scholarly journals Layer-by-Layer Assembly of Electroactive Dye/LDHs Nanoplatelet Matrix Film for Advanced Dual Electro-optical Sensing Applications

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Sepehr Lajevardi Esfahani ◽  
Shohre Rouhani ◽  
Zahra Ranjbar
Keyword(s):  
Solid State ◽  
Molecular Design ◽  
High Sensitivity ◽  
Optical Methods ◽  
Detection Methods ◽  
Layer By Layer ◽  
Alizarin Red ◽  
Sensing Applications ◽  
Lbl Assembly ◽  
Assembly Technique

Abstract It proved that the most destructive effects of the toxic Al3+ ion on the human nervous system and disease that are involved with this system, such as Alzheimer's. The development of solid-state electrodes is still in its infancy during the sensor-based detection methods for Al3+. Hence, in this study, a novel flexible ITO/PET-based electrochemical solid-state sensor was designed and constructed. Modification of the surface of electrode bedding was done by layer-by-layer (LbL) assembly of Mg–Al LDH. nanoplatelets along with alizarin red S (ARS) in an interconnected matrix film. In the molecular design of sensing base of the electrode, the electroactive organic units (ARS molecules) present in the ITO/PET-layered (ARS/LDHs)n matrix are involved in electrochemical reactions when exposed to the target molecule (Al3+ ion), so the electrochemical changes of the new formed Al-chelated system are detectable. This type of sensor is used for sensitive and selective detection of Al3+. The minimum sheet resistance, morphology and high electrocatalytic activity of the modified matrix film are obtained in the fifth cycle of LbL assembly technique. In this electrochemical sensor, both electrochemical and optical methods were detected with high sensitivity and selectivity of Al3+, so that in a cyclic voltammetry electrochemical method, the lower detection limit of 10.1 nM with a linear range of [0.2–120 μM] was obtained compared to the fluorescence-based optical method.

scholarly journals Encapsulation of Phase Change Materials Using Layer-by-Layer Assembled Polyelectrolytes

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Qiangying Yi ◽  
Gleb B. Sukhorokov ◽  
Jin Ma ◽  
Xiaobo Yang ◽  
Zhongwei Gu
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Low Cost ◽  
Sodium Dodecyl ◽  
Layer By Layer ◽  
Latent Heat Storage ◽  
Good Thermal Stability ◽  
Lbl Assembly ◽  
Acid Sodium Salt ◽  
Assembly Technique

Phase change materials absorb the thermal energy when changing their phases (e.g., solid-to-liquid) at constant temperatures to achieve the latent heat storage. The major drawbacks such as limited thermal conductivity and leakage prevent the PCMs from wide application in desired areas. In this work, an environmentally friendly and low cost approach, layer-by-layer (LbL) assembly technique, was applied to build up ultrathin shells to encapsulate the PCMs and therefore to regulate their changes in volume when the phase change occurs. Generally, the oppositely charged strong polyelectrolytes Poly(diallyldimethylammonium chloride) (PDADMAC) and Poly(4-styrenesulfonic acid) sodium salt (PSS) were employed to fabricate multilayer shells on emulsified octadecane droplets using either bovine serum albumin (BSA) or sodium dodecyl sulfate (SDS) as surfactant. Specifically, using BSA as the surfactant, polyelectrolyte encapsulated octadecane spheres in size of ∼500 nm were obtained, with good shell integrity, high octadecane content (91.3% by mass), and good thermal stability after cycles of thermal treatments.

Electric-field induced layer-by-layer assembly technique with single component for construction of conjugated polymer films

RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58499-58503 ◽  
Author(s):  
Shiwei Wang ◽  
Zhuo Chen ◽  
Ahmad Umar ◽  
Yao Wang ◽  
Peng-gang Yin
Keyword(s):  
Electric Field ◽  
Conjugated Polymer ◽  
Multilayer Films ◽  
Single Component ◽  
Layer By Layer ◽  
Lbl Assembly ◽  
Layer By Layer Assembly ◽  
Universal Approach ◽  
Assembly Technique ◽  
Layer Assembly

Single component was used to construct conjugated polymer multilayer films by electric-field induced layer-by-layer assembly technique, which provides a universal approach for CPs and broadens the applicable scope of LBL assembly technique.

