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This study seeks to develop smart hydrogel formulations for injectable controlled drug delivery from Pluronics to enhance patients compliance, decrease side effects, reduce dose and frequency. A biocompatible copolymer, Pluronic F127 was probed as the main ingredient for the injectable systems owing its low gelation concentration and ease of modification the system properties through excipients addition. The matrix properties were studied through a series of thermal, rheological and structural (SAXS/SANS) experiments as a function of concentration and shear rate, covering both static and dynamic environments. It has shown that gelled viscosity (and structure) can be critically controlled by shear rate and the structures recorded do not match those predicted for sheared colloids. Two further Pluronics F68 and F108, were studied showing similar but shifted gelation properties to F127. Effects of additives were studied by introducing different Mw PEGs and a model hydrophobic drug 'ibuprofen' to a F127 20% formulation. PEGs addition effects on the system properties and gelation transition were largely dependent on the Mw used in the blend, which became more prominent with increasing chain length. Ibuprofen's addition has resulted in reduced gelation temperature and smaller hard spheres without having a great effect on the system rheological properties compared to neat gels. Blends containing both additives PEG and ibuprofen exhibited a synergistic effect, where comparisons show that Ibuprofen had the largest effect on the blends lowering gelation boundaries and slightly increasing the size of the hard spheres indicating the necessity of full characterisation of the formulation with any API.

The purpose of this study is to identify and quantify factors governing extrudate swell and melt fracture. In the first part, the factors which control the extrudate swell of carbon black (N330) filled styrene-butadiene rubber (SBR) compounds at various states-of-mix were investigated. State-of-mix is quantified by effective filler volume fraction (EFVF), based on an estimate of the amount of rubber immobilised in the carbon black agglomerates. Extrudate swell was found to be dominated by recoverable strain and relaxation time, which are controlled by EFVF. In contrast, shear rate and the rubber-carbon black tridimensional transient network were not found to influence extrudate swell significantly. In the second part, melt fracture of the rubber compounds was investigated in terms of surface texture wavelength. The longer the wavelength, the greater the severity of the surface disruption. It was found that wavelength was controlled strongly by state-of mix (or by EFVF). In addition, a mechanism for melt fracture of the compounds studied has been proposed, based on average energy at the extrudate surface (t.E). Lastly, the influences of additives; paraffinic processing oil, stearic acid or a mixture of predominantly calcium fatty acid soaps on extrudate swell and melt fracture were investigated. For the rubber compounds with paraffinic processing oil or stearic acid, EFVF was found to play an important role in extrudate swell. The mixture of fatty acid soaps was shown to reduce significantly extrudate swell due to the presence of wall slip. The influence of the fatty acid soaps on extrudate swell is more noticeable for extrudates obtained from long dies, in which flow is dominated by shear. The major factors shown to exert a significant influence on melt fracture for the compounds with paraffinic processing oil or stearic acid are EFVF and green strength of the extrudate. Wall slip, promoted by a mixture of fatty acid soaps, was also found to decrease the melt fracture severity, particularly for long dies in which shear stresses are dominant.

Enriched lentil protein vegetable purees (10% zucchini, 10% carrots, 2.5% extra virgin olive oil and 21.8% lentil protein concentrate) suitable for people with dysphagia were developed with 0.8% xanthan gum (XG) or 600 MPa/5 min high pressure processing (HPP) treatment with the aim of comparing their rheological and textural properties. Selection of the appropriate XG % and HPP conditions was made by performing initial pilot trials. Purees showed a good nutritional profile (12% protein, 3.4% fiber, 100 Kcal/100 g), being adequate for people with dysphagia. Microbiological testing of HPP treated purees indicated that it has a good shelf-life under refrigerated conditions 14 days). Both types of purees showed a gel-like character (tan delta 0.161-0.222) and higher firmness, consistency and cohesiveness than control samples. Comparing XG and HPP samples at time 0, HPP treated purees showed the highest stiffness ( G '), the lowest deformability capacity (yield strainLVR) and the lowest structural stability (yield stressLVR). With storage, HPP treatment samples showed significant increases in all rheological and textural parameters. These results confirm the suitability of HPP as an alternative technology to hydrocolloids for the obtained dysphagia dishes.

