Summer Research Experience Program

2019–2020 projects

2019–2020 applications are closed.

1. Development of nitrogen selective adsorbents

Supervisor: Dr Gang (Kevin) Li

Adsorption is an important technique for gas separation. In this project, a major research project on adsorbents synthesis and characterisation will be conducted to accommodate the purpose of separating N2 from CH4 for the purpose of nitrogen rejection in natural gas purification. The student is expected to have a sound knowledge of coordination chemistry.

2. Wearable energy harvesters from piezoelectric polymers

Supervisors: Dr Peter Sherrell, Prof Amanda Ellis

Capturing the energy of human motion will allow for the development of a new generation of wearable electronic devices that don’t need a traditional power source. These energy harvesting devices need to be light weight, durable, moisture resistance, and flexible so they can harvest energy without restricting motion or causing discomfort. To maintain power supply during sleep or sedentary periods the energy harvester needs to be coupled to an energy storage device to regulate energy delivery to the device. Polymer piezoelectric are flexible, transparent and lightweight and have emerged as promising materials to harvest the power from human motion, and flexible, lightweight graphene supercapacitors are excellent energy storage options for wearable electronics. Combining these energy devices, which work on different timescales and energy storage principles is challenging, however it is crucial to achieve for future wearable electronic devices.

This project will investigate how we can best couple polymer piezoelectric energy harvesters with planar and flexible graphene supercapacitors. During this project the student will develop skills in electrochemistry, thin film preparation, supercapacitor devices, and develop a deep knowledge of graphene and 2D materials, working in a collaborative environment to test an integrated piezo-supercapacitor energy harvesting device.

3. Investigating reversible DNA-based biomaterials

Supervisors: Dr Simone Hendrikse, Prof Amanda Ellis

Thousands of people suffer each year from organ failure. To recover lost organ function, organ transplantation is required. The ever-growing transplantation waiting list, however, forces patients to wait several years before an organ with the right match is being appointed. Therefore, there is an increasing need for growing patient-specific tissues in a dish on demand to treat patients in short time frames.

In order to grow tissue in a dish, a specific 3D cellular environment is necessary to aid in cell growth, self-organisation and commitment. Rather than utilising ill-defined animal-extracted proteins, synthetic biomaterials serve as promising candidates to arrive at this goal. In our group, DNA is used as a versatile tool to fabricate polymers with pendant DNA groups allowing complementary sequence recognition. These specific temporary interactions allows us to fabricate reversible hydrogels with high control. A library of homo- and copolymers with pendant DNA nucleotides are being fabricated to investigate biomaterial properties. In addition, detailed studies are being performed to understand polymer-DNA interactions to further tune the system. The student will assist in both synthesizing new polymers, as well as investigating the materials properties.

4. Tweaking polymers through ultrasound

Supervisors: Prof Greg Qiao, Mr Amrish Kumar

The development of controlled/living radical polymerizations (CRP) is among the most important advances in polymer chemistry of the last decade offering outstanding control over polymer molecular weight, polydispersity and pre-determined physical properties. Traditionally, chemical initiators are used to trigger the radical polymerization leading to issues with product contamination and safety concerns, especially for food and healthcare products. To address this, we recently developed the use of ultrasound to generate the required radical species directly from the solvent, thereby eliminating the need for an exogenous chemical initiator.

This project will investigate the use of applying ultrasound to prepare new polymers with desirable chemical and physical properties. The student will learn a wide array of advanced laboratory techniques, including synthesis and characterisation, with the potential to contribute their findings to a major scientific journal. This project would be suited to a student with an interest in bridging applied chemistry and chemical engineering.

Prof Greg Qiao’s Group

5. Peptide eco-polymers: synthesis of next generation renewable plastics

Supervisors: Dr Paul Gurr, Prof Greg Qiao

Amino acids have evolved over millions of years to be the building blocks of proteins and life on Earth. The potential of this molecular paradigm can be seen in many examples of proteins that have exceeded the properties of man-made materials. For example, spider silk has miraculous mechanical properties due to its secondary structure, combining (high tensile) strength and stretch (extensibility)1. Unlike synthetic plastics that are based mainly on carbon-carbon backbones, polypeptides contain backbone repeat units consisting of degradable amide linkages, which are readily decomposed by enzymes into their amino acid building blocks, ensuring biodegradability.

Significant efforts to mimic natural peptide material has resulted in recombinant protein production (RPP), however this technique is limited by its high cost, the limited number of available proteins, and the difficulty in purification. Synthetic peptides have been prepared under conventional chemical engineering processes, however they lacked sequence control and thus secondary and tertiary structures that lead to the unique properties of natural peptides.

