Nanopatterned polymer brushes: conformation, fabrication and applications

Nanoscale ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 680-700 ◽  
Author(s):  
Qian Yu ◽  
Linnea K. Ista ◽  
Renpeng Gu ◽  
Stefan Zauscher ◽  
Gabriel P. López
Keyword(s):  
Polymer Brushes ◽  
Wide Range

Nanopatterned polymer brushes provide versatile platforms for investigation of nanoscale phenomena at biointerfaces and for a wide range of applications in biotechnology and electronics.

scholarly journals Facile Molecular Weight Determination of Polymer Brushes Grafted from One-Dimensional Diffraction Grating by SI-ATRP Using Reflective Laser System

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4270
Author(s):  
Jem-Kun Chen ◽  
Feng-Ping Lin ◽  
Chi-Jung Chang ◽  
Chien-Hsing Lu ◽  
Chih-Feng Huang
Keyword(s):  
Molecular Weight ◽  
Polymer Brushes ◽  
Diffraction Effect ◽  
Molecular Weight Determination ◽  
Diffraction Intensity ◽  
Simple Method ◽  
Grafting Polymerization ◽  
One Dimensional ◽  
Wide Range

Gelatin was immobilized selectively on the amide groups-modified bottom of a trench array of a photoresist template with 2 μm resolution by the ethyl(dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide reaction. The gelatin-immobilized line array was brominated to generate a macroinitiator for atom transfer radical polymerization. Poly(methacrylic acid) (PMAA) brushes were grafted from the macroinitiator layer as line arrays of one-dimensional diffraction gratings (DGs) for various grafting polymerization times. A laser beam system was employed to analyze the optical feature with a characteristic diffraction effect of the PMAA DGs at a 45° incident angle along the transverse magnetic and transverse electric polarization. The growth of the PMAA brush lines increased both their heights and widths, leading to a change in the reflective diffraction intensity. The PMAA brushes under various grafting polymerization times were cleaved from the substrate by digestion of gelatin with trypsin, and their molecular weights were obtained by gel permeation chromatography. The change degree of the diffraction intensity varied linearly with the molecular weight of the PMAA brushes over a wide range, from 135 to 1475 kDa, with high correlation coefficients. Molecular weight determination of polymer brushes using the reflective diffraction intensity provides a simple method to monitor their growth in real time without polymer brush cleavage.

Nanografting of Polymer Brushes on Gold Substrate by RAFT-RIGP

2021 ◽  
Vol 7 (1) ◽  
pp. 5
Author(s):  
Bin Jeremiah D. Barba ◽  
Patricia Nyn L. Heruela ◽  
Patrick Jay E. Cabalar ◽  
John Andrew A. Luna ◽  
Allan Christopher C. Yago ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Optical Sensors ◽  
Self Assembly ◽  
Polymer Brushes ◽  
Incident Light ◽  
Organosulfur Compounds ◽  
Layer By Layer ◽  
Label Free ◽  
Sensing Applications ◽  
Wide Range

Optical sensors based on surface plasmon resonance (SPR) have made great strides in the detection of various chemical and biological analytes. A surface plasmon is a bound, non-radiative evanescent wave generated as resonant electrons on a metal–dielectric surface to absorb energy from an incident light. As analytes bind to a functionalized metal substrate, the refractometric response generated can be used for quantitation with great selectivity, sensitivity, and capacity for label-free real-time analysis. Polymer nanobrushes are ideal recognition elements because of their greater surface area and their wide range of functional versatility. Here, we introduce a simple “grafting-from” method to covalently attach nanometer-thick polymer chains on a gold surface. Nanografting on gold-coated BK-7 glass was performed in two steps: (1) self-assembly of organosulfur compounds; and (2) RAFT-mediated radiation-induced graft polymerization (RAFT-RIGP) of polyglycidyl methacrylate (PGMA). Surface modification was monitored and verified using FTIR and SPR. Layer-by-layer thickness calculated based on Winspall 3.02 simulation fitted with experimental SPR curves showed successful self-assembly of 1-dodecanethiol (DDT) monolayer with thickness measuring 1.4 nm. These alkane chains of DDT served as the graft initiation sites for RAFT-RIGP. Nanografting was controlled by adjusting the absorbed dose in the presence of chain transfer agent, 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid. The molecular weight of grafted polymers measuring 2.8 and 4.3 kDa corresponded to a thickness increase of 3.6 and 7.9 nm, respectively. These stable nanografted gold substrates may be further functionalized for sensing applications.

