scholarly journals Organic multicomponent microparticle libraries

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dandan Zhang ◽  
Jianbo De ◽  
Yilong Lei ◽  
Hongbing Fu
Keyword(s):  
Spatial Distribution ◽  
Organic Semiconductors ◽  
Structural Complexity ◽  
Metallic Elements ◽  
Synthetic Methodology ◽  
Mixed Composition ◽  
Single Nanoparticle ◽  
Emission Color ◽  
Complex Architectures ◽  
Great Advance

AbstractMultimetallic nanostructures can be synthesized by integrating up to seven or eight metallic elements into a single nanoparticle, which represent a great advance in developing complex multicomponent nanoparticle libraries. Contrary, organic micro- and nanoparticles beyond three π-conjugated components have not been explored because of the diversity and structural complexity of molecular assemblies. Here, we report a library of microparticles composed of an arbitrary combination of four luminescent organic semiconductors. We demonstrate that the composition and emission color of each domain as well as its spatial distribution can be rationally modulated. Unary, binary, ternary, and quaternary microparticles are thus realized in a predictable manner based on the miscibility of the components, resulting in mixed-composition phases or alloyed or phase separated heterostructures. This work reports a simple yet available synthetic methodology for rational modulation of organic multicomponent microparticles with complex architectures, which can be used to direct the design of functional microparticles.

scholarly journals The Effect of Acceptor Structure on Emission Color Tuning in Organic Semiconductors with D–π–A–π–D Structures

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1179 ◽  
Author(s):  
Przemyslaw Ledwon ◽  
Gabriela Wiosna-Salyga ◽  
Marian Chapran ◽  
Radoslaw Motyka
Keyword(s):  
Organic Semiconductors ◽  
Fluorescence Spectra ◽  
Near Infrared ◽  
Energy Levels ◽  
Light Emitting ◽  
Emission Color ◽  
Donor Acceptor ◽  
Homo And Lumo ◽  
Emission Quenching ◽  
Homo And Lumo Energy

A series of novel donor–acceptor D–π–A–π–D compounds were synthesized and characterized in order to determine the influence of different acceptor units on their properties. The introduction of acceptor moieties had a direct impact on the HOMO and LUMO energy levels. Fluorescence spectra of compounds can be changed by the choice of an appropriate acceptor and were shifted from the green to the near-infrared part of spectra. Due to observed concentration induced emission quenching, the green exciplex type host was used to evaluate the potential of synthesized molecules as emitters in organic light emitting diodes (OLEDs).

Emergence of complexity in hierarchically organized chiral particles

Science ◽  
2020 ◽  
Vol 368 (6491) ◽  
pp. 642-648 ◽  
Author(s):  
Wenfeng Jiang ◽  
Zhi-bei Qu ◽  
Prashant Kumar ◽  
Drew Vecchio ◽  
Yuefei Wang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Multiple Scales ◽  
Chemical Properties ◽  
Structural Complexity ◽  
Large Family ◽  
Building Blocks ◽  
Geometrical Complexity ◽  
Complex Architectures ◽  
Gold Thiolate ◽  
Emergence Of Complexity

The structural complexity of composite biomaterials and biomineralized particles arises from the hierarchical ordering of inorganic building blocks over multiple scales. Although empirical observations of complex nanoassemblies are abundant, the physicochemical mechanisms leading to their geometrical complexity are still puzzling, especially for nonuniformly sized components. We report the self-assembly of hierarchically organized particles (HOPs) from polydisperse gold thiolate nanoplatelets with cysteine surface ligands. Graph theory methods indicate that these HOPs, which feature twisted spikes and other morphologies, display higher complexity than their biological counterparts. Their intricate organization emerges from competing chirality-dependent assembly restrictions that render assembly pathways primarily dependent on nanoparticle symmetry rather than size. These findings and HOP phase diagrams open a pathway to a large family of colloids with complex architectures and unusual chiroptical and chemical properties.

scholarly journals Patterns of gall infestation in Heteropterys byrsonimifolia A. Juss. in a forest-savannah ecotone

Revista CERES ◽  
2017 ◽  
Vol 64 (2) ◽  
pp. 143-150
Author(s):  
Marcela de Castro Nunes Santos Terra ◽  
Rubens Manoel dos Santos ◽  
Warley Augusto Caldas Carvalho ◽  
Polyanne Aparecida Coelho ◽  
Geovany Heitor Reis ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Host Plant ◽  
Specific Interaction ◽  
Structural Complexity ◽  
The State ◽  
Resource Concentration ◽  
Resource Concentration Hypothesis ◽  
Ecological Reserve ◽  
Complexity Hypothesis ◽  
Semideciduous Seasonal Forest

ABSTRACT Galls are the result of a specific interaction between an inducer and a host plant. The species Heteropterys byrsonimifolia A. Juss. occurs in abundance in semideciduous seasonal forest ecotones and adjacent open formations. In the ecological reserve Quedas do Rio Bonito, located in the state of Minas Gerais, Brazil, this species is affected by a single gall morphotype. The present study aimed to evaluate whether the structural complexity of the host (test of the structural complexity hypothesis) and the distance between hosts (test of the resource concentration hypothesis) affect gall density in H. byrsonimifolia and to characterize the spatial distribution of the infestation. The results corroborate the two hypotheses tested, suggesting a metapopulation pattern of gall infestation in H. byrsonimifolia. Gallers were more successful in abrupt forest-savannah transition environments, which may be associated with greater stress-induced host vulnerability that plants usually experience in ecotones.

