Chemical Engineering Commons^™

Remote Controlled Hydrogel Nanocomposites: Synthesis, Characterization, And Applications, Nitin S. Satarkar

University of Kentucky Doctoral Dissertations

There is significant interest in the development of hydrogels and hydrogel nanocomposites for a variety of biomedical applications including drug delivery, sensors and actuators, and hyperthermia cancer treatment. The incorporation of nanoparticulates into a hydrogel matrix can result in unique material characteristics such as enhanced mechanical properties, swelling response, and capability of remote controlled (RC) actuation. In this dissertation, the development of hydrogel nanocomposites containing magnetic nanoparticles/carbon nanotubes, actuation with remote stimulus, and some of their applications are highlighted.

The primary hydrogel nanocomposite systems were synthesized by incorporation of magnetic nanoparticles into temperature responsive N-isopropylacrylamide (NIPAAm) matrices. Various nanocomposite properties …

Synthesis And Characterization Of Magnetic Hydrogel Nanocomposites For Cancer Therapy Applications, Samantha Ann Meenach

University of Kentucky Doctoral Dissertations

Currently, cancer is the second leading cause of death in the United States. Conventional cancer treatment includes chemotherapy, radiation, and surgical resection, but unfortunately, all of these methods have significant drawbacks. Hyperthermia, the heating of cancerous tissues to between 41 and 45°C, has been shown to improve the efficacy of cancer therapy when used in conjunction with irradiation and/or chemotherapy. In this work, a novel method for remotely administering heat is presented. This method involves heating of tumor tissue using hydrogel nanocomposites containing magnetic nanoparticles which can be remotely heated upon exposure to an external alternating magnetic field (AMF). The …

Characterization Of Rock/Fluids Interactions At Reservoir Conditions, Dayanand Saini

LSU Doctoral Dissertations

In this study, interfacial phenomena of spreading, wettability, and rock/oil adhesion interactions in complex rock/oil/water systems were characterized at reservoir conditions of elevated pressures and temperatures. Capabilities of both ambient and reservoir condition optical cells were used for measuring the oil/water interfacial tension and dynamic (the water-receding and the water-advancing) contact angles for various complex rock/oil/water systems. Well known sessile oil drop volume alteration method was successfully used in this study for evaluating the applicability of the modified Young’s equation for characterizing the line tension in complex rock/oil/water systems at reservoir conditions. This appears to be first time when rock/fluids …

Designing A Whey Protein Based Material As A Scaffold For Bone Regeneration, Mia Dvora

LSU Doctoral Dissertations

A novel gel material was designed and optimized for use as a bone tissue regeneration scaffold. Whey protein isolate (WPI), the primary component of the material, underwent considerable testing for conformity to a set of known material characteristics required for application in bone regeneration. WPI gels of different compositions were fabricated by thermally inducing gelation of high-concentration protein suspensions, and characterized for compressive strength and modulus, hydration swelling and drying properties, mechanical behavior change due to polysaccharide additives, and intrinsic pore network structure. The gels were also tested for their compatibility with MC3T3-E1 cells, and interactions such as cell adhesion, …

Integrating Bioprocesses Into Industrial Complexes For Sustainable Development, Debalina Sengupta

LSU Doctoral Dissertations

The objective of this research is to propose, develop and demonstrate a methodology for the optimal integration of bioprocesses in an existing chemical production complex. Chemical complex optimization is determining the optimal configuration of chemical plants in a superstructure of possible plants based on economic, environmental and sustainable criteria objective function (triple bottomline) and solves a mixed integer non linear programming problem. This research demonstrated the transition of production of chemicals from non-renewable to renewable feedstock. A conceptual design of biochemical processes was converted to five industrial scale designs in Aspen HYSYS® process simulator. Fourteen input-output block models were created …

Biodiesel Production Using Supercritical Methanol, Dhaval Nitin Modi

Masters Theses

"The catalyst-free transesterification of oil (triglycerides) in supercritical methanol at a temperature and pressure above 239⁰C and 8.1MPa, respectively, provides a new way of producing biodiesel. High reaction temperature and pressure help to accelerate the transesterification because the supercritical methanol becomes non-polar and has enhanced contact with oil. The supercritical transesterification of soybean oil was carried out in a 170 ml volume high-pressure batch reactor. The pressure within the batch reactor was self-generated from heating the contents since no pumps were used. Transesterification of soybean oil with supercritical methanol readily produced biodiesel. Since the supercritical transesterification is carried out without …

Enhanced Photorefractivity In A Polymeric Composite Photosensitized With Modified Carbon Nanotubes, Naveen Kumar Lingam

