scholarly journals Growth of Nacre Biocrystals by Self-Assembly of Aragonite Nanoparticles with Novel Subhedral Morphology

Crystals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 3
Author(s):  
Ruohe Gao ◽  
Rize Wang ◽  
Xin Feng ◽  
Gangsheng Zhang
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
The Self ◽  
Growth Stages ◽  
Research Model ◽  
Biomimetic Materials ◽  
Transmission Electron ◽  
Nanoparticle Morphology ◽  
Different Growth Stages ◽  
Scanning Electron

Nacre has long served as a research model in the field of biomineralization and biomimetic materials. It is widely accepted that its basic components, aragonite biocrystals, namely, tablets, are formed by the nanoparticle-attachment pathway. However, the details of the nanoparticle morphology and arrangement in the tablets are still a matter of debate. Here, using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), we observed the nanostructure of the growing tablets at different growth stages and found that: (1) the first detectable tablet looked like a rod; (2) tablets consisted of subhedral nanoparticles (i.e., partly bounded by crystal facets and partly by irregular non-crystal facets) that were made of aragonite single crystals with a width of 160–180 nm; and (3) these nanoparticles were ordered in orientation but disordered in position, resulting in unique subhedral and jigsaw-like patterns from the top and side views, respectively. In short, we directly observed the growth of nacre biocrystals by the self-assembly of aragonite nanoparticles with a novel subhedral morphology.

Fabrication of Nanosheets and Micro-Spheres from the Self-Assembly and Polymerization of N-Octadecyltrichlorosilane

2011 ◽  
Vol 311-313 ◽  
pp. 485-488 ◽  
Author(s):  
Shuai Zhang ◽  
Qing Ping Ke ◽  
Lei Zhang ◽  
Tian Di Tang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Self Assembly ◽  
Micelle Formation ◽  
The Self ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hydrolysis Process ◽  
Scanning Electron

Formation of layered nanosheets and micro-spheres from a simple self-assembly and polycondensation of n-octadecylsilane (PODS) in water and toluene is demonstrated, respectively. The structure of the micro-spheres was characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD). According to the TEM images, it was firstly confirmed that the micro-spheres consist of stacks of bilayered polymerized n-octadecylsilane with head-to-head arrangements. The co-effects of water and solvent were proposed to control the octadecyltrichlsilane hydrolysis process and eventually the morphology of the micro-spheres. A micelle formation mechanism for the formation of the PODS micro-spheres under the co-effects of water and solvent were firstly proposed.

Click Synthesis of Shape-Persistent Azodendrimers and their Orthogonal Self-Assembly to Nanofibres

2018 ◽  
Vol 71 (6) ◽  
pp. 463 ◽  
Author(s):  
Tamer El Malah ◽  
Hany F. Nour
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Self Assembly ◽  
Molecular Structures ◽  
Side Chain ◽  
Spectroscopic Techniques ◽  
Molecular Weights ◽  
Transmission Electron ◽  
Click Synthesis ◽  
Scanning Electron

The copper(i)-catalyzed azide–alkyne cycloaddition (CuAAC) reaction has been efficiently utilized to synthesize a series of dendrons with amino functionalities. The aminodendrons successfully underwent azodimerization to furnish a series of pyridyl- and phenyl-based azodendrimers with peripheral alkyl or ether side chain substituents. The molecular structures of the azodendrimers were fully assigned using different spectroscopic techniques, such as 1H NMR and 13C NMR, and the molecular weights were determined using MALDI-TOF mass spectrometry. The molecular self-assembly of the azodendrimers was investigated by scanning electron microscopy and transmission electron microscopy, which revealed the formation of highly ordered and uniform self-assembled nanofibres.

Controlled Growth and Self-Assembly of CaCO3 Superstructures between the Organic-Water Interfaces

2010 ◽  
Vol 434-435 ◽  
pp. 597-600
Author(s):  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
Li Xing ◽  
Bo Song ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Carbonate ◽  
Self Assembly ◽  
Crystallization Behavior ◽  
Gas Diffusion ◽  
The Self ◽  
Assembly Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

In this paper, the crystallization behavior of calcium carbonate between the organic-water interfaces using a slow gas-diffusion procedure is studied. The organic-water interfaces can control the crystallization of calcium carbonate to form a flower-shaped superstructure. The precipitates of calcium carbonate were identified by X-ray diffraction (XRD) and scanning electron microscopy (SEM). A possible mechanism about the self-assembly process of CaCO3 crystals has been analyzed. It is found that the morphology of CaCO3 superstructure depends on the properties of organic solvent. This paper also presents the influence of surfactant monolayer, between the biphase interfaces, on the CaCO3 superstructure. This study suggests that it is possible to control morphogenesis of calcium carbonate by a combination of a surfactant monolayer with the organic-water interfaces.

scholarly journals Micromorphology of the epidermis of the floral nectary of Rhododendron japonicum (A. Gray) J. V. Suringar ex E.H. Wilson.

