Effect of initial conformation, flow strength, and hydrodynamic interaction on polymer molecules in extensional flows

2000 ◽  
Vol 113 (8) ◽  
pp. 3397-3403 ◽  
Author(s):  
U. S. Agarwal
Keyword(s):  
Hydrodynamic Interaction ◽  
Flow Strength ◽  
Polymer Molecules ◽  
Extensional Flows

scholarly journals Coil–stretch-like transition of elastic sheets in extensional flows

Soft Matter ◽  
2021 ◽  
Author(s):  
Yijiang Yu ◽  
Michael D. Graham
Keyword(s):  
Linear Polymers ◽  
Flow Strength ◽  
Extensional Flows ◽  
Elastic Sheets ◽  
Biaxial Flow

A thin soft sheet suspended in a fluid undergoing planar or biaxial flow displays a hysteretic transition between compact and stretched states as the flow strength changes. This transition is analogous to the “coil–stretch transition” observed for long linear polymers in these flows.

Theory of hydrodynamic interaction of two spheres in wall-bounded shear flow

2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Itzhak Fouxon ◽  
Boris Rubinstein ◽  
Zhouyang Ge ◽  
Luca Brandt ◽  
Alexander Leshansky
Keyword(s):  
Shear Flow ◽  
Hydrodynamic Interaction

scholarly journals Interfacial Tension Measurements in Microfluidic Quasi-Static Extensional Flows

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 272
Author(s):  
Doojin Lee ◽  
Amy Q. Shen
Keyword(s):  
Interfacial Tension ◽  
Microfluidic Device ◽  
Extensional Flow ◽  
Immiscible Fluids ◽  
Droplet Microfluidics ◽  
Channel Height ◽  
Deformation Model ◽  
Droplet Deformation ◽  
Extensional Flows ◽  
2D Model

Droplet microfluidics provides a versatile tool for measuring interfacial tensions between two immiscible fluids owing to its abilities of fast response, enhanced throughput, portability and easy manipulations of fluid compositions, comparing to conventional techniques. Purely homogeneous extension in the microfluidic device is desirable to measure the interfacial tension because the flow field enables symmetric droplet deformation along the outflow direction. To do so, we designed a microfluidic device consisting of a droplet production region to first generate emulsion droplets at a flow-focusing area. The droplets are then trapped at a stagnation point in the cross junction area, subsequently being stretched along the outflow direction under the extensional flow. These droplets in the device are either confined or unconfined in the channel walls depending on the channel height, which yields different droplet deformations. To calculate the interfacial tension for confined and unconfined droplet cases, quasi-static 2D Darcy approximation model and quasi-static 3D small deformation model are used. For the confined droplet case under the extensional flow, an effective viscosity of the two immiscible fluids, accounting for the viscosity ratio of continuous and dispersed phases, captures the droplet deformation well. However, the 2D model is limited to the case where the droplet is confined in the channel walls and deforms two-dimensionally. For the unconfined droplet case, the 3D model provides more robust estimates than the 2D model. We demonstrate that both 2D and 3D models provide good interfacial tension measurements under quasi-static extensional flows in comparison with the conventional pendant drop method.

Advancing conjugated polymers into nanometer-scale devices

2006 ◽  
Vol 78 (10) ◽  
pp. 1803-1822 ◽  
Author(s):  
Wenping Hu ◽  
Hiroshi Nakashima ◽  
Erjing Wang ◽  
Kazuaki Furukawa ◽  
Hongxiang Li ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Molecular Level ◽  
Nanometer Scale ◽  
Transport Mechanisms ◽  
Phenylene Ethynylene ◽  
Polymer Molecules ◽  
Polymer Electronics ◽  
End Groups

In this article, we review the possibility of combining conjugated polymers with nanometer-scale devices (nanodevices), in order to introduce the properties associated with conjugated polymers into such nanodevices. This approach envisages combining the highly topical disciplines of polymer electronics and nanoelectronics to engender a new subdirection of polymer nanoelectronics, which can serve as a tool to probe the behavior of polymer molecules at the nanometer/molecular level, and contribute to clarifying transport mechanisms in conjugated polymers. In this study, we exemplify this combination, using a family of linear and conjugated polymers, poly(p-phenylene-ethynylene)s (PPEs) with thiolacetate-functionalized end groups.

Factors Controlling Hole Injection in Single Conjugated Polymer Molecules†

2009 ◽  
Vol 113 (16) ◽  
pp. 4739-4745 ◽  
Author(s):  
Leonid Fradkin ◽  
Rodrigo E. Palacios ◽  
Joshua C. Bolinger ◽  
Kwang-Jik Lee ◽  
William M. Lackowski ◽  
...  
Keyword(s):  
Conjugated Polymer ◽  
Hole Injection ◽  
Polymer Molecules
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