Rheology of Colloidal Dispersions: Deflocculation of Kaolin Dispersions
Guerreiro, M.I.A.; Růžička, Marek; Pěnkavová, Věra
2013 - English
All inorganic additives in their optimal concentrations proved to be effective at reducing the initial viscosity to 1%. In the case of NaOH two different trends were observed: firstly this additive behaved as a deflocculant agent where, at its optimal range of concentrations, the viscosity of kaolin dispersion reduced to its minimal value, secondly when used at concentrations above its optimal range, sodium hydroxide behaved like a flocculant agent increasing strongly the viscosity of kaolin dispersions. The possible cause was attributed to an excess of Na+ and OH- species in bulk media that promoted the reversible effect. Similar effect was also reported for NaCMC at high and medium molar weight, were the viscosity firstly decreased to a certain concentration of additive and then above that concentration started to increase. Thus low molar weight NaCMC was the most effective among the organic additives since it decreased the viscosity to 10% of initial viscosity. Qualitative evaluation showed that organic additives promoted more stable dispersions, in contrast to poor stability offered by the inorganic additives, with exception of NaOH that provided dispersions with good stability inside of its optimal range.
Keywords:
kaolin dispersions; yield strss; viscoplastic fluids
Available at various institutes of the ASCR
Rheology of Colloidal Dispersions: Deflocculation of Kaolin Dispersions
All inorganic additives in their optimal concentrations proved to be effective at reducing the initial viscosity to 1%. In the case of NaOH two different trends were observed: firstly this additive ...
6M-IMMEDIATE Research Report: Preparation of Pt on Carbon Black Supported Catalysts
Kaluža, Luděk; Zdražil, Miroslav; Gulková, Daniela; Vít, Zdeněk; Šolcová, Olga; Soukup, Karel; Maixnerová, Lucie
2013 - English
The purpose of the present work is to elucidate on carbon black materials as a support for high loading of Pt in highly dispersed form. There are three main methodologies described in the .literature for deposition of Pt: i) impregnation of the support with solution of well soluble Pt precursors, ii) deposition of a colloidal form of Pt onto the support, and iii) deposition of Pt onto the supports from microemulsion of Pt precursor with the assistance of surfactant. The Pt containing species are deposited either by spontaneous adsorption or by evaporation of the solvent. The deposited platinum compound is transformed to metallic platinum with some chemical or physical (temperature) treatment. Remainders of the deposited compound other than platinum must be removed from the catalysts (for instance by washing, calcination, etc.).
Keywords:
elucidate; carbon black materials; platinum
Available at various institutes of the ASCR
6M-IMMEDIATE Research Report: Preparation of Pt on Carbon Black Supported Catalysts
The purpose of the present work is to elucidate on carbon black materials as a support for high loading of Pt in highly dispersed form. There are three main methodologies described in the .literature ...
WP5 Status Report Months 31 to 50
Křišťál, Jiří; Stavárek, Petr; Jiřičný, Vladimír
2013 - English
Within WP5 in this reporting period focused on the development of a new intensified reactor concept for sulph(on)ation reaction. Based on the previous hydrodynamic experiments and mathematical models we designed a new reactor – microSulphonator. We also constructed and manufactured several prototypes that were later tested with model fluids. Experimental data were used for the validation of the models defined previously. Results of this period served as a basis for the final microSulphonators to be tested in the PGB pilot plant during the demonstration phase of the F3 project.
Keywords:
microreactor desing; gas-liquid reaction; pilot plant demonstration
Available at various institutes of the ASCR
WP5 Status Report Months 31 to 50
Within WP5 in this reporting period focused on the development of a new intensified reactor concept for sulph(on)ation reaction. Based on the previous hydrodynamic experiments and mathematical models ...
Edge Effects in Rotational Viscometry III. ZZ and KK Sensors, Total Slip Pseudosimilarity
Wein, Ondřej
2013 - English
This report presents a next step of our effort in developing a system of corrections on edge effects in rotational AWS viscometry. In the previous two reports [4, 5], the edge corrections are given for Newtonian and pseudoplastic liquids with no-slip (adherence) boundary conditions at solid walls (BC).
