scholarly journals Polymer Nanocomposites for Photocatalytic Degradation and Photoinduced Utilizations of Azo-Dyes

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1215
Author(s):  
Emily Z. Wang ◽  
Yigui Wang ◽  
Dequan Xiao
Keyword(s):  
Polymer Nanocomposites ◽  
Azo Dyes ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Hexagonal Boron Nitride ◽  
Liquid Crystal Display ◽  
Pure Tio2 ◽  
Memory Storage ◽  
Natural Polymers ◽  
Electron Recombination

Specially designed polymer nanocomposites can photo-catalytically degrade azo dyes in wastewater and textile effluents, among which TiO2-based nanocomposites are outstanding and extensively explored. Other nanocomposites based on natural polymers (i.e., chitosan and kaolin) and the oxides of Al, Au, B, Bi, Fe, Li, and Zr are commonly used. These nanocomposites have better photocatalytic efficiency than pure TiO2 through two considerations: (i) reducing the hole/electron recombination rate by stabilizing the excited electron in the conducting band, which can be achieved in TiO2-nanocomposites with graphene, graphene oxide, hexagonal boron nitride (h-BN), metal nanoparticles, or doping; (ii) decreasing the band energy of semiconductors by forming nanocomposites between TiO2 and other oxides or conducting polymers. Increasing the absorbance efficiency by forming special nanocomposites also increases photocatalytic performance. The photo-induced isomerization is exploited in biological systems, such as artificial muscles, and in technical fields such as memory storage and liquid crystal display. Heteroaryl azo dyes show remarkable shifts in photo-induced isomerization, which can be applied in biological and technical fields in place of azo dyes. The self-assembly methods can be employed to synthesize azo-dye polymer nanocomposites via three types of interactions: electrostatic interactions, London forces or dipole/dipole interactions between azo dyes, and photo alignments.

In situ Time-Resolved Small-Angle X-ray Scattering Reveals the Formation Kinetics of Polyelectrolyte Complex Micelles

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Polyelectrolyte Complex ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.

High-Nanofiller-Content Graphene Oxide-Polymer Nanocomposites via Vacuum-Assisted Self-Assembly

2010 ◽  
Vol 20 (19) ◽  
pp. 3322-3329 ◽  
Author(s):  
Karl W. Putz ◽  
Owen C. Compton ◽  
Marc J. Palmeri ◽  
SonBinh T. Nguyen ◽  
L. Catherine Brinson
Keyword(s):  
Graphene Oxide ◽  
Polymer Nanocomposites ◽  
Self Assembly ◽  
Nanofiller Content

Research on the self-assembly of exfoliated perovskite nanosheets (LaNb2O7−) and cobalt porphyrin utilized for the electrocatalytic oxidation of ascorbic acid

RSC Advances ◽  
2016 ◽  
Vol 6 (52) ◽  
pp. 46388-46393 ◽  
Author(s):  
Binbin Pan ◽  
Wenlei Zhao ◽  
Xiaobo Zhang ◽  
Jinpeng Li ◽  
Jiasheng Xu ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Electrocatalytic Oxidation ◽  
Hybrid Film ◽  
The Self ◽  
Cobalt Porphyrin

A sandwich-structured nanocomposite of LaNb2O7/CoTMPyP was fabricated via electrostatic interactions between LaNb2O7− nanosheets and cobalt porphyrin cations, and the obtained hybrid film exhibited excellent electrocatalytic activities toward AA.

scholarly journals Evaporation-driven self-assembly of binary and ternary colloidal polymer nanocomposites for abrasion resistant applications

2021 ◽  
Vol 581 ◽  
pp. 729-740
Author(s):  
James D. Tinkler ◽  
Alberto Scacchi ◽  
Harsh R. Kothari ◽  
Hanna Tulliver ◽  
Maialen Argaiz ◽  
...  
Keyword(s):  
Polymer Nanocomposites ◽  
Self Assembly

scholarly journals Ethylene glycol assisted three-dimensional floral evolution of BiFeO 3 -based nanostructures with effective magneto-electric response

2020 ◽  
Vol 7 (8) ◽  
pp. 200642
Author(s):  
Syed Kumail Abbas ◽  
Ghulam M. Mustafa ◽  
Murtaza Saleem ◽  
Muhammad Sufyan ◽  
Saira Riaz ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Self Assembly ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Functional Materials ◽  
Bias Field ◽  
Memory Storage ◽  
High Coercivity ◽  
Electric Response ◽  
Ferromagnetic Behaviour

Controlled growth of nanostructures plays a vital role in tuning the physical and chemical properties of functional materials for advanced energy and memory storage devices. Herein, we synthesized hierarchical micro-sized flowers, built by the self-assembly of highly crystalline, two-dimensional nanoplates of Co- and Ni-doped BiFeO 3 , using a simple ethylene glycol-mediated solvothermal method. Pure BiFeO 3 attained scattered one-dimensional nanorods-type morphology having diameter nearly 60 nm. Co-doping of Co and Ni at Fe-site in BiFeO 3 does not destabilize the morphology; rather it generates three-dimensional floral patterns of self-assembled nanoplates. Unsaturated polarization loops obtained for BiFeO 3 confirmed the leakage behaviour of these rhombohedrally distorted cubic perovskites. These loops were then used to determine the energy density of the BiFeO 3 perovskites. Enhanced ferromagnetic behaviour with high coercivity and remanence was observed for these nanoplates. A detailed discussion about the origin of ferromagnetic behaviour based on Goodenough–Kanamori's rule is also a part of this paper. Impedance spectroscopy revealed a true Warburg capacitive behaviour of the synthesized nanoplates. High magneto-electric (ME) coefficient of 27 mV cm −1 Oe −1 at a bias field of −0.2 Oe was observed which confirmed the existence of ME coupling in these nanoplates.