Masters Theses

"This work involves the photosensitization of photorefractive polymeric composites through the inclusion of multiwalled and singlewalled carbon nanotubes grafted to poly(N-vinyl carbazole). The photorefractive nature of the holograms gratings was established using two-beam-coupling, yielding two-beam-coupling gain coefficients approaching 80 cm⁻¹. Degenerate-four-wave-mixing experiments exhibited diffraction efficiencies as high as 60% as well as over-modulation voltages as low as ~ 40 V/µm. These notable figures of merit indicate that the grafting of the various carbon nanotubes to the poly(N-vinyl carbazole) polymer resulted in enhanced photorefractive performance. The mechanism responsible for this enhancement in photorefractive performance is investigated using a variety of experimental …

Optimization Of Parameters And Study Of Kinetics In Lactulose Production By Lactose Isomerization Using Strong Basic Anion Exchange Resin, Arvind Nanduri

Masters Theses

"In this work, an experimental design was employed to investigate the effects of different operating conditions on the isomerization of lactose to lactulose by using strong basic anion exchange resin (AMBERLITE-IRA 402). Temperature, resin/lactose mass ratio and pH were considered to be the three factors affecting the conversion of lactose. Box-Behnken design was then used to optimize the operating conditions for maximum response and also to study the various interaction and main effects of the factors. The analysis of variance (ANOVA) of the experimental data showed a high correlation coefficient R² (0.99) and a low root mean square error (2.84) …

Supercritical Pyrolysis Of N-Decane, Sean Bagley

LSU Doctoral Dissertations

Fuels used in future generations of high-speed jet aircraft will be required to take on increasing heat loads in their role as the primary coolant for the absorption of waste heat from the engine. As a consequence, the hydrocarbon fuels will be exposed to elevated temperatures and pressures prior to their use as fuels, conditions which are beyond the critical point of the fuel and which lead to the formation of carbonaceous solid deposits in the pre-combustion environment.

Deposition of solids causes reduced engine performance and eventual failure, so understanding the mechanisms by which thermally stressed hydrocarbons become solids is …

Electrodeposited Cu-Based Catalysts For Alcohols From Co Hydrogenation And Electrodeposition Of Cuniw/Cuni Multilayered Alloys, Mayank Gupta

LSU Doctoral Dissertations

Ethanol and higher alcohols can be used as a fuel or fuel additive in gasoline engines as well as a hydrogen carrier. One of the promising methods to synthesize these alcohols is based on thermochemical conversion of CO and H2 (CO hydrogenation). Conventional catalysts used for the conversion CO and H2 (syngas) to ethanol typically give yields less than 20% with the balance resulting mostly in the formation of the thermodynamically favored products CH4 and CO2. New catalysts with compositions designed to kinetically favor the formation of ethanol and higher alcohols are needed. Electrodeposition of nanowires offers a means to …

Modeling And Multiresolution Characterization Of Micro/Nano Surface For Novel Tailored Nanostructures, Rajib Mukherjee

LSU Doctoral Dissertations

Nanofabrication is state of the art technology. Various chemical, mechanical, biochemical and semiconductor products have characteristics controlled by the nanostructures of the surface and interphase. Surface microscopic imaging is generally used to capture different surface features. By properly analyzing the surface image, valuable information regarding manufacturing process and product performance can be extracted. While microscopy measurements can offer very accurate qualitative information about surface features, for many applications, it is critical to obtain a quantitative description of the surface morphology. Various statistical features can be used to characterize the surface in quantitative way. Such an analysis can be done by …

Fabrication Of A Memory Device Using Polyaniline Nanofibers And Gold Nanoparticles, Krunal R. Waghela

Masters Theses

"Fabrication of a memory device using one-step/one-pot synthesis for making a PANI (polyaniline)/Au nanocomposite is reported. Although various devices with horizontal and vertical electrode structures were made, the basic structure used consisted of a PANI/Au thin film sandwiched between two electrodes. The ratio of the current in the OFF state to the current in the ON state was seen to be as high as 5000. These devices showed a bistable behavior, which is typical of memory devices. The PANI/Au nanocomposite thin film was constructed right on the electrode using microfabrication techniques with ultraviolet irradiation. The fabrication techniques discussed in this …

Microalgae Harvesting By Flocculation With Polymer-Coated Magnetite Particles, Humayun Shariff

Masters Theses

"Although microalgae are considered to be one of the potentially significant feedstock for renewable biofuels, harvesting them efficiently from culture ponds has been a major hurdle. The conventional harvesting methods such as centrifugation and filtration are very time and labor intensive processes. Gravimetrical settlement with the aid of cationic flocculants is the most widely employed technique, but suffers from the difficulty in recovering microalgae floes. Furthermore, recycling of these flocculants after the harvesting process is not possible. Polymer-coated magnetite particles have been investigated for applications in various fields. This research has focused on the development of a novel and efficient …

Strength Evaluation And Transportation Behavior Of Preformed Particle Gel Using Screens And Tubes, Rajesh Sarma Challa

Masters Theses

"This research included a series of experiments, using screen models to evaluate the strength of swollen gel particles. It also includes the study of PPG propagation and extrusion behavior through tubes of various internal diameters. The effect of the particle gel swelling ratio (depending on brine concentration), flow rate; and mesh size on the gel injection pressure and injectivity were studied. The results show that gel injection pressure depends primarily on the swelling ratio and the mesh size. However, the injection pressure does not increase significantly with injection rates, behavior consistent with the real-time injection pressure and injection rate change …

