Use this URL to cite or link to this record in EThOS:
Title: Studies of ion exchange membranes, with particular focus on synthesis of cation exchange membranes
Author: Jiang, Shanxue
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2020
Availability of Full Text:
Access from EThOS:
Access from Institution:
A series of studies on ion exchange membranes (IEMs), with a particular focus on synthesis of cation exchange membranes (CEMs), were carried out in this thesis. Firstly, a comprehensive statistical study was carried out on the research of IEMs via a scientometric approach. It was found that, from 2001 to 2016, over 18000 articles were published on IEMs. Also, these articles were spread across over 1000 different journals, nearly 100 countries/regions and over 5000 research institutes. Secondly, in this thesis, different methods to prepare CEMs were discussed. It was found that membranes prepared without support was very fragile. Therefore, a support was necessary. Also, it was found that linear polystyrene sulfonate was not suitable for making CEMs. In order to prepare good CEMs, the functional polymers had to be cross-linked. Therefore, chemical reaction was necessary which could introduce new bonds to make crosslinking happen. Thirdly, a new methodology was proposed for making CEMs with high ion exchange capacity (IEC) using porous membrane support and functional polymers. The synthesized membranes demonstrated superior IEC. Besides, the semi-finished membrane demonstrated hydrophobic property while the final membranes showed super hydrophilic property. In addition, when sulfonation reaction time increased, the conductivity of membranes also showed a tendency to increase. Fourthly, another effective methodology to prepare high performance CEMs was proposed. Water as selected as the solvent and also no sulfonation was needed. A series of membranes were synthesized using this methodology and different preparation conditions were investigated. Water played an important role in membrane synthesis. IEC could be greatly increased by reducing the amount of water used for synthesis. The synthesized membranes demonstrated high electrodialysis performance. It is envisioned that this one-step synthesis methodology may open up new possibilities for synthesis of IEMs in an effective and environment-friendly way.
Supervisor: Ladewig, Bradley Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral