Large-Scale Continuous Immersion System for Layer-by-Layer Deposition of Flame Retardant and Conductive Nanocoatings on Fabric

2014 ◽  
Vol 53 (15) ◽  
pp. 6409-6416 ◽  
Author(s):  
Arturo J. Mateos ◽  
Amanda A. Cain ◽  
Jaime C. Grunlan
Keyword(s):  
Flame Retardant ◽  
Large Scale ◽  
Layer By Layer ◽  
Layer Deposition

scholarly journals Top-Down Polyelectrolytes for Membrane-Based Post-Combustion CO2 Capture

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 323 ◽  
Author(s):  
Daria Nikolaeva ◽  
Patricia Luis
Keyword(s):  
Large Scale ◽  
Polymer Materials ◽  
Layer By Layer ◽  
Solvent Casting ◽  
Top Down ◽  
Layer Deposition ◽  
Recent Developments ◽  
Synthesis And Processing ◽  
Cost Efficient ◽  
Physical And Chemical

Polymer-based CO2 selective membranes offer an energy efficient method to separate CO2 from flue gas. ‘Top-down’ polyelectrolytes represent a particularly interesting class of polymer materials based on their vast synthetic flexibility, tuneable interaction with gas molecules, ease of processability into thin films, and commercial availability of precursors. Recent developments in their synthesis and processing are reviewed herein. The four main groups of post-synthetically modified polyelectrolytes discern ionised neutral polymers, cation and anion functionalised polymers, and methacrylate-derived polyelectrolytes. These polyelectrolytes differentiate according to the origin and chemical structure of the precursor polymer. Polyelectrolytes are mostly processed into thin-film composite (TFC) membranes using physical and chemical layer deposition techniques such as solvent-casting, Langmuir-Blodgett, Layer-by-Layer, and chemical grafting. While solvent-casting allows manufacturing commercially competitive TFC membranes, other methods should still mature to become cost-efficient for large-scale application. Many post-synthetically modified polyelectrolytes exhibit outstanding selectivity for CO2 and some overcome the Robeson plot for CO2/N2 separation. However, their CO2 permeance remain low with only grafted and solvent-casted films being able to approach the industrially relevant performance parameters. The development of polyelectrolyte-based membranes for CO2 separation should direct further efforts at promoting the CO2 transport rates while maintaining high selectivities with additional emphasis on environmentally sourced precursor polymers.

scholarly journals Atomistic simulation of PDADMAC/PSS oligoelectrolyte multilayers: overall comparison of tri- and tetra-layer systems

Soft Matter ◽  
2019 ◽  
Vol 15 (46) ◽  
pp. 9437-9451 ◽  
Author(s):  
Pedro A. Sánchez ◽  
Martin Vögele ◽  
Jens Smiatek ◽  
Baofu Qiao ◽  
Marcello Sega ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solutions ◽  
Molecular Dynamics Simulations ◽  
Atomistic Simulation ◽  
Large Scale ◽  
Layer By Layer ◽  
Layer Deposition ◽  
Dynamics Simulations

By employing large-scale molecular dynamics simulations of atomistically resolved oligoelectrolytes in aqueous solutions, we study in detail the first four layer-by-layer deposition cycles of a PDADMAC/PSS oligoelectrolyte multilayer.

scholarly journals Layer-by-Layer Deposition: A Promising Environmentally Benign Flame-Retardant Treatment for Cotton, Polyester, Polyamide and Blended Textiles

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 432
Author(s):  
Eva Magovac ◽  
Bojana Vončina ◽  
Igor Jordanov ◽  
Jaime C. Grunlan ◽  
Sandra Bischof
Keyword(s):  
Flame Retardant ◽  
Inorganic Compounds ◽  
Green Technology ◽  
Layer By Layer ◽  
Covalent Bonds ◽  
Layer Deposition ◽  
Low Concentrations ◽  
Recent Developments ◽  
Finishing Processes ◽  
Oppositely Charged

A detailed review of recent developments of layer-by-layer (LbL) deposition as a promising approach to reduce flammability of the most widely used fibers (cotton, polyester, polyamide and their blends) is presented. LbL deposition is an emerging green technology, showing numerous advantages over current commercially available finishing processes due to the use of water as a solvent for a variety of active substances. For flame-retardant (FR) purposes, different ingredients are able to build oppositely charged layers at very low concentrations in water (e.g., small organic molecules and macromolecules from renewable sources, inorganic compounds, metallic or oxide colloids, etc.). Since the layers on a textile substrate are bonded with pH and ion-sensitive electrostatic forces, the greatest technological drawback of LbL deposition for FR finishing is its non-resistance to washing cycles. Several possibilities of laundering durability improvements by different pre-treatments, as well as post-treatments to form covalent bonds between the layers, are presented in this review.

scholarly journals Multimaterial 3D Printing for Arbitrary Distribution with Nanoscale Resolution

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1108 ◽  
Author(s):  
Fengqiang Zhang ◽  
Changhai Li ◽  
Zhenlong Wang ◽  
Jia Zhang ◽  
Yukui Wang
Keyword(s):  
High Resolution ◽  
3D Printing ◽  
Large Scale ◽  
Arbitrary Distribution ◽  
Layer By Layer ◽  
Actual Process ◽  
Complex Objects ◽  
Layer Deposition ◽  
Special Surface ◽  
Multiple Materials

At the core of additive manufacturing (3D printing) is the ability to rapidly print with multiple materials for arbitrary distribution with high resolution, which can remove challenges and limits of traditional assembly and enable us to make increasingly complex objects, especially exciting meta-materials. Here we demonstrate a simple and effective strategy to achieve nano-resolution printing of multiple materials for arbitrary distribution via layer-by-layer deposition on a special deposition surface. The established physical model reveals that complex distribution on a section can be achieved by vertical deformation of simple lamination of multiple materials. The deformation is controlled by a special surface of the mold and a contour-by-contour (instead of point-by-point) printing mode is revealed in the actual process. A large-scale concentric ring array with a minimum feature size below 50 nm is printed within less than two hours, verifying the capacity of high-throughput, high-resolution and rapidity of printing. The proposed printing method opens the way towards the programming of internal compositions of object (such as functional microdevices with multiple materials).