Keywords:
edge effects; rotational viscometry; zz and kk sensors
Available on request at various institutes of the ASCR
Edge Effects in Rotational Viscometry III. ZZ and KK Sensors, Total Slip Pseudosimilarity
This report presents a next step of our effort in developing a system of corrections on edge effects in rotational AWS viscometry. In the previous two reports [4, 5], the edge corrections are given ...
F3 Factory Deliverable D8.5 on Demonstration Activities in Intensified Surfactant Making
Vanhoutte, D.; Křišťál, Jiří; Stavárek, Petr; Jiřičný, Vladimír; Haas-Santo, K.; Tarchini, R.
2013 - English
the continuos report abou of the project completed within the demonstration stage of the F3 Factory project.
Keywords:
process intensification; microreactors
Available at various institutes of the ASCR
F3 Factory Deliverable D8.5 on Demonstration Activities in Intensified Surfactant Making
the continuos report abou of the project completed within the demonstration stage of the F3 Factory project.
Comprehensive Suite of Coarse-grain Modeling Tools Formulated upon Dissipative Particle Dynamics.
Moore, J.D.; Larentzos, J.P.; Izvekov, S.; Lísal, Martin; Brennan, J.K.
2013 - English
Keywords:
dissipative particle dynamics; modeling tools
Available at various institutes of the ASCR
Comprehensive Suite of Coarse-grain Modeling Tools Formulated upon Dissipative Particle Dynamics.
Exploration of 9-Bromo[7]helicene Reactivity
Žádný, Jaroslav; Jakubec, Martin; Velíšek, Petr; Sýkora, Jan; Storch, Jan
2012 - English
Our new microwave assisted photodehydrocyclisation and completely reviewed synthetic approach for a multi-gram scale production of 9-bromo-[7]helicene led us to explore the reactivity of this compound mainly in Pd-catalysed reactions and to the further functionalization of this molecule. Next to other transformations, palladium catalysed carbon – heteroatom coupling reactions provide a large portfolio of racemic helicenes bearing different functional groups in good to excellent yields. Many of the reactions are performed in the microwave initiator saving reaction time to a minimum comparing with conventional and known synthetic methods. Such prepared compounds can undergo further synthetic reactions or can be used on a field of molecular electronics, surface chemistry or in other applications. The separation of racemic mixtures is under running in our lab. Optically pure compounds of such a type can open new possibilities in their use.
Keywords:
helicene; palladium cross-coupling; microwave synthesis
Available at various institutes of the ASCR
Exploration of 9-Bromo[7]helicene Reactivity
Our new microwave assisted photodehydrocyclisation and completely reviewed synthetic approach for a multi-gram scale production of 9-bromo-[7]helicene led us to explore the reactivity of this compound ...
Heat Transfer in MicroSAR Mixers
Křišťál, Jiří; Vajglová, Zuzana
2012 - English
The report presents the finding of the investigation of the heat transfer in microSAR mixers and the comparison with the conventional heat exchangers.
Keywords:
heat transfer; microSAR mixers; conventional heat exchangers
Available at various institutes of the ASCR
Heat Transfer in MicroSAR Mixers
The report presents the finding of the investigation of the heat transfer in microSAR mixers and the comparison with the conventional heat exchangers.
Preparation of Porphyrin Based HPLC Columns for the Separation of Fullerenes
Slavíček, J.; Šabata, Stanislav; Lang, Kamil; Lhoták, P.
2012 - English
Keywords:
fullerens; porphyrin; separation
Available at various institutes of the ASCR
Preparation of Porphyrin Based HPLC Columns for the Separation of Fullerenes
Final Report on Microprocessing of Fluids 2010 – 2011
Křišťál, Jiří; Vajglová, Zuzana
2012 - English
The report summarizes the work carried out within the reseach agreement no. 170306 in 2011/2012.
Keywords:
report; microprocessing of fluids
Available at various institutes of the ASCR
Final Report on Microprocessing of Fluids 2010 – 2011
The report summarizes the work carried out within the reseach agreement no. 170306 in 2011/2012.
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