The Microstructure and Rheology of Complex Fluids Containing Na-caseinate

<p>Emulsions are widely utilised in commercial environments, such as in the food and cosmetic industries. In their simplest form, emulsions are a system consisting of two immiscible liquids in the presence of emulsifiers. To form an emulsion, an input of energy is required. In this thesis, Na-caseinate was used as the emulsifier and three systems were studied: soybean oil/Na-caseinate/water, palm oil/Na-caseinate/water and tetradecane/Nacaseinate/ water. Four main techniques were used to characterise the stabilised emulsions: laser diffraction particle sizing, PGSTE-NMR, rheology and cryo-SEM. Emulsion systems are extremely complex making control and predictability over their phase behaviour practically difficult. This is because the required overall characteristics of these colloids are strongly dependent on both the energy of formulation and the choice of an appropriate combination of emulsifier, dispersed phase and continuous phase. A full understanding of the microstructure, stability and physicochemical properties of caseinatestabilised emulsions has as yet not been achieved. For example, how does caseinate selfassembly control emulsion stability? How do concentrated caseinate-based emulsions differ from dilute ones and how do the different oils (food grade oils vs. straight chain hydrocarbon) affect the formation of emulsions? The aim of this PhD programme was to obtain data to allow a better fundamental understanding of the underlying parameters defining emulsion behaviour to be obtained ...</p>

The Microstructure and Rheology of Complex Fluids Containing Na-caseinate

<p>Emulsions are widely utilised in commercial environments, such as in the food and cosmetic industries. In their simplest form, emulsions are a system consisting of two immiscible liquids in the presence of emulsifiers. To form an emulsion, an input of energy is required. In this thesis, Na-caseinate was used as the emulsifier and three systems were studied: soybean oil/Na-caseinate/water, palm oil/Na-caseinate/water and tetradecane/Nacaseinate/ water. Four main techniques were used to characterise the stabilised emulsions: laser diffraction particle sizing, PGSTE-NMR, rheology and cryo-SEM. Emulsion systems are extremely complex making control and predictability over their phase behaviour practically difficult. This is because the required overall characteristics of these colloids are strongly dependent on both the energy of formulation and the choice of an appropriate combination of emulsifier, dispersed phase and continuous phase. A full understanding of the microstructure, stability and physicochemical properties of caseinatestabilised emulsions has as yet not been achieved. For example, how does caseinate selfassembly control emulsion stability? How do concentrated caseinate-based emulsions differ from dilute ones and how do the different oils (food grade oils vs. straight chain hydrocarbon) affect the formation of emulsions? The aim of this PhD programme was to obtain data to allow a better fundamental understanding of the underlying parameters defining emulsion behaviour to be obtained ...</p>

Evaluation on Microstructure Stability and Thermal Resistant Ability at High Temperature of Ternary-Blended Geopolymer

Stability of microstructure and heat resistant ability at high temperature is one of the important properties in ceramics or silicate materials which are normally exposed with fire such as refractories and insulation or other materials used in furnaces. This study used a ternary-blended geopolymer which was synthesized from an optimized mixture of red mud (RM), rice husk ash (RHA), diatomaceous earth (DE), and water glass solution (WGS) with silica modulus of 2.5. The geopolymer samples were tested thermal properties of heat resistance (%), volumetric shrinkage (%), mass loss (%) at 1000°C to evaluate thermal resistant ability. Changes of microstructure of the ternary-blended geopolymer samples were also characterized before and after exposed at high temperature using methods of X-ray diffraction (XRD), Thermogravimetric analysis or thermal gravimetric analysis (DTA-TGA), and Scanning electron microscope (SEM). The experimental results showed the ternary-blended geopolymer has high thermal stability and unchanged microstructure even at high temperatures. Hence, the geopolymer in this study is suggested to apply as an insolation with the upper limit of temperature to work at 1000°C.

Blocking lithium dendrite growth in solid-state batteries with an ultrathin amorphous Li-La-Zr-O solid electrolyte

Lithium dendrites have become a roadblock in the realization of solid-state batteries with lithium metal as high-capacity anode. The presence of surface and bulk defects in crystalline electrolytes such as the garnet Li7La3Zr2O12 (LLZO) facilitates the growth of these hazardous lithium filaments. Here we explore the amorphous phase of LLZO as a lithium dendrite shield owing to its grain-boundary-free microstructure, stability against lithium metal, and high electronic insulation. By tuning the lithium stoichiometry, the ionic conductivity can be increased by 4 orders of magnitude while retaining a negligible electronic conductivity. In symmetric cells, plating-stripping shows no signs of lithium penetration up to 3.2 mA cm−2. The dense conformal nature of the films enables microbatteries with an electrolyte thickness of only 70 nm, which can be cycled at 10C for over 500 cycles. The application of this material as a coating on crystalline LLZO lowers the interface resistance and increases the critical current density. The effectiveness of the amorphous Li-La-Zr-O as dendrite blocking layer can accelerate the development of better solid-state batteries.