Open Access Theses and Dissertations

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You searched for subject:(Biphasic separation). Showing records 1 – 3 of 3 total matches.

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1. Belchior, Diana Cléssia Vieira. Application of aqueous biphasic systems for the separation of amino acids and proteins .

Degree: 2019, Universidade de Aveiro

URL: http://hdl.handle.net/10773/29456 

This work was focused on the application of aqueous biphasic systems (ABS) composed of tetraalkylammonium-based ionic liquids (ILs) aiming at developing more effective separation processes for amino acids and proteins. It is first demonstrated the impact of the alkyl chain length of the IL anion on the ABS formation and on these systems performance to extract amino acids, where odd-even effects have been identified. ILs composed of anions with even alkyl chains exhibit a slightly higher capacity to form ABS, whereas systems formed by ILs with anions comprising odd alkyl chains lead to slightly higher amino acid partition coefficients. After addressing the ILbased ABS performance to extract amino acids, it is then demonstrated the influence of the IL chemical structure and the effect of pH on the extraction and recovery yield of ovalbumin and lysozyme, two proteins present in egg white. At pH 7, the complete extraction and recovery of lysozyme to the ILrich phase was achieved with all systems; however, low ovalbumin recovery yields were obtained with ABS formed by ILs with longer alkyl side chains. Molecular docking studies revealed that ILs that preferentially establish hydrophobic interactions with these proteins lead to their aggregation and lower recovery yields. The recovery of the proteins (up to 99%) from the ILrich phase by precipitation with ice-cold ethanol was also demonstrated. Finally, polymer-salt ABS comprising ILs as adjuvants (at 5 wt%) were investigated to tailor the phases polarities and these systems selectivity to simultaneously separate ovalbumin and lysozyme. Studies with commercial proteins and directly from egg white were carried out. With the systems in which no IL was added it was observed a preferential partition of ovalbumin to the polymer-rich phase, which contains the IL, whereas lysozyme tends to precipitate at the interphase. A similar trend was observed when applying the same systems to separate both proteins from egg white. However, when ILs are added, the ovalbumin and lysozyme preferentially partition to the salt-rich and PEG-rich phases, respectively, while avoiding the precipitation of the latter protein. Nevertheless, when the same systems are applied to egg white, the same behavior was not observed, indicating that a more complex phenomenon occurs due to the presence of other proteins in egg white. Although further research on the viability of some of the studied ILs and systems is still required, the results presented in this work disclose the relevance of ABS comprising ILs in the development of efficient separation processes for amino acids and proteins. Advisors/Committee Members: Duarte, Iola Melissa Fernandes (advisor), Martins, Guadalupe Freire (advisor).

Subjects/Keywords: Aqueous biphasic system; Ionic liquid; Polymer; Extraction; Separation; Amino acids; Proteins

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Belchior, D. C. V. (2019). Application of aqueous biphasic systems for the separation of amino acids and proteins . (Thesis). Universidade de Aveiro. Retrieved from http://hdl.handle.net/10773/29456

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Belchior, Diana Cléssia Vieira. “Application of aqueous biphasic systems for the separation of amino acids and proteins .” 2019. Thesis, Universidade de Aveiro. Accessed January 18, 2021. http://hdl.handle.net/10773/29456.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Belchior, Diana Cléssia Vieira. “Application of aqueous biphasic systems for the separation of amino acids and proteins .” 2019. Web. 18 Jan 2021.

Vancouver:

Belchior DCV. Application of aqueous biphasic systems for the separation of amino acids and proteins . [Internet] [Thesis]. Universidade de Aveiro; 2019. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/10773/29456.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Belchior DCV. Application of aqueous biphasic systems for the separation of amino acids and proteins . [Thesis]. Universidade de Aveiro; 2019. Available from: http://hdl.handle.net/10773/29456

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. Broeke, J. (Joep) van den. Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media.

Degree: 2003, University Utrecht

URL: https://dspace.library.uu.nl/handle/1874/771  ; URN:NBN:NL:UI:10-1874-771 ; 1874/771 ; URN:NBN:NL:UI:10-1874-771 ; https://dspace.library.uu.nl/handle/1874/771 

The recycling of homogeneous catalysts is highly desirable from both an environmental and an economical point of view. However, the fact that catalysts and products are distributed homogeneously throughout the reaction mixture hampers catalyst separation. An elegant approach facilitating catalyst recovery is its immobilisation in a liquid support. Three solvent systems that have shown promise in this respect are fluorous biphasic solvent systems, supercritical carbon dioxide and ionic liquids. This thesis addresses the development of highly fluorous tetraarylborate anions which can be employed as such, or in combination with fluorous ligands, to enhance the solubility and performance of ionic catalysts in perfluorinated solvents and supercritical carbon dioxide. Furthermore, these anions have been used in the design of ionic liquids with unprecedented physical properties.

