Complex Fluids Commons^™

Fundamental Studies Of Surfactant Templated Metal Oxide Materials Synthesis And Transformation For Adsorption And Energy Applications, Saikat Das

Theses and Dissertations--Chemical and Materials Engineering

This work addresses fundamental aspects of designing templates and curing conditions for the synthesis of mesoporous metal oxide thin films. The first section addresses selection of cationic-carbohydrate surfactant mixtures to synthesize templated silica thin films for selective adsorption of simple carbohydrates based on molecular imprinting. Nuclear magnetic resonance and fluorescence spectroscopy results suggest a novel structure for mixtures of alkyl glucopyranosides or xylopyranosides with cationic (trimethylammonium) surfactants. Despite thermodynamically favorable mixing, the carbohydrate headgroups in the mixed micelle adopt an inverted configuration with their headgroups in the micelle core, and therefore are inaccessible for molecular imprinting. This orientation occurs even …

Zespół Energii Odnawialnej I Zrównoważonego Rozwoju (Eozr), Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Effect Of Sodium Dodecyl Sulfate And Sodium Chloride On The Stability Of Aqueous Dispersions Of Tio2 Particles Against Aggregation And Sedimentation, Xilan Zhu, Guanrong Bai, Elias I. Franses, David S. Corti, Yung-Jih Yang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Dispersions of TiO₂ particles are widely used as the main pigment in white inks for inkjet printers due to its brightness and high opacity. The TiO₂ particles, however, have a high density, and so the possible fast settling of these particles can cause maintenance problems for the printers and lower the printing quality. We studied the effect of sodium dodecyl sulfate (SDS), a commonly used dispersant, on the stability of 1 wt% TiO2 aqueous dispersions, both with and without NaCl, against aggregation and sedimentation. The sedimentation half time (t50), defined as the time need for the particles to …

Stability Of Aqueous Dispersions Of Titanium Dioxide Against Sedimentation And Aggregation, Guanrong Bai, Xilan Zhu, Elias I. Franses, David S. Corti, Yung-Jih Yang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Particles of titanium dioxide (TiO₂) are widely used as white pigments in paints and inks, due to their brightness and high refractive index. Yet, with TiO₂ having a high density (4.2 g/cm³), particles with typical sizes of 300 nm sediment rapidly even before significant agglomeration can occur. Thus, increasing the stability of TiO2 dispersions against sedimentation as well as aggregation is important. We studied the effect of sodium dodecyl sulfate (SDS), a commonly used dispersant, on the stability of aqueous dispersions of TiO₂ with weight fractions from 0.01 to 40. The sedimentation time of …

A Soft Condensed Matter Approach Towards Mathematical Modelling Of Mass Transport And Swelling In Food Grains, Michael Chapwanya, N. Misra

Articles

Soft condensed matter (SCM) physics has recently gained importance for a large class of engineering materials. The treatment of food materials from a soft matter perspective, however, is only at the surface and is gaining importance for understanding the complex phenomena and structure of foods. In this work, we present a theoretical treatment of navy beans from a SCM perspective to describe the hydration kinetics. We solve the transport equations within a porous matrix and employ the Flory–Huggin’s equation for polymer–solvent mixture to balance the osmotic pressure. The swelling of the legume seed is modelled as a moving boundary with …

The Hydrodynamic Behavior Of An Inverse Liquid-Solid Circulating Fluidized Bed, Amin Jaberi

Electronic Thesis and Dissertation Repository

In this work the hydrodynamic behavior of an inverse liquid-solid circulating fluidized bed (ILSCFB) system was studied. In addition, the hydrodynamic characteristic of the inverse liquid-solid fluidization under the conventional fluidization regime was also studied. The system consists of a downer with an inner column diameter of 7.6 cm and a height of 5.4 meters, an upcomer (riser) with an inner column diameter of 20 cm, a separator, and feeding and returning pipes which connect the downer and the upcomer. Based on the axial hydrodynamic behavior of the ILSCFB, it was found that the axial solids holdup in the downer …

Extraction Of Dibenzothiophene From N-Dodecane Using Ionic Liquids, M. Zulhaziman M. Salleh

Zulhaziman Salleh

Deep desulfurization of fuels has attracted lot of attention from growing number of researchers due to more stringent regulations imposed on sulfur content. There is a great demand to comply the regulation in current technology (hydrodesulfurization) because it requires high pressure, high temperature and high hydrogen consumption. Furthermore, aromatic sulfur compounds are also inefficient to be removed in current technology. Ionic Liquids (ILs) as class of green solvent actually plays important role as a promising alternative for desulfurization of fuels. This study focuses on the selection of potential ILs for extraction of aromatic sulfur compound involving the effect of higher …

Termodynamika Procesowa I Techniczna Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Tematyka Prac Dyplomowych Dla Studentów Wydziału Mechaniczno-Energetycznego Pwr., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Tematyka Prac Dyplomowych Dla Studentów Wydziału Chemicznego Pwr., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Mechanika Płynów Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Effect Of Ionic Liquid Electrolytes In Dsscs With Titanium Dioxide (Tio2) Inverse Opal Structures, Naomi S. Ramesar

