scholarly journals Synthesis and Self-Assembly of Gold Nanoparticles by Chemically Modified Polyol Methods under Experimental Control

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Nguyen Viet Long ◽  
Michitaka Ohtaki ◽  
Masayoshi Yuasa ◽  
Satoshi Yoshida ◽  
Taiga Kuragaki ◽  
...  
Keyword(s):  
Self Assembly ◽  
Au Nanoparticles ◽  
Collective Oscillation ◽  
Synthesis Time ◽  
Chemical Mechanisms ◽  
Chemically Modified ◽  
Valence Electrons ◽  
Surface Electrons ◽  
General Physical ◽  
Physical And Chemical

In our present research, bottom-up self-assembly of gold (Au) nanoparticles on a flat copper (Cu) substrate is performed by a facile method. The very interesting evidence of self-assembly of Au nanoparticles on the top of the thin assembled layer was observed by scanning electron microscopy (SEM). We had discovered one of the most general and simple methods for the self-assembly of metal nanoparticles. The general physical and chemical mechanisms of the evaporation process of the solvents can be used for self-assembly of the as-prepared nanoparticles. The important roles of molecules of the used solvents are very critical to self-assembly of the as-prepared Au nanoparticles in the case without using any polymers for those processes. It is clear that self-assembly of such one nanosystem of the uniform Au nanoparticles is fully examined. Finally, an exciting surface plasmon resonance (SPR) phenomenon of the pure Au nanoparticles in the solvent was fully discovered in their exciting changes of the narrow and large SPR bands according to synthesis time. The SPR was considered as the collective oscillation of valence electrons of the surfaces of the pure Au nanoparticles in the solvent by incident ultraviolet-visible light. Then, the frequency of light photons matches the frequency of the oscillation of surface electrons of the Au nanoparticles that are excited.

One-step deposition of Au nanoparticles onto chemically modified ceramic hollow spheres via self-assembly

2012 ◽  
Vol 7 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Shakiela Begum ◽  
Ian P. Jones ◽  
Daniel E. Lynch ◽  
Jon A. Preece
Keyword(s):  
Self Assembly ◽  
Au Nanoparticles ◽  
Hollow Spheres ◽  
Chemically Modified ◽  
One Step

scholarly journals Information capacity of specific interactions

2016 ◽  
Vol 113 (21) ◽  
pp. 5841-5846 ◽  
Author(s):  
Miriam H. Huntley ◽  
Arvind Murugan ◽  
Michael P. Brenner
Keyword(s):  
Self Assembly ◽  
Physical Parameters ◽  
Specific Interactions ◽  
Color Coding ◽  
Chemical Mechanisms ◽  
Experimental Systems ◽  
Shape Coding ◽  
Target Binding ◽  
Strongly Sublinear ◽  
Physical And Chemical

Specific interactions are a hallmark feature of self-assembly and signal-processing systems in both synthetic and biological settings. Specificity between components may arise from a wide variety of physical and chemical mechanisms in diverse contexts, from DNA hybridization to shape-sensitive depletion interactions. Despite this diversity, all systems that rely on interaction specificity operate under the constraint that increasing the number of distinct components inevitably increases off-target binding. Here we introduce “capacity,” the maximal information encodable using specific interactions, to compare specificity across diverse experimental systems and to compute how specificity changes with physical parameters. Using this framework, we find that “shape” coding of interactions has higher capacity than chemical (“color”) coding because the strength of off-target binding is strongly sublinear in binding-site size for shapes while being linear for colors. We also find that different specificity mechanisms, such as shape and color, can be combined in a synergistic manner, giving a capacity greater than the sum of the parts.

scholarly journals Changes in Optical Properties upon Dye–Clay Interaction: Experimental Evaluation and Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Giorgia Giovannini ◽  
René M. Rossi ◽  
Luciano F. Boesel
Keyword(s):  
Optical Properties ◽  
Hybrid Materials ◽  
High Performance ◽  
Fluorescent Properties ◽  
Chemical Mechanisms ◽  
Strong Electrostatic Interaction ◽  
Potential Applications ◽  
Photochemical Properties ◽  
Physical And Chemical ◽  
The Relationship

The development of hybrid materials with unique optical properties has been a challenge for the creation of high-performance composites. The improved photophysical and photochemical properties observed when fluorophores interact with clay minerals, as well as the accessibility and easy handling of such natural materials, make these nanocomposites attractive for designing novel optical hybrid materials. Here, we present a method of promoting this interaction by conjugating dyes with chitosan. The fluorescent properties of conjugated dye–montmorillonite (MMT) hybrids were similar to those of free dye–MMT hybrids. Moreover, we analyzed the relationship between the changes in optical properties of the dye interacting with clay and its structure and defined the physical and chemical mechanisms that take place upon dye–MMT interactions leading to the optical changes. Conjugation to chitosan additionally ensures stable adsorption on clay nanoplatelets due to the strong electrostatic interaction between chitosan and clay. This work thus provides a method to facilitate the design of solid-state hybrid nanomaterials relevant for potential applications in bioimaging, sensing and optical purposes.