Subjects/Keywords: homogeneous catalysis; tetraarylborate anions; fluorous biphasic catalyst separation; supercritical carbon dioxide; ionic liquids

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Broeke, J. (. v. d. (2003). Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media. (Doctoral Dissertation). University Utrecht. Retrieved from https://dspace.library.uu.nl/handle/1874/771 ; URN:NBN:NL:UI:10-1874-771 ; 1874/771 ; URN:NBN:NL:UI:10-1874-771 ; https://dspace.library.uu.nl/handle/1874/771

Chicago Manual of Style (16th Edition):

Broeke, J (Joep) van den. “Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media.” 2003. Doctoral Dissertation, University Utrecht. Accessed January 18, 2021. https://dspace.library.uu.nl/handle/1874/771 ; URN:NBN:NL:UI:10-1874-771 ; 1874/771 ; URN:NBN:NL:UI:10-1874-771 ; https://dspace.library.uu.nl/handle/1874/771.

MLA Handbook (7th Edition):

Broeke, J (Joep) van den. “Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media.” 2003. Web. 18 Jan 2021.

Vancouver:

Broeke J(vd. Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media. [Internet] [Doctoral dissertation]. University Utrecht; 2003. [cited 2021 Jan 18]. Available from: https://dspace.library.uu.nl/handle/1874/771 ; URN:NBN:NL:UI:10-1874-771 ; 1874/771 ; URN:NBN:NL:UI:10-1874-771 ; https://dspace.library.uu.nl/handle/1874/771.

Council of Science Editors:

Broeke J(vd. Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media. [Doctoral Dissertation]. University Utrecht; 2003. Available from: https://dspace.library.uu.nl/handle/1874/771 ; URN:NBN:NL:UI:10-1874-771 ; 1874/771 ; URN:NBN:NL:UI:10-1874-771 ; https://dspace.library.uu.nl/handle/1874/771


Universiteit Utrecht

3. Broeke, J. (Joep) van den. Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media.

Degree: 2003, Universiteit Utrecht

URL: http://dspace.library.uu.nl:8080/handle/1874/771 

The recycling of homogeneous catalysts is highly desirable from both an environmental and an economical point of view. However, the fact that catalysts and products are distributed homogeneously throughout the reaction mixture hampers catalyst separation. An elegant approach facilitating catalyst recovery is its immobilisation in a liquid support. Three solvent systems that have shown promise in this respect are fluorous biphasic solvent systems, supercritical carbon dioxide and ionic liquids. This thesis addresses the development of highly fluorous tetraarylborate anions which can be employed as such, or in combination with fluorous ligands, to enhance the solubility and performance of ionic catalysts in perfluorinated solvents and supercritical carbon dioxide. Furthermore, these anions have been used in the design of ionic liquids with unprecedented physical properties.

Subjects/Keywords: Scheikunde; homogeneous catalysis; tetraarylborate anions; fluorous biphasic catalyst separation; supercritical carbon dioxide; ionic liquids

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❌

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Broeke, J. (. v. d. (2003). Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media. (Doctoral Dissertation). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/771

Chicago Manual of Style (16th Edition):

Broeke, J (Joep) van den. “Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media.” 2003. Doctoral Dissertation, Universiteit Utrecht. Accessed January 18, 2021. http://dspace.library.uu.nl:8080/handle/1874/771.

MLA Handbook (7th Edition):

Broeke, J (Joep) van den. “Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media.” 2003. Web. 18 Jan 2021.

Vancouver:

Broeke J(vd. Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media. [Internet] [Doctoral dissertation]. Universiteit Utrecht; 2003. [cited 2021 Jan 18]. Available from: http://dspace.library.uu.nl:8080/handle/1874/771.

Council of Science Editors:

Broeke J(vd. Highly Fluorous Tetraarylborate Anions : Versatile Counterions for Homogeneous Catalysis in Novel Reaction Media. [Doctoral Dissertation]. Universiteit Utrecht; 2003. Available from: http://dspace.library.uu.nl:8080/handle/1874/771

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