Dye aggregation in layer-by-layer dyeing of cotton fabrics

RSC Advances ◽  
2016 ◽  
Vol 6 (24) ◽  
pp. 20286-20293 ◽  
Author(s):  
Farzana Khan ◽  
Panpan Liu ◽  
Fujun Xu ◽  
Ying Ma ◽  
Yiping Qiu
Keyword(s):  
Cotton Fabrics ◽  
Layer By Layer ◽  
Lbl Assembly ◽  
Dye Aggregation ◽  
Assembly Technique

This work utilizes layer-by-layer (LbL) assembly technique to dye cotton fabrics and investigates the dye aggregation in these polymer matrixes.

Intumescent flame retardant finishing of polyester fabrics via the layer-by-layer assembly technique

2017 ◽  
Vol 29 (1) ◽  
pp. 96-105 ◽  
Author(s):  
Warunee Wattanatanom ◽  
Sireerat Churuchinda ◽  
Pranut Potiyaraj
Keyword(s):  
Thermal Properties ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Intumescent Flame Retardant ◽  
Layer By Layer ◽  
Polyester Fabrics ◽  
Content Type ◽  
Lbl Assembly ◽  
Assembly Technique ◽  
Coated Fabrics

Purpose The purpose of this paper is to investigate the potential use of the layer-by-layer (LbL) assembly as an intumescent flame retardant for polyester, cotton and their blended fabrics. Design/methodology/approach In this study, polyester (PET), cotton and their blends were applied with the flame retardant coating via the LbL assembly technique. The flame retardancy, melt dripping, thermal properties and morphology of coated polyester fabrics were then examined. Findings The scanning electron micrograph of uncoated and coated fabrics revealed that the LbL assembly coating on the fabric surface was successful. The assessment of the flame retardancy and thermal properties of the coated fabrics showed that the after-flame time and melt dripping during the vertical burning test decreased. The char residue at temperatures ranging from 450 to 800°C during thermogravimetric analysis was enhanced as compared with the uncoated fabric. Furthermore, the morphology of the char residual of coated fabrics was rougher and bulkier than the uncoated fabrics, suggesting the typical behavior of intumescence. Social implications The LbL technique generally uses much fewer chemicals, thus making this flame retardant finishing much more environmentally friendly. It is also expected that these fabrics will show better touch characteristics. These fabrics may be tested for their comfort compared to that of conventional coating to enable their use on an industrial scale. Originality/value This work demonstrated the ability to apply an effective intumescent coating on polyester, cotton and blend fabric. In order to maintain fabric handle property, the Lbl coating technique is also employed.

Assembly of neutral conjugated polymers with layered double hydroxide nanosheets by the layer-by-layer method

RSC Advances ◽  
2016 ◽  
Vol 6 (97) ◽  
pp. 94739-94747 ◽  
Author(s):  
Ping Zhang ◽  
Hailong Li ◽  
Jingjing Shi ◽  
Jun Lu
Keyword(s):  
Conjugated Polymers ◽  
Layered Double Hydroxide ◽  
Ultrathin Films ◽  
Layer By Layer ◽  
Organic Hybrid ◽  
Lbl Assembly ◽  
Layer Method ◽  
Assembly Technique ◽  
Double Hydroxide

This article reports that the neutral conjugated polymers (NCPs) can also be assembled with exfoliated MgAl-layered double hydroxide (LDH) nanosheets to form the ordered inorganic/organic hybrid ultrathin films via the LbL assembly technique.

