ADSORPTION AND ADVANCED MATERIALS

The creation of super adsorbent nano materials with the potential to make chemotherapy less toxic, to improve gas storage and transportation, and improve gas filtration

There is an endless number of possibilities for MOF structures

The performance of MOFs in computer simulations (red) are almost identical to their performance in lab experiments (black)

Our workOur work focuses on enhancing adsorption on porous materials. By creating new materials with a porosity on a nano scale, we are enabling high levels of adsorption in very small spaces, or super adsorption. In particular we are working on creating new nano metal-organic frameworks, or MOFs, which have the highest surface area of any porous material (10,000 m2 per gram), that is hundreds of times greater than classic materials.

What is a MOF?

MOFs are a new class of high surface area nano-materials, akin to graphene. We create the structures by combining metals (as corner units) and organic molecules (as linkers). Their pores are up to 6 nm in size. They can encapsulate therapeutic agents (such as drugs) as well as hold gases or purify mixtures that will also diffuse through the MOFs. MOFs can be synthesised (or created) with a particle size from 150 nm to several microns.

Methodology

We design and study MOFs first on computers using molecular simulation and so tailor them to our needs. This allows us to predict the properties of thousands of materials virtually – their adsorption capacity or selectivity and how guest molecules (eg drugs) diffuse through the MOFs – before creating them in the lab. Our virtual results are highly accurate (see graph). Due to this process, there is an endless number of possibilities, with more than 40,000 existing MOFs so far.

MOFs photographed using electonic microscopy shown here at 10,000 times their actual size

http://www.ceb.cam.ac.uk/data/files/cebdeptlogo.jpg[06/11/2014 14:34:02]

Creating a metal-organic framework (MOF) from metal (red) and organic ligands (blue)

Applications we are currently working on

1. Less toxic drug deliveryMOFs have the potential to deliver drugs (including siRNAs and small peptides) in a more targeted and timely way, with the potential of radically improving patients’ experience of treatments for Alzheimer’s and chemotherapy for cancer. This comes from the fact that we have designed MOFs to release, or ‘desorb’, drugs slowly. Work is at advanced stage.

2. Cheaper separation of gasses, including CO2 captureMOFs are effective agents for separating gasses. Applications include gas masks which need to separate oxygen from toxic gasses in the environment, and many processes in the petro-chemical industry. CO2 capture: MOFs can quite cheaply adsorb CO2 and have the potential to reduce the amount of CO2 emitted by power stations at lower cost. Work is at advanced stage.

3. More efficient gas storageMOFs inserted into gas canisters can adsorb large amounts of gas such as oxygen, hydrogen or methane. This reduces the pressure inside the canister by 75%, which therefore needs less thick walls and is lighter and cheaper to transport. Work is at advanced stage.

Our techniques and skills• Molecular simulation techniques: grand canonical Monte Carlo

(GCMC) and molecular dynamics (MD).• Synthesis and engineering of optimal materials: synthesis of

MOF nanocrystals and other porous materials• Shaping of materials: creating membranes, pellets, monoliths, etc.• Characterisation: Gas adsorption, PXRD, mechanical essays, SAXS. • Performance: Pressure Swing Adsorption and Temperature Swing

Adsorption (PSA, TSA), dynamic adsorption, drug delivery in vivo and in vitro

How does our work differ from existing technologies? We are the only team in Cambridge working on adsorption technologies, porous materials and MOFs. We are unique worldwide in integrating computational studies with experimental performance to study not only gas adsorption but also drug delivery. No other researchers apply this integral methodology.

Current industrial partnerships• With Johnson Matthey on shaping MOFs for gas adsorption

applications• With BP on gas purification

‘Blue sky’ applications• Liquid phase adsorption (xylene separations,

water remediation, chiral separation)• Catalysis (Fischer Tropsch)• Photo-luminiscent sensors• Cryopreservation

Dr David Fairen-Jimenez, University of Cambridge, Department of Chemical Engineering and Biotechnology, Pembroke Street, Cambridge, CB2 3RA Tel: 0044 1223 334785 Email: df334@cam.ac.uk Web: http://people.ds.cam.ac.uk/df334

Current chemo drugs are released too fast showing a burst effect, which means higher levels of chemo drugs tend to be administered than are needed in order to impact on the cancer, with damaging side effects. Our MOFs desorb drugs gradually over 40 or 50 days. They can also be designed with binding agents to improve target tissue recognition.

The team

ADSORPTION AND ADVANCED MATERIALS continued

Optical pictures of a standard powder MOF (left) and a mechanically robust monolithic MOF ontained without using any binders or high pressure.

CNG Tank MOF Tank

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MOFs inserted into a gas canister reduces the pressure by 75%.

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