Formation of Polymer Brushes Inside Cylindrical Pores

2012 ◽  
pp. 127-144
Keyword(s):  
Polymer Brushes ◽  
Cylindrical Pores

Polymer Brush-Lined Membranes for Flow and Filtration Control

1995 ◽  
Vol 385 ◽  
Author(s):  
Edith M. Sevick ◽  
Frank A. Bruce ◽  
David R.M. Williams
Keyword(s):  
Shear Rate ◽  
Poisson’S Ratio ◽  
Polymer Brushes ◽  
Polymer Brush ◽  
Poisson's Ratio ◽  
Negative Poisson’S Ratio ◽  
Critical Shear Rate ◽  
Cylindrical Pores ◽  
Negative Poisson's Ratio

ABSTRACTWe describe the flow and filtration control imparted to membranes through the adsorption of polymer brushes onto the interior pores. The brushes exhibit a negative Poisson's ratio, i.e. they swell under shear, and as a result behave as sensors and valves controlling the flow and filtration through the pore. The valve-behavior of brushes adsorbed onto cylindrical pores displays the same constant discharge control but also exhibits a critical shear rate for brush swelling.

scholarly journals Polymer brushes in cylindrical pores: Simulation versus scaling theory

2006 ◽  
Vol 125 (3) ◽  
pp. 034905 ◽  
Author(s):  
D. I. Dimitrov ◽  
A. Milchev ◽  
K. Binder
Keyword(s):  
Polymer Brushes ◽  
Scaling Theory ◽  
Cylindrical Pores

Formation of polymer brushes inside cylindrical pores: A computer simulation study

2009 ◽  
Vol 131 (4) ◽  
pp. 044901 ◽  
Author(s):  
Alexandros G. Koutsioubas ◽  
Nikolaos Spiliopoulos ◽  
Dimitris L. Anastassopoulos ◽  
Alexandros A. Vradis ◽  
Chris Toprakcioglu
Keyword(s):  
Computer Simulation ◽  
Simulation Study ◽  
Polymer Brushes ◽  
Computer Simulation Study ◽  
Cylindrical Pores

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 Polyelectrolyte Functionalisation of Track Etched Membranes: Towards Charge-Tuneable Adsorber Materials

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 509
Author(s):  
Lisa Wiedenhöft ◽  
Mohamed M. A. Elleithy ◽  
Mathias Ulbricht ◽  
Felix H. Schacher
Keyword(s):  
Methylene Blue ◽  
Heavy Metal Ions ◽  
Glycolic Acid ◽  
Organic Dyes ◽  
Langmuir Model ◽  
Surface Grafting ◽  
Hydraulic Permeability ◽  
Cylindrical Pores ◽  
Model Substances ◽  
External Stimuli

Porous adsorber membranes are promising materials for the removal of charged pollutants, such as heavy metal ions or organic dyes as model substances for pharmaceuticals from water. Here, we present the surface grafting of polyethylene terephthalate (PET) track-etched membranes having well defined cylindrical pores of 0.2 or 1 µm diameter with two polyelectrolytes, poly(2-acrylamido glycolic acid) (PAGA) and poly(N-acetyl dehydroalanine) (PNADha). The polyelectrolyte functionalised membranes were characterised by changes in wettability and hydraulic permeability in response to the external stimuli pH and the presence of Cu2+ ions. The response of the membranes proved to be consistent with functionalisation inside the pores, and the change of grafted polyelectrolyte macro-conformation was due to the reversible protonation or binding of Cu2+ ions. Moreover, the adsorption of the model dye methylene blue was studied and quantified. PAGA-grafted membranes showed an adsorption behavior following the Langmuir model for methylene blue.

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