Stratification in Bidisperse Polymer Brushes from Neutron Reflectivity

1998 ◽  
Vol 31 (8) ◽  
pp. 2616-2621 ◽  
Author(s):  
Rastislav Levicky ◽  
Nagraj Koneripalli ◽  
Matthew Tirrell ◽  
Sushil K. Satija
Keyword(s):  
Polymer Brushes ◽  
Neutron Reflectivity

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).

Determining the density profile of confined polymer brushes with neutron reflectivity

2004 ◽  
Vol 42 (17) ◽  
pp. 3290-3301 ◽  
Author(s):  
W. A. Hamilton ◽  
G. S. Smith ◽  
N. A. Alcantar ◽  
J. Majewski ◽  
R. G. Toomey ◽  
...  
Keyword(s):  
Density Profile ◽  
Polymer Brushes ◽  
Neutron Reflectivity ◽  
Confined Polymer

Neutron Reflectivity Study of the Structure of pH-Responsive Polymer Brushes Grown from a Macroinitiator at the Sapphire−Water Interface

Langmuir ◽  
2010 ◽  
Vol 26 (15) ◽  
pp. 12684-12689 ◽  
Author(s):  
Mauro Moglianetti ◽  
John R. P. Webster ◽  
Steve Edmondson ◽  
Steven P. Armes ◽  
Simon Titmuss
Keyword(s):  
Polymer Brushes ◽  
Neutron Reflectivity ◽  
Water Interface ◽  
Ph Responsive ◽  
Responsive Polymer

Neutron Reflectivity Study of Free-End Distribution in Polymer Brushes

2009 ◽  
Vol 42 (16) ◽  
pp. 6209-6214 ◽  
Author(s):  
Nikolaos Spiliopoulos ◽  
Alexandros G. Koutsioubas ◽  
Dimitris L. Anastassopoulos ◽  
Alexandros A. Vradis ◽  
Chris Toprakcioglu ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Neutron Reflectivity

Structure of End-Grafted Polymer Brushes in Liquid and Supercritical Carbon Dioxide:  A Neutron Reflectivity Study

2003 ◽  
Vol 36 (9) ◽  
pp. 3365-3373 ◽  
Author(s):  
Stephen M. Sirard ◽  
Ravi R. Gupta ◽  
Thomas P. Russell ◽  
James J. Watkins ◽  
Peter F. Green ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Polymer Brushes ◽  
Neutron Reflectivity ◽  
Grafted Polymer ◽  
Supercritical Carbon

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).

Structure of Bimodal Polymer Brushes in a Good Solvent by Neutron Reflectivity

1996 ◽  
Vol 29 (8) ◽  
pp. 2843-2849 ◽  
Author(s):  
M. S. Kent ◽  
B. J. Factor ◽  
Sushil Satija ◽  
G. S. Smith
Keyword(s):  
Polymer Brushes ◽  
Neutron Reflectivity

Novel evaluation method of neutron reflectivity data applied to stimulus-responsive polymer brushes

Soft Matter ◽  
2008 ◽  
Vol 4 (3) ◽  
pp. 500 ◽  
Author(s):  
Jianming Zhang ◽  
Tommy Nylander ◽  
Richard A. Campbell ◽  
Adrian R. Rennie ◽  
Stefan Zauscher ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Evaluation Method ◽  
Neutron Reflectivity ◽  
Stimulus Responsive ◽  
Responsive Polymer ◽  
Reflectivity Data

scholarly journals Responsive Adsorption of N-Isopropylacrylamide Based Copolymers on Polymer Brushes

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 153 ◽  
Author(s):  
Guillaume Sudre ◽  
Elodie Siband ◽  
Bruno Gallas ◽  
Fabrice Cousin ◽  
Dominique Hourdet ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Polymer Brushes ◽  
Electrostatic Interactions ◽  
Neutron Reflectivity ◽  
Ph Responsive ◽  
Temperature Responsive ◽  
Wide Range ◽  
Scaling Models ◽  
Solvophobic Interactions ◽  
Chain Lengths

We investigate the adsorption of pH- or temperature-responsive polymer systems by ellipsometry and neutron reflectivity. To this end, temperature-responsive poly (N-isopropylacrylamide) (PNIPAM) brushes and pH-responsive poly (acrylic acid) (PAA) brushes have been prepared using the “grafting onto” method to investigate the adsorption process of polymers and its reversibility under controlled environment. To that purpose, macromolecular brushes were designed with various chain lengths and a wide range of grafting density. Below the transition temperature (LCST), the characterization of PNIPAM brushes by neutron reflectivity shows that the swelling behavior of brushes is in good agreement with the scaling models before they collapse above the LCST. The reversible adsorption on PNIPAM brushes was carried out with linear copolymers of N-isopropylacrylamide and acrylic acid, P(NIPAM-co-AA). While these copolymers remain fully soluble in water over the whole range of temperature investigated, a quantitative adsorption driven by solvophobic interactions was shown to proceed only above the LCST of the brush and to be totally reversible upon cooling. Similarly, the pH-responsive adsorption driven by electrostatic interactions on PAA brushes was studied with copolymers of NIPAM and N,N-dimethylaminopropylmethacrylamide, P(NIPAM-co-MADAP). In this case, the adsorption of weak polycations was shown to increase with the ionization of the PAA brush with interactions mainly located in the upper part of the brush at pH 7 and more deeply adsorbed within the brush at pH 9.

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