Planar Molecular and Macromolecular Gradients: Preparation and Properties

2001 ◽  
Vol 707 ◽  
Author(s):  
J. Genzer ◽  
T. Wu ◽  
K. Efimenko

ABSTRACTWe present a method for fabricating polymer brushes with a gradual variation of grafting density on solid substrates. The technique for generating such structures consists of: i) deposition of a molecular gradient of polymerization initiator on the solid substrate, and ii) polymerization from the substrate bound initiator centers (“grafting from”). In this publication we describe the preparation of gradient polymer brushes of poly(acryl amide) on silica-covered substrates. We show that the polymer density within the gradient polymer brush can be varied by controlling the polymerization time.

2001 ◽  
Vol 705 ◽  
Author(s):  
J. Genzer ◽  
T. Wu ◽  
K. Efimenko

AbstractWe present a method for fabricating polymer brushes with a gradual variation of grafting density on solid substrates. The technique for generating such structures consists of: i) deposition of a molecular gradient of polymerization initiator on the solid substrate, and ii) polymerization from the substrate bound initiator centers (“grafting from”). In this publication we describe the preparation of gradient polymer brushes of poly(acryl amide) on silica-covered substrates. We show that the polymer density within the gradient polymer brush can be varied by controlling the polymerization time.


2013 ◽  
Vol 791-793 ◽  
pp. 208-211 ◽  
Author(s):  
Xiao Meng Chu ◽  
Shao Jie Liu ◽  
Hui Jiao Yang ◽  
Feng Qing Zhao

This paper firstly summarized the latest research progress on the polymer brushes preparation by surface-initiated ARGET ATRP polymerization. It mainly includes the surface modifications of inorganic substrate (silicon dioxide and carbon nanotubes), and the organic substrate (cellulose and polymer microspheres). This method needs less catalyst and operates more easily, compared to the classical ATRP. Besides, it also has good polymerization controllability, and the polymer brushes have higher grafting density and molecular weight. Therefore, surface-initiated ARGET ATRP polymerization has become an effective method for modifying the surface of materials. Then, we prepared the polymer brush supported TEMPO by the surface-initiated ARGET ATRP and characterized.


2003 ◽  
Vol 804 ◽  
Author(s):  
Rajendra R. Bhat ◽  
Jan Genzer

ABSTRACTWe discuss methods leading to the fabrication of orthogonal substrates comprising surface-anchored polymer brushes, in which the polymer brush grafting density and molecular weight vary independently in two mutually perpendicular directions. We demonstrate that these orthogonal polymer substrates can be used as intelligent combinatorial platforms that facilitate the spatial distribution of nanoparticles and allow screening of protein adsorption on surfaces.


2002 ◽  
Vol 727 ◽  
Author(s):  
Denys Usov ◽  
Manfred Stamm ◽  
Sergiy Minko ◽  
Christian Froeck ◽  
Andreas Scholl ◽  
...  

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.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jingang Li ◽  
Yaoran Liu ◽  
Linhan Lin ◽  
Mingsong Wang ◽  
Taizhi Jiang ◽  
...  

AbstractConstructing colloidal particles into functional nanostructures, materials, and devices is a promising yet challenging direction. Many optical techniques have been developed to trap, manipulate, assemble, and print colloidal particles from aqueous solutions into desired configurations on solid substrates. However, these techniques operated in liquid environments generally suffer from pattern collapses, Brownian motion, and challenges that come with reconfigurable assembly. Here, we develop an all-optical technique, termed optothermally-gated photon nudging (OPN), for the versatile manipulation and dynamic patterning of a variety of colloidal particles on a solid substrate at nanoscale accuracy. OPN takes advantage of a thin surfactant layer to optothermally modulate the particle-substrate interaction, which enables the manipulation of colloidal particles on solid substrates with optical scattering force. Along with in situ optical spectroscopy, our non-invasive and contactless nanomanipulation technique will find various applications in nanofabrication, nanophotonics, nanoelectronics, and colloidal sciences.


2021 ◽  
Vol 63 (4) ◽  
pp. 385-391
Author(s):  
T. K. Meleshko ◽  
A. B. Razina ◽  
N. N. Bogorad ◽  
M. P. Kurlykin ◽  
A. V. Kashina ◽  
...  

Abstract New polymer brushes with an ester backbone and poly(methyl methacrylate) side chains are synthesized by polycondensation and polymerization methods. The initiating groups are sulfonyl chloride groups laterally attached to the polyester chain. PMMA side chains are grafted by the ATRP method according to the “grafting from” multicenter macroinitiator strategy. The conditions for the polymerization processes in a controlled mode are selected, and the ways of targeted regulation of the degree of polymerization of methacrylate side chains are determined. Using the synthesized copolymers self-supporting films are obtained, and their physical and mechanical properties are studied.


Small ◽  
2012 ◽  
Vol 8 (23) ◽  
pp. 3567-3567 ◽  
Author(s):  
Xuechang Zhou ◽  
Zhilu Liu ◽  
Zhuang Xie ◽  
Xuqing Liu ◽  
Zijian Zheng

2007 ◽  
Vol 1049 ◽  
Author(s):  
Jeffrey B. Sokoloff

AbstractIt is shown using a method based on the mean field theory of Miklavic Marcelja that it should be possible for osmotic pressure due to the counterions associated with the two polyelectrolyte polymer brush coated surfaces to support a reasonable load (i.e., about 105 Pa) with the brushes held sufficiently far apart to prevent entanglement of polymers belonging to the two brushes, thus avoiding what is likely to be the dominant mechanisms for static and dry friction.


Soft Matter ◽  
2018 ◽  
Vol 14 (10) ◽  
pp. 1887-1896 ◽  
Author(s):  
Wenjuan Qiu ◽  
Baohui Li ◽  
Qiang Wang

Ring brushes are slightly less stretched than, thus nearly but not completely identical to, the “equivalent” linear brushes having half the chain length and double the grafting density.


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