scholarly journals Constructing 3D heterogeneous hydrogels from electrically manipulated prepolymer droplets and crosslinked microgels

2016 ◽  
Vol 2 (10) ◽  
pp. e1600964 ◽  
Author(s):  
Min-Yu Chiang ◽  
Yao-Wen Hsu ◽  
Hsin-Yi Hsieh ◽  
San-Yuan Chen ◽  
Shih-Kang Fan
Keyword(s):  
Liquid Phase ◽  
Three Dimensional ◽  
Building Blocks ◽  
Liquid Droplets ◽  
New Materials ◽  
General Technique ◽  
Materials By Design ◽  
Wide Range ◽  
Manufacturing Complexity ◽  
Complex Architectures

Formation of multifunctional, heterogeneous, and encoded hydrogel building blocks, or microgels, by crosslinking and assembly of microgels are two essential steps in establishing hierarchical, complicated, and three-dimensional (3D) hydrogel architectures that recapitulate natural and biological structures or originate new materials by design. However, for the variety of the hydrogel materials crosslinked differently and for the varied scales of microgels and architectures, the formation and assembly processes are usually performed separately, which increases the manufacturing complexity of designed hydrogel materials. We show the construction of hydrogel architectures through programmable formation and assembly on an electromicrofluidic platform, adopting two reciprocal electric manipulations (electrowetting and dielectrophoresis) to manipulate varied objects (i) in multiple phases, including prepolymer liquid droplets and crosslinked microgels, (ii) on a wide range of scales from micrometer functional particles or cells to millimeter-assembled hydrogel architectures, and (iii) with diverse properties, such as conductive and dielectric droplets that are photocrosslinkable, chemically crosslinkable, or thermally crosslinkable. Prepolymer droplets, particles, and dissolved molecules are electrically addressable to adjust the properties of the microgel building blocks in liquid phase that subsequently undergo crosslinking and assembly in a flexible sequence to accomplish heterogeneous and seamless hydrogel architectures. We expect the electromicrofluidic platform to become a general technique to obtain 3D complex architectures.

scholarly journals High-Throughput Electron Diffraction Reveals a Hidden Novel Metal-Organic Framework for Electrocatalysis

2021 ◽  
Author(s):  
Meng Ge ◽  
Yanzhi Wang ◽  
Francesco Carraro ◽  
Weibin Liang ◽  
Morteza Roostaeinia ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
High Throughput ◽  
Metal Organic Framework ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
New Materials ◽  
X Ray Diffraction ◽  
Zeolitic Imidazolate Framework ◽  
Wide Range ◽  
Metal Organic

<p>Metal-organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X-ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high-throughput approach for structural analysis of MOF nano- and sub-microcrystals by three-dimensional electron diffraction (3DED). A new zeolitic-imidazolate framework (ZIF), denoted ZIF-EC1<a>, </a>was first discovered in a trace amount during the study of a known ZIF-CO<sub>3</sub>-1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF-EC1 has a dense 3D framework structure, which is built by linking mono- and bi-nuclear Zn clusters and 2-methylimidazolates (mIm<sup>-</sup>). With a composition of Zn<sub>3</sub>(mIm)<sub>5</sub>(OH), ZIF-EC1 exhibits high N and Zn densities. We show that the N-doped carbon material derived from ZIF-EC1 is a promising electrocatalysis for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications. </p>

scholarly journals Supramolecular Fuzziness of Intracellular Liquid Droplets: Liquid–Liquid Phase Transitions, Membrane-Less Organelles, and Intrinsic Disorder

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3265 ◽  
Author(s):  
Vladimir N. Uversky
Keyword(s):  
Phase Transitions ◽  
Liquid Phase ◽  
Intrinsically Disordered Proteins ◽  
Intrinsically Disordered Protein ◽  
Disordered Proteins ◽  
Bacterial Cells ◽  
Liquid Droplets ◽  
Intrinsically Disordered ◽  
Wide Range ◽  
Characteristic Features

