High-Strength Multifunctional Conducting Polymer Hydrogels

2010 ◽  
Vol 123-125 ◽  
pp. 117-120 ◽  
Author(s):  
Ting Yang Dai ◽  
Xu Tang Qing ◽  
Chen Shen ◽  
Jing Wang ◽  
Yun Lu
Keyword(s):  
Conducting Polymer ◽  
Self Assembly ◽  
High Strength ◽  
Polymer Chains ◽  
Electromechanical Actuators ◽  
Polymer Hydrogels ◽  
The Matrix ◽  
One Step ◽  
Multiple Network ◽  
Optimized Conditions

A simple and versatile method has been invented to fabricate conducting polymer hydrogels via supramolecular self-assembly between polymers and multivalent cations. As-prepared hydrogels composed of poly(3,4-ethylenedioxythiophene) and poly(styrenesulfonate) (PEDOT-PSS) exhibit expanded-coil conformation in polymer chains, phase-separate at nanometer scale, possess controllable microstructure, and is responsive to external stimulus. The conducting PEDOT-PSS hydrogels have then been introduced into multiple-network hydrogels to obtain composite hydrogels combining enhanced mechanical strength and excellent electrical activity. Triple-network (TN) and special double-network (sDN) hydrogels, containing poly(acrylic acid) (PAA) and poly(acrylamide) (PAAm) as the matrix respectively, are successfully prepared. Finally, PEDOT-PSS hydrogels with self-strengthening function are directly fabricated via a one-step process under optimized conditions. The strengthening mechanisms for each kind of hydrogels are proposed, and the applicability in electrosensors, supercapacitors and electromechanical actuators are briefly demonstrated.

Facile fabrication of conducting polymer hydrogels via supramolecular self-assembly

2008 ◽  
pp. 4279 ◽  
Author(s):  
Tingyang Dai ◽  
Xiujuan Jiang ◽  
Shouhu Hua ◽  
Xiaoshu Wang ◽  
Yun Lu
Keyword(s):  
Conducting Polymer ◽  
Self Assembly ◽  
Polymer Hydrogels ◽  
Facile Fabrication

Effect of One-Step and Two-Step Aging Treatments on Microstructure and Properties of an Al-9.0Zn-2.0Mg-2.0Cu Alloy

2018 ◽  
Vol 941 ◽  
pp. 949-954 ◽  
Author(s):  
Kai Wen ◽  
Bai Qing Xiong ◽  
Yong An Zhang ◽  
Zhi Hui Li ◽  
Xi Wu Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aging Treatment ◽  
High Strength ◽  
High Resolution Electron Microscopy ◽  
Slow Increase ◽  
Microstructure Observation ◽  
Resolution Electron ◽  
The Matrix ◽  
One Step ◽  
Diffraction Patterns

Aging treatments of an Al-9.0Zn-2.0Mg-2.0Cu alloy, which belongs to high strength aluminum alloy widely used in aerospace industry, are investigated by various techniques, including hardness, electrical conductivity, mechanical properties, transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). The result shows that hardness and conductivity for one-step aging treatment increase with aging time prolongs while those for two-step aging treatment exhibit increment and decrement, respectively. Besides, the ultimate tensile strength (UTS) and yield strength (YS) for one-step and two-step aging treatments show slow increase and obvious decrease, respectively. Based on these, typical T6 and T76 aging regimes are extracted for microstructure observation. The matrix precipitates for the T6 alloy have small size and dispersive distribution while that for the T76 alloy has big size and sparse distribution. The grain boundary precipitates for both exhibit discontinuous distribution and the T76 alloy has larger size and broader precipitate free zones. The selected area diffraction patterns and HREM observations reveal that main precipitates for the T6 alloy are GPI zone, GPII zone and η' phase while for the T76 alloy are η' phase and η phase.

Hierarchical Self-Assembly of Tryptic Peptides From Wheat Gluten

2009 ◽  
Author(s):  
Ahmad Athamneh ◽  
Justin Barone
Keyword(s):  
Self Assembly ◽  
Preliminary Investigation ◽  
Wheat Gluten ◽  
Fiber Axis ◽  
Tryptic Peptides ◽  
Transmission Electron ◽  
The Matrix ◽  
One Step ◽  
20 Nm ◽  
Micrometer Scale

We have prepared nanocomposites in one step by hydrolyzing wheat gluten (WG) with trypsin and then drying the solution. Some tryptic peptides from WG can self-assemble into fibrous structures under benign conditions (37 °C, pH 8) to form a reinforcing phase while the balance do not to form the matrix phase. Here we describe the characterization of the self-assembled fibers, which were hierarchically structured and showed organization from the nanometer to the micrometer scale. The basic building block of the fiber was a stack of beta–sheets. Scanning and transmission electron micrographs showed large fibers about 10–15 μm in diameter with left-handed helical configuration and appeared to be bundles of 10–20 nm diameter fibrils. Preliminary investigation suggested that the elastic modulus of the WG-based fibers was 0.16 ± 0.03 GPa, consistent with reported values for natural protein fibers. Fourier transform infrared spectroscopy, X-ray diffraction, and thioflavin-T binding assay indicated that the framework of the fibrils was composed of cross-beta structures, where beta-strands ran perpendicular to the fiber axis.

