Determination of Ideal Broth Formulations Needed to Prepare Hydrous Aluminum Oxide Microspheres via the Internal Gelation Process

Collins, J.L.; Pye, S. L.

doi:10.2172/947140

Cited by 4 publications

(1 citation statement)

References 6 publications

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“…Collins e colaboradores propuseram diferentes rotas para eliminar o principal problema do processo de produção, que é o surgimento de trincas nas microesferas durante as etapas de secagem e calcinação. Uma das propostas apresentadas por Collins e co-autores, por exemplo, foi a prévia fervura por longos períodos, da solução contendo ureia e HMTA, sob refluxo (26) ; os autores sugeriam que com esta fervura podia-se eliminar moléculas de gases dispersas na solução, que seriam a causa da formação de trincas durante a secagem e/ou calcinação. Em publicação recente (27,28) , Alguns autores (20) propõem a não utilização de solvente orgânico durante a lavagem das microesferas, que são imersas diretamente em solução de amônia a uma temperatura de 80 ºC, com posterior lavagem em água destilada, também a 80 ºC.…”

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Efeitos de variáveis do processo de gelificação interna nas propriedades físicas e químicas de microesferas de alumina

Christe¹

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Ceramic microspheres have been used in various applications, related to the nuclear, pharmaceutical, chemical, medical, environmental, biotechnology, etc. It is possible to obtain, by internal gelation method, microspheres of different ceramic materials, dense or porous (with controlled porosity) and different sizes. However, the major obstacle is the formation of cracks on drying and / or calcination, which can hinder their use. This study have an objective at the production of alumina (Al 2 O 3) based microspheres by internal gelation process, varying processing parameters in order to control the chemical and physical characteristics such as size, porosity, specific surface area, etc., in addition to specific characteristics that enable their application in filling of the elution columns of 99 Mo-99m Tc generators. It was developed a simple and efficient method of washing treatment of the microspheres, which enables the extraction of a significant portion of the organic phase present prior to drying and calcination; thus virtually eliminates all cracks that arise during drying, and particularly in calcination step. In addition, process parameters were varied for controlling the porosity and specific surface of the microspheres. Were also characterized in parallel, two transition aluminas in the form of powders currently used in filling of elution columns of 99 Mo-99m Tc generator so as to get an idea of the current requirements for physical properties of the filling material.

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Efeitos de variáveis do processo de gelificação interna nas propriedades físicas e químicas de microesferas de alumina

Christe¹

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Impurity levels in cerium oxide microspheres prepared by internal gelation sol–gel methods

Katalenich

2019

J Sol-Gel Sci Technol

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Use of a pressurized water treatment to prevent cracking of internal gelation sol-gel microspheres

Katalenich

2020

J Sol-Gel Sci Technol

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Determination of Ideal Broth Formulations Needed to Prepare Hydrous Aluminum Oxide Microspheres via the Internal Gelation Process

Cited by 4 publications

References 6 publications

Efeitos de variáveis do processo de gelificação interna nas propriedades físicas e químicas de microesferas de alumina

Efeitos de variáveis do processo de gelificação interna nas propriedades físicas e químicas de microesferas de alumina

Impurity levels in cerium oxide microspheres prepared by internal gelation sol–gel methods

Use of a pressurized water treatment to prevent cracking of internal gelation sol-gel microspheres

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