Porous Liquids (PLs): Understanding, scope and applications

Lead Research Organisation: Queen's University of Belfast
Department Name: Sch of Chemistry and Chemical Eng


The invention of new materials with useful properties is essential to meet global challenges, such as generating energy cleanly and using it efficiently. The invention of Porous Liquids (PLs), recently reported jointly by the investigators in this project [Nature 2015, 527, 216], is an important advance with broad implications for future technologies. PLs are liquids which have permanent holes (micropores) within them, and as such are hybrids of two well-known and widely-used classes of material, specifically microporous solids and liquid solvents. Each of these classes of material provide the basis for many current industries globally. PLs bring together the ability to selectively absorb large amounts of gas (as with microporous solids) with the ability to flow (as with liquids). With development, they are expected to become the basis of a range of new technologies in the coming years.
The vision of this proposal is that through greater basic understanding and application-driven development, PLs will ultimately provide the basis for new technologies in the areas of clean energy, chemical separations and as 'super solvents' - advances that would not be possible with porous solids or conventional liquid solvents alone.
This project has been designed as a critical step toward reaching this goal. Initially, we will obtain better basic understanding of these material by studying how they absorb, transport and release various industrially important gases, under a range of conditions. We will also synthesise new types of PLs with a range of different compositions and structures to understand better the full scope of this new class of materials, and how the structure and composition may ultimately be used to design the materials for a specific application. Computational modelling will be used to provide accurate molecular-scale models of these PLs which will help in understanding their observed properties. Based upon these findings we will begin to explore possible future applications for PLs, such as in more energy-efficient industrial gas separation processes, safer chemical processes and more efficient battery technology. Overall the project will be a key step in realizing technical and commercial benefits to the UK from the invention of this new class of materials. The project is multidisciplinary, involving experts in materials synthesis, computational modelling and chemical engineering and will provide a first rate training for three early-career scientists in this exciting new field.

Planned Impact

We have a strong collective track record in achieving impact based on fundamental science and are committed to this in the future. The PI, SLJ, founded a spin-out company, MOF Technologies (www.moftechnologies.com), in 2012 based on IP arising from an EPSRC-sponsored project (GR/T23145/01, 'Solventless synthesis of metal organic frameworks,' £113K, 2005-2008). He acted as CTO until Series A funding was secured in 2016. MOF Technologies now employs 12 staff and in 2016 enabled the first commercial application for a MOF (in partnership with Decco US Post Harvest Inc.), which is a major milestone for the impact of these materials. Likewise, AIC was a scientific cofounder of IOTA NanoSolutions Ltd (now trading as Tandem Nano Ltd), and is an inventor of its primary patent base (e.g., WO2004/011537A1, WO2005/075546A1, http://www.tandemnano.com/patents). This colloid technology also stemmed from EPSRC-funded science (GR/N39999/01). More recently, we initated discussions to commercialize a pollutant capture technology arising from an EPSRC Programme Grant in 2014 (EP/H000925/1).

A further spin-out company is currently being considered to advance PL technologies, and discussions are being held with potential stakeholders. IP generated through this EPSRC project will belong to QUB and/or U Liv depending on where Invention Disclosure Documents are filed (an agreement will be drawn up prior to project commencement). IP may be licensed to the new spin-out or to more established companies, as appropriate. A partnership between QUB and Shell has been developing since 2015 (see Letter of Support). Discussions with Shell have identified potential applications in sour gas sweetening (Task 6.1). Current amine-based scrubbing methods are problematic in terms of the energetics for amine regeneration, corrosion, and toxicity. If made scalable, PLs are uniquely poised to solve these problems with minimal or no retrofitting of plant. MOF Technologies may also be interested in exploiting he outcomes of this project, especially since Type 3 PLs (Task 4) contain MOFs, providing a new avenue for the commercialisation of MOF materials. We will also develop further potential stakeholders by organizing up to five industrial visits to QUB and/or Liverpool for one-to-one clinics to demonstrate the continuous flow gas separation process (Task 6.1 in the Case for Support) or other developments (e.g., porous electrolytes, Task 6.3).

We will provide up to 6 summer studentships over the grant period for undergraduates and potentially school students in order to provide them with potentially career-changing experience. Porous liquids are at the cutting edge of materials research, as evidenced by our publication in Nature in late 2015, and we will seek to disseminate the results from this project at a comparable level. Academic conferences will be used to disseminate the work to academia and industry, where present. The new £68M Materials Innovation Factory in Liverpool offers additional possibilities for industrial engagement (>100 industry researchers to be collocated there as of Q2 2017). For advocacy, we will engage with the media to disseminate results to non-academic researchers and the general public; PLs have attracted much media attention since 2015 from national press and radio (e.g., SLJ explained these materials on the Radio 4 World at One programme in 2015) as well as over 200 online sources, and we anticipate high levels of interest for our new findings. We will set up a dedicated web site to publicize the project to the public and to act as a focus to interact with industrialists and media. We will also commission a professional video for dissemination via this web site and YouTube. Lastly, the two PDRAs will establish and manage a dedicated Twitter feed on the subject of PLs to highlight progress in this new field, either in our project or in others, and to serve as a discussion forum for researchers interested in this subject.


