Inhomogeneous Structure of Collapsed Polymer Brushes Under Deformation

1995 ◽  
Vol 28 (25) ◽  
pp. 8612-8620 ◽  
Author(s):  
E. B. Zhulina ◽  
T. M. Birshtein ◽  
V. A. Priamitsyn ◽  
L. I. Klushin
Keyword(s):  
Polymer Brushes ◽  
Inhomogeneous Structure

The Interpretation of Line Profiles

1977 ◽  
Vol 36 ◽  
pp. 191-215
Author(s):  
G.B. Rybicki
Keyword(s):  
Magnetic Fields ◽  
Atomic Physics ◽  
Velocity Fields ◽  
Spectral Lines ◽  
Inhomogeneous Structure ◽  
The Sun ◽  
Line Profiles ◽  
Physical Phenomena

Observations of the shapes and intensities of spectral lines provide a bounty of information about the outer layers of the sun. In order to utilize this information, however, one is faced with a seemingly monumental task. The sun’s chromosphere and corona are extremely complex, and the underlying physical phenomena are far from being understood. Velocity fields, magnetic fields, Inhomogeneous structure, hydromagnetic phenomena – these are some of the complications that must be faced. Other uncertainties involve the atomic physics upon which all of the deductions depend.

Forces between asymmetric polymer brushes

1990 ◽  
Vol 51 (8) ◽  
pp. 701-707 ◽  
Author(s):  
D.F.K. Shim ◽  
M. E. Cates
Keyword(s):  
Polymer Brushes

Nanostructured Polymer Brushes With Reversibly Changing Properties

2002 ◽  
Vol 727 ◽  
Author(s):  
Denys Usov ◽  
Manfred Stamm ◽  
Sergiy Minko ◽  
Christian Froeck ◽  
Andreas Scholl ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Phase Segregation ◽  
Water Contact ◽  
Angle Measurements ◽  
Nanostructured Polymer ◽  
Contact Angle Measurements ◽  
Vertical Segregation ◽  
Oxygen Plasma Etching ◽  
Grafting From ◽  
Photoemission Electron

AbstractWe investigated the interplay between different mechanisms of the lateral and vertical segregation in the synthesized via “grafting from” approach symmetric A/B (where A and B are poly(styrene-co-2,3,4,5,6-pentafluorostyrene) and poly(methylmethacrylate), respectively) polymer brushes upon exposure to different solvents. We used X-ray photoemission electron spectroscopy and microscopy (X-PEEM), AFM, water contact angle measurements, and oxygen plasma etching to study morphology of the brushes. The ripple morphology after toluene (nonselective solvent) revealed elongated lamellar-like domains of A and B polymers alternating across the surface. The dimple-A morphology consisting of round clusters of the polymer A was observed after acetone (selective solvent for B). The top layer was enriched with the polymer B showing that the brush underwent both the lateral and vertical phase segregation. A qualitative agreement with predictions of SCF theory was found.

Multi-Stimuli-Responsive Mesoporous Membranes and Effect of Molecular Architecture on Thermo- and pH-Responsive Behavior of the grafted Block Copolymer brushes

2019 ◽  
Author(s):  
Yanchun Tang ◽  
Kohzo Ito ◽  
Hideaki Yokoyama
Keyword(s):  
Polymer Brushes ◽  
Diblock Copolymers ◽  
Neutron Reflectivity ◽  
Molecular Architecture ◽  
Stimuli Responsive ◽  
Responsive Polymer ◽  
The Matrix ◽  
Stable Part ◽  
Copolymer Brushes ◽  
Mesoporous Membranes

In this study, we prepared ultrafiltration membranes with a decoupled responses of filtration property to temperature and pH. The membrane preparation method was developed based on our previous work. We utilized methanol-supercritical carbon dioxide (methanol-scCO<sub>2</sub>) selective swelling method to introduce nanopores to block copolymers containing poly(diethylene glycol) methyl ether methacrylate (PMEO<sub>2</sub>MA), poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) and polystyrene (PS) blocks. Formation of the mesoporous barrier layer with PS being the mechanically stable part of the matrix was driven by selective swelling of the PMEO<sub>2</sub>MA-b-PDMAEMA domains. Due to the selective swelling of PMEO<sub>2</sub>MA or PDMAEMA domains to introduce pores, the interior of the pores are covered with PMEO<sub>2</sub>MA or PDMAEMA blocks after pore formation. The PMEO<sub>2</sub>MA-b-PDMAEMA polymer brushes are naturally attached on the pore walls and worked as functional gates. PMEO<sub>2</sub>MA is a non-toxic, neutral thermo-responsive polymer with LCST at 26 ᴼC. PDMAEMA is a typical weak polyelectrolyte with pK<sub>a</sub> value at 7.0-7.5 and also a thermo-responsive polymer revealed a LCST of 20-80 °C in aqueous solution. Therefore, these membranes were expected to have multi dimensions as function of the combination of temperature and pH. Moreover, to understand the detail of the temperature and pH depended conformation transitions of PMEO<sub>2</sub>MA-b-PDMAEMA brushes, those diblock copolymers were end-tethered on flat substrates and analyzed via neutron reflectivity (NR).