2012 ◽  
Vol 60 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Mirosława Chwil
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Growth Stages ◽  
Mosaic Pattern ◽  
Floral Nectary ◽  
Half Height ◽  
Floral Nectaries ◽  
Small Clusters ◽  
Different Growth Stages ◽  
Scanning Electron

The conducted study related to the structure of the floral nectaries of <i>Rhododendron japonicum</i> (A. Gray) J. V. Suringar ex E. H. Wilson. The structure of the secretory epidermis of the nectaries was analysed by using scanning electron microscopy (SEM). <i>Rhododendron japonicum</i> develops the superior pistil with a 5-loculed ovary equipped in five ribs. The nectary gland is located in the lower part of the ovary. In the nectary regions located on the extension of the ribs of the ovary, stomata were very numerous. In the upper part of the nectary, stomata were arranged individually or in small clusters, whereas at its half- -height they formed stomatal areas. The stomata were at different growth stages. They were arranged in different directions. The stomata developed on the nectary surface according to the mosaic pattern. The stomata from the lower situated part of the nectary had a different structure than those occurring in the upper half of the nectary. The stomata in the nectaries of <i>Rh. japonicum</i> belong to the actinocytic type. The cuticle layer in the upper part of the nectary was better developed and had a characteristic sculpture, whereas in the lower part it was smooth.

Self-Assembled Alcohol Sensor of In2O3 Nanorods

2013 ◽  
Vol 834-836 ◽  
pp. 46-49
Author(s):  
Zhao Qiang Zheng ◽  
Huan Yu Wu ◽  
Bing Wang
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Thermal Evaporation ◽  
Alcohol Concentration ◽  
Sensor Response ◽  
The Self ◽  
Excellent Performance ◽  
Transmission Electron ◽  
Alcohol Sensor ◽  
Prepared Nanorods

In2O3nanorods have been fabricated on Cr comb-shaped interdigitating electrodes using thermal evaporation of the mixed powders of In2O3and active carbon with Au catalysts. The morphology and structure of the prepared nanorods are determined on the basis of field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The self-assembly grown sensors of In2O3nanorods have excellent performance in sensor response to alcohol concentration of 500 ppm under operated temperature of 300°C.

Self-Assembly of Amphiphilic Graft Copolymer with Poly(acrylic Acid) Backbone and N-Octylphenyl Poly(oxyethylene) Side Chains in Water

2011 ◽  
Vol 233-235 ◽  
pp. 2138-2144 ◽  
Author(s):  
Fang Ping Wang ◽  
Xin Zhen Du ◽  
Hu Po Mu ◽  
Dong Xia Zhang ◽  
Yun Jun Ma
Keyword(s):  
Electron Microscopy ◽  
Graft Copolymer ◽  
Self Assembly ◽  
Inorganic Salt ◽  
The Self ◽  
Fluorescence Technique ◽  
Preparation Methods ◽  
Amphiphilic Graft Copolymer ◽  
Ph Values ◽  
Transmission Electron

The self-assembly of the amphiphilic graft copolymer AA-C8PhEO10Ac in water was investigated by fluorescence technique using 8-anilino-1-naphthalene sulfonate(ANS) as a probe and transmission electron microscopy (TEM), the effects of inorganic salt , copolymer concentration and pH on the micellar size and structures of AA-C8PhEO10Ac were discussed. It was found that the micelle morphologies and sizes were related with the micellar preparation methods. The sizes of micelles increased with the addition of NaCl and decreased at high pH values.

scholarly journals Self-Assembly of Diphenylalanine-Based Nanostructures in Water and Electrolyte Solutions

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Sergio M. Acuña ◽  
María C. Veloso ◽  
Pedro G. Toledo
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Hydrophobic Interactions ◽  
Electrolyte Solutions ◽  
Salt Solutions ◽  
Shape Information ◽  
Transmission Electron ◽  
Structure Breaking ◽  
Scanning Electron

Diphenylalanine (FF) is a peptide that can form different nanostructures; this makes it particularly attractive for both biological and technological applications. However, any application using this type of nanostructures requires controlling their size and shape. Information is provided about the various structures formed through the peptide FF self-assembly in different salt solutions (NaCl, CaCl2, and AlCl3), concentrations (50 mM, 100 mM, and 200 mM), and pH (3 to 10). Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy were used to characterize the nanotubes. Results show that FF nanotube formation through self-assembly is a delicate balance between electrostatic, hydrogen bonding, and hydrophobic interactions; any imbalance in these can impede nanotube formation. Our results demonstrate that salts, such as NaCl and CaCl2, along with the studied concentrations promote the formation of very long nanotube agglomerates. This would be due to a combined screening effect and the fact that cations are structure-forming and promote hydrophobic interactions; therefore, nanotube agglomeration occurs and also benefits electrostatic interactions, hydrogen bonds, and longer nanotubes. The presence of AlCl3 produces an imbalance in the abovementioned interactions because of excess Cl-, a structure-breaking anion that impedes the nanostructure formation.

