scholarly journals Crystallization of nanoparticles induced by precipitation of trace polymeric additives

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yiwen Qian ◽  
Alessandra da Silva ◽  
Emmy Yu ◽  
Christopher L. Anderson ◽  
Yi Liu ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Evaporation Rate ◽  
Crystallization Process ◽  
High Yield ◽  
Dilute Solutions ◽  
Guided Growth ◽  
Cohesive Energy Density ◽  
Kinetic Growth ◽  
Multiple Length Scales ◽  
Polymeric Additives

AbstractOrthogonal to guided growth of nanoparticle (NP) crystals using DNA or supramolecules, a trace amount of polymeric impurities (<0.1 wt.%) leads to reproducible, rapid growth of 3D NP crystals in solution and on patterned substrates with high yield. When polymers preferentially precipitate on the NP surfaces, small NP clusters form and serve as nuclei for NP crystal growth in dilute solutions. This precipitation-induced NP crystallization process is applicable for a range of polymers, and the resultant 3-D NP crystals are tunable by varying polymeric additives loading, solvent evaporation rate, and NP size. The present study elucidates how to balance cohesive energy density and NP diffusivity to simultaneously favor nuclei formation energetically and kinetic growth in dilute solutions to rapidly crystalize NPs over multiple length scales. Furthermore, the amount of impurities needed to grow NP crystals (<0.1%) reminds us the importance of fine details to interpret experimental observations in nanoscience.

scholarly journals Crystallize Nanoparticles by Precipitating Trace Polymeric Additives

2020 ◽  
Author(s):  
Yiwen Qian ◽  
Alessandra da Silva ◽  
Wolfgang Theis ◽  
Ting Xu ◽  
emmy yu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Crystallization Process ◽  
High Yield ◽  
Process Window ◽  
Patterned Surfaces ◽  
Dilute Solution ◽  
Cohesive Energy Density ◽  
Kinetic Growth ◽  
Multiple Length Scales ◽  
Polymeric Additives

<p>Growing nanoparticle (NP) crystals has been pursued extensively using ligand chemistries such as DNA and supramolecules, controlled evaporation and patterned surfaces. Here, we show that a trace amount of polymeric impurities (<0.1 wt.%) leads to reproducible, rapid growth of high quality 3-D NP crystals in solution and on patterned substrates with high yield. The polymers preferentially precipitate on the NP surfaces inducing the formation of small NP clusters, which subsequently act as nuclei to initiate NP crystal growth in dilute solution. This precipitation-induced NP crystallization process is applicable for a range of polymers and the resultant 3-D NP crystals can be tuned by varying polymeric additives loading, solvent evaporation rate and NP size. Fundamentally, the present study elucidates how to balance cohesive energy density and NP diffusivity in the self-assembly to favor nuclei formation energetically and kinetic growth in dilute solutions. The results shown also opened up the process window to rapidly and reliably fabricate NP crystals over multiple length scales. Furthermore, the amount of these impurities needed to grow NP crystals (<0.1 %) reminds us the need to pay special attention to fine details to interpret experimental observations in nanoscience.</p>

scholarly journals Crystallize Nanoparticles by Precipitating Trace Polymeric Additives

2020 ◽  
Author(s):  
Yiwen Qian ◽  
Alessandra da Silva ◽  
Wolfgang Theis ◽  
Ting Xu ◽  
emmy yu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Crystallization Process ◽  
High Yield ◽  
Process Window ◽  
Patterned Surfaces ◽  
Dilute Solution ◽  
Cohesive Energy Density ◽  
Kinetic Growth ◽  
Multiple Length Scales ◽  
Polymeric Additives

<p>Growing nanoparticle (NP) crystals has been pursued extensively using ligand chemistries such as DNA and supramolecules, controlled evaporation and patterned surfaces. Here, we show that a trace amount of polymeric impurities (<0.1 wt.%) leads to reproducible, rapid growth of high quality 3-D NP crystals in solution and on patterned substrates with high yield. The polymers preferentially precipitate on the NP surfaces inducing the formation of small NP clusters, which subsequently act as nuclei to initiate NP crystal growth in dilute solution. This precipitation-induced NP crystallization process is applicable for a range of polymers and the resultant 3-D NP crystals can be tuned by varying polymeric additives loading, solvent evaporation rate and NP size. Fundamentally, the present study elucidates how to balance cohesive energy density and NP diffusivity in the self-assembly to favor nuclei formation energetically and kinetic growth in dilute solutions. The results shown also opened up the process window to rapidly and reliably fabricate NP crystals over multiple length scales. Furthermore, the amount of these impurities needed to grow NP crystals (<0.1 %) reminds us the need to pay special attention to fine details to interpret experimental observations in nanoscience.</p>