This project aims to develop a new, scalable route to prepare synthetic polypeptides for targeted commercial applications. The SREP student will gain experience in synthetic organic and polymer chemistry at the forefront of new materials design. Such a project is well suited to students with an interest in innovative chemical research with potential for interacting with industry and publishing work in a leading international chemistry journal.

1 Rat, C.; Heiby, J. C.; Bunz, J. P.; Neuweiler, H. (2018). Nature Communications 9(1), 4779.
2 Synthetic Polypeptide Shoes by Adidas using AMSilk’s BioSteel plastic.

Prof Greg Qiao’s Group

6. Crystal structure of coalescing CdSe nanoparticles

Supervisor: Dr Eirini Goudeli

Cd-Se nanoparticles with diameter of 5 nm at t = 0 (top) and 1 ns (bottom).

Cadmium selenide (CdSe) nanoparticles are widely used for CdSe/CdTe heterojunction photovoltaic devices due to their intermediate energy band gap that allows reasonable conversion efficiency, stability, and low cost. Such nanocrystals find a score of applications including tunable light emitting diodes, photovoltaics and single electron transistors. Despite their extensive investigation, atomic level description of the entire nanocrystal (both core and surface) is not trivial due to the difficulty of probing the nanocrystal surface. Surface composition and stoichiometry, however, is important since it affects the presence of ligands. Thus, it is essential to characterize nanocrystal surface during sintering to facilitate implementation of these nanocrystals in electronic, opto-electronic, and electro-optic devices.

In this project, the evolution of surface composition of free-standing, coalescing CdSe nanoparticles will be investigated for different particle sizes during sintering at various temperatures by atomistic molecular dynamics (MD) simulations, as shown in [1,2]. The effect of the Cd:Se atomic ratio on the CdSe sintering rate and the mobility of Cd and Se atoms upon coalescence will be quantified. Furthermore, the X-ray diffraction patterns (XRD) of CdSe nanoparticles will be calculated during sintering and the end-product phase composition (eg, zinc blende and cubic structure) will be revealed for several initial particle sizes and will be compared to experimental data.

[1] Goudeli, E.; Pratsinis, S. E. (2016). “Crystallinity dynamics of gold nanoparticles during sintering or coalescence.” AIChE J. 62(2), 589.
[2] Goudeli, E.; Pratsinis, S. E. (2017). “Surface composition and crystallinity of coalescing silver–gold nanoparticles.” ACS Nano 11(11), 11653.

7. Understanding and monitoring the formation of picocavities

Supervisor: Dr Eirini Goudeli

Picocavities are structures with a volume smaller than 1 nm3, forming an extreme class of optical localisation that enables optical experiments on the atomic scale. They are stable at cryogenic temperatures but are dynamically created and destroyed at room temperature [1]. Stabilising such picocavities opens widespread possibilities for studying and exploiting light-molecule coupling in molecular interactions, chemical reactions, electron transfers and single-molecule electrochemistry.

In this project, the crystallinity dynamics and void formation mechanism between gold nanoparticles (NPs) and gold films spaced by a self-assembled monolayer (SAM) will be investigated by Molecular Dynamics simulations [2]. The effect of the substrate crystal orientation, NP size and process temperature on their crystallinity and adhesion properties will be elucidated. Understanding the dynamics of NP-SAM-substrate interactions will set the basis for developing nanoscale nonlinear quantum optics on the single-molecule level. This work will help understanding the formation mechanism of picocavities and facilitate their monitoring and selective control which is important in photochemistry, photophysics, optomechanics and quantum information devices.

(a) Schematic of NP-on-mirror geometry [3]. (b) Near-field intensity across the gap between the Au NP and film with and without picocavity [1].

[1] Benz, F. et al. (2016). “Single-molecule optomechanics in ‘picocavities’.” Science 354(6313), 726.
[2] Goudeli, E.; Pratsinis, S. (2016). “Crystallinity dynamics of gold nanoparticles during sintering or coalescence.” AIChE J. 62(2), 589.
[3] Benz, F.; Tserkezis, C.; Herrmann, L. O.; de Nijs, B.; Sanders, A.; Sigle, D. O.; Pukenas, L.; Evans; S. D.; Aizpurua, J.; Baumberg, J. J. (2014). Nano Letters 15(1), 669.

8. Transport properties of agglomerates in liquids

Supervisor: Dr Eirini Goudeli

Coagulation and settling of agglomerates

Agglomeration is the formation of clusters of primary particles by coagulation. It occurs in industrial processes (eg, particle synthesis, flocculation, and fluidization) and clearing of liquid suspensions resulting in filamentary structures. The transport properties of the formed agglomerates in liquids are a key factor for ecotoxicological models predicting the environmental fate of nanomaterials, or for enhancing the stability of engineered nanofluids [1].