Dissertations and Theses

Dye-sensitized solar cells (DSSC) are low-cost alternatives to conventional solar cells that can work well in low-light conditions. Despite considerable study on improving the efficiency of DSSCs, the current liquid electrolyte cell has plateaued at a conversion efficiency of ~ 12%. A major problem with these cells regarding their applicability is the low viscosity and high volatility of the toxic electrolyte, i.e., acetonitrile, which cause leakage and volatilization. We propose that using ionic liquids (ILs), which are more viscous, less volatile, and conductive, may be more suitable electrolytes. However, one unwanted side effect of the higher viscosity of the ILs …

Studies On Microscopic Flow Structure Inside A Rectangular Circulating Fluidized Bed Through Image Analysis, Jingsi Yang

Electronic Thesis and Dissertation Repository

The microscopic flow structure is studied systematically and comprehensively through a visualization system in a narrow rectangular circulating fluidized bed (CFB) transparent Plexiglas riser with a height of 7.6 m and a cross section of 19 mm × 114 mm. A visualization system consisting of a high-speed video camera, a light source, and image processing and analyzing programs is designed and developed to enable the flow structure to be visualized directly and studied quantitatively. FCC particles of 67 μm are used as the bed materials under different operating conditions with superficial gas velocity (U_g) and solids circulation rate …

Hydrodynamics In Recirculating Fluidized Bed Mimicking The Stripper Section Of The Fluid Coker, Francisco J. Sanchez Careaga

Electronic Thesis and Dissertation Repository

The stripper section of a Fluid Coker^TM consists of a system of baffles (sheds) that enhances the removal of interstitial and adsorbed hydrocarbon vapors from the fluidized coke-particles. Most of the hydrocarbon-vapors released below a stripper shed flow up to the stripper shed, where they may crack and form coke deposits that foul the shed. Extensive fouling changes the shapes of the sheds, makes them thicker and reduces the free-space between the adjacent sheds until downward solids flow is so impaired that the Coker has to be shut down.

The Radioactive Particle Tracking (RPT) technique allows the determination of …

The Onset Of Purely Elastic And Thermo-Elastic Instabilities In The Taylor-Couette Flow: Influence Of Gap Ratio And Fluid Thermal Sensitivity, Mohammadreza Ghanbari

Masters Theses

Linear stability analysis of Taylor-Couette flow of dilute polymeric solutions has been performed by using two prototypical constitutive equations for polymeric solutions namely, the Oldroyd-B and the FENE-P models. The hydrodynamic stability characteristics of the flow in presence and absence of thermal effects and in the limit of vanishing fluid inertia have been determined using an eigenvalue analysis. Particular attention has been paid to accurate determination of the instability onset conditions as a function of fluid thermal sensitivity and gap ratio. We observe a reduction in the critical Deborah, Dec for the instability onset as the gap ratio and fluid …

Oil-In-Water Emulsification Using Oscillatory Micro-Screen, Jiangshan Liu

Electronic Thesis and Dissertation Repository

A novel emulsification technique has been developed for high throughput production of uniform emulsion droplets using high porosity oscillating stainless steel wire woven micro-screen. Different surfactants were investigated including dispersed/continuous bi-surfactant systems using Span80/SDS and Span80/Tween20. The effects of oscillation amplitude and frequency as well as the dispersed phase flux on emulsion average droplet size and uniformity were investigated. It was found that the droplet average size decreased with increasing the surface sheer stress. The emulsion droplet uniformity determined using the coefficient of variation (CV) changed with oscillations such that there was an optimal oscillating frequency for each amplitude where …

Method And Apparatus For Measurement Of Fluid Properties, Feredoon Behroozi

Patents (University of Northern Iowa)

A method and apparatus for determining the contact angle and/or surface tension of a liquid on a solid surface is described. The method involves placing a fluid drop on a solid surface, and gradually increasing its volume by adding more fluid, while continuing to determine the corresponding increase in fluid height, until the drop attains maximum height beyond which additional fluid only increases the drop footprint and not height, and determining the equilibrium height and in turn the contact angle by means of an equation that correlates contact angle with depth below the fluid surface, together with the fluid surface …

Efficient Numerical Scheme Of The Dynamics Of Nonisothermal Thin Film Flow, Moustafa A. Soliman, Khalid I. Alhumaizi

Chemical Engineering

In this work we use Lubrication type method, based on the possibility of the separation of longitudinal and transversal length scales to simplify the analysis of thin film dynamics. We study the dynamics of evaporating thin liquid films on an inclined plane, where the effect of van der Waal forces is significant. The numerical solution of the evolution equation is carried out using the method of orthogonal collocation and is used for the study of the instabilities of evaporating thin film to identify conditions for efficient operation. For symmetric cases where the plane is horizontal, a two spline collocation second …

Mechaniczny Rozdział Faz Proj., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Challenges And Prospects Of Processes Utilising Carbonic Anhydrase For Co2 Separation, Patrycja Szeligiewicz, Wojciech M. Budzianowski

Wojciech Budzianowski

This article provides an analysis of processes for separation CO2 by using carbonic anhydrase enzyme with particular emphasis on reactive-membrane solutions. Three available processes are characterised. Main challenges and prospects are given. It is found that in view of numerous challenges practical applications of these processes will be difficult in near future. Further research is therefore needed for improving existing processes through finding methods for eliminating their main drawbacks such as short lifetime of carbonic anhydrase or low resistance of reactive membrane systems to impurities contained in flue gases from power plants.