Cells are inhomogeneously crowded, possessing a wide range of intracellular liquid droplets abundantly present in the cytoplasm of eukaryotic and bacterial cells, in the mitochondrial matrix and nucleoplasm of eukaryotes, and in the chloroplast’s stroma of plant cells. These proteinaceous membrane-less organelles (PMLOs) not only represent a natural method of intracellular compartmentalization, which is crucial for successful execution of various biological functions, but also serve as important means for the processing of local information and rapid response to the fluctuations in environmental conditions. Since PMLOs, being complex macromolecular assemblages, possess many characteristic features of liquids, they represent highly dynamic (or fuzzy) protein–protein and/or protein–nucleic acid complexes. The biogenesis of PMLOs is controlled by specific intrinsically disordered proteins (IDPs) and hybrid proteins with ordered domains and intrinsically disordered protein regions (IDPRs), which, due to their highly dynamic structures and ability to facilitate multivalent interactions, serve as indispensable drivers of the biological liquid–liquid phase transitions (LLPTs) giving rise to PMLOs. In this article, the importance of the disorder-based supramolecular fuzziness for LLPTs and PMLO biogenesis is discussed.

scholarly journals High-Throughput Electron Diffraction Reveals a Hidden Novel Metal-Organic Framework for Electrocatalysis

2021 ◽  
Author(s):  
Meng Ge ◽  
Yanzhi Wang ◽  
Francesco Carraro ◽  
Weibin Liang ◽  
Morteza Roostaeinia ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
High Throughput ◽  
Metal Organic Framework ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
New Materials ◽  
X Ray Diffraction ◽  
Zeolitic Imidazolate Framework ◽  
Wide Range ◽  
Metal Organic

<p>Metal-organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X-ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high-throughput approach for structural analysis of MOF nano- and sub-microcrystals by three-dimensional electron diffraction (3DED). A new zeolitic-imidazolate framework (ZIF), denoted ZIF-EC1<a>, </a>was first discovered in a trace amount during the study of a known ZIF-CO<sub>3</sub>-1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF-EC1 has a dense 3D framework structure, which is built by linking mono- and bi-nuclear Zn clusters and 2-methylimidazolates (mIm<sup>-</sup>). With a composition of Zn<sub>3</sub>(mIm)<sub>5</sub>(OH), ZIF-EC1 exhibits high N and Zn densities. We show that the N-doped carbon material derived from ZIF-EC1 is a promising electrocatalysis for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications. </p>

scholarly journals High-Throughput Electron Diffraction Reveals a Hidden Novel Metal-Organic Framework for Electrocatalysis

2021 ◽  
Author(s):  
Meng Ge ◽  
Yanzhi Wang ◽  
Francesco Carraro ◽  
Weibin Liang ◽  
Morteza Roostaeinia ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
High Throughput ◽  
Metal Organic Framework ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
New Materials ◽  
X Ray Diffraction ◽  
Zeolitic Imidazolate Framework ◽  
Wide Range ◽  
Metal Organic

<p>Metal-organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X-ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high-throughput approach for structural analysis of MOF nano- and sub-microcrystals by three-dimensional electron diffraction (3DED). A new zeolitic-imidazolate framework (ZIF), denoted ZIF-EC1<a>, </a>was first discovered in a trace amount during the study of a known ZIF-CO<sub>3</sub>-1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF-EC1 has a dense 3D framework structure, which is built by linking mono- and bi-nuclear Zn clusters and 2-methylimidazolates (mIm<sup>-</sup>). With a composition of Zn<sub>3</sub>(mIm)<sub>5</sub>(OH), ZIF-EC1 exhibits high N and Zn densities. We show that the N-doped carbon material derived from ZIF-EC1 is a promising electrocatalysis for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications. </p>

Speed and Eccentricity Tuning Reveal a Central Role for the Velocity-Based Cue to 3D Visual Motion

2010 ◽  
Vol 104 (5) ◽  
pp. 2886-2899 ◽  
Author(s):  
Thaddeus B. Czuba ◽  
Bas Rokers ◽  
Alexander C. Huk ◽  
Lawrence K. Cormack
Keyword(s):  
Visual Perception ◽  
Moving Objects ◽  
Visual Motion ◽  
Three Dimensional ◽  
Building Blocks ◽  
3D Motion ◽  
Direction Discrimination ◽  
Retinal Motion ◽  
Wide Range ◽  
Over Time