The Varied Causes of Color in Glass

1985 ◽  
Vol 61 ◽  
Author(s):  
K. Nassau
Keyword(s):  
Chalcogenide Glasses ◽  
Water Ligand ◽  
Ligand Field ◽  
Energy Bands ◽  
Metal Compounds ◽  
Chemical Mechanisms ◽  
Doped Glasses ◽  
Blue Eyes ◽  
Physical And Chemical ◽  
Ice Water

ABSTRACTAll but two of the fifteen physical and chemical mechanisms which are necessary to explain all the varied causes of color apply in one way or another to glass. These fifteen causes of color derive from a variety of physical and chemical mechanisms and are summarized in five groups with concentration on those mechanisms that apply to glass and the related glazes and enamels. Vibrations and simple excitations explain the colors of incandescence (e.g. flames, hot glass), gas excitations (neon tube, aurora), and vibrations and rotations (blue ice, water, glasses based on water). Ligand field effect colors are seen in transition metal compounds (turquoise, chrome oxide green, glasses based on copper sulfate) and impurities (ruby, emerald, many doped glasses). Molecular orbitals explain the colors of organic compounds (indigo, chlorophyll, organic glasses) and charge transfer compounds (blue sapphire, lapis lazuli, “beer-bottle” brown and chromate glasses). Energy bands are involved in the colors of metals and alloys (gold, brass, glassy metals), of semiconductors (cadmium yellow, vermillion, chalcogenide glasses), doped semiconductors (blue and yellow diamond), and color centers (amethyst, topaz, irradiated glass). Geometrical and physical optics are involved in the colors derived from dispersive refraction (rainbow, green flash, glass prism spectrum), scattering (blue sky, blue eyes, red sunset, ruby gold and opal glasses), interference (soap bubbles, iridescent beetles, cracks in glasses, interference filters), and diffraction (the corona aureole, diffraction grating spectrum).

scholarly journals Polymeric Drug Delivery System Based on Pluronics for Cancer Treatment

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3610
Author(s):  
Jialin Yu ◽  
Huayu Qiu ◽  
Shouchun Yin ◽  
Hebin Wang ◽  
Yang Li
Keyword(s):  
Drug Delivery ◽  
Self Assembly ◽  
Drug Delivery Systems ◽  
Tumor Therapy ◽  
Chemical Properties ◽  
Drug Carriers ◽  
Disease Diagnosis ◽  
Delivery Systems ◽  
Polymeric Drug Delivery ◽  
Physical And Chemical

Pluronic polymers (pluronics) are a unique class of synthetic triblock copolymers containing hydrophobic polypropylene oxide (PPO) and hydrophilic polyethylene oxide (PEO) arranged in the PEO-PPO-PEO manner. Due to their excellent biocompatibility and amphiphilic properties, pluronics are an ideal and promising biological material, which is widely used in drug delivery, disease diagnosis, and treatment, among other applications. Through self-assembly or in combination with other materials, pluronics can form nano carriers with different morphologies, representing a kind of multifunctional pharmaceutical excipients. In recent years, the utilization of pluronic-based multi-functional drug carriers in tumor treatment has become widespread, and various responsive drug carriers are designed according to the characteristics of the tumor microenvironment, resulting in major progress in tumor therapy. This review introduces the specific role of pluronic-based polymer drug delivery systems in tumor therapy, focusing on their physical and chemical properties as well as the design aspects of pluronic polymers. Finally, using newer literature reports, this review provides insights into the future potential and challenges posed by different pluronic-based polymer drug delivery systems in tumor therapy.

scholarly journals Formation of Au-Silane Bonds

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Shira Yochelis ◽  
Eran Katzir ◽  
Yoav Kalcheim ◽  
Vitaly Gutkin ◽  
Oded Millo ◽  
...  
Keyword(s):  
Molecular Electronics ◽  
Self Assembly ◽  
Au Nanoparticles ◽  
Electrical Coupling ◽  
Gold Surface ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Fundamental Study ◽  
Covalent Bonds ◽  
Anchoring Groups

Many intriguing aspects of molecular electronics are attributed to organic-inorganic interactions, yet charge transfer through such junctions still requires fundamental study. Recently, there is a growing interest in anchoring groups, which considered dominating the charge transport. With this respect, we choose to investigate self-assembly of disilane molecules sandwiched between gold surface and gold nanoparticles. These assemblies are found to exhibit covalent bonds not only between the anchoring Si groups and the gold surfaces but also in plane crosslinks that increase the monolayer stability. Finally, using scanning tunneling spectroscopy we demonstrate that the disilane molecules provide strong electrical coupling between the Au nanoparticles and a superconductor substrate.

Kinetic theory of protein filament growth: Self-consistent methods and perturbative techniques

2014 ◽  
Vol 29 (02) ◽  
pp. 1530002 ◽  
Author(s):  
Thomas C. T. Michaels ◽  
Tuomas P. J. Knowles
Keyword(s):  
Self Assembly ◽  
Protein Structures ◽  
Filamentous Growth ◽  
Molecular Structures ◽  
The Self ◽  
Rate Equations ◽  
Disease States ◽  
Self Consistent ◽  
Monomeric Proteins ◽  
General Physical

Filamentous protein structures are of high relevance for the normal functioning of the cell, where they provide the structural component for the cytoskeleton, but are also implicated in the pathogenesis of many disease states. The self-assembly of these supra-molecular structures from monomeric proteins has been studied extensively in the past 50 years and much interest has focused on elucidating the microscopic events that drive linear growth phenomena in a biological setting. Master equations have proven to be particularly fruitful in this context, allowing specific assembly mechanisms to be linked directly to experimental observations of filamentous growth. Recently, these approaches have increasingly been applied to aberrant protein polymerization, elucidating potential implications for controlling or combating the formation of pathological filamentous structures. This article reviews recent theoretical advances in the field of filamentous growth phenomena through the use of the master-equation formalism. We use perturbation and self-consistent methods for obtaining analytical solutions to the rate equations describing fibrillar growth and show how the resulting closed-form expressions can be used to shed light on the general physical laws underlying this complex phenomenon. We also present a connection between the underlying ideas of the self-consistent analysis of filamentous growth and the perturbative renormalization group.

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