Homo- and mixed polymer brushes prepared by surface-grafting of asymmetric non-sticky/sticky diblock copolymers and their stimuli–responsive behaviors

2013 ◽  
Vol 73 (1) ◽  
pp. 66-72 ◽  
Author(s):  
Mingu Han ◽  
Jae-Seol Ryu ◽  
Ji-Woong Park
Keyword(s):  
Polymer Brushes ◽  
Diblock Copolymers ◽  
Surface Grafting ◽  
Stimuli Responsive

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).

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).

Stimuli-Responsive Y-Shaped Polymer Brushes Based on Junction-Point-Reactive Block Copolymers

2012 ◽  
Vol 24 (41) ◽  
pp. 5559-5563 ◽  
Author(s):  
Christoph Tonhauser ◽  
Ali A. Golriz ◽  
Christian Moers ◽  
Rebecca Klein ◽  
Hans-Jürgen Butt ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Polymer Brushes ◽  
Junction Point ◽  
Stimuli Responsive

scholarly journals Conformation Study of Dual Stimuli-Responsive Core-Shell Diblock Polymer Brushes

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1084
Author(s):  
Kaimin Chen ◽  
Lan Cao ◽  
Ying Zhang ◽  
Kai Li ◽  
Xue Qin ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Core Shell ◽  
Stimuli Responsive ◽  
Research Topics ◽  
Design And Synthesis ◽  
Mild Conditions ◽  
The Core ◽  
Responsive Polymer ◽  
Stimuli Responsive Polymer ◽  
Shed Light

Stimuli-responsive nanoparticles are among the most popular research topics. In this study, two types of core-shell (polystyrene with a photoiniferter (PSV) as the core and diblock as the shell) polymer brushes (PSV@PNIPA-b-PAA and PSV@PAA-b-PNIPA) were designed and prepared using surface-initiated photoiniferter-mediated polymerization (SI-PIMP). Moreover, their pH- and temperature-stimuli responses were explored by dynamic light scattering (DLS) and turbidimeter under various conditions. The results showed that the conformational change was determined on the basis of the competition among electrostatic repulsion, hydrophobic interaction, hydrogen bonding, and steric hindrance, which was also confirmed by protein adsorption experiments. These results are not only helpful for the design and synthesis of stimuli-responsive polymer brushes but also shed light on controlled protein immobilization under mild conditions.

Thermoswitchable Janus Gold Nanoparticles with Stimuli-Responsive Hydrophilic Polymer Brushes

Langmuir ◽  
2016 ◽  
Vol 32 (17) ◽  
pp. 4297-4304 ◽  
Author(s):  
Xiaoqin Niu ◽  
Fen Ran ◽  
Limei Chen ◽  
Gabriella Jia-En Lu ◽  
Peiguang Hu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Polymer Brushes ◽  
Hydrophilic Polymer ◽  
Stimuli Responsive

scholarly journals Self-restoring polymer brushes under tribological stress and the biomedical applications

MRS Advances ◽  
2016 ◽  
Vol 1 (27) ◽  
pp. 1971-1976
Author(s):  
Troels Røn ◽  
Irakli Javakhishvili ◽  
Søren Hvilsted ◽  
Katja Jankova ◽  
Seunghwan Lee
Keyword(s):  
Polymer Brushes ◽  
Diblock Copolymers ◽  
Polymer Chains ◽  
Aqueous Environment ◽  
Pdms Film ◽  
Pdms Surface ◽  
Tribological Application ◽  
Optimal Functions ◽  
Amphiphilic Diblock Copolymers

ABSTRACTFor biological and mechanical systems involving moving parts, surface slipperiness is often a critical attribute for their optimal functions. Surface grafting with hydrophilic polymers is a powerful means to render materials slippery in aqueous environment. In “inverted grafting-to approach”, the hydrophilic polymer chains of amphiphilic diblock copolymers dispersed within a poly(dimethylsiloxane) (PDMS) network are selectively segregated upon exposure to aqueous solution. This allows formation of extremely stable brush-like polymer layers. Tribological application of inverted grafting-to approach was successfully demonstrated with PDMS-block-poly(acrylic acid) (PDMS-b-PAA) dispersed within thin PDMS films on PDMS blocks by showing friction coefficients (µ) of ca 10-2 to 10-3, depending on the load, pH and buffer salinity in the absence of other external re-supply of PAA chains. Further manipulations of the thin PDMS film incorporating PDMS-b-PAA to optimize the tribological properties are presented. Lastly, first trials to employ PAA-grafted PDMS surface to generate in-vitro mucosae model are also presented and discussed.

scholarly journals Effect of Structure of Polymers Grafted from Graphene Oxide on the Compatibility of Particles with a Silicone-Based Environment and the Stimuli-Responsive Capabilities of Their Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 591 ◽  
Author(s):  
Monika Zygo ◽  
Miroslav Mrlik ◽  
Marketa Ilcikova ◽  
Martina Hrabalikova ◽  
Josef Osicka ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Graphene Oxide ◽  
Radical Polymerization ◽  
Polymer Brushes ◽  
Silicone Oil ◽  
Polymer Chains ◽  
Butyl Methacrylate ◽  
Raman Shift ◽  
Stimuli Responsive ◽  
Grafted Polymer

This study reports the utilization of controlled radical polymerization as a tool for controlling the stimuli-responsive capabilities of graphene oxide (GO) based hybrid systems. Various polymer brushes with controlled molecular weight and narrow molecular weight distribution were grafted from the GO surface by surface-initiated atom transfer radical polymerization (SI-ATRP). The modification of GO with poly(n-butyl methacrylate) (PBMA), poly(glycidyl methacrylate) (PGMA), poly(trimethylsilyloxyethyl methacrylate) (PHEMATMS) and poly(methyl methacrylate) (PMMA) was confirmed by thermogravimetric analysis (TGA) coupled with online Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Various grafting densities of GO-based materials were investigated, and conductivity was elucidated using a four-point probe method. Raman shift and XPS were used to confirm the reduction of surface properties of the GO particles during SI-ATRP. The contact angle measurements indicated the changes in the compatibility of GOs with silicone oil, depending on the structure of the grafted polymer chains. The compatibility of the GOs with poly(dimethylsiloxane) was also investigated using steady shear rheology. The tunability of the electrorheological, as well as the photo-actuation capability, was investigated. It was shown that in addition to the modification of conductivity, the dipole moment of the pendant groups of the grafted polymer chains also plays an important role in the electrorheological (ER) performance. The compatibility of the particles with the polymer matrix, and thus proper particles dispersibility, is the most important factor for the photo-actuation efficiency. The plasticizing effect of the GO-polymer hybrid filler also has a crucial impact on the matrix stiffness and thus the ability to reversibly respond to the external light stimulation.

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