Abstract
Membrane technology is a well-developed technology and membranes are used in a wide range of applications, such as wastewater treatment, and fractionation of products in the food industry. However, the application of membranes under more demanding industrial conditions is more challenging, mainly because of the limited stability of commercial membranes. Therefore, research has focused on the development of new types of membranes that have improved stability, and that can expand the range of membrane applications. This thesis focuses on the synthesis of such new types of membranes, for two types of demanding applications. Firstly, nanofiltration membranes for use under extreme pH conditions. Secondly, membranes for hot gas separation applications.
Chapter 2, involves the synthesis of poly(aryl cyanurate) NF membranes by interfacial polymerization of 1,1,1-tris(4-hydroxyphenyl)ethane and cyanuric chloride. The resulting network does not contain the hydrolysis susceptible carbonyl group that limits the stability of traditional polyamide NF membranes, and therefore is expected to have a superior pH stability.
Secondly, in Chapter 3, a new organic phase monomer is studied; 1,3,5-tris(bromomethyl)benzene. Thin-film composite nanofiltration membranes are prepared by interfacial polymerization of this monomer with the traditional amines para- and meta-phenylenediamine. In these membranes, again, the lack of carbonyl groups is expected to lead to pH stable membranes.
Layer-by-layer coating of polyelectrolyte multilayers is an alternative approach to prepare pH stable NF membranes. In Chapter 4, a systematic study towards the pH stability of four different PEM NF membranes is presented. The systems studied represent combinations of both strong polyelectrolytes (charged over the full pH regime) and weak polyelectrolytes (charge dependent on pH), allowing for a comprehensive study of the effect of choice of polyelectrolyte on the final pH stability.
In Chapter 5, a new type of thermally stable gas separation membrane is introduced, prepared by interfacial polymerization on top of a ceramic support. For this, hexachlorocyclotriphosphazene is reacted with octa aminopropyl POSS. The resulting hybrid network is highly cross-linked, which is expected to lead to a high thermal stability.
Chapter 6 reflects on the obtained results in this thesis, discusses the challenges faced in this work and gives recommendations for future work.
Chapter 2, involves the synthesis of poly(aryl cyanurate) NF membranes by interfacial polymerization of 1,1,1-tris(4-hydroxyphenyl)ethane and cyanuric chloride. The resulting network does not contain the hydrolysis susceptible carbonyl group that limits the stability of traditional polyamide NF membranes, and therefore is expected to have a superior pH stability.
Secondly, in Chapter 3, a new organic phase monomer is studied; 1,3,5-tris(bromomethyl)benzene. Thin-film composite nanofiltration membranes are prepared by interfacial polymerization of this monomer with the traditional amines para- and meta-phenylenediamine. In these membranes, again, the lack of carbonyl groups is expected to lead to pH stable membranes.
Layer-by-layer coating of polyelectrolyte multilayers is an alternative approach to prepare pH stable NF membranes. In Chapter 4, a systematic study towards the pH stability of four different PEM NF membranes is presented. The systems studied represent combinations of both strong polyelectrolytes (charged over the full pH regime) and weak polyelectrolytes (charge dependent on pH), allowing for a comprehensive study of the effect of choice of polyelectrolyte on the final pH stability.
In Chapter 5, a new type of thermally stable gas separation membrane is introduced, prepared by interfacial polymerization on top of a ceramic support. For this, hexachlorocyclotriphosphazene is reacted with octa aminopropyl POSS. The resulting hybrid network is highly cross-linked, which is expected to lead to a high thermal stability.
Chapter 6 reflects on the obtained results in this thesis, discusses the challenges faced in this work and gives recommendations for future work.
| Original language | English |
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| Qualification | Doctor of Philosophy |
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| Supervisors/Advisors |
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| Award date | 19 Mar 2021 |
| Place of Publication | Enschede |
| Publisher | |
| Print ISBNs | 978-90-365-5118-2 |
| DOIs | |
| Publication status | Published - 19 Mar 2021 |