The liquid-liquid phase separation (LLPS) of biomolecules is a phenomenon which received a lot of attention in the last years because it is not only related to theformation of membraneless organelles but also to neurodegenerative diseases. Lysozyme is a globular protein that undergoes LLPS in a buffer salt system andfor that it is well investigated with several techniques like microscopy, dynamic lightscattering (DLS) or small-angle X-ray scattering. In this work we investigate the effect of temperature, solvent and sample con-centration on the diffusion coefficient, the hydrodynamic radius and the viscosity oflysozyme using a DLS setup. Furthermore, the influence of these parameters on thecluster formation is addressed. Finally, we investigate the question if the LLPS oflysozyme in a buffer environment effects the formation of dynamic clusters.

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In this project, the optimization of obtaining adsorption isotherms for the ion pair reagent, tributylamine was tested. The goal was to have a better understanding of the chromatographic process when separating biomolecules, such as oligonucleotides. To do this one ion pair reagent was tested in different buffers with different compositions of acetonitrile. These solutions adsorbed into a C18 column at different temperatures and stripped into fractions of 35 mL. To analyze the results Liquid-liquid extraction was performed on the fractions and the organic phase was then injected into a gas chromatography. The results showed that at a temperature of 24°C the ion pair reagent adsorbed more to the column than at 37°C and 50°C. For the different compositions of acetonitrile buffers which were tested the one that stood out was the 50% acetonitrile buffert. At all temperature it showed to always be able to adsorb more to the column than the other buffers. To calculate the concentrations of the analytes, standard curves for both tributylamine and dibutylamine were made. For dibutylamine, four unknown samples were provided to test out if the methods could be used to determine the concentrations of dibutylamine in the samples. The methods for acquiring adsorption isotherms and analyzing samples with the gas chromatography showed good results and could be used for more studies. However, to validate the results of the 50% acetonitrile buffer, more work in the future is required.

Liquid-liquid phase separation (LLPS) is an important phenomenon in soft condensed matter that explains many properties of membraneless organelles in living cells. The research on this topic is, therefore, a field with a wide range of applications such as biopharmacy and biomaterials. In this project, we investigate the LLPS of the antibody protein Immunoglobulin G (IgG) by analyzing the liquid dynamics of IgG solutions at a wide range of temperatures with dynamic light scattering (DLS). It was found that the slow component of the autocorrelation function increases with decreasing temperature below 0 °C. This can be attributed to either the number of protein clusters increasing as the sample approaches phase separation or LLPS droplets forming in the solution. LLPS was detected through optical microscopy, visualising the droplet formation in the IgG solution. This work confirms that LLPS can be detected for bovine IgG solutions without the presence of cosolvents and without water freezing in the sample.

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MnO2 continues to gain traction in the research and development of advanced supercapacitor materials due to its arsenal of advantages, such as high capacitance, low cost, natural abundance, and environmental benignity. However, its low conductivity has hindered its adoption into real-life applications. Compositing MnO2 with conductive additives has proved to be a promising route for the improvement of its power-energy characteristics. Four novel colloidal techniques were developed for the synthesis of MnO2-CNT composites with enhanced performance at high active mass loading. One strategy utilized a Schiff-based linkage of dispersants such as 3,4-Dihydroxybenzaldehyde (DHB) and Toluidine Blue O (TDB) to effectively mix and disperse MnO2 and CNT. Secondly, a co-dispersion technique was also investigated using Gallocyanine to improve dispersion and mixing of MnO2 and MWCNT. Third, a novel liquid-liquid extraction technique opened new avenues in agglomerate-free processing of individual components, which allowed enhanced electrode performance. Lastly, a morphology-modification strategy was also undertaken by synthesizing MnO2 nanorods with the use of advanced organic dispersants to control the aspect ratio and composite nanorods with MWCNT. The second major material investigated was polypyrrole (PPy), a polymer material with high conductivity, ease of synthesis, low-cost, and non-toxicity. However, its low cyclic stability was prevented it from being applied for real-world applications. Certain anionic and aromatic dopants have shown to improve the conductivity and cyclic stability. Therefore, one of the investigations in this work attempted to improve the performance of PPy-CNT composites by use of a novel anionic dopant, Sunset Yellow (SY). For all investigations electrodes with high mass loadings were produced to achieve high areal capacitance, thus ensuring the practicality of the techniques / Thesis / Master of Applied Science (MASc) / Supercapacitors (SCs) and batteries are both electrochemical energy storage devices. While batteries excel at storing energy in high volumes, supercapacitors excel in charging (and discharging) at extremely high rates. It is desirable to obtain the best of both worlds in a single device; high energy volume and fast charging speeds. Although such a feat is not out of the realm of theoretical possibility, current projections forecast supercapacitors to compliment battery technologies instead of replacing them. Nonetheless, constant progression in the field of SCs is needed to sustain and proliferate their adoption into emerging markets. Therefore, the aim of this research was to assist in the endeavours to improve current SC technologies from a materials science standpoint.

The effects of polymer concentration and solvents on cocrystal morphology of low solubility drugs were investigated, both of which had an impact. The melting temperatures also decreased with increasing polymer concentration. Placing the binding agent, benzene, at different interfaces induced morphological changes, such as formation of porous cocrystals. Previously liquid-liquid phase separation (LLPS) has been reported as a hindrance in the crystallisation process impeding further development. A phase diagram was constructed, and different phases were categorised into 4 types. After separation of the highly concentrated amorphous Oil Phase II, it was prone to gradual crystallisation. Crystallisation took place over 30-60 minutes; this allowed the in-situ monitoring. A novel cocrystallisation technique was developed; from (LLPS). Cocrystals of indomethacin with saccharin and nicotinamide were obtained by mixing Oil Phase II with the coformers. In-situ monitoring by spectroscopic had gradual changes in spectra; characteristic peaks increased in height and area with the formation of crystals until the reaction was complete. With crystal formation, the XRD spectra gradually had a sharper baseline due to a decrease in the amorphous indomethacin. The photoluminescence (PL) spectra displayed several peaks coupling into one large hump together with increasing intensity as the sample crystallised. There was a shift in the peak absorbance of the pure drug crystals obtained from LLPS and the indomethacin:saccharin cocrystal obtained from LLPS. Amorphous stabilisation was achieved by mixing polymer (PVP) with Oil Phase II. There were no changes to the XRD diffractogram as the sample did not undergo crystallisation.

Yes / The extraction of bioactive compounds, produced by plant cell cultures, directly from their culture medium, which contains other by-products, is a great challenge. Resveratrol extraction from its grapevine cell cultures is considered here as an example to improve the extraction processes from plant cell cultures using solubility parameters. Successive liquid-liquid extraction (LLE) processes were exploited to extract resveratrol from the culture medium with an extraction ratio approaching 100%, high selectivity and minimum amounts of solvents. The calculations of partition coefficients as a function of solubility parameters demonstrated that benzyl benzoate is the most suitable intermediate solvent to extract resveratrol from its aqueous medium. The calculations also illustrated the high ability of methanol and ethanol to extract resveratrol from benzyl benzoate. The physicochemical properties of benzyl benzoate and processing conditions were exploited to separate it from aqueous media and organic solvents. The agitation method, component ratios and extraction time were studied to maximize the extraction yield. Under the best studied conditions, the recovery of resveratrol from different culture media approached ∼100% with a selectivity of ∼92%. Ultimately, the improved extraction processes of resveratrol are markedly efficient, selective, rapid and economical. / Mohammad Amin Mohammad gratefully acknowledges CARA (The Council for At-Risk Academics, Stephen Wordsworth and Ryan Mundy) for providing the financial support for an academic fellowship.