Novel thin film composite membranes for solvent-based molecular separation
File(s)
Author(s)
Liu, Dezhi
Type
Thesis or dissertation
Abstract
Membranes are semi-permeable filter materials that are broadly used in separation industries. Polyamide thin film composite membranes can be massively produced via interfacial polymerization directly on porous supporting substrates. Over the past decade, facilitated mass transport in microporous membranes and minimizing transport resistance by reducing membrane thickness have drawn great interests. Alas, ultra-thin membranes have poor mechanical properties. Additional gutter layer and backing substrate must be used in composite membrane production which raises greater costs and technical challenges in the process.
Here in this thesis, a new interfacial synthesis mechanism was revealed to prepare microporous polyamide thin film membranes. This work shows crosslinked asymmetric membranes with well defined separate pore structures can be prepared from singular independent interfacial polymerization.
This new mechanism takes advantage of microporosity in the synthesized solid polymer film, and could achieve one-piece integrated membranes with sub-100nm selective skin layer with autonomous micron-level porous support layer, coupled with superior solvent permeability and selectivity in organic solvent nanfiltration.
PIM-type amine-functionalized molecules with tetra-planar contortion were used to react with acylchlorides. From singular interfacial synthesis of self-supported polyamide (SPA) membranes, selective skin layer and a porous supporting layer can be prepared through one-step reaction and one
set of reagents. This represents a benchmark discovery to prepare asymmetric crosslinked membranes. Further, enantiomeric separation in static diffusion was achieved using DBMPA-TPC thin film composite membrane functionalized by (R)-binaphthalene diamine (RBA). ~16% enantiomeric
excess was stable in the permeate over 196 hour operation. In addition, thin film composite membranes with semi-crystalline TAPA-TFP skin layers have been prepared from templated growth method. TAPA-TFP and PPD-TFP thin film composite membranes show promising performances in
neutral pH redox flow batteries.
Here in this thesis, a new interfacial synthesis mechanism was revealed to prepare microporous polyamide thin film membranes. This work shows crosslinked asymmetric membranes with well defined separate pore structures can be prepared from singular independent interfacial polymerization.
This new mechanism takes advantage of microporosity in the synthesized solid polymer film, and could achieve one-piece integrated membranes with sub-100nm selective skin layer with autonomous micron-level porous support layer, coupled with superior solvent permeability and selectivity in organic solvent nanfiltration.
PIM-type amine-functionalized molecules with tetra-planar contortion were used to react with acylchlorides. From singular interfacial synthesis of self-supported polyamide (SPA) membranes, selective skin layer and a porous supporting layer can be prepared through one-step reaction and one
set of reagents. This represents a benchmark discovery to prepare asymmetric crosslinked membranes. Further, enantiomeric separation in static diffusion was achieved using DBMPA-TPC thin film composite membrane functionalized by (R)-binaphthalene diamine (RBA). ~16% enantiomeric
excess was stable in the permeate over 196 hour operation. In addition, thin film composite membranes with semi-crystalline TAPA-TFP skin layers have been prepared from templated growth method. TAPA-TFP and PPD-TFP thin film composite membranes show promising performances in
neutral pH redox flow batteries.
Version
Open Access
Date Issued
2024-03-14
Date Awarded
2024-10-01
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Song, Qilei
Livingston, Andrew G
Sponsor
China Scholarship Council
European Research Council
Exactmer Limited (Firm)
Publisher Department
Chemical Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)