Microwave Assisted Direct Nucleation Control for Batch Crystallization: Crystal Size Control with Reduced Batch Time

2015 ◽  
Vol 16 (1) ◽  
pp. 440-446 ◽  
Author(s):  
Rohit Kacker ◽  
Pedro M. Salvador ◽  
Guido S. J. Sturm ◽  
Georgios D. Stefanidis ◽  
Richard Lakerveld ◽  
...  
Keyword(s):  
Crystal Size ◽  
Size Control ◽  
Batch Crystallization ◽  
Microwave Assisted ◽  
Batch Time

Batch Crystallization with Crystals Attrition

1993 ◽  
Vol 58 (8) ◽  
pp. 1855-1860 ◽  
Author(s):  
Jaroslav Nývlt ◽  
Stanislav Žáček
Keyword(s):  
Mathematical Model ◽  
Calcium Sulfate ◽  
Crystal Size ◽  
Theoretical Description ◽  
Secondary Nucleation ◽  
Batch Crystallization ◽  
Batch Time ◽  
The Mean

The dependence of the mean crystal size of the products from batch crystallizers on the batch time occasionally exhibits a maximum, which can be explained by secondary nucleation due to the attrition of crystals. A kinetic equatation of nucleation, comprising a term for crystal attrition, can be used for the theoretical description of such behaviour. A mathematical model of a batch crystallizer with crystal attrition has been verified on the calcium sulfate precipitation.

Synthesis and size control of Si nanocrystals by SiO/SiO2 superlattices and Er doping

2002 ◽  
Vol 737 ◽  
Author(s):  
J. Heitmann ◽  
D. Kovalev ◽  
M. Schmidt ◽  
L.X. Yi ◽  
R. Scholz ◽  
...  
Keyword(s):  
Phase Separation ◽  
Crystal Size ◽  
Radiative Lifetime ◽  
Size Control ◽  
Luminescence Signal ◽  
Er Doping ◽  
Size Dependent ◽  
Transmission Electron ◽  
Si Nanocrystals ◽  
Ultrathin Layers

ABSTRACTThe synthesis of nc-Si by reactive evaporation of SiO and subsequent thermal induced phase separation is reported. The size control of nc-Si is realized by evaporation of SiO/SiO2 superlattices. By this method an independent control of crystal size and density is possible. The phase separation of SiO into SiO2 and nc-Si in the limit of ultrathin layers is investigated. Different steps of this phase separation are characterized by photoluminescence, infrared absorption and transmission electron microscopy measurements. The strong room temperature luminescence of nc-Si shows a strong blueshift of the photoluminescence signal from 850 to 750 nm with decreasing crystal size. Several size dependent properties of this luminescence signal, like decreasing radiative lifetime and increasing no-phonon transition properties with decreasing crystal size are in good agreement with the quantum confinement model. Er doping of the nc-Si shows an enhancement of the Er luminescence at 1.54 μm by a factor of 5000 compared to doped SiO2 layers. The decreasing transfer time for the nc-Si to Er transition with decreasing crystal size can be understood as additional proof of increasing recombination probability within the nc-Si for decreasing crystal size.

Application of an Empirical FBRM Model to Estimate Crystal Size Distributions in Batch Crystallization

2014 ◽  
Vol 14 (2) ◽  
pp. 607-616 ◽  
Author(s):  
Huayu Li ◽  
Yoshiaki Kawajiri ◽  
Martha A. Grover ◽  
Ronald W. Rousseau
Keyword(s):  
Crystal Size ◽  
Size Distributions ◽  
Batch Crystallization ◽  
Crystal Size Distributions

Particle Size Control in Batch Crystallization of Pyrazinamide on Different Scales

2016 ◽  
Vol 20 (12) ◽  
pp. 2100-2107 ◽  
Author(s):  
Zai-Qun Yu ◽  
Alvin Yeoh ◽  
Pui Shan Chow ◽  
Reginald B. H. Tan
Keyword(s):  
Particle Size ◽  
Size Control ◽  
Batch Crystallization ◽  
Particle Size Control

Crystal size control of TiO2 using experimental strategies in sol–gel process

2010 ◽  
Vol 5 (6) ◽  
pp. 361 ◽  
Author(s):  
R.-J. Tan ◽  
Y.-H. Tseng ◽  
C.-H. Kuo
Keyword(s):  
Crystal Size ◽  
Sol Gel ◽  
Size Control ◽  
Sol Gel Process ◽  
Experimental Strategies

Size-Controlled Microwave-Assisted Synthesis of Water-Dispersible Cd(Se,S) Quantum Dots for Potential Biological Applications

2015 ◽  
Vol 1784 ◽  
Author(s):  
E. Calderón-Ortiz ◽  
S. Bailón-Ruiz ◽  
L. Alamo-Nole ◽  
J. Rodriguez-Orengo ◽  
O. Perales-Perez
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Quantum Confinement Effect ◽  
Reactive Oxygen Species Generation ◽  
Size Control ◽  
Average Crystallite Size ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted

