Morphology control of laser-induced dandelion-like crystals of sodium acetate through the addition of acidic polymers

2021 ◽  
Vol 54 (4) ◽  
Author(s):  
Yao Liu ◽  
Huilin He ◽  
Yanjun Liu
Keyword(s):  
Crystal Growth ◽  
Sodium Acetate ◽  
Morphological Difference ◽  
Underlying Mechanism ◽  
Crystal Nucleation ◽  
Bulk Solid ◽  
Mass Fractions ◽  
Morphological Modification ◽  
Experimental Trend ◽  
Polymaleic Acid

Crystal growth speeds, crystal sizes and the morphology of sodium acetate (CH3COONa) crystals in the presence of polymaleic acid and polyacrylic acid with different concentrations were investigated in supersaturated solutions of sodium acetate. The technique of non-photochemical laser-induced nucleation (NPLIN) was used to produce initial crystallites of anhydrous CH3COONa. The anhydrous CH3COONa crystal growth in solution after laser irradiation resembled the formation of dandelion seed heads. Even though NPLIN could offer temporal–spatial control of crystal nucleation without the addition of acidic polymers, the crystal growth rates were heterogeneous for crystallites along the laser pathway, which led to irregular crystalline sizes and morphologies. Here, a controllable approach from crystal nucleation to crystal growth has been designed through the addition of acidic polymers in the laser-induced growth of anhydrous CH3COONa crystals. In the presence of an acidic polymer, both the crystal growth and the morphological modification were controlled from tuft-shaped crystals to dandelion-like crystals. As bulk solid thicknesses and crystal growth speeds can be modified by different mass fractions of acidic polymer, a mathematical model was established to analyse the dynamics of crystal growth under the effect of acidic polymers. The model reproduces remarkably well the experimental trend and predicts experimental results. The changes in supersaturation and the number of nuclei through the addition of acidic polymers were analysed to investigate the underlying mechanism of morphological difference.

scholarly journals Determination of Crystal Growth Geometry Factors and Nucleation Site Densities of Electrodeposited Ferromagnetic Cobalt Nanowire Arrays

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 142 ◽  
Author(s):  
Ryusei Saeki ◽  
Takeshi Ohgai
Keyword(s):  
Crystal Growth ◽  
Electrochemical Reduction ◽  
Spontaneous Magnetization ◽  
Frequency Factor ◽  
Nucleation Site ◽  
Nanowire Arrays ◽  
Crystal Nucleation ◽  
Anodized Aluminum ◽  
Cobalt Electrodeposition ◽  
Ferromagnetic Cobalt

The time-dependence of electrochemical reduction current, which was observed during the one-dimensional (1-D) crystal growth of ferromagnetic cobalt nanowire arrays, was analyzed by Johnson–Mehl–Avrami–Kolmogorov (JMAK) theory. Textured hcp-Co nanowire arrays were synthesized by potentio-static electrochemical reduction of Co2+ ions in anodized aluminum oxide (AAO) nanochannel films. Crystal growth geometry factor n in the JMAK equation was determined to be ca. 1. Hence, the electrochemical crystal growth process of a numerical nanowires array can be explained by 1-D geometry. The crystal nucleation frequency factor, k in JMAK equation was estimated to be the range between 10−4 and 10−3. Our experimental results revealed that the crystal nucleation site density Nd increased up to 2.7 × 10−8 nm−3 when increasing the overpotential for cobalt electrodeposition by shifting the cathode potential down to −0.85 V vs. Ag/AgCl. The (002) crystal orientation of hcp-Co nanowire arrays was, remarkably, observed by decreasing Nd. Spontaneous magnetization behavior was observed in the axial direction of nanowires. By decreasing the overpotential for cobalt electrodeposition, the coercivity of the nanocomposite film increased and reached up to 1.88 kOe, with a squareness of ca. 0.9 at room temperature.

Kinetics of Crystal Nucleation and Growth in Thin Films of Amorphous Te Alloys measured by Atomic Force Microscopy

2003 ◽  
Vol 803 ◽  
Author(s):  
J. Kalb ◽  
F. Spaepen ◽  
M. Wuttig
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Crystal Growth ◽  
Data Storage ◽  
Optical Data Storage ◽  
Crystal Nucleation ◽  
Ex Situ ◽  
Optical Data ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTBoth the crystal nucleation rate and the crystal growth velocity of sputtered amorphous Ag0.055In0.065Sb0.59Te0.29 and Ge4Sb1Te5 thin films used for optical data storage were determined as a function of temperature. Crystals were directly observed using ex-situ atomic force microscopy, and their change in size after each anneal was measured. Between 140°C and 185°C, these materials exhibited similar crystal growth characteristics, but differed in their crystal nucleation characteristics. These observations provide an explanation for the different re-crystallization mechanisms observed upon laser-induced crystallization of amorphous marks.

Characteristic Modification of Catalysts by Use of a Chloride Source

2016 ◽  
Vol 247 ◽  
pp. 106-110
Author(s):  
Xiang Meng ◽  
Hiroaki Suzuki ◽  
Kenta Sasaki ◽  
Hirokazu Tatsuoka
Keyword(s):  
Liquid Phase ◽  
Structural Control ◽  
Crystal Nucleation ◽  
Si Nanowires ◽  
Vapor Liquid Solid ◽  
Vapor Liquid Solid Mechanism ◽  
Phase Crystal ◽  
Morphological Modification ◽  
Growth Evolution ◽  
Modification Of Catalysts

Structural control and morphological modification of a series of Si-based nanostructures were studied from the viewpoint of modifying the catalyst’s characteristics. The catalyst was modified from a liquid to a solid during its growth. The growth evolution of the faceted Si nanowires occurred via a vapor–liquid–solid mechanism followed by a silicide vapor–solid–solid mechanism. The shapes of the catalysts defined the shapes of the nanowires during the vapor–solid–solid growth. The catalyst was further modified by the deposition of MnCl2. Only irregularly shaped Si particles or MnCl2 particles were observed on top of the Si nanowires. The characteristic modification of catalysts by liquid-phase crystal nucleation and deposition of liquid-phase droplets was discussed. In addition, the synthesis of a CrSi2 nanowire bundle by the formation of dense nanoparticles was studied.