Several private and public agencies are exploring ways in which the use of reclaimed asphalt pavement (RAP) can be increased in the construction of new pavements. However, such an increase must not come at the expense of reduced durability or life cycle cost. The use of RAP is often accompanied by some form of adjustment to the virgin binder that is being used. In Texas, the current practice of incorporating RAP is controlled by a simplified table that lists a substitute binder grade and recycled binder ratio (RBR) when RAP is incorporated in a mix. There are a few shortcomings with this simple approach of specifying a maximum ratio: (1) it does not address the potential difference in the quality of recycled binders from RAP, (2) it may result in the use of substituted binders with little or no polymer (elastomer) and (3) it does not account for the influence of recycling agents. The goal of this study was to evaluate the change in performance of binders and mixtures using different grades of virgin binder and percentages of RAP. Two different Job Mix Formulae (JMF) and corresponding materials were obtained from asphalt plants in the state of Texas. A test matrix was developed to evaluate binders and mixtures with different ratios of recycled binder to virgin binder and different ratios of RAP to virgin material, respectively. The results from this study show that addition of RAP or recycled binder (from RAP) results in an increase in stiffness and resistance to rutting, which was expected. However, the resistance to cracking showed mixed results. The test results also show that the properties of the recycled binder from RAP can vary significantly with source and have a drastic effect on the properties of the binder and mixture.

Oats are minor cereal crop and widely used as breakfast cereals. Oat starch is a by-product derived from the β-glucan extraction process and is widely used in food and non-food products such as oat meal, soups, gravies, coating agents for tablets and gloves and cosmetic products. It is also used for oat meal and other novel oat based food products such as oat puddings and oat-based sports gel consisting of oat starch and milk protein ingredients. These products normally undergo thermal treatment, where starch-milk protein interactions could affect the product’s final rheological and sensory properties. Oat starch also exhibits unique properties including small granule size, a well developed granule surface and high lipid content. Hence, the overall aim of this thesis was to determine the effect of milk protein ingredients on oat starch and to advance our understanding of how starches and milk proteins interact with each other. The effect of substituition of oat starch and oat flour at various concentrations (5% and 10%, w/w) with three different readily available milk protein ingredients, namley whey protein concentrate (WPC), whey α-lactalbumin (WLAC) and skim milk powder (SMP) were investigated. All three ingredients decreased the pasting responses of oat starch. SMP showed a greater effect on oat starch characteristics in oat starch and flour systems in comaprison with WPC and WLAC. It was evident that even a small (5%) substituition of oat starch/flour with milk protein ingredients resulted in loss of native properties of oat starch/flour systems, where SMP affected these properties most. SMP increased the pasting temperature and decreased the starch swelling. The effect of the addition of different concentrations (25%, 50%, 75% and 100%) of pure protein fractions, whey protein isolate (WPI) and calcium caseinate (CaCN) on oat starch were also investigated. Studies on the thermal behaviour of oat starch/milk proteins mixtures by differential scanning calorimetry (DSC) showed that WPI and CaCN increased the peak temperature (TP), suggested delaying of starch gelatinisation, where WPI had a greater effect on oat starch than CACN. The X-ray diffraction and Fourier transform infrared spectroscopy studies revealed that oat starch/WPI mixtures increased the relative crytallinity suggesting an increase in ordered structure, while a decrease in IR bands at 1024 cm-1 and 1080 cm-1 indicated less gelatinisation of starch molecules. CaCN did not affect the relative crystallinity and showed an increase in amorphous structuration in FTIR analysis, which is an indication of complete gelatinisation. The qualitative viscoelastic behaviour of oat starch/milk proteins gels were studied in terms of steady state flow behaviour, amplitude strain sweep and thixotropic analyis. WPI and CaCN increased the shear thinning behaviour of oat starch/milk proteins gels, while WPI decreased the elastic modulus (G’) up to 75% concentration and increased at 100%. However, CaCN resulted in an increase in viscous modulus (G”), indicating weak viscous gels in comparison with WPI/ oat starch gels. WPI and CaCN at high concentration (100%) resulted in an increase in elastic nature, but gels were found to be brittle in nature. Finally, it was concluded that WPI illustrated high potency to affect oat starch gelatinisation in comparison with CaCN. This study is a first step to understand the oat starch- milk protein ingredients behaviour during thermal processing, and the trends obtained from the resultant work could predict the usage of oat starch/milk proteins in the development of oat-milk based foods.