Epoxy/polyurethane nanocomposite coatings for anti-erosion/wear applications: A review

2020 ◽  
Vol 54 (22) ◽  
pp. 3189-3203 ◽  
Author(s):  
Hamed Bahramnia ◽  
Hamidreza Mohammadian Semnani ◽  
Ali Habibolahzadeh ◽  
Hassan Abdoos
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix ◽  
Composite Coatings ◽  
High Strength ◽  
Polymer Chains ◽  
Erosion Wear ◽  
Nano Composite ◽  
Offshore Pipelines ◽  
The Matrix ◽  
Coating Characteristics

Offshore pipelines are vulnerable against erosion/wear deterioration mechanisms that can be controlled through the use of proper surface coatings, such as polymer matrix nano-composite (PMNC) coatings that are well-known for their ease of production, availability and applicability. Epoxy, as a versatile rigid and brittle resin and polyurethane with proper chemical/mechanical properties, are potential candidates to make the matrix of these composites. A combination of these polymers can also enhance the mechanical behaviors, glass transition temperature and flexibility. In addition, the desired coating characteristics, such as adhesion to metal substrate, mechanical properties, erosion/wear resistivity and UV absorbance, can be further improved through the addition of appropriate nanoparticles within the polymer matrix. Especially, nanoparticles can improve the erosion/wear resistance of polymers because of establishing high strength bonds between the polymer chains and the reinforcements besides enhancing other required properties. The present work is a review on PMNC coatings that contain epoxy, polyurethane or EP/polyurethane as a polymer matrix along with the details of the nanoparticle reinforcements, such as alumina, silica, titanium oxide, zinc oxide, clay and carbon-based materials. The effect of these nanoparticles on the properties of composite coatings has also been investigated.

Investigation of Au SAMs Photoclick Derivatization by PM-IRRAS

2019 ◽  
Author(s):  
Mark Workentin ◽  
François Lagugné-Labarthet ◽  
Sidney Legge
Keyword(s):  
Cell Adhesion ◽  
Self Assembly ◽  
Materials Science ◽  
Fibroblast Cell ◽  
Fine Tuning ◽  
Chemical System ◽  
Infrared Reflection ◽  
Assembled Monolayers ◽  
One Step ◽  
High Degree

In this work we present a clean one-step process for modifying headgroups of self-assembled monolayers (SAMs) on gold using photo-enabled click chemistry. A thiolated, cyclopropenone-caged strained alkyne precursor was first functionalized onto a flat gold substrate through self-assembly. Exposure of the cyclopropenone SAM to UV-A light initiated the efficient photochemical decarbonylation of the cyclopropenone moiety, revealing the strained alkyne capable of undergoing the interfacial strain-promoted alkyne-azide cycloaddition (SPAAC). Irradiated SAMs were derivatized with a series of model azides with varied hydrophobicity to demonstrate the generality of this chemical system for the modification and fine-tuning of the surface chemistry on gold substrates. SAMs were characterized at each step with polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS) to confirm successful functionalization and reactivity. Furthermore, to showcase the compatibility of this approach with biochemical applications, cyclopropenone SAMs were irradiated and modified with azide-bearing cell adhesion peptides to promote human fibroblast cell adhesion, then imaged by live cell fluorescence microscopy. Thus, the “photoclick” methodology reported here represents an improved, versatile, catalyst-free protocol that allows for a high degree of control over the modification of material surfaces, with applicability in materials science as well as biochemistry.<br>

scholarly journals Ab initio molecular dynamics study of AlCl4− adsorption on PEDOT conducting polymer chains

2021 ◽  
Vol 7 ◽  
pp. 111-119
Author(s):  
Ben Craig ◽  
Chris-Kriton Skylaris ◽  
Carlos Ponce de Leon ◽  
Denis Kramer
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Conducting Polymer ◽  
Polymer Chains ◽  
Ab Initio Molecular Dynamics

scholarly journals Constructing Large 2D Lattices Out of DNA-Tiles

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1502
Author(s):  
Johannes M. Parikka ◽  
Karolina Sokołowska ◽  
Nemanja Markešević ◽  
J. Jussi Toppari
Keyword(s):  
Self Assembly ◽  
Dna Nanotechnology ◽  
Building Blocks ◽  
High Yield ◽  
Dna Nanostructures ◽  
Liquid Interfaces ◽  
Basic Principles ◽  
Dna Tiles ◽  
One Step ◽  
Solid Liquid

The predictable nature of deoxyribonucleic acid (DNA) interactions enables assembly of DNA into almost any arbitrary shape with programmable features of nanometer precision. The recent progress of DNA nanotechnology has allowed production of an even wider gamut of possible shapes with high-yield and error-free assembly processes. Most of these structures are, however, limited in size to a nanometer scale. To overcome this limitation, a plethora of studies has been carried out to form larger structures using DNA assemblies as building blocks or tiles. Therefore, DNA tiles have become one of the most widely used building blocks for engineering large, intricate structures with nanometer precision. To create even larger assemblies with highly organized patterns, scientists have developed a variety of structural design principles and assembly methods. This review first summarizes currently available DNA tile toolboxes and the basic principles of lattice formation and hierarchical self-assembly using DNA tiles. Special emphasis is given to the forces involved in the assembly process in liquid-liquid and at solid-liquid interfaces, and how to master them to reach the optimum balance between the involved interactions for successful self-assembly. In addition, we focus on the recent approaches that have shown great potential for the controlled immobilization and positioning of DNA nanostructures on different surfaces. The ability to position DNA objects in a controllable manner on technologically relevant surfaces is one step forward towards the integration of DNA-based materials into nanoelectronic and sensor devices.

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