ABSTRACTNanomedicine is fostering significant advances in the development of platforms for early detection and treatment of diseases. Nanoparticles (NPs) like quantum dots (QDs) exhibit size-dependent optical properties for light-driven technologies, which might become important in bio-imaging, sensing and photo-dynamic therapy (PDT) applications. The present research addresses the synthesis of water-stable Cd-based QDs via a Microwave-Assisted synthesis approach using cadmium sulfate salt, and thioglycolic acid as Cd- and S-precursors, respectively. Selenide ions were available by reductive leaching of metallic Selenium in Sodium bisulfite solution. The size control and the tunability of the optical properties were achieved by a suitable control of the reaction temperature (in the 140°C- 190°C range) and reaction time (10 minutes-40 minutes). X-ray diffraction analyses suggested the development of a CdSe,S face cubic centered structure; the broadening of the diffraction peaks indicated the presence of very small nanocrystals in the samples. The average crystallite size was estimated at 5.50 nm ± 1.17nm and 3.72 nm ± 0.04 nm, for nanoparticles synthesized at 180°C after 40 minutes or 10 minutes of reaction, respectively. HRTEM images confirmed the crystalline nature and the small size of the synthesized nanocrystals. In turn, the exciton was red-shifted from 461nm to 549 nm when the reaction temperature was prolonged from 140°C to 190 °C, suggesting the crystal growth. The corresponding band gap values were approximately 2.2 eV, confirming the quantum confinement effect (bulk value 1.74eV). This red shift was also evidenced in PL measurements where the main emission peak was shifted from 507 nm to 564 nm when the samples were excited at 420 nm. A narrow size-tunable emission also was supported by the full width at half maximum (∼ 45 nm) for the synthesized nanocrystals. The reactive oxygen species generation capability of as-synthesized QDs was also investigated. The correlation between the particle size and the generation of (ROS) by the degradation of methylene blue was evident with a reduction of MB concentration from 10μM to 7.5μM and 6.7μM after 15 minutes of UV irradiation for reaction time of 10 min. and 40 min. respectively. No additional degradation was noticed after 60 minutes of irradiation.

Meso-mechanics simulation analysis of microwave-assisted mineral liberation

2015 ◽  
Author(s):  
Qin Like ◽  
Dai Jun ◽  
Yuan Liqun
Keyword(s):  
Energy Consumption ◽  
Microwave Irradiation ◽  
Power Density ◽  
Microwave Power ◽  
Mineral Content ◽  
Crystal Size ◽  
Irradiation Time ◽  
Mineral Crystal ◽  
Microwave Assisted ◽  
Time And Energy

Microwave-assisted crushing and grinding can improve efficiency and reduce energy consumption. This paper takes rock grains with galena and calcite as the research object to establish a two-dimensional computational model through the finite difference software FLAC2D. It analyzes the process and law of mineral boundary failure under microwave irradiation, and assesses the effects of four factors, namely, microwave irradiation time, power density, mineral crystal size, and mineral content, on mineral boundary failure. Results indicate an optimal microwave irradiation period for the rapid failure of mineral boundary. Moreover, irradiation time and energy consumption can be reduced by increasing the microwave power density. However, irradiation time and energy consumption are basically unchanged when the microwave power density is above a certain threshold. Mineral content slightly affects the microwave irradiation time, whereas mineral crystal size significantly affects the microwave irradiation time. In addition, a larger-sized mineral crystal requires less irradiation time and energy consumption to reach the same failure rate. However, irradiation time and energy consumption slightly change when the crystal size is larger than a certain value.

scholarly journals Microwave assisted freezing part 2: Impact of microwave energy and duty cycle on ice crystal size distribution

2020 ◽  
Vol 62 ◽  
pp. 102359
Author(s):  
Mathieu Sadot ◽  
Sébastien Curet ◽  
Sylvie Chevallier ◽  
Alain Le-Bail ◽  
Olivier Rouaud ◽  
...  
Keyword(s):  
Size Distribution ◽  
Duty Cycle ◽  
Crystal Size ◽  
Microwave Energy ◽  
Crystal Size Distribution ◽  
Ice Crystal ◽  
Microwave Assisted ◽  
Ice Crystal Size

Size control of SSZ-13 crystals with APAM and its influence on the coking behaviour during MTO reaction

2019 ◽  
Vol 9 (11) ◽  
pp. 2888-2897 ◽  
Author(s):  
Zhiqiang Xu ◽  
Jianwen Li ◽  
Yuxuan Huang ◽  
Hongfang Ma ◽  
Weixin Qian ◽  
...  
Keyword(s):  
Crystal Size ◽  
Size Control ◽  
Size Reduction ◽  
Mto Reaction

Crystal size reduction of SSZ-13 with APAM activates more naphthalene in the CHA cages.

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