Polycaprolactone (PCL) is a PDA-approved biodegradable polymer with excellent biocompatibility and flexibility. My work has been designed to find out how different functional end groups in star-like PCL samples affect the surface properties (such as hydrophilicity, morphology) and bulk properties (such as thermal, mechanical, rheological properties, and crystallization), and consequently the behavior and functions of primary rat aortic smooth muscle cells (SMCs). I focused on the synthesis of PCL with different functional groups and their characterizations. In chapter 2, PCL samples with four or six hydroxyl end groups were synthesized with different molecular weights ranging from 8,000 to 30,000 g/mol [gram per mole]. The hydroxyl end groups in PCL were converted into carboxyl, methyl, amino, and acrylate groups, with conversion percentage confirmed by nuclear magnetic resonance (NMR) spectra. Thermal properties of these PCL samples were determined with a Differential Scanning Calorimeter (DSC). In chapter 3, the different spherulitic morphologies formed by 4-arm and 6-arm star-like PCL in isothermal crystallization were explored. In chapter 4, the rheological properties of linear and star-like polymers were determined by using a strain controlled rheometer, which aims to find out the dependence of viscosity on frequency and molecular weight. The rheological properties of star like polymers were compared with the linear ones. In chapter 5, cytotoxicity tests of the star-PCL samples using SMCs were performed, and cell study of SMC attachment, spreading, proliferation on the star-PCL samples with different functional groups were also performed.

Abstract: There is a growing demand for innovative and affordable technologies in the food industry to modify ingredient functionality and to ensure product safety. Proteins are essential components in many food systems, and their structure can be modified in a variety of ways to control and improve functional characteristics of a food system. The enzymatic modification of proteins with transglutaminase is one such novel technology that has a broad range of applications, and was the focus of this research. In the first study of this research, hydrolyzed pea protein were modified by microbial transglutaminase (MTGase) from the Streptomyces mobaraensis species. Biologically active (biogenic) amines histamine and tyramine were used as amine donor substrates in this enzyme-catalyzed reaction. Conjugation of biogenic amines and pea protein hydrolysates was achieved in the presence of MTGase after 6 h of incubation at 37°C. Conjugation progress was monitored by high performance liquid chromatography and fluorescence spectroscopy. Seventy six percent of histamine was covalently incorporated to protein hydrolysates by MTGase, thereby reduced the concentration of undesirable biogenic amine. Also, the MTGase-catalyzed introduction of tyramine into pea protein hydrolysates substantially improved the antioxidant potential of the newly formed conjugates. In the second study, porcine skin gelatin was modified by MTGase-induced amination with tyramine in an aqueous media at 50°C. Gelation and melting iii temperatures, viscoelastic behaviour, as well as gelation rate and gel strength of tyramine-gelatin conjugates and MTGase-cross-linked gelatin were determined. MTGase-catalyzed cross-linking increased the gelation and melting temperatures of the gel. Incorporation of tyramine via MTGase did not change the gelling and melting temperatures of the gelatin. Tyramine incorporation negatively affected the gelling behaviour of the gelatin and was likely due to covalent tyramine-gelatin bonds that interfered with the normal formation of triple helix networks. Overall, this research demonstrated biogenic amines, as potential substrates for MTGase, were able to introduce into food proteins and peptides. A combination of glutamine-containing peptides together with MTGase has the potential to decontaminate fermented foods and beverages for biogenic amines.

