Self-assembly of photonic crystals by controlling the nucleation and growth of DNA-coated colloids

DNA-coated colloids can self-assemble into an incredible diversity of crystal structures, but their applications have been limited by poor understanding and control over the crystallization dynamics. To address this challenge, we use microfluidics to quantify the kinetics of DNA-programmed self-assembly along the entire crystallization pathway, from thermally activated nucleation through reaction-limited and diffusion-limited phases of crystal growth. Our detailed measurements of the temperature and concentration dependence of the kinetics at all stages of crystallization provide a stringent test of classical theories of nucleation and growth. After accounting for the finite rolling and sliding rates of micrometer-sized DNA-coated colloids, we show that modified versions of these classical theories predict the absolute nucleation and growth rates with quantitative accuracy. We conclude by applying our model to design and demonstrate protocols for assembling large single crystals with pronounced structural coloration, an essential step in creating next-generation optical metamaterials from colloids.

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Investigation of irradiation-induced nucleation processes in silicon and germanium

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100137495 ◽

1995 ◽

Vol 53 ◽

pp. 224-225

Author(s):

Harry A. Atwater ◽

C.M. Yang ◽

K.V. Shcheglov

Keyword(s):

Room Temperature ◽

Crystal Size ◽

Initial Distribution ◽

Engineering Control ◽

Size Evolution ◽

Silicon And Germanium ◽

Ge Quantum Dot ◽

And Control ◽

Germanium Quantum Dots ◽

Kinetics Of

Studies of the initial stages of nucleation of silicon and germanium have yielded insights that point the way to achievement of engineering control over crystal size evolution at the nanometer scale. In addition to their importance in understanding fundamental issues in nucleation, these studies are relevant to efforts to (i) control the size distributions of silicon and germanium “quantum dots𠇍, which will in turn enable control of the optical properties of these materials, (ii) and control the kinetics of crystallization of amorphous silicon and germanium films on amorphous insulating substrates so as to, e.g., produce crystalline grains of essentially arbitrary size.Ge quantum dot nanocrystals with average sizes between 2 nm and 9 nm were formed by room temperature ion implantation into SiO2, followed by precipitation during thermal anneals at temperatures between 30°C and 1200°C[1]. Surprisingly, it was found that Ge nanocrystal nucleation occurs at room temperature as shown in Fig. 1, and that subsequent microstructural evolution occurred via coarsening of the initial distribution.

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In situ observation of the martensitic transformation in (Mg,Y)-PSZ

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144036 ◽

1986 ◽

Vol 44 ◽

pp. 500-501

Author(s):

R-R. Lee

Keyword(s):

Martensitic Transformation ◽

High Strength ◽

Nucleation And Growth ◽

In Situ Observation ◽

Considerable Potential ◽

Transmission Electron ◽

Structural Applications ◽

Applied Stresses ◽

Kinetics Of

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.

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Kinetic Control of Interpenetration in Fe-Biphenyl-4,4′-dicarboxylate MOFs by Coordination and Oxidation Modulation

10.26434/chemrxiv.7466633 ◽

2018 ◽

Author(s):

Dominic Bara ◽

Claire Wilson ◽

Max Mörtel ◽

Marat M. Khusniyarov ◽

ben slater ◽

...

Keyword(s):