Arsenite Oxidation By Pure Cultures Of Thiomonas Arsenivorans Strain B6 In Bioreactor Systems, Aniruddha Dastidar

University of Kentucky Doctoral Dissertations

The removal of arsenic toxicity from water is accomplished by a preliminary preoxidative step transforming the most toxic form, arsenite (As (III)), to the least toxic form, arsenate (As (V)). The potential of As (III) oxidation to As (V) was initially investigated in batch reactors using the chemoautotrophic Thiomonas arsenivorans strain b6 under varying initial As (III) and cell concentrations and at optimal pH and temperature conditions (pH 6.0 and temperature 30°C). The strain b6 completely oxidized As (III) to As (V) during exponential growth phase for lower levels of As (III) concentrations (≤ 100 mg/L) but continued into stationary …

Characterization Of Poly(Methyl Methacrylate Based Nanocomposites Enhanced With Carbon Nanotubes, Andrew Jonathan Placido

University of Kentucky Master's Theses

The viscoelastic relaxation dynamics of a series of poly(methyl methacrylate) [PMMA] based nanocomposites filled with carbon nanotubes have been studied using dynamic mechanical analysis and broadband dielectric spectroscopy. The networks were prepared using four methods: (i) melt mixing, (ii) solution processing, (iii) in-situ polymerization, and (iv) polymer grafting. Nanotube modifications included surface oxidation via acid exposure and surface functionalization for polymer grafting. The effect of variations in processing method and nanotube modification on glass transition temperature (T_g) and relaxation dynamics was investigated. The relaxation behavior of the nanocomposites was sensitive to processing method and nanotube functionalization. Nanotube loading …

Synthesis And Characterization Of Metal Decorated Bamboo Structured Carbon Nanotubes For Hydrogen Storage, Sean Charles Mickey

Doctoral Dissertations

"Although hydrogen has been considered as a viable alternative fuel, the storage systems used to contain the hydrogen must be improved for large scale use. A variety of conceivable storage options exist ranging from compressed gas, cryogenic liquid, chemical solid state storage, and adsorptive surfaces. Carbon nanotubes (CNTs) provide a potentially viable option for hydrogen storage applications as a high surface area, lightweight media for adsorptive storage, but do not efficiently store hydrogen at ambient temperatures. Metal hydrides, on the other hand, are able to store large weight percents of hydrogen in a chemical solid state, but generally have unfavorable …

Improved Method For The Determination Of Kinetic Parameters From Non-Isothermal Thermogravimetric Analysis (Tga) Data, Thomas H. Fletcher, James L. Hillier, Trent Bezzant

Faculty Publications

Thermogravimetric analysis (TGA) at a constant heating rate is a popular technique for characterizing reaction behavior. Determination of kinetic coefficients from suchTGAdata has given rise to a large range of reported activation energies for similar samples. In general, rate coefficients are determined using either a linearized integral method or a derivative method. A new method incorporating several well-known techniques is presented that avoids the problems with the linearized techniques as they are generally used. This paper compares results from the new method with results using either the integral or derivative method. Mathematically generated data were used with known kinetic parameters …

The Surface Characteristics And Reactivity Of Residual Carbon In Coal Gasification Slag, Xianglong Zhao, Cai Zeng, Yanyan Mao, Wenhua Li, Yun Peng, Tao Wang, Boris Eiteneer, Vladimir Zamansky, Thomas H. Fletcher

Faculty Publications

In a slagging entrained-flow coal gasifier, a large portion of the inorganic matter will form liquid slag that may have strong physical and chemical interactions with char. Understanding the char-slag interaction is important for improving the modeling and design of gasifiers. This paper reports the characteristics of residual carbon in both coarse and fine slag from a typical entrained-flow coal water slurry gasifier. The surface characteristics of slag and residual carbon in slag were evaluated by scanning electron microscopy and energy dispersive X-ray spectroscopy. The reactivity of the residual carbon in slag was compared through thermal gravimetric analysis. It was …

Investigation Of Nitrogen Release During Coal Pyrolysis In An Oxy-Fuel Combustion Process, John M. Sowa, Kolbein K. Kolste, Thomas H. Fletcher

Faculty Publications

Three coals were studied in a flat flame burner (FFB) to determine nitrogen release during pyrolysis as a function of the temperature from 1600 to 1900 K in an oxy-fuel environment. The oxy-fuel environment was created by replacing the background N2 with CO2 in the FFB experiments. Both types of experiments were conducted under fuel-rich conditions, with no O2 present in the postflame gases. The oxy-fuel results were compared to previous results from FFB experiments in a N2 atmosphere. A bituminous coal showed no difference in mass and nitrogen release between the two environments. The sub-bituminous coal exhibited higher mass …