Two binocular cues are thought to underlie the visual perception of three-dimensional (3D) motion: a disparity-based cue, which relies on changes in disparity over time, and a velocity-based cue, which relies on interocular velocity differences. The respective building blocks of these cues, instantaneous disparity and retinal motion, exhibit very distinct spatial and temporal signatures. Although these two cues are synchronous in naturally moving objects, disparity-based and velocity-based mechanisms can be dissociated experimentally. We therefore investigated how the relative contributions of these two cues change across a range of viewing conditions. We measured direction-discrimination sensitivity for motion though depth across a wide range of eccentricities and speeds for disparity-based stimuli, velocity-based stimuli, and “full cue” stimuli containing both changing disparities and interocular velocity differences. Surprisingly, the pattern of sensitivity for velocity-based stimuli was nearly identical to that for full cue stimuli across the entire extent of the measured spatiotemporal surface and both were clearly distinct from those for the disparity-based stimuli. These results suggest that for direction discrimination outside the fovea, 3D motion perception primarily relies on the velocity-based cue with little, if any, contribution from the disparity-based cue.

Surfactant-Assisted Synthesis of Tetragonal Porphyrin Microparticles

MRS Advances ◽  
2018 ◽  
Vol 3 (45-46) ◽  
pp. 2757-2762
Author(s):  
Kaifu Bian ◽  
Leanne Alarid ◽  
Casey Karler ◽  
Austin Hwang ◽  
Dongmei Ye ◽  
...  
Keyword(s):  
Energy Transport ◽  
Three Dimensional ◽  
Building Blocks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cooperative Interactions ◽  
Wide Range ◽  
Ligand Coordination ◽  
Microscopy Characterization ◽  
Surfactant Assisted

ABSTRACTIn an effort to utilize their unique photoactive properties, porphyrin monomers were assembled into tetragonal microparticles by a surfactant-assisted neutralization method through the cooperative interactions between the porphyrin building blocks including π-π stacking, J-aggregation and metal-ligand coordination. Electron microscopy characterization in combination with x-ray diffraction confirmed the three-dimensional ordered tetragonal microstructures with stable crystalline frameworks and well defined external surface morphology. Optical absorption and fluorescence spectroscopy revealed enhanced absorbance properties as compared with the raw porphyrin material, favourable for chromophore excitation and energy transport. With active and responsive optical properties, these new porphyrin microparticles look to serve as promising components for a wide range of applications including sensing, diagnostics, solar cells, and optoelectronic devices.

Luminescent Gold(I)-Thallium(I) Arrays through N-Bidentate Building Blocks

2004 ◽  
Vol 59 (11-12) ◽  
pp. 1379-1386 ◽  
Author(s):  
Eduardo J. Fernández ◽  
Peter G. Jones ◽  
Antonio Laguna ◽  
José M. López-de-Luzuriaga ◽  
Miguel Monge ◽  
...  
Keyword(s):  
Solid State ◽  
Crystal Structures ◽  
Three Dimensional ◽  
Building Blocks ◽  
Donor Ligands ◽  
X Ray Diffraction ◽  
Donor Ligand ◽  
X Ray ◽  
Wide Range

Heteropolynuclear gold(I)-thallium(I) complexes of the type [TlLn][Au(C6F5)2] (L = py (2), 2,2’- bipy (3), 1,10-phen (4) or 4,4’-bipy and THF (5); n = 1, 2) have been obtained from reactions of the corresponding N-donor ligands with the precursor {Tl[Au(C6F5)2]}n (1). The crystal structures of complexes 3 - 5 have been determined by X-ray diffraction showing one- (3, 4) or three-dimensional (5) arrays. All complexes are photoluminescent in the solid state at RT and at 77 K. The strong visible emissions of complexes 2 - 5 are displayed over a wide range of wavelengths (460 - 620 nm) depending on the environment of the thallium(I) centres and on the nature of the N-donor ligand.

Nest Building and Self-Assembling

1999 ◽  
Author(s):  
Eric Bonabeau ◽  
Marco Dorigo ◽  
Guy Theraulaz
Keyword(s):  
Social Insects ◽  
Social Life ◽  
Fitness Function ◽  
Three Dimensional ◽  
Building Blocks ◽  
Nest Building ◽  
Nest Construction ◽  
Polistes Dominulus ◽  
Self Assembling ◽  
Complex Architectures