Fluorescent Rosette Nanotubes from the C-analogue of the Guanine–Cytosine (G∧C) Motif

2015 ◽  
Vol 1796 ◽  
pp. 1-6 ◽  
Author(s):  
Belete Legesse ◽  
Jae-Young Cho ◽  
Rachel L. Beingessner ◽  
Takeshi Yamazaki ◽  
Hicham Fenniri
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
The Self ◽  
Visible Spectroscopy ◽  
Fluorescent Properties ◽  
Force Microscopy ◽  
Rosette Nanotubes ◽  
Atomic Force ◽  
Transmission Electron ◽  
Uv Visible

ABSTRACTRosette nanotubes (RNTs) are tubular architectures generated through the hierarchical self-assembly of the guanine-cytosine (G∧C) motif 1 or 2 (Figure 1). Motif 2 differs from 1 by the substitution at the N-atom in the G-ring with a C-atom as shown in red. In this paper, we prepare a new tricyclic G∧C base 3 from a functionalized derivative of 2 and demonstrate its self-assembly into fluorescent helical RNTs in N,N-dimethylformamide (DMF). The self-assembly and fluorescent properties of RNTs 3 were established using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and UV-visible spectroscopy.

Self-Assembly of Aligned Multi-Walled Carbon Nanotubes in Polypropylene-Coated Multi-Walled Carbon Nanotubes Composites

2013 ◽  
Vol 669 ◽  
pp. 55-62 ◽  
Author(s):  
Yi Na Xiong ◽  
Xiao Hua Chen ◽  
Qun Huang ◽  
Long Shan Xu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Self Assembly ◽  
Butyl Methacrylate ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Polypropylene (PP)-coated multi-walled carbon nanotubes (MWNTs) composite with MWNTs exceptional alignment dispersed and improved mechanical properties was prepared with maleic anhydride (MAH) as a compatibilizer and poly (butyl methacrylate) (PBMA) as a binding. Scanning electron microscopy (SEM) results showed that MWNTs within composite were aligned without aggregation and the oriented MWNTs were connected by matrix. High-resolution transmission electron microscopy (HRTEM) results demonstrated that the nanotubes were densely coated with a PP layer. Infrared spectroscopy (IR) results revealed that there was covalently linkage of MWNTs with PP via MAH. The interactions between MWNTs-PP and MWNTs-PBMA induced orientation of MWNTs. The improved mechanical properties of PP - coated MWNTs composite was also shown.

Spontaneous Self-Assembly of Thiol-Capped CdTe Nanoparticles Into Nanowires Under Dark Conditions

2015 ◽  
Vol 15 (10) ◽  
pp. 8275-8278
Author(s):  
Yea Eun Lee ◽  
Jeong Won Kang ◽  
Ki-Sub Kim
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Self Assembly ◽  
Driving Forces ◽  
Evolutionary Process ◽  
Cdte Nanoparticles ◽  
Transmission Electron ◽  
Synthetic Procedure ◽  
Dark Conditions ◽  
Scanning Electron

Thiol-capped cadmium telluride (CdTe) nanoparticles (NPs) self-assembled into nanowires (NWs) under dark conditions, and the evolutionary process was investigated. Thiolglycolic acid (TGA) was selected as one of the stabilizers and a TGA-to-Cd ion ratio of 1.3 rather than the traditional 2.4 ratio was used. The reduced amount of the stabilizer and the oxidation of tellurium ions on CdTe NP surface under dark conditions resulted in reorganization from individual NPs into NWs consisting of multi-layers of individual NPs. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were performed to characterize the synthesized nanostructures. The NWs produced were straight and long, with lengths ranging from 500 nm to 10 μm. Photoluminescence (PL) showed that the nanostructure wavelengths were slightly blue-shifted from 546 to 539 nm. Both control of the amount of stabilizer and oxidation of Te ions acted as driving forces to form NWs. Thus, small modifications in synthesis yielded a major difference in the final nanomaterial structure. The suggested synthetic procedure provides a viable pathway for the fabrication of nanomaterials.

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