Slurry wall is a geotechnical engineering application to control the migration of contaminants by retarding groundwater flow. Sand-bentonite slurry walls are commonly used as levees and containment liners. The performance of bentonite slurry in sand-bentonite slurry walls was investigated by studying the rheological properties of bentonite suspensions, the penetration length of bentonite slurry into clean sand, and stability of the trench under in-situ hydraulic gradients. In this study, the rheological parameters of bentonite suspensions were measured at various bentonite fractions by weight from 6 to 12% with 0-3% of sodium pyrophosphate; an ionic additive to control the rheological properties of the bentonite slurries. The penetrability of the bentonite slurries through Ottawa sand was studied by injecting the slurries into sand columns at different bentonite fractions. The injection tests were performed with the permeameters having different diameters to eliminate any bias on test results due to the different size of permeameter. An empirical correlation for predicting the penetration length of bentonite slurry based on apparent viscosity, yield stress, effective particle size, relative density, and injection pressures was updated by taking into account the effects of the permeameter diameter size. Moreover, the stability of sand-bentonite slurry walls was inspected by studying the hydraulic performance of sand permeated with bentonite suspensions under increasing hydraulic gradients. The critical hydraulic gradient at which washing out of bentonite suspensions is initiated was examined. For specimens with bentonite contents less than the threshold value, the flow occurred through the sand voids and minimal washing out occurred. On the other hand, when the bentonite content was high enough to fill up all the void space between the sand particles, the flow was controlled by the clay void ratio. In this case, washing out did occur with increasing gradients accompanied by an increase in hydraulic conductivity. Accordingly, a relation between the yield stress of bentonite suspensions and the critical hydraulic conductivity was developed.

Under appropriate conditions, surfactants in water are known to self-assemble into threadlike micelles which reduce the drag of the solution in turbulent flow compared to that of the water solvent at the same flow rate. The phenomenon is called turbulent drag reduction (DR). Using surfactant DR additives (DRA) can save up to 70% pumping energy in turbulent pipe flow water circulating systems, such as district cooling/heating systems, in which a large amount of water is temperature controlled in a central station and recirculated within a district to heat/cool the buildings therein. A new approach to energy saving in district cooling systems is to replace water with 20% ethylene glycol (EG) in water as the cooling medium, which can be cooled down to –5°C (compared to 5°C for water). The coolant typically warms up to 15°C and is then returned to the central station for recooling. The temperature difference for the 20%EG/W medium is 20°C (-5°C to 15°C), twice as much as the 10°C for water (5°C to 15°C), increasing its cooling capacity and reducing the amount of recirculating coolant and pumping energy needed by about 50%. Pumping energy could be reduced by an additional 50% if effective surfactant DRAs can be used in such mixed solvents. However, co-solvents such as EG are known to inhibit micelle formation which may decrease the effectiveness of DRAs compared to pure water systems. This study investigated and developed effective surfactant DRAs in several water/co-solvent systems at low temperatures. DR, rheological, cryogenic transmission electron microscopy (cryo-TEM) and 1H NMR experiments are being carried out to develop correlations among DR, rheological properties and micelle microstructures. In addition to the practical application in district cooling systems using EG-water mixed solvent or other co-solvent systems, the results of this study provide more fundamental understanding of the effects of solvent properties on threadlike micelle microstructure, drag reduction and system rheology, which are poorly understood now.

The purpose of this work is to investigate the rheological properties of epoxy resin filled with high concentrations of aluminum borate (9Al2O3-2B2O3) whiskers. Rheological measurements are performed with parallel plate rheometer. The rheology exhibits nonlinear viscoelasticity from low strain region through entire range studied. The presence of an effective network of whiskers comprising an internal structure is proposed. The thesis is consisted of three parts. The first is the conformation of the internal structure of whisker network and its deformation. By applying the external shearing force, both steady and dynamic, to the whisker suspension, the responses of the rheological properties have been monitored. The data is interpreted and quantitative analyses are carried out. The second is the reformation behavior of the deformed internal structure. No major study is done about reformation behavior of the internal structure of short fiber suspension. In this part, the condition of deformed internal structure is analyzed and then reformation behavior under zero shearing force is studied. The third is the phenomenological similarity of rheological properties between the whisker suspension and the liquid crystal polymer. This phenomenon is observed f or only whisker suspension not for ordinary glass fiber suspension due to whiskers' small dimension. The fourth is the investigation about effects of whisker/whisker interaction and whisker/resin interaction on the rheological behavior. From these studies, the change of rheological status upon the external force such as processing procedure has been clarified.