On these pages you will find various articles and slides about the BRACE technology. Due to the large amount of available information we only publish a selection.

Hf and ZrHf mixed Microspheres

Trends in ceramics development have recently been moving toward increasingly high quality ceramic materials such as partly stabilized Zirconia. Metal oxides such as CaO, MgO, Y2O3, CeO4, etc. are used as stabilizing additives.

The object of the recent development was to find a method for producing stabilized Hafnia, Hafnia containing or Zirconia high density spheres or spheres with tailored pore size and surface area with a uniform spherical geometry and a narrow grain size distribution. Aqueous solutions or sols of Hf or Zr preneutralized with ammonia are the precursors to get microspheres. The liquid is gently pumped through a vibrating nozzle system where upon exiting the fluid stream breaks up into uniform droplets. The surface tension of these droplets molds them into perfect spheres in which gelation is induced during a short period of free fall. Solidification can be induced in an ammonia gaseous and liquid medium through chemical reaction.

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Ultra spherical granulation (english)

Trends in plastic development and processing have recently been moving toward increasingly high quality and free flowing particles. The well approved industrial processes do not always meet the exacting standards which modern manufacturing demands of them due to their varying size distribution and odd shapes. These properties are detrimental to efficient processing and lead to agglomeration, inexact dosage, abrading with loss of material or low reproducibility of castings. The use of small and perfectly round microspheres with exactly the same size circumvents all of the disadvantages that are encountered while using powders and granulates.

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Ultra spherical granulation (francais)

Les tendances dans le développement du plastique et sa transformation ont tout récemment évolué vers la « high quality » et une libre circulation des particules, les procédés industriels généralement agrées ne répondent pas toujours aux normes précises de la fabrication moderne, conséquence de leur répartition à dimensions variées et aux structures particulières. Ces propriétés vont au détriment d'une mise en œuvre efficace et ont pour effet une agglomération, un dosage inexact, une abrasion entraînant une perte de matériau ou une reproductibilité faible des coulées. L'emploi de microbilles parfaitement rondes et de même taille permet de contourner tous les désavantages que l'on rencontre avec l'emploi des poudres et granulés.

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Des microbilles de granulométrie précise

Aujourd'hui, les microbilles de granulométrie "mono-dispersion" et de composition précise, fabriquées par un procédé original à partir de buses et d'une phase liquide, utilisées pour les substances galéniques courantes en pharmacie et cosmétologie, s'ouvrent à de nouveaux marchés.

A l'issue de nombreuses années de travaux de recherche et développement, de mise au point de procédés et d'équipements de production, et de contrôle qualité de microbilles, a rendu possible la fabrication de microbilles parfaitement rondes de composition définie, tout en leur conférant des caractéristiques particulières.

Par quel procédé ? La production de ces microbilles est réalisée à partir d'une phase liquide : une fusion, une solution ou une suspension.

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Runde Sache

Mikrokugeln können in einem Vibrationstropfverfahren hergestellt werden. Ihre Aushärtung wird durch chemische Reaktionen in der Gas- oder der Flüssigphase unterstützt. Dadurch erreicht man eine monodisperse Verteilung der Korngrößen. Derartig hochpräzise Mikrokugeln können in zahlreichen Anwendungen zum Einsatz kommen, beispielsweise als Katalysatorenträger in chemischen Reaktionen oder in Fermentierungsprozessen. Durch ihre physikalischen Eigenschaften bieten sie darüber hinaus Vorteile beim Kalzinieren oder Sintern. Mikrokugeln, die mit Wirkstoffeinlagerungen versehen wurden, können zur exakten Dosierung von Wirkstoffen in pharmazeutischen und medizinischen Anwendungen eingesetzt werden.

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Probiotics Encapsulation

Probiotic ingredients are nowadays used for a wide range of health benefits, many of those can be shown in studies to have good health effects on the end user. It is possible to buy probiotic food and nutraceuticals, as well as pharmaceuticals in pharmacies and supermarkets all over Europe. However, the health benefit of those available products is very much depending on the time of use, as those contain free and untreated probiotics, that tend to degrade over time of transport and storage. Pharmaceutical products containing probiotics have often to be stored at last refrigerated, in some cases even deep frozen. That adds a lot of costs to transport and storage and renders a product inconvenient for the user. To overcome those drawbacks, new ways of delivering probiotics have to be found.

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Fraunhofer UMSICHT Tage

Die meisten technischen Produkte werden in Form von Schuppen, Blöcken, Granulaten oder Pulvern hergestellt. Durch diese Darreichungsform ergeben sich verschiedene Nachteile: Schuppen lassen sich oft schlecht dosieren, Blöcke müssen vor der Anwendung aufgeschmolzen werden, Granulate und Pulver sind selten staubfrei, und es besteht die Gefahr der Staubexplosion.