Even though the collision rate and structural characteristics of agglomerates in the gas-phase has been quantified [2,3], their collision frequency function and transport properties remain unknown in the continuum regime. In this project, the transport properties (ie, diffusion coefficients and mobility diameters) of silica agglomerates will be quantified accurately in aqueous solutions by coarse-grained molecular dynamics simulations.

These properties will be imported in Brownian dynamics simulations along with the structural characteristics of agglomerates, such as fractal dimension and primary particle polydispersity, for the investigation of concurrent agglomeration and settling in water for the first time. This work will complement experiments as current methods, such as optical absorption spectroscopy or precipitate bed height measurements from photographs, can only provide an average deposition rate through measurement of the evolution of the overall deposited mass fraction with time.

[1] Spyrogianni, A.; Karadima, K. S.; Goudeli, E.; Mavrantzas, V. G.; Pratsinis, S. E. (2018). “Mobility and settling rate of agglomerates of polydisperse nanoparticles.” The Journal of Chemical Physics 148(6), 064703.
[2] Goudeli, E.; Eggersdorfer, M. L.; Pratsinis, S. E. (2015). “Coagulation–agglomeration of fractal-like particles: Structure and self-preserving size distribution.” Langmuir 31(4), 1320.
[3] Goudeli, E.; Eggersdorfer, M. L.; Pratsinis, S. E. (2016). “Coagulation of agglomerates consisting of polydisperse primary particles.” Langmuir 32(36), 9276.

9. Interaction of Au nanoparticle with thiol-like molecules by molecular dynamics

Supervisor: Dr Eirini Goudeli

Snapshots of alkanethiol on gold NP (top) and surface (bottom) at (a) 300 & (b) 600 K

Self-assembled monolayers of long chain molecules adsorb on solid substrates via their head groups providing an approach for fabricating tunable surfaces with well-defined size, shape, and composition. Molecular assembly such as thiol-like structures have broad application in chemical, optical, electronic, medicine, microfabrication, and biological fields as their properties can be modified by selectively changing specific functional groups [1].

Here, the effect of the crystallinity of gold substrate and nanoparticle on the assembly of thiol-like organic layers relevant for optomechanic applications will be investigated by molecular dynamics simulations. The adhesion characteristics (eg, tilt angle, probability of distribution) of the organic layer will be quantified as function the NP size, NP & substrate crystallinity, molecule length and temperature. This study will facilitate understanding the formation of optical hotspots observed in NP-on-substrate geometries spaced by such self-assembled molecules.

[1] Ghorai, P. K.; Glotzer, S. C. (2007). “Molecular dynamics simulation study of self-assembled monolayers of alkanethiol surfactants on spherical gold nanoparticles.” The Journal of Physical Chemistry C 111(43), 15857.

10. Understanding the limits of the tools we use for nanomedicine

Supervisors: Dr Matthew Faria, Dr Joseph J. Richardson, Dr Stuart Johnston, Jingqu Chen, Prof Edmund Crampin, Prof Frank Caruso

Design of stealthy or targeted materials is an exciting area of nanomedicine that has the potential to change how we develop new drugs. However, many challenges remain in understanding and quantifying the interactions between cells and newly developed nanoparticle systems. In this project, you will use cell culture, flow cytometry, nanoparticle synthesis, and 3D microscopy to gather data on cell-particle interactions. This data will be integrated together to help us to understand how cells bind to and subsequently internalize nanomaterials in a collaborative effort between chemical engineering and systems biologists. Ultimately, this data will help us design better nanomedicine systems.

Prof Edmund Crampin’s Group
Prof Frank Caruso’s Group

11. Deconstructing blood: cell and particle migration under flow (collaboration with CSL)

Supervisors: Nilanka Ekanayake, Dr Joe Berry, Prof David Dunstan, Dr Ineke Muir, Assoc Prof Dalton Harvie

Cell migration in microfluidic devices has drawn considerable interest owing to its wide application in cell sorting capabilities. In the biological flow context, inward migration of red blood cells in micro vessels results in a Cell Free Layer (CFL) forming adjacent to blood vessel walls. CFL development is crucial for blood clot formation, as the presence of this layer increases the platelet concentration near (damaged) vasculature walls, enhancing the coagulation rates. As part of a continuing project focusing on the blood clotting process, one of our interests is to predict the distribution of cells in micro vessels/capillaries.

This project aims to validate existing hard sphere migration theories using experimental measurements of the distribution of platelets, red blood cells, or hard microspheres within rectangular capillaries. The project involves quantifying the distribution of fluorescently labelled cells and particles in rectangular capillaries at different flow-rates and volume fractions via high speed confocal microscopy.

During this project, the student will gain skills in fluorescent confocal microscopy and 3D dynamic image processing, and in-depth knowledge on hydrodynamic forces and suspension rheology.Assoc Prof Dalton Harvie’s Group