scholarly journals Nanocoatings of Bovine Serum Albumin on Glass: Effects of pH and Temperature

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Sergio-Miguel Acuña-Nelson ◽  
José-Miguel Bastías-Montes ◽  
Fabiola-Rossana Cerda-Leal ◽  
Julio-Enrique Parra-Flores ◽  
Juan-Salvador Aguirre-García ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Self Assembly ◽  
Glass Surface ◽  
Bovine Serum ◽  
Electrostatic Interactions ◽  
Dynamic Contact ◽  
Dlvo Theory ◽  
Contact Angles ◽  
Protein Size

Protein adsorption is influenced by many factors such as temperature, pH, protein size and structure, or surface energy and roughness, among others. Self-assembled monolayers (SAMs) and the Langmuir-Blodgett (LB) technique are two of the techniques more used to produces ultrathin films of proteins on surfaces. In this work, we established protocols for the preparation of nanocoatings of bovine serum albumin (BSA) protein on glass surface using SAMs and LB. Furthermore, we determined how small changes in temperature and pH can affect the covering when SAMs are used. Using a combination of different analyses, such as relative roughness, dynamic contact angles, and atomic force microscopy (AFM), it was possible to establish conditions to obtain a uniform nanocoating using SAMs. The results of the analysis of the nanocoating performed using the LB technique were very similar to those obtained using SAMs. The Derjaguin–Landau–Verwey–Overbeek (DLVO) theory in conjunction with the AFM images showed that electrostatic interactions are very important in the self-assembly process, but a process dominated solely by attraction is not sufficient to achieve a good SAM nanocoating, since it does not allow proper orientation and packaging of BSA molecules on the glass surface.

scholarly journals Nanohydrogels Based on Self-Assembly of Cationic Pullulan and Anionic Dextran Derivatives for Efficient Delivery of Piroxicam

Pharmaceutics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 622 ◽  
Author(s):  
Dorota Lachowicz ◽  
Przemyslaw Mielczarek ◽  
Roma Wirecka ◽  
Katarzyna Berent ◽  
Anna Karewicz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Dextran Sulfate ◽  
Force Microscopy ◽  
Grafting Reaction ◽  
Atomic Force ◽  
Transmission Electron ◽  
Efficient Delivery ◽  
Model Drug

A cationic derivative of pullulan was obtained by grafting reaction and used together with dextran sulfate to form polysaccharide-based nanohydrogel cross-linked via electrostatic interactions between polyions. Due to the polycation-polyanion interactions nanohydrogel particles were formed instantly and spontaneously in water. The nanoparticles were colloidally stable and their size and surface charge could be controlled by the polycation/polyanion ratio. The morphology of the obtained particles was visualized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The resulting structures were spherical, with hydrodynamic diameters in the range of 100–150 nm. The binding constant (Ka) of a model drug, piroxicam, to the cationic pullulan (C-PUL) was determined by spectrophotometric measurements. The value of Ka was calculated according to the Benesi—Hildebrand equation to be (3.6 ± 0.2) × 103 M−1. After binding to cationic pullulan, piroxicam was effectively entrapped inside the nanohydrogel particles and released in a controlled way. The obtained system was efficiently taken up by cells and was shown to be biocompatible.

scholarly journals Controlling the Self-Assembly of Biomolecules into Functional Nanomaterials through Internal Interactions and External Stimulations: A Review

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 285 ◽  
Author(s):  
Li Wang ◽  
Coucong Gong ◽  
Xinzhu Yuan ◽  
Gang Wei
Keyword(s):  
Self Assembly ◽  
Electrostatic Interactions ◽  
Materials Science ◽  
Hydrophobic Interactions ◽  
The Self ◽  
Functional Nanomaterials ◽  
Light Stimulation ◽  
Dna Base ◽  
Wide Range ◽  
Structure And Functions

Biomolecular self-assembly provides a facile way to synthesize functional nanomaterials. Due to the unique structure and functions of biomolecules, the created biological nanomaterials via biomolecular self-assembly have a wide range of applications, from materials science to biomedical engineering, tissue engineering, nanotechnology, and analytical science. In this review, we present recent advances in the synthesis of biological nanomaterials by controlling the biomolecular self-assembly from adjusting internal interactions and external stimulations. The self-assembly mechanisms of biomolecules (DNA, protein, peptide, virus, enzyme, metabolites, lipid, cholesterol, and others) related to various internal interactions, including hydrogen bonds, electrostatic interactions, hydrophobic interactions, π–π stacking, DNA base pairing, and ligand–receptor binding, are discussed by analyzing some recent studies. In addition, some strategies for promoting biomolecular self-assembly via external stimulations, such as adjusting the solution conditions (pH, temperature, ionic strength), adding organics, nanoparticles, or enzymes, and applying external light stimulation to the self-assembly systems, are demonstrated. We hope that this overview will be helpful for readers to understand the self-assembly mechanisms and strategies of biomolecules and to design and develop new biological nanostructures or nanomaterials for desired applications.

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