Pressure-Sensitive Microvalves Made from Polymer Brushes

1994 ◽  
Vol 360 ◽  
Author(s):  
E.M. Sevick ◽  
D.R.M. Williams
Keyword(s):  
Polymer Brushes ◽  
Critical Pressure ◽  
Feedback Mechanism ◽  
Polymer Chains ◽  
Narrow Slit ◽  
Solvent Quality ◽  
Pressure Sensitive ◽  
Wide Range ◽  
Valve Assembly ◽  
Valve Operation

AbstractWe describe a novel microvalve, constructed from polymer chains end-grafted onto opposing surfaces of a narrow slit. The assembly of polymer chains acts as both sensor and valve for microflow control and bypasses the need to construct an external feedback mechanism. This microflow control results from densely grafted chains which repel one another and stretch away from the surface, forming a brush which acts as an elastic and impenetrable layer. The height of a sheared brush increases or decreases depending upon solvent quality, i.e the layer can show a negative Poission's ratio. The discharge through the brushlined conduit is a non-linear function of pressure enabling different modes of valve operation. For brushes which extend moderately into the inter-slit region the valve assembly maintains constant discharge over a wide range of pressure. For brushes which extend far into the inter-slit region the valve assembly cuts off flow above a critical pressure, limiting the maximum discharge.

scholarly journals Research progress in self-oscillating polymer brushes

RSC Advances ◽  
2022 ◽  
Vol 12 (3) ◽  
pp. 1366-1374
Author(s):  
Bao-ying Zhang ◽  
Hai-nan Luo ◽  
Wei Zhang ◽  
Yang Liu
Keyword(s):  
Polymer Brushes ◽  
Chemical Properties ◽  
Research Progress ◽  
Physical And Chemical Properties ◽  
Wide Range ◽  
External Stimuli ◽  
Physical And Chemical ◽  
And Chemical Properties

Polymer brushes possess unique changes in physical and chemical properties when they are exposed to external stimuli and have a wide range of applications.

scholarly journals Hairy Polydopamine Particles as Platforms for Photonic and Magnetic Materials

Photonics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 36 ◽  
Author(s):  
Michinari Kohri ◽  
Kanako Uradokoro ◽  
Yuri Nannichi ◽  
Ayaka Kawamura ◽  
Tatsuo Taniguchi ◽  
...  
Keyword(s):  
Magnetic Materials ◽  
Polymer Brushes ◽  
Electrostatic Interactions ◽  
Functional Materials ◽  
Amino Acid Derivative ◽  
Photonic Materials ◽  
Color Changes ◽  
Lanthanide Elements ◽  
Novel Approach ◽  
Wide Range

By selecting the core materials and grafted-hair polymers, hairy particles with polymer brushes can create various types of functional materials. In recent years, polydopamine (PDA) particles that are obtained by polymerizing dopamine, which is an amino acid derivative, have attracted attention for various applications. Herein, we present a novel approach for creating photonic and magnetic materials from hairy PDA particles. By grafting a hydrophilic hair polymer, we have succeeded in producing photonic materials capable of structural color changes. Furthermore, we have demonstrated the preparation of magnetic materials by immobilizing holmium, which is one of the lanthanide elements, by electrostatic interactions onto a cationic hair polymer. These results demonstrate the possibility of hairy PDA particles for a wide range of applications, such as for photonic and magnetic materials.

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.

scholarly journals Photocatalytic Lithography

2019 ◽  
Vol 9 (7) ◽  
pp. 1266 ◽  
Author(s):  
Guido Panzarasa ◽  
Guido Soliveri
Keyword(s):  
Polymer Brushes ◽  
State Of The Art ◽  
Chemical Properties ◽  
Metal Nanoparticle ◽  
Self Assembled Monolayers ◽  
Nanometer Scale ◽  
Semiconducting Oxides ◽  
Physico Chemical ◽  
Wide Range ◽  
Assembled Monolayers

Patterning, the controlled formation of ordered surface features with different physico-chemical properties, is a cornerstone of contemporary micro- and nanofabrication. In this context, lithographic approaches owe their wide success to their versatility and their relative ease of implementation and scalability. Conventional photolithographic methods require several steps and the use of polymeric photoresists for the development of the desired pattern, all factors which can be deleterious, especially for sensitive substrates. Efficient patterning of surfaces, with resolution down to the nanometer scale, can be achieved by means of photocatalytic lithography. This approach is based on the use of photocatalysts to achieve the selective chemical modification or degradation of self-assembled monolayers, polymers, and metals. A wide range of photoactive compounds, from semiconducting oxides to porphyrins, have been demonstrated to be suitable photocatalysts. The goal of the present review is to provide a comprehensive state-of-the-art photocatalytic lithography, ranging from approaches based on semiconducting oxides to singlet oxygen-based lithography. Special attention will be dedicated to the results obtained for the patterning of polymer brushes, the sculpturing of metal nanoparticle arrays, and the patterning of graphene-based structures.

Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

1978 ◽  
Vol 36 (3) ◽  
pp. 470-482 ◽  
Author(s):  
R.W. Horne
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Analytical Techniques ◽  
Staining Technique ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Full Potential ◽  
Virus Particles ◽  
Resolution Electron ◽  
Wide Range

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

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