Polyallylamine–montmorillonite as super flame retardant coating assemblies by layer-by layer deposition on polyamide

2013 ◽  
Vol 98 (2) ◽  
pp. 627-634 ◽  
Author(s):  
Kadir Apaydin ◽  
Abdelghani Laachachi ◽  
Vincent Ball ◽  
Maude Jimenez ◽  
Serge Bourbigot ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Layer By Layer ◽  
Layer Deposition

Evolution of Metastable Structures in Bimetallic Catalysts from Microscopy and Machine-Learning Molecular Dynamics

2020 ◽  
Author(s):  
Jin Soo Lim ◽  
Jonathan Vandermause ◽  
Matthijs A. van Spronsen ◽  
Albert Musaelian ◽  
Christopher R. O’Connor ◽  
...  
Keyword(s):  
Machine Learning ◽  
Molecular Dynamics ◽  
Large Scale ◽  
Materials Science ◽  
Complete Characterization ◽  
Layer By Layer ◽  
Surface Restructuring ◽  
Metastable Structures ◽  
Mechanistic Investigation ◽  
Underlying Mechanisms

Restructuring of interface plays a crucial role in materials science and heterogeneous catalysis. Bimetallic systems, in particular, often adopt very different composition and morphology at surfaces compared to the bulk. For the first time, we reveal a detailed atomistic picture of the long-timescale restructuring of Pd deposited on Ag, using microscopy, spectroscopy, and novel simulation methods. Encapsulation of Pd by Ag always precedes layer-by-layer dissolution of Pd, resulting in significant Ag migration out of the surface and extensive vacancy pits. These metastable structures are of vital catalytic importance, as Ag-encapsulated Pd remains much more accessible to reactants than bulk-dissolved Pd. The underlying mechanisms are uncovered by performing fast and large-scale machine-learning molecular dynamics, followed by our newly developed method for complete characterization of atomic surface restructuring events. Our approach is broadly applicable to other multimetallic systems of interest and enables the previously impractical mechanistic investigation of restructuring dynamics.

scholarly journals Mechanically Sustainable Starch-Based Flame-Retardant Coatings on Polyurethane Foams

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1286
Author(s):  
Kyung-Who Choi ◽  
Jun-Woo Kim ◽  
Tae-Soon Kwon ◽  
Seok-Won Kang ◽  
Jung-Il Song ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Coating Layer ◽  
Real Life ◽  
Polyurethane Foams ◽  
Layer By Layer ◽  
Toxic Substances ◽  
Cone Calorimetry ◽  
Coating Agent ◽  
Cone Calorimeter Test

The use of halogen-based materials has been regulated since toxic substances are released during combustion. In this study, polyurethane foam was coated with cationic starch (CS) and montmorillonite (MMT) nano-clay using a spray-assisted layer-by-layer (LbL) assembly to develop an eco-friendly, high-performance flame-retardant coating agent. The thickness of the CS/MMT coating layer was confirmed to have increased uniformly as the layers were stacked. Likewise, a cone calorimetry test confirmed that the heat release rate and total heat release of the coated foam decreased by about 1/2, and a flame test showed improved fire retardancy based on the analysis of combustion speed, flame size, and residues of the LbL-coated foam. More importantly, an additional cone calorimeter test was performed after conducting more than 1000 compressions to assess the durability of the flame-retardant coating layer when applied in real life, confirming the durability of the LbL coating by the lasting flame retardancy.

Control of humping phenomenon and analyzing mechanical properties of Al–Si wire-arc additive manufacturing fabricated samples using cold metal transfer process

2021 ◽  
pp. 095440622199840
Author(s):  
Yashwant Koli ◽  
N Yuvaraj ◽  
Aravindan Sivanandam ◽  
Vipin
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Heat Input ◽  
Large Scale ◽  
High Deposition Rate ◽  
Bead Geometry ◽  
Layer By Layer ◽  
Cold Metal Transfer ◽  
Geometrical Shapes ◽  
Wire Arc Additive Manufacturing

Nowadays, rapid prototyping is an emerging trend that is followed by industries and auto sector on a large scale which produces intricate geometrical shapes for industrial applications. The wire arc additive manufacturing (WAAM) technique produces large scale industrial products which having intricate geometrical shapes, which is fabricated by layer by layer metal deposition. In this paper, the CMT technique is used to fabricate single-walled WAAM samples. CMT has a high deposition rate, lower thermal heat input and high cladding efficiency characteristics. Humping is a common defect encountered in the WAAM method which not only deteriorates the bead geometry/weld aesthetics but also limits the positional capability in the process. Humping defect also plays a vital role in the reduction of hardness and tensile strength of the fabricated WAAM sample. The humping defect can be controlled by using low heat input parameters which ultimately improves the mechanical properties of WAAM samples. Two types of path planning directions namely uni-directional and bi-directional are adopted in this paper. Results show that the optimum WAAM sample can be achieved by adopting a bi-directional strategy and operating with lower heat input process parameters. This avoids both material wastage and humping defect of the fabricated samples.

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