Insight into crystallization process of rubrene by binary solvent mixtures

RSC Advances ◽  
2016 ◽  
Vol 6 (5) ◽  
pp. 3532-3538 ◽  
Author(s):  
Lijuan Wang ◽  
Yiping Li ◽  
Fengjun Zou ◽  
Hao Du ◽  
Lijing Sun ◽  
...  
Keyword(s):  
Boiling Point ◽  
Evaporation Rate ◽  
Crystallization Process ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Blend Ratio ◽  
Binary Solvent Mixtures ◽  
High Boiling Point ◽  
Insight Into

Rubrene crystals have been prepared by properly tuning the blend ratio and evaporation rate of the high-boiling-point solvent.

The Effect of Sample Substrate on the Structural Properties of Co-Deposited Films of A-Ge:H

1990 ◽  
Vol 192 ◽  
Author(s):  
S.J. Jones ◽  
W.A. Turner ◽  
D. Pang ◽  
W. Paul
Keyword(s):  
Yield Strength ◽  
Crystallization Process ◽  
Exothermic Peak ◽  
High Yield ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Strength Differential ◽  
Substrate Temperatures ◽  
Deposited Films

ABSTRACTResults from structural measurements on r.f. glow discharge produced a-Ge:H films have been found to be substrate dependent. The variations in the results were found to depend on both the substrate temperature, Ts, and the substrate yield strength. Differential scanning calorimetry results were particularly affected by these parameters. For films prepared at Ts = 150°C, the DSC spectra contain two exothermic peaks when the films are deposited on low yield strength substrates while only one exothermic peak is present for films deposited on high yield strength substrates. One exothermic DSC peak is seen in spectra for all films prepared at Ts = 300°C no matter what substrates were used. This DSC spectral dependence is attributed to differences in the microstructure of films deposited at the two substrate temperatures, as seen in TEM micrographs. X-ray diffraction measurements performed on films annealed to various temperatures show that all of the exothermic DSC peaks described above are associated with the crystallization process. Thus, for the films prepared at low Ts, crystallization is either a one or two step process depending on the yield strength of the substrate.

Function and engineering of the 15β-hydroxylase CYP106A2

2006 ◽  
Vol 34 (6) ◽  
pp. 1215-1218 ◽  
Author(s):  
C. Virus ◽  
M. Lisurek ◽  
B. Simgen ◽  
F. Hannemann ◽  
R. Bernhardt
Keyword(s):  
Escherichia Coli ◽  
Cytochrome P450 ◽  
Steroid Hormones ◽  
Bacillus Megaterium ◽  
Crystallization Process ◽  
High Yield ◽  
Recent Developments ◽  
Adrenodoxin Reductase ◽  
Hydroxylation Activity

CYP106A2 from Bacillus megaterium ATCC 13368 is a bacterial cytochrome P450 that is capable of transforming steroid hormones. It can be easily expressed in Escherichia coli with a high yield. Its activity in vitro can be achieved by using the adrenal redox proteins adrenodoxin and adrenodoxin reductase. So far, it was not possible to crystallize CYP106A2 because of degradation during the crystallization process. Nevertheless, CYP106A2 is an interesting enzyme for biotechnological use. It hydroxylates pharmaceutically important steroids such as progesterone and 11-deoxycortisol. However, it will be necessary for efficient application of CYP106A2 in biotechnology to improve the hydroxylation activity and manipulate the regiospecificity. The present paper gives an overview of recent developments in protein engineering of CYP106A2.

Crystal Growth in Amorphous Binary Alloys of Zr-Ni System

2007 ◽  
Vol 26-28 ◽  
pp. 675-678 ◽  
Author(s):  
Takeshi Fukami ◽  
I. Noda ◽  
M. Asada ◽  
D. Okai ◽  
T. Yamasaki
Keyword(s):  
Activation Energy ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Crystal Growth ◽  
Crystallization Process ◽  
Isothermal Annealing ◽  
Binary Alloys ◽  
Isothermal Condition ◽  
Amorphous State ◽  
Dta Curves

