Título: | GELLAN-BASED MICROCAPSULES: PRODUCTION AND APPLICATIONS | ||||||||||||
Autor: |
BRUNA COSTA LEOPERCIO |
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Colaborador(es): |
MARCIO DA SILVEIRA CARVALHO - Orientador MARIANO MICHELON - Coorientador |
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Catalogação: | 11/JUN/2021 | Língua(s): | ENGLISH - UNITED STATES |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=53226&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=53226&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.53226 | ||||||||||||
Resumo: | |||||||||||||
Microcapsules are applied in several sectors of industry when a physical
barrier between the core material and the external environment is required. They
protect their cargo and ultimately release it in a controlled way. In the present
work, microcapsules with hydrogel-based shells are produced. Monodispersed
microcapsules are formed by ionotropic gelation of gellan gum from monodispersed
oil-in-water-in-oil (O/W/O) double emulsion templates obtained using glasscapillary
microfluidic devices. An oil extraction step was added after the shell
gelation process to enable the dispersion of the microcapsules in an aqueous medium.
We report the operability window for the production of monodispersed
microcapsules as a function of the flow rate of each fluid phase and the dimensions
of the device. Microcapsules with mean diameters ranging from 95 to 260
um and a maximum coefficient of variation of 5 per cent were formed. The results show
how to independently control the capsule diameter and shell thickness by varying
the outer and middle phase flow rates. After that, we experimentally investigate
the flow of monodispersed gellan gum microcapsules through a constricted capillary
tube by measuring the evolution of the pressure difference and flow visualization.
The maximum pressure difference and capsule deformation is obtained
for capsules with different diameter and shell thickness. We map the conditions
at which the capsule membrane ruptures during the flow, releasing its internal
phase. Then, the gastro-resistance of gellan microcapsules is verified through an
in vitro test that mimics the gastric and intestinal phases of digestion. Confocal
fluorescence microscopy is used to track microcapsules integrity and we show
that microcapsules cargo is released in the intestine mostly due to its pH. Finally,
we demonstrate that it is possible to produce magnetic microcapsules with well
controlled magnetic response by adding different amounts of ferrofluid to their
core or shell. The microcapsules produced have great potential for different applications
in food, biomedical, pharmaceutical and oil and gas industries.
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