scholarly journals Self-regenerating giant hyaluronan polymer brushes

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Wenbin Wei ◽  
Jessica L. Faubel ◽  
Hemaa Selvakumar ◽  
Daniel T. Kovari ◽  
Joanna Tsao ◽  
...  
Keyword(s):  
Wound Healing ◽  
Polymer Brushes ◽  
Functional Materials ◽  
Polymer Physics ◽  
High Density ◽  
Hyaluronan Synthase ◽  
Dynamic Interface ◽  
Continuous Source

AbstractTailoring interfaces with polymer brushes is a commonly used strategy to create functional materials for numerous applications. Existing methods are limited in brush thickness, the ability to generate high-density brushes of biopolymers, and the potential for regeneration. Here we introduce a scheme to synthesize ultra-thick regenerating hyaluronan polymer brushes using hyaluronan synthase. The platform provides a dynamic interface with tunable brush heights that extend up to 20 microns – two orders of magnitude thicker than standard brushes. The brushes are easily sculpted into micropatterned landscapes by photo-deactivation of the enzyme. Further, they provide a continuous source of megadalton hyaluronan or they can be covalently-stabilized to the surface. Stabilized brushes exhibit superb resistance to biofilms, yet are locally digested by fibroblasts. This brush technology provides opportunities in a range of arenas including regenerating tailorable biointerfaces for implants, wound healing or lubrication as well as fundamental studies of the glycocalyx and polymer physics.

scholarly journals Dark photon dark matter in the presence of inhomogeneous structure

2020 ◽  
Vol 2020 (6) ◽  
Author(s):  
Samuel J. Witte ◽  
Salvador Rosauro-Alcaraz ◽  
Samuel D. McDermott ◽  
Vivian Poulin
Keyword(s):  
Dark Matter ◽  
Inhomogeneous Structure ◽  
Dark Photon

scholarly journals Antifouling and Flux Enhancement of Reverse Osmosis Membrane by Grafting Poly (3-Sulfopropyl Methacrylate) Brushes

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 213
Author(s):  
Reema Mushtaq ◽  
Muhammad Asad Abbas ◽  
Shehla Mushtaq ◽  
Nasir M. Ahmad ◽  
Niaz Ali Khan ◽  
...  
Keyword(s):  
Contact Angle ◽  
Reverse Osmosis ◽  
Polymer Brushes ◽  
Surface Composition ◽  
Reverse Osmosis Membrane ◽  
Optical Profilometry ◽  
Thin Film Composite ◽  
Membrane Sample ◽  
Contact Angle Analysis ◽  
And Staphylococcus Aureus

A commercial thin film composite (TFC) polyamide (PA) reverse osmosis membrane was grafted with 3-sulfopropyl methacrylate potassium (SPMK) to produce PA-g-SPMK by atom transfer radical polymerization (ATRP). The grafting of PA was done at varied concentrations of SPMK, and its effect on the surface composition and morphology was studied by Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), optical profilometry, and contact angle analysis. The grafting of hydrophilic ionically charged PSPMK polymer brushes having acrylate and sulfonate groups resulted in enhanced hydrophilicity rendering a reduction of contact angle from 58° of pristine membrane sample labeled as MH0 to 10° for a modified membrane sample labeled as MH3. Due to the increased hydrophilicity, the flux rate rises from 57.1 L m−2 h−1 to 71.2 L m−2 h−1, and 99% resistance against microbial adhesion (Escherichia coli and Staphylococcus aureus) was obtained for MH3 after modification

Layer by layer assembled functionalized graphene oxide-based polymer brushes for superlubricity on steel-steel tribocontact

Soft Matter ◽  
2021 ◽  
Author(s):  
Suprakash Samanta ◽  
Rashmi Ranjan Sahoo
Keyword(s):  
Graphene Oxide ◽  
Nucleophilic Addition ◽  
Polymer Brushes ◽  
Addition Reaction ◽  
Layer By Layer ◽  
Functionalized Graphene ◽  
Covalent Functionalization ◽  
Functionalized Graphene Oxide ◽  
Nucleophilic Addition Reaction ◽  
Branched Polyethylenimine

Present study demonstrates a simple and multistep approach for the preparation of covalent functionalization of chemically prepared graphene oxide (GO) by branched polyethylenimine (PEI) through nucleophilic addition reaction to prepare...

scholarly journals FRET‐Integrated Polymer Brushes for Spatially‐Resolved Sensing of Changes in Polymer Conformation

2021 ◽  
Author(s):  
Quinn Alexander Besford ◽  
Huaisong Yong ◽  
Holger Merlitz ◽  
Andrew J. Christofferson ◽  
Jens-Uwe Sommer ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Polymer Conformation ◽  
Spatially Resolved

Vapor sorption in binary polymer brushes: The effect of the polymer–polymer interface

2021 ◽  
Vol 155 (5) ◽  
pp. 054904
Author(s):  
Leon A. Smook ◽  
Guido C. Ritsema van Eck ◽  
Sissi de Beer
Keyword(s):  
Polymer Brushes ◽  
Vapor Sorption ◽  
Polymer Interface ◽  
Binary Polymer ◽  
Binary Polymer Brushes
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