Self Assembly ◽

Surface Areas ◽

Metal Precursors ◽

Additional Coordination ◽

Fine Control ◽

Multiple Alternative ◽

Metal Organic ◽

Dft Simulations ◽

High Valent ◽

And Control

Phase control in the self-assembly of metal-organic frameworks (MOFs) – materials wherein organic ligands connect metal ions or clusters into network solids with potential porosity – is often a case of trial and error. Judicious control over a number of synthetic variables is required to select for the desired topology and control features such as interpenetration and defectivity, which have significant impact on physical properties and application. Herein, we present a comprehensive investigation of self-assembly in the Fe-biphenyl-4,4'-dicarboxylate system, demonstrating that coordination modulation, the addition of competing ligands into solvothermal syntheses, can reliably tune between the kinetic product, non-interpenetrated MIL-88D(Fe), and the thermodynamic product, two-fold interpenetrated MIL-126(Fe). DFT simulations reveal that correlated disorder of the terminal anions on the metal clusters in the interpentrated phase results in H-bonding between adjacent nets and is the thermodynamic driving force for its formation. Coordination modulation slows self-assembly and therefore selects the thermodynamic product MIL-126(Fe), while offering fine control over defectivity, inducing mesoporosity, but electron microscopy shows the MIL-88D(Fe) phase persists in many samples despite not being evident in diffraction experiments, suggesting its presence accounts for the lower than predicted surface areas reported for samples to date. Interpenetration control is also demonstrated by utilizing the 2,2'-bipyridine-5,5'-dicarboxylate linker; DFT simulations show that it is energetically prohibitive for it to adopt the twisted conformation required to form the interpenetrated phase, and are confirmed by experimental data, although multiple alternative phases are identified due to additional coordination of the Fe cations to the N-donors of the ligand. Finally, we introduce oxidation modulation – the concept of using metal precursors in a different oxidation state to that found in the final MOF – as a further protocol to kinetically control self-assembly. Combining coordination and oxidation modulation allows the synthesis of pristine MIL-126(Fe) with BET surface areas close to the predicted maximum capacity for the first time, suggesting that combining the two may be a powerful methodology for the controlled self-assembly of high-valent MOFs.<br><br>

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

10.26434/chemrxiv.9876395.v1 ◽

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.

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Guided Self-Assembly and Control of Vortices in Ensembles of Active Magnetic Rollers

Langmuir ◽

10.1021/acs.langmuir.9b03023 ◽

2019 ◽

Vol 36 (25) ◽

pp. 6957-6962 ◽

Cited By ~ 3

Author(s):

Gašper Kokot ◽

Andrey Sokolov ◽

Alexey Snezhko

Keyword(s):

Self Assembly ◽

And Control

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Controlling the Kinetics of an Enzymatic Reaction through Enzyme or Substrate Confinement into Lipid Mesophases with Tunable Structural Parameters

International Journal of Molecular Sciences ◽

10.3390/ijms21145116 ◽

2020 ◽

Vol 21 (14) ◽

pp. 5116

Author(s):

Marco Mendozza ◽

Arianna Balestri ◽

Costanza Montis ◽

Debora Berti

Keyword(s):

Reaction Kinetics ◽

Self Assembly ◽

Liquid Crystalline ◽

Structural Parameters ◽

Enzymatic Reaction ◽

X Ray Scattering ◽

Nitrophenyl Phosphate ◽

Vis Spectroscopy ◽

Kinetics Of ◽

Enzyme Alkaline Phosphatase

Lipid liquid crystalline mesophases, resulting from the self-assembly of polymorphic lipids in water, have been widely explored as biocompatible drug delivery systems. In this respect, non-lamellar structures are particularly attractive: they are characterized by complex 3D architectures, with the coexistence of hydrophobic and hydrophilic regions that can conveniently host drugs of different polarities. The fine tunability of the structural parameters is nontrivial, but of paramount relevance, in order to control the diffusive properties of encapsulated active principles and, ultimately, their pharmacokinetics and release. In this work, we investigate the reaction kinetics of p-nitrophenyl phosphate conversion into p-nitrophenol, catalysed by the enzyme Alkaline Phosphatase, upon alternative confinement of the substrate and of the enzyme into liquid crystalline mesophases of phytantriol/H2O containing variable amounts of an additive, sucrose stearate, able to swell the mesophase. A structural investigation through Small-Angle X-ray Scattering, revealed the possibility to finely control the structure/size of the mesophases with the amount of the included additive. A UV–vis spectroscopy study highlighted that the enzymatic reaction kinetics could be controlled by tuning the structural parameters of the mesophase, opening new perspectives for the exploitation of non-lamellar mesophases for confinement and controlled release of therapeutics.