The Nature and Crystal Growth of Otoconia in the Rat

1975 ◽  
Vol 84 (1) ◽  
pp. 22-36 ◽  
Author(s):  
Muriel D. Ross ◽  
Donald R. Peacor
Keyword(s):  
Crystal Growth ◽  
Structural Unit ◽  
Integrated Approach ◽  
Nucleation And Growth ◽  
Organic Substrate ◽  
Crystal Nucleation ◽  
Chemical Factor ◽  
Adult Type ◽  
Inorganic Crystal ◽  
Parallel Growth

Several types of otoconia are present in the macular regions of young rats. These include multifaceted, transitional and rounded body forms, some variant otoconia and a few rhombohedrons. The adult form has typically rounded but nonsmooth body surfaces and pointed ends with three planar faces. The multifaceted and transitional otoconia fracture and etch more readily than do the adult type. The differences in properties of the otoconia are considered in the light of known facts concerning inorganic crystal nucleation and growth. This integrated approach indicates that many otoconia originate by seeding of multiple subunits on an organic substrate and develop by the mechanism of parallel growth. The basic structural unit is the rhombohedron. By analogy to inorganic crystals of calcite, it would seem that the typical otoconium grows on the end faces but growth on the side faces is suppressed by some unknown chemical factor. Some otoconia are exceptions, evidently seeding and growing in the pure rhombohedral form. Decalcification of cleaved otoconia shows that organic material is incorporated during growth. The observations are interpreted to indicate that organic substance influences growth and achievement of the adult otoconial form.

Electrical Initiation of Solidification and Preservation of Supercooled State for Sodium Acetate Trihydrate

2010 ◽  
Author(s):  
Tetsuo Munakata ◽  
Shinichi Nagata
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Sodium Acetate ◽  
Growth Direction ◽  
Crystal Growth Rate ◽  
Sodium Acetate Trihydrate ◽  
Supercooled State ◽  
Acetate Trihydrate ◽  
Thermal Energy Storage Material ◽  
Bottom To Top

Electrical initiation of solidification from supercooled state and preservation of supercooled state of sodium acetate trihydrate solution, which is considered as a promising thermal energy storage material, are experimentally investigated with varying the configuration of electrodes and confirmed that the initiation of solidification and preservation of supercooled state are both possible by using the electric field. Further, effect of crystal growth direction on crystal growth rate is also investigated by using the newly developed electrical nucleation method. The result shows that the crystal growth rate, which growth direction is bottom to top, is slightly decreased compared with the direction of top to bottom at certain supercooling temperature range.

Phase Field Method Simulation of Dendrite Crystal Growth of Metal Nickel Based on Fractal Theory

2012 ◽  
Vol 190-191 ◽  
pp. 522-527
Author(s):  
Zhi Yi Ruan ◽  
Sheng Da Zeng ◽  
Li Xin Lin ◽  
Lu Rong Wu
Keyword(s):  
Crystal Growth ◽  
Growth Model ◽  
Phase Field ◽  
Field Model ◽  
Fractal Theory ◽  
Phase Field Model ◽  
Crystal Nucleation ◽  
Pure Substance ◽  
Simulation Results ◽  
Matlab Programming

Using fractal theory simulation of dendrite crystal DLA growth model of pure substance, the undercooling during solidification process of crystal nucleation is simulated; and then in the crystal nuclei are formed on the basis of a pure substance, the phase field model and combined with the finite difference method further differentiation simulation of dendrite crystal growth. According to MATLAB programming, the simulation results obtained by field and temperature field can be seen in the DLA growth, growth model with random premise, for the same kind of material simulated dendrite crystal have both similarities and differences exist. Then, we can get the conclusion, through fractal growth of DLA model with phase field model of dendrite nucleation, growth process is carried out the simulation results, a simple by phase field model is more accord with the dendrite crystal in the experiment.

A flow-free droplet-based device for high throughput polymorphic crystallization

Lab on a Chip ◽  
2015 ◽  
Vol 15 (12) ◽  
pp. 2680-2687 ◽  
Author(s):  
Shih-Mo Yang ◽  
Dapeng Zhang ◽  
Wang Chen ◽  
Shih-Chi Chen
Keyword(s):  
Crystal Growth ◽  
High Throughput ◽  
Crystal Nucleation

Arrays of NaCl crystal nucleation and crystal growth on a flow-free droplet-based device.

A double cell for controlling nucleation and growth of protein crystals

1989 ◽  
Vol 22 (2) ◽  
pp. 115-118 ◽  
Author(s):  
M. Przybylska
Keyword(s):  
Crystal Growth ◽  
Protein Crystallization ◽  
Heavy Atom ◽  
Nucleation And Growth ◽  
The Other ◽  
Crystal Nucleation ◽  
Diffusion Method ◽  
Vapour Diffusion ◽  
Reservoir Solution ◽  
The Stability

A simple device for protein crystallization is described that consists of two connected cells, one for the hanging- or sitting-drop vapour diffusion method and the other for changing the concentration of the reservoir solution. It has been found useful for decoupling crystal nucleation from crystal growth, for improving the size and the stability of crystals, and in the preparation of heavy-atom derivatives.

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