adsorbed interfacial layer, significant structural changes within the calcite surface, and increased surface roughness. No evidence for an often-assumed thin-brine wetting layer at the calcite–petroleum interface is observed. These features differ from those observed at the calcite–brine interface, and for parallel measurements using model synthetic petroleum mixtures (consisting of representative components, including dodecane, toluene, and asphaltene). Changes to the interface after petroleum displacement by aqueous brines are also discussed.

Calcium isotope fractionation in groundwater: Molecular scale processes influencing field scale behavior

2013 ◽  
Vol 119 ◽  
pp. 93-116 ◽  
Author(s):  
Jennifer L. Druhan ◽  
Carl I. Steefel ◽  
Kenneth H. Williams ◽  
Donald J. DePaolo
Keyword(s):  
Isotope Fractionation ◽  
Calcium Isotope ◽  
Field Scale ◽  
Molecular Scale ◽  
Scale Behavior

Shear heating, flow, and friction of confined molecular fluids at high pressure

2019 ◽  
Vol 21 (10) ◽  
pp. 5813-5823 ◽  
Author(s):  
James P. Ewen ◽  
Hongyu Gao ◽  
Martin H. Müser ◽  
Daniele Dini
Keyword(s):  
High Pressure ◽  
Solid Surfaces ◽  
Molecular Fluids ◽  
Molecular Scale ◽  
Shear Heating ◽  
Scale Behavior

Understanding the molecular-scale behavior of fluids confined and sheared between solid surfaces is important for many applications, particularly tribology where this often governs the macroscopic frictional response.

STM of freeze-fracture replicas: Problems and promises

1993 ◽  
Vol 51 ◽  
pp. 68-69
Author(s):  
J. T. Woodward ◽  
J. A. N. Zasadzinski
Keyword(s):  
Scanning Tunneling Microscope ◽  
Organic Materials ◽  
Freeze Fracture ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Molecular Scale ◽  
Organic Surfaces ◽  
Metal Layers ◽  
Conductive Surfaces

The Scanning Tunneling Microscope (STM) offers exciting new ways of imaging surfaces of biological or organic materials with resolution to the sub-molecular scale. Rigid, conductive surfaces can readily be imaged with the STM with atomic resolution. Unfortunately, organic surfaces are neither sufficiently conductive or rigid enough to be examined directly with the STM. At present, nonconductive surfaces can be examined in two ways: 1) Using the AFM, which measures the deflection of a weak spring as it is dragged across the surface, or 2) coating or replicating non-conductive surfaces with metal layers so as to make them conductive, then imaging with the STM. However, we have found that the conventional freeze-fracture technique, while extremely useful for imaging bulk organic materials with STM, must be modified considerably for optimal use in the STM.

Oriented Luminescent Nanostructures From Single Molecules Of Conjugated Polymers

2003 ◽  
Vol 771 ◽  
Author(s):  
Adosh Mehta ◽  
Pradeep Kumar ◽  
Jie Zheng ◽  
Robert M. Dickson ◽  
Bobby Sumpter ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Polarization Anisotropy ◽  
Emission Pattern ◽  
Spectral Signatures ◽  
Dipole Emission ◽  
Ink Jet ◽  
Molecular Scale ◽  
Jet Printing ◽  
Photochemical Stability ◽  
Printing Techniques

AbstractDipole emission pattern imaging experiments on single chains of common conjugated polymers (solubilized poly phenylene vinylenes) isolated by ink-jet printing techniques have revealed surprising uniformity in transition moment orientation perpendicular to the support substrate. In addition to uniform orientation, these species show a number of striking differences in photochemical stability, polarization anisotropy,[1] and spectral signatures[2] with respect to similar (well-studied) molecules dispersed in dilute thin-films. Combined with molecular mechanics simulation, these results point to a structural picture of a folded macromolecule as a highly ordered cylindrical nanostructure whose long-axis (approximately collinear with the conjugation axis) is oriented, by an electrostatic interaction, perpendicular to the coverglass substrate. These results suggest a number of important applications in nanoscale photonics and molecular-scale optoelectronics.

Programming Technology for Molecular-Scale Computing

2004 ◽  
Author(s):  
Hal Abelson ◽  
Gerald J. Sussman ◽  
Thomas F. Knight ◽  
Radhika Nagpal
Keyword(s):  
Molecular Scale

Introduction to molecular simulations in soft matter

2017 ◽  
Author(s):  
J.-L. Barrat ◽  
J. J. de Pablo
Keyword(s):  
Phase Space ◽  
Numerical Methods ◽  
Theoretical Basis ◽  
Soft Matter ◽  
Relevant Literature ◽  
Coarse Grained ◽  
Soft Interfaces ◽  
Molecular Scale ◽  
Soft Matter Physics ◽  
The Continuum

We describe the main features of the coarse-grained models that are typically useful in modelling soft interfaces, from force fields to the continuum descriptions involving density fields. We explain the theoretical basis of the main numerical methods that are used to explore the phase space associated with these models. Finally, three recent examples, illustrating the spirit in which relatively simple simulations can contribute to solving pending problems in soft matter physics, are briefly described. Clearly, a short series of lectures can offer, at best, a biased and restricted view of the available approaches. Our aim here will be to provide the reader with such an overview, with a focus on methods and descriptions that ‘bridge the scale’ between the molecular scale and the continuum or quasi-continuum one. The objective to present a guide to the relevant literature—which has now to a large extent appeared in the form of textbooks.

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