Social insect nest architectures can be complex, intricate structures. Stigmergy (see section 1.2.3), that is, the coordination of activities through the environment, is an important mechanism underlying nest construction in social insects. Two types of stigmergy are distinguished: quantitative, or continuous stigmergy, in which the different stimuli that trigger behavior are quantitatively different; and qualitative, or discrete stigmergy, in which stimuli can be classified into different classes that differ qualitatively. If quantitative stigmergy can explain the emergence of pillars in termites, the building behavior of the paper wasps Polistes dominulus seems to be better described by qualitative stigmergy. In this chapter, a simple agent-based model inspired by discrete stigmergy is introduced. In the model, agents move in a three-dimensional grid and drop elementary building blocks depending on the configuration of blocks in their neighborhood. From the viewpoint of bricks, this model is a model of self-assembly. The model generates a large proportion of random or space-filling forms, but some patterns appear to be structured. Some of the patterns even look like wasp nests. The properties of the structured shapes obtained with the model, and of the algorithms that generate them, are reviewed. Based on these properties, a fitness function is constructed so that structured architectures have a large fitness and unstructured patterns a small fitness. A genetic algorithm based on the fitness function is used to explore the space of architectures. Several examples of self-assembling systems in robotics, engineering, and architecture are described. Self-assembling or self-reconfigurable robotic systems, although they are not directly inspired by nest construction in social insects, could benefit from the discrete-stigmergy model of nest building. The method of evolutionary design, that is, the creation of new designs by computers using evolutionary algorithms, is a promising way of exploring the patterns that self-assembling models can produce. Many animals can produce very complex architectures that fulfill numerous functional and adaptive requirements (protection from predators, substrate of social life and reproductive activities, thermal regulation, etc.).

scholarly journals High-Throughput Electron Diffraction Reveals a Hidden Novel Metal-Organic Framework for Electrocatalysis

2021 ◽  
Author(s):  
Meng Ge ◽  
Yanzhi Wang ◽  
Francesco Carraro ◽  
Weibin Liang ◽  
Morteza Roostaeinia ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
High Throughput ◽  
Metal Organic Framework ◽  
Three Dimensional ◽  
Reduction Reaction ◽  
New Materials ◽  
X Ray Diffraction ◽  
Zeolitic Imidazolate Framework ◽  
Wide Range ◽  
Metal Organic

<p>Metal-organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X-ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high-throughput approach for structural analysis of MOF nano- and sub-microcrystals by three-dimensional electron diffraction (3DED). A new zeolitic-imidazolate framework (ZIF), denoted ZIF-EC1<a>, </a>was first discovered in a trace amount during the study of a known ZIF-CO<sub>3</sub>-1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF-EC1 has a dense 3D framework structure, which is built by linking mono- and bi-nuclear Zn clusters and 2-methylimidazolates (mIm<sup>-</sup>). With a composition of Zn<sub>3</sub>(mIm)<sub>5</sub>(OH), ZIF-EC1 exhibits high N and Zn densities. We show that the N-doped carbon material derived from ZIF-EC1 is a promising electrocatalysis for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications. </p>

Silicon layers grown over SiO2 by liquid phase epitaxy: Electron Microscopical study

1990 ◽  
Vol 48 (4) ◽  
pp. 566-567
Author(s):  
F. Banhart ◽  
F.O. Phillipp ◽  
R. Bergmann ◽  
E. Czech ◽  
M. Konuma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Plasma Etching ◽  
Liquid Phase Epitaxy ◽  
Three Dimensional ◽  
Microscopical Study ◽  
Sample Temperature ◽  
Structural Defects ◽  
Si Substrates ◽  
Etched Surface

Defect-free silicon layers grown on insulators (SOI) are an essential component for future three-dimensional integration of semiconductor devices. Liquid phase epitaxy (LPE) has proved to be a powerful technique to grow high quality SOI structures for devices and for basic physical research. Electron microscopy is indispensable for the development of the growth technique and reveals many interesting structural properties of these materials. Transmission and scanning electron microscopy can be applied to study growth mechanisms, structural defects, and the morphology of Si and SOI layers grown from metallic solutions of various compositions.The treatment of the Si substrates prior to the epitaxial growth described here is wet chemical etching and plasma etching with NF3 ions. At a sample temperature of 20°C the ion etched surface appeared rough (Fig. 1). Plasma etching at a sample temperature of −125°C, however, yields smooth and clean Si surfaces, and, in addition, high anisotropy (small side etching) and selectivity (low etch rate of SiO2) as shown in Fig. 2.

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