A crystallization process in an amorphous state under isothermal condition is examined for binary alloys ZrNi and ZrNi2 by differential thermal analysis (DTA). Time dependence of DTA curves is measured at several constant temperatures just below crystallization temperature. The fraction of crystallized volume in amorphous state and its time evolution during isothermal annealing are measured. These data are analyzed by the Johnson-Mehl–Avrami formula. The Avrami exponent is 2.4±0.1 for ZrNi and 3~4 depending on the set temperature for ZrNi2. The activation energy for crystallization of amorphous ZrNi and ZrNi2 was estimated by plots of lnt1/2 vs. 1/T.

scholarly journals EXPOENTE DE AVRAMI PELA EQUAÇÃO DE JMAK PARA MÉTODO NÃO-ISOTÉRMICO DE ANÁLISE TÉRMICA

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Salmo Moreira Sidel ◽  
Elio Idalgo ◽  
Keizo Yukimitu ◽  
João Carlos Silos Moraes ◽  
Fabio Alencar Dos Santos
Keyword(s):  
Crystal Growth ◽  
General Theory ◽  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Nucleation Process ◽  
Vitreous System ◽  
Isothermal Measurements ◽  
Dimensional Crystal

This work reports a discussion about of the general theory for phase transformations of Melh-Johnson-Avrami-Kolmogorov in process involving non-isothermal crystallization. This model allows determine as occurs the mechanism of the nucleus formation and of growth of crystalline phases during the crystallization process. To demonstrate the validity this theory, the Avrami exponent (n) of the LiO2-TeO2-WO3 vitreous system was determined from DSC non-isothermal measurements. The obtained results indicate that the nucleation process is volumetric with two-dimensional or three-dimensional crystal growth. DOI: http://dx.doi.org/10.30609/JETI.2018-2.5566

A NEW METHOD FOR SUPERSATURATION MEASUREMENT: IDEA, IMPLEMENTATION AND RESULTS

2002 ◽  
Vol 16 (01n02) ◽  
pp. 391-398 ◽  
Author(s):  
M. LÖFFELMANN ◽  
A. MERSMANN
Keyword(s):  
Crystal Growth ◽  
Physical Properties ◽  
Crystallization Process ◽  
Measurement Methods ◽  
Time Dependent ◽  
Sensor Surface ◽  
Dependent Development ◽  
Starting Time ◽  
Metastable Zone ◽  
Kinetics Of

Up to now supersaturation measurement can be generalized as using physical properties that show a dependence on concentration as measurands for supersaturation. Impurities, foreign particles or ions influence the metastable zone width as well as the kinetics of nucleation and crystal growth, but most of the existing measurement methods are not able to incorporate those disturbances in the measured supersaturation. Therefore, a supersaturation sensor considering the actual crystallization process itself has been developed. The idea of the new supersaturation sensor is to induce crystallization on the sensor surface by generating an additional supersaturation by cooling and to observe the time-dependent development of the incrustation. Assuming a constant cooling rate and constant properties of the sensor surface the starting time of the incrustation on the sensor surface depends only on the prevailing supersaturation in the process solution. Experimental results obtained for inorganic ( KNO 3) and organic (Adipicacid) crystallizing solutes proved the applicability of the new sensor.

Modeling the crystal growth of cubic silicon carbide by molecular dynamics simulations

2002 ◽  
Vol 742 ◽  
Author(s):  
Nicoletta Resta ◽  
Christopher Kohler ◽  
Hans-Rainer Trebin
Keyword(s):  
Molecular Dynamics ◽  
Crystal Growth ◽  
Molecular Dynamics Simulations ◽  
Crystallization Process ◽  
Amorphous Material ◽  
Thick Layer ◽  
Atomic Interactions ◽  
Dynamics Simulations ◽  
Amorphous Sic ◽  
Cubic Silicon Carbide

ABSTRACTThe crystal growth of a seed of cubic SiC into the amorphous material has been investigated by means of classical molecular dynamics simulations. The crystallization process was studied with a set of supercells containing up to 2000 atoms, initially consisting of a 12 Å thick layer of crystalline SiC and a 18 Å thick layer of amorphous SiC at high pressure. The dynamic evolution of crystallization was then followed for several nanoseconds with the simulated annealing technique performed at constant pressure and temperature. The atomic interactions were described by the Tersoff potential. We studied the dependence of the growth process on the crystallographic orientation of the crystalline/amorphous interface by considering three different crystal planes, namely the {100}, {110}, and {111} planes. Within the pressure-temperature range considered in our simulations, we observed the crystal growth only for the {110} and the {111} orientations, but not for the {100} ones. The atomistic details of the growth mechanism are described and discussed.

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