10 25 50
Description We have found that certain porous liquids are highly compressible. This is a fundamental finding that may be important. Specifically, whereas gases are known to be easily compressed, liquids are not because their constituent molecules are closely packed. We have demonstrated that correctly designed porous liquids can be far more compressible than normal liquids (around 4 times greater so far) since under pressure molecules of the liquid are able to move into the pore space.
We have also begun to identify other molecular structures that can be used to generate porous liquid phases. These materials are easier to synthesise and are mosre chemically and thermally stable than our original materials. We have also demonstrated for the first time that porous liquids are a highly flexible platform of materials that may be tuned toward challenging applications such as gas separations. Specifically, as detailed in our recent paper (Chemical Science, 2020, doi. 10.1039/C9SC05770F ) we have massively increased the number of known porous liquids (we reported 90 new ones, whereas only around 10 were known previously), and we showed that they can out-perform exisiting solvents for natural gas and biogas sweetening. We also showed that they have promise for ethane-ethene separation and may even be engineered to be biocompatible, or indeed edible.
Exploitation Route To date the findings are fundamental, but we have begun a dialogues with researchers in the governament defence sectors regarding potential future applications in shock energy absorption. WE are actively pursing possible applications through our spin-out company, Porous Liquid Technologies Ltd. Further funding has been secured from InvestNI (£250K) to take the biogas upgrading work from TRL4 to 5 with an on-site demonstration.
Sectors Aerospace, Defence and Marine,Chemicals,Energy

Description Analysis of porous liquids by Positron Annihilation Lifetime Spectroscopy (PALS) 
Organisation University of Bristol
Country United Kingdom 
Sector Academic/University 
PI Contribution We provided samples for analysis and discussion of results.
Collaborator Contribution They analysed our materials using PALS and determined unambiguously the presence of pores in one liquid phase and the absence of pores in another, in line with our predictions.
Impact Publication submitted to Angewandte Chemie International Edition, under review.
Start Year 2017
Description Continuous Solventless Synthesis of porous organic cages by twin screw extrusion 
Organisation University of Liverpool
Department Department of Chemistry
Country United Kingdom 
Sector Academic/University 
PI Contribution We have hosted and trained a visiting PDRA for two weeks in the use of twin screw extrusion for the synthesis of novel materials developed at Liverpool, specifically porous organic cages. We have held discussions with the PI Prof. Andy Cooper subsequently and are drafting a paper.
Collaborator Contribution Provided PDRA visit for two weeks and held discussion of results.
Impact The work was successful and showed that such compounds were amenable to this type of synthesis for the first time. We are drafting a joint paper and considering a patent application as well as potential follow-up work. The project is significant in demonstrating an economic and scalable way to make these materials and so makes their application more realistic.
Start Year 2017
Description Study of compressible liquids by neutron scattering 
Organisation Rutherford Appleton Laboratory
Country United Kingdom 
Sector Academic/University 
PI Contribution We have provided samples and conducted experiments at RAL.
Collaborator Contribution They provided expertise in the design of the experiments, running the experiments and interpretation of the findings.
Impact This collaboration has provided exciting proof-of-principle data that show high compressibility of ceretain porous liquid phases (conventional liquids are effectively incompressible). This is potentially very significant work which we hope will lead on to high-profil publications and further EPSRC support. There is potential for applications in the area of shock absorption.
Start Year 2019
Description Spin-out from Queen's University Belfast and University of Liverpool. Has exclusive licenses to porous liquid IP from both universities. Pursuing a number of possible commercial opportunities for porous liquids in gas separations and liquid-liquid separations. 
Year Established 2017 
Impact Around 30 significant contacts/discussions with potential partner companies to date.
Website http://www.porousliquidtechnologies.com/
Description Invited presentations 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited presentations including closing Plenary Lecture at a 500+ delegate event (MOF2019) in Paris, at KAUST (KAUST Research Conference: Advanced materials for energy-efficient separations: Addressing Vision 2030 and beyond) in 2020. Attended primarily by academics but also industrialists. .
Year(s) Of Engagement Activity 2019,2020
Description Johnson Matthey 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact A visit to the Johnson Matthey Technology Research Centre to present and discuss our work on synthesis by extrusion and how it might relate to future joint work.
Year(s) Of Engagement Activity 2017