Metallic elements and Pb isotopes in PM2.5 in three Chinese typical megacities: spatial distribution and source apportionment

2020 ◽  
Vol 22 (8) ◽  
pp. 1718-1730
Author(s):  
H. M. Xu ◽  
K. L. He ◽  
R. Feng ◽  
Z. X. Shen ◽  
J. J. Cao ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Spatial Distribution ◽  
Particulate Matter ◽  
Source Apportionment ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Fine Particulate Matter ◽  
Health Concern ◽  
Metallic Elements ◽  
Fine Particulate

Heavy metal pollution in fine particulate matter (PM2.5) is a serious environmental and health concern in China, particularly during winter.

Synthetic Aspects of Organic Semiconductors

MRS Bulletin ◽  
2008 ◽  
Vol 33 (7) ◽  
pp. 698-705 ◽  
Author(s):  
John E. Anthony ◽  
Martin Heeney ◽  
Beng S. Ong
Keyword(s):  
Organic Semiconductors ◽  
Small Molecule ◽  
Synthetic Methodology ◽  
Synthetic Approaches ◽  
By Products

AbstractThis article discusses the importance of the choice of synthetic methodology in the purity, and therefore performance, of both small-molecule and polymeric organic semiconductors. We discuss common methodologies used in the preparation of organic semiconductors, paying particular attention to the impurities and by-products that can arise during these synthetic approaches and how they can have an impact on semiconductor performance.

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

Conformation of eukaryotic ribosomal RNAs

1983 ◽  
Vol 41 ◽  
pp. 592-593
Author(s):  
M. Boublik ◽  
G. Thornton ◽  
G. Oostergetel ◽  
J.F. Hainfeld ◽  
J.S. Wall
Keyword(s):  
Molecular Weight ◽  
Mass Measurement ◽  
Carbon Film ◽  
Structural Complexity ◽  
Scanning Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Pure Nitrogen ◽  
Freeze Dried ◽  
Scanning Transmission ◽  
Partially Unfolded

Understanding the structural complexity of ribosomes and their role in protein synthesis requires knowledge of the conformation of their components - rRNAs and proteins. Application of dedicated scanning transmission electron microscope (STEM), electrical discharge of the support carbon film in an atmosphere of pure nitrogen, and determination of the molecular weight of individual rRNAs enabled us to obtain high resolution electron microscopic images of unstained freeze-dried rRNA molecules from BHK cells in a form suitable for evaluation of their 3-D structure. Preliminary values for the molecular weight of 28S RNA from the large and 18S RNA from the small ribosomal subunits as obtained by mass measurement were 1.84 x 106 and 0.97 x 106, respectively. Conformation of rRNAs consists, in general, of alternating segments of intramolecular hairpin stems and single stranded loops in a proportion which depends on their ionic environment, the Mg++ concentration in particular. Molecules of 28S RNA (Fig. 1) and 18S RNA (not shown) obtained by freeze-drying from a solution of 60 mM NH+4 acetate and 2 mM Mg++ acetate, pH 7, appear as partially unfolded coils with compact cores suggesting a high degree of ordered secondary structure.

SEM evaluation of the TEM cold-stage double-film specimen

1984 ◽  
Vol 42 ◽  
pp. 272-273
Author(s):  
Jayesh Bellare
Keyword(s):  
Spatial Distribution ◽  
Sample Preparation ◽  
Sample Thickness ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Liquid Sample ◽  
Thin Specimen ◽  
Sample Preparation Technique ◽  
Cold Stage ◽  
Film Specimen

Seeing is believing, but only after the sample preparation technique has received a systematic study and a full record is made of the treatment the sample gets.For microstructured liquids and suspensions, fast-freeze thermal fixation and cold-stage microscopy is perhaps the least artifact-laden technique. In the double-film specimen preparation technique, a layer of liquid sample is trapped between 100- and 400-mesh polymer (polyimide, PI) coated grids. Blotting against filter paper drains excess liquid and provides a thin specimen, which is fast-frozen by plunging into liquid nitrogen. This frozen sandwich (Fig. 1) is mounted in a cooling holder and viewed in TEM.Though extremely promising for visualization of liquid microstructures, this double-film technique suffers from a) ireproducibility and nonuniformity of sample thickness, b) low yield of imageable grid squares and c) nonuniform spatial distribution of particulates, which results in fewer being imaged.

Macroprobe Mode for the Study of Segregation in Steels

1990 ◽  
Vol 48 (2) ◽  
pp. 260-261
Author(s):  
Auclair Gilles ◽  
Benoit Danièle
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
High Performance ◽  
Volume Fraction ◽  
Sheet Steel ◽  
Acquisition Time ◽  
Chemical Information ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Optical Micrographs

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.

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