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The Formation of Cu3Si from Cu/a-Si Multilayers

MRS Proceedings ◽

10.1557/proc-481-581 ◽

1997 ◽

Vol 481 ◽

Cited By ~ 1

Author(s):

R. R. Chromik ◽

W. K. Neils ◽

E. J. Cotts

Keyword(s):

Diffusion Couples ◽

X Ray Diffraction ◽

Limited Growth ◽

Scanning Calorimetry ◽

Individual Layer ◽

Diffusion Limited ◽

Reaction Constant ◽

Multilayered Composites ◽

Reaction Constants ◽

Kinetics Of

ABSTRACTThe kinetics of the formation of Cu3Si in Cu/a-Si diffusion couples have been investigated by means of differential scanning calorimetry and x-ray diffraction. Multilayered composites of average stoichiometry Cu3Si were prepared by sputter deposition with individual layer thicknesses varying in different samples between 2 and 100 nm. We observed diffusion limited growth of Cu3 Si upon annealing these diffusion couples below 500 K. Reaction constants were measured for a temperature range of 455 to 495 K for thicknesses of growing Cu3Si between 2.6 and 80 nm. The temperature dependence of the reaction constant, k2, was characterized as k2 = k0 exp(− Ea/kbT) with activation energy, Ea = 1.0 eV/atom and pre-factor, k0 = 1.9×10−3 cm2/s.

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Inhomogeneous Swelling Near Grain Boundaries in Irradiated Materials: Cavity Nucleation and Growth Saturation Effects

MRS Proceedings ◽

10.1557/proc-650-r1.4 ◽

2000 ◽

Vol 650 ◽

Author(s):

S. L. Dudarev

Keyword(s):

Grain Boundary ◽

Grain Boundaries ◽

Nucleation And Growth ◽

Homogeneous Distribution ◽

Rate Theory ◽

Diffusional Growth ◽

Standard Rate ◽

Saturation Effects ◽

Kinetics Of ◽

Cascade Damage

ABSTRACTThe effect of inhomogeneous nucleation and growth of cavities near grain boundaries illustrates the failure of the standard rate theory to describe the kinetics of phase transformations in irradiated materials under cascade damage conditions. The enhanced swelling observed near grain boundaries is believed to result from the competition between the diffusional growth of cavities and their shrinkage due to the interaction with mobile interstitial clusters. Swelling rates associated with the two processes behave in a radically different way as a function of the size of growing cavities. For a spatially homogeneous distribution of cavities this gives rise to the saturation of swelling in the limit of large irradiation doses.We investigate the evolution of the population of cavities nucleating and growing near a planar grain boundary. We show that a cavity growing near the boundary is able to reach a size that is substantially larger than the size of a cavity growing in the interior region of the grain. For a planar grain boundary the magnitude of swelling at maximum is found to be up to eight times higher than the magnitude of swelling in the grain interior.

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Experimental Investigations of the Kinetics of a Catalytic Trapping Reaction in Confined Spaces

MRS Proceedings ◽

10.1557/proc-464-225 ◽

1996 ◽

Vol 464 ◽

Author(s):

Mark S. Feldman ◽

Anna L. Lin ◽

Raoul Kopelman

Keyword(s):

Reaction Front ◽

Rate Coefficient ◽

Capillary Tube ◽

One Dimension ◽

Experimental Investigations ◽

Confined Spaces ◽

Diffusion Limited ◽

Kinetics Of ◽

Oxidation Of Glucose ◽

Theoretical Results

AbstractWe investigate the anomalous kinetics in one dimension of a diffusion limited catalytic trapping reaction, A + T → T, by measuring the oxidation of glucose. The reaction is carried out in a thin capillary tube, and the depletion of oxygen in the vicinity of the reaction front is monitored by the fluorescence of a Ru(II) dye. Theoretical results and simulations have predicted an asymptotic t1/2 dependence for the rate coefficient. We observe a depedence on t0.56, with what appears to be an asymptotic behavior approaching t1/2.

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