Stabilization of starch-based microgel-lysozyme complexes using a layer-by-layer assembly technique

2017 ◽  
Vol 214 ◽  
pp. 213-217 ◽  
Author(s):  
Bao Zhang ◽  
Yi Pan ◽  
Hanqing Chen ◽  
Tengfei Liu ◽  
Han Tao ◽  
...  
Keyword(s):  
Layer By Layer ◽  
Layer By Layer Assembly ◽  
Assembly Technique ◽  
Layer Assembly

scholarly journals Electrical Field-Assisted Gene Delivery from Polyelectrolyte Multilayers

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 133
Author(s):  
Yu-Che Cheng ◽  
Shu-Lin Guo ◽  
Kun-Da Chung ◽  
Wei-Wen Hu
Keyword(s):  
Gene Delivery ◽  
Electric Field ◽  
Treatment Time ◽  
Transfection Efficiency ◽  
Polyelectrolyte Multilayers ◽  
Aqueous Environment ◽  
Layer By Layer ◽  
Electrical Field ◽  
Lbl Assembly ◽  
Electric Field Treatment

To sustain gene delivery and elongate transgene expression, plasmid DNA and cationic nonviral vectors can be deposited through layer-by-layer (LbL) assembly to form polyelectrolyte multilayers (PEMs). Although these macromolecules can be released for transfection purposes, their entanglement only allows partial delivery. Therefore, how to efficiently deliver immobilized genes from PEMs remains a challenge. In this study, we attempt to facilitate their delivery through the pretreatment of the external electrical field. Multilayers of polyethylenimine (PEI) and DNA were deposited onto conductive polypyrrole (PPy), which were placed in an aqueous environment to examine their release after electric field pretreatment. Only the electric field perpendicular to the substrate with constant voltage efficiently promoted the release of PEI and DNA from PEMs, and the higher potential resulted in the more releases which were enhanced with treatment time. The roughness of PEMs also increased after electric field treatment because the electrical field not only caused electrophoresis of polyelectrolytes and but also allowed electrochemical reaction on the PPy electrode. Finally, the released DNA and PEI were used for transfection. Polyplexes were successfully formed after electric field treatment, and the transfection efficiency was also improved, suggesting that this electric field pretreatment effectively assists gene delivery from PEMs and should be beneficial to regenerative medicine application.

scholarly journals Spatially Ordered Matrix of Nanostructured Tin–Tungsten Oxides Nanocomposites Formed by Ionic Layer Deposition for Gas Sensing

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4169
Author(s):  
Gennady Gorokh ◽  
Natalia Bogomazova ◽  
Abdelhafed Taleb ◽  
Valery Zhylinski ◽  
Timur Galkovsky ◽  
...  
Keyword(s):  
Tungsten Oxide ◽  
Gas Sensing ◽  
Oxide Films ◽  
High Sensitivity ◽  
Anodic Alumina ◽  
Film Deposition ◽  
Silicon Substrates ◽  
Layer By Layer ◽  
Gas Sensitivity ◽  
Nanoporous Anodic Alumina

The process of layer-by-layer ionic deposition of tin-tungsten oxide films on smooth silicon substrates and nanoporous anodic alumina matrices has been studied. To achieve the film deposition, solutions containing cationic SnF2 or SnCl2 and anionic Na2WO4 or (NH4)2O·WO3 precursors have been used. The effect of the solution compositions on the films deposition rates, morphology, composition, and properties was investigated. Possible mechanisms of tin-tungsten oxide films deposition into the pores and on the surface of anodic alumina are discussed. The electro-physical and gas-sensitive properties of nanostructured SnxWyOz films have been investigated. The prepared nanocomposites exhibit stable semiconductor properties characterized by high resistance and low temperature coefficient of electrical resistance of about 1.6 × 10−3 K−1. The sensitivity of the SnxWyOz films to 2 and 10 ppm concentrations of ammonia at 523 K was 0.35 and 1.17, respectively. At concentrations of 1 and 2 ppm of nitrogen dioxide, the sensitivity was 0.48 and 1.4, respectively, at a temperature of 473 K. At the temperature of 573 K, the sensitivity of 1.3 was obtained for 100 ppm of ethanol. The prepared nanostructured tin-tungsten oxide films showed promising gas-sensitivity, which makes them a good candidate for the manufacturing of gas sensors with high sensitivity and low power consumption.

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