On crystal growth of orthorhombic alkali acid phthalates. An application of fourier transform of crystal morphology to tracht and habitus

1985 ◽  
Vol 20 (3) ◽  
pp. 351-359 ◽  
Author(s):  
H. Schwarz ◽  
R. Fiedler ◽  
H. Follner
2020 ◽  
Vol 18 (1) ◽  
pp. 951-961
Author(s):  
Qiuju Chen ◽  
Tao Hui ◽  
Hongjuan Sun ◽  
Tongjiang Peng ◽  
Wenjin Ding

AbstractVarious morphologies of magnesium carbonate hydrate had been synthesized without using any organic additives by carefully adjusting the reaction temperature and time during the talc carbonation process. At lower temperatures, magnesium carbonate hydrate was prone to display needle-like morphology. With the further increase of the carbonation temperature, the sheet-like crystallites became the preferred morphology, and at higher aging temperatures, these crystallites tended to assemble into layer-like structures with diverse morphologies, such as rose-like particles and nest-like structure. The reaction time had no effect on the crystal morphology, but it affected the particle size and situation of the crystal growth. X-Ray diffraction results showed that these various morphologies were closely related to their crystal structure and compositions. The needle-like magnesium carbonate hydrate had a formula of MgCO3·3H2O, whereas with the morphological transformation from needle-like to sheet-like, rose-like, and nest-like structure, their corresponding compositions also changed from MgCO3·3H2O to 4MgCO3·Mg(OH)2·8H2O, 4MgCO3·Mg(OH)2·5H2O, and 4MgCO3·Mg(OH)2·4H2O.


2020 ◽  
Author(s):  
Jinzi Deng ◽  
Elana Apfelbaum ◽  
Ran Drori

<p>Since some antifreeze proteins and glycoproteins (AF(G)Ps) cannot directly bind to all crystal planes, they change ice crystal morphology by minimizing the area of the crystal planes to which they cannot bind until crystal growth is halted. Previous studies found that growth along the <i>c</i>-axis (perpendicular to the basal plane, the crystal plane to which these AF(G)Ps cannot bind) is accelerated by some AF(G)Ps, while growth of other planes is inhibited. The effects of this growth acceleration on crystal morphology and on the thermal hysteresis activity are unknown to date. Understanding these effects will elucidate the mechanism of ice growth inhibition by AF(G)Ps. Using cold stages and an Infrared laser, ice growth velocities and crystal morphologies in AF(G)P solutions were measured. Three types of effects on growth velocity were found: concentration-dependent acceleration, concentration-independent acceleration, and concentration-dependent deceleration. Quantitative crystal morphology measurements in AF(G)P solutions demonstrated that adsorption rate of the proteins to ice plays a major role in determining the morphology of the bipyramidal crystal. These results demonstrate that faster adsorption rates generate bipyramidal crystals with diminished basal surfaces at higher temperatures compared to slower adsorption rates. The acceleration of growth along the <i>c</i>-axis generates crystals with smaller basal surfaces at higher temperatures leading to increased growth inhibition of the entire crystal.<a></a></p>


2019 ◽  
Vol 19 (11) ◽  
pp. 6398-6404
Author(s):  
Riku Matsuura ◽  
Shunsuke Horii ◽  
Saman Alavi ◽  
Ryo Ohmura

1994 ◽  
Vol 9 (6) ◽  
pp. 1519-1525 ◽  
Author(s):  
K. Byrappa ◽  
Umesh B.V. Dutt ◽  
A. Clearfield ◽  
Damodara M. Poojary

The HNaMP2O7 (where M = Co and Ni) new Na+ superionic pyrophosphates were obtained by the hydrothermal method at lower PT conditions (T = 250 °C, P = 100 atm). The solubility, complexation with reference to the solvent-solute interaction, and the growth process have been studied in detail. A new investigation on the crystal structure of these compounds showed that the title compounds do not contain Zr as reported previously. The crystal morphology and properties have also been studied.


2013 ◽  
Vol 709 ◽  
pp. 36-39 ◽  
Author(s):  
Shu Jie Zhuang ◽  
Bing Teng ◽  
Li Feng Cao ◽  
De Gao Zhong ◽  
Ke Feng ◽  
...  

4-dimethylamino-N-methyl -4-stilbazolium tosylate(DAST) was synthesized by the condensation and ion exchange reaction of 4-methyl-N-methyl pyridinium tosylate, 4-N,N-dimethylamino -benzaldehyde and silver p-toluenesulfonate, the reaction procedure was easy with high efficiency. The purity of the product was further improved by successive abstersion and recrystallization. The powder was investigated by Fourier transform infrared spectrum, nuclear magnetic resonance and elemental analysis. The results showed that the quality of the powder as crystal raw material was very high, the product could meet the requirements for crystal growth, the procedure of washing the product by chloroform was important to achieve the high quality.


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