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Powering Green Chemistry with Microspheres and Microcapsules

The world of today needs and uses huge amount of energy. As second and third world countries rise and first world countries improve their level of life, a slowing of energy consumption cannot be seen, despite the efforts for energy conservation. Fossil energies as gas and oil have an even increasing importance, despite their environmental drawbacks. Nuclear energy – even though that some countries as Germany try to replace it with renewable energies – plays still an important factor, not only because of the low costs and a carbon dioxide free operation, but also for new applications as the destruction of nuclear waste. Renewable energies are used and developed strongly and will play a very important role in the future. Even solar technology, were recent price falls and loss of subsidiaries forced many companies out of business, is not dead and is still used in an increasing number of installations. Rising applications for biofuel and new processes are on their way replacing fossil fuels by using electricity during low use times from renewable sources such as off shore wind turbines and simultaneously harvest carbon dioxide.

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Shaping of Alginate–Silica Hybrid Materials into Microspheres through Vibrating-Nozzle Technology and Their Use for the Recovery of Neodymium from Aqueous Solutions

The vibrating-nozzle technology is very interesting to very easily and very rapidly produce industrial amounts of functional microspheres. The technology was used to make hybrid alginate–silica microspheres by droplet coagulation. The microspheres were formed starting from suspensions of sodium alginate, and coagulation occurred in an aqueous solution of calcium ions. To enhance the mechanical properties of the alginate raw material, it was combined with two different silica sources: tetramethyl orthosilicate (TMOS) and commercial silica powder. The two different batches of alginate–silica microspheres were fully compared with regard to their morphology, composition, shrinking behavior, and stability in acidic conditions. It was shown that the incorporation of an inorganic matrix resulted in a material with a better stabilized porous structure and a higher resistance in an acidic environment. Both are important when functional particles are designed to be used for adsorption of metal ions, either as a stirred suspension or as a stationary phase in a chromatographic column. A study of the adsorption performance was conducted in batch mode for neodymium(III), a representative element for the group of critical rare-earth elements. The effect of stripping (desorption) on the adsorption performance and reusability was also investigated. The functional alginate–silica microspheres show a sustainable character.

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Recovery of cobalt from dilute aqueous solutions using activated carbon–alginate composite spheres impregnated with Cyanex 272

A novel adsorbent was designed for selective recovery of cobalt(II) from synthetic binary cobalt(II)–nickel(II) and cobalt(II)–manganese(II) solutions, a synthetic multi-element solution and a real aqueous waste stream from the petrochemical sector. The adsorbent consisted of shaped activated carbon–alginate spheres impregnated with Cyanex 272. The synthesis was followed by characterisation using SEM, infrared spectroscopy, BET analysis and elemental analysis. Good selectivity for cobalt(II) over nickel(II) could be achieved during adsorption, while this was not the case for cobalt(II) over manganese(II). Cobalt(II) and manganese(II) were therefore fully adsorbed and stripped using a dilute sulphuric acid solution. The adsorbent was shown to be reusable in a column setup. Finally, the adsorbent material was used for the purification of a real aqueous waste stream from the petrochemical sector.

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Development of alumina microspheres with controlled size and shape by vibrational droplet coagulation

Monodisperse alumina microspheres were shaped by making use of the vibrational droplet coagulation technique. A combination of both physical and chemical parameters provided a flexible basis to widely regulate the size of the microspheres. The controlled granulation is based on a stable alumina suspension containing sodium alginate. The sodium alginate binder is used to coagulate the microspheres jetted into a bath of CaCl2. Several parameters have been varied to study the impact on the suspension’s rheology. This in turn dictates the physical parameters required for controlled shaping by the vibrational droplet coagulation technique. The decomposition of the calcium alginate in the alumina microspheres was monitored during the thermal post processing. In this step, the formation of CaCO3 was revealed, resulting in the presence of CaO during the calcination process. Subsequently, this existence of CaO in the alumina matrix leads to the formation of calcium hexaluminate (CaO·6Al2O3) during sintering.

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Prilling technology at Gala

Prilling is a technical process of generating uniform spherical particles and capsules from solutions, molten solids, emulsions and dispersions.

Prilling essentially consists of two operations: firstly a liquid is pushed by the pressure through a nozzle (applying a vibration at a defined frequency),producing liquid drops with a close size distribution. Secondly, the drops are solidifying them individually, either by coolling them as they fall through a rising ambiant air stream, or by plunging them in a gelling bath.

The prilling process has to make uniformly sized drops (narrow size distribution).

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