Research
Professor D’Souza’s main research interests are in the bulk and interfacial properties of heterogeneous materials. Recent and current research areas include: multifunctional composites, environmental friendly packaging, sensor textiles, biocomposites and magnetorheological fluid rheology. The use of functional nanoparticles coupled with functional matrices enables gains in properties that may, on first glance, appear incongruent. Thus comes the laboratory focus in "having one’s cake".
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Fibers and Nanofibers
We have developed biofibers based on Levan in collaboration with Montana Polysaccarides and harness the processing-property potential for water soluble systems for biodegradable textiles.
Student partners
Shailesh Vidhate (graduate student)
Sandeep Manandhar (undergraduate student)
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Environmentally friendly materials and manufacturing
Biodegradable foams are a key area of growth for the packaging applications. Starch based materials (SBM) have been a successful environmentally degradable polymer. However, making foams out of these materials has been challenging due to their chemical composition and consequent low miscibility in CO2. We examine the potential for developing biodegradable foams with one component being a starch based polymer by introducing it into polycaprolactone (PCL). PCL has thus far shown very high expansion ratios for foams with supercritical CO2 (scCO2).
Student partners
Koffi Dagnon (graduate student)
Sandeep Manandhar (undergraduate student)
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Biocomposites
Working with Dr’s Ayre, Chapman and Steven, Center for Plant Lipid Research, we are focused on understanding the properties of biocomposites based on domestic plants, their potential as a renewable material substitute for engineered nonrenewable materials and their interfaces with biopolymers. We have thus far examined the use of lower volume fractions that typically considered for short fiber composites (5% compared to 30%) and found comparative gains can be made in mechanical properties.
Student partners
Sunny Ogbomo
Sarah Ballilo |
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Bio-nanocomposites
We have investigated bio-nanocomposites based on PLLA and PHBV. Nanoclays based on layer double hydroxides which are anion exchanging synthetic clays have proven to mechanically outperform parallel natural cation exchanged systems such as montmorillonite. Unique crystallization nucleation and growth phenomena are currently being probed.
Student partners
Koffi Dagnon
Helen Chen (TAMS)
Clark Robinson (TAMS) |
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Piezoresistive Sensors
We are examining the piezoresistive sensor potential of polymers modified by piezo ceramic nanoparticles, carbon nanofiber and multiwalled nanotubes. We examine the role of processing on polymer structure, dispersion and sensor gauge factors.
Student partners
Shailesh Vidhate
Larry Kuo (undergraduate, MTSE)
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1 Ibuprofen molecule replaces
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Biomaterials for Drug Delivery
We have functionalized nanoplates (with a surface functionality of 1 active site per square nanometer) with ibuprofen and examined the drug release potential in PLA films. Parallel investigations into heparin etc. have shown promise. In addition, the use of drugs as functional agents in the polymer-nanoparticle interface has led to decreased cell toxicity.
Research Partners
Teresa Golden, Chemistry, UNT
Kytai Nguyen, Bioengineering, UTA |
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Flame retardant polymer nanocomposites
By two UNT patented technologies, we have developed a V0 rated PET nanocomposite which provides flame retardance at 5% by weight nanoclay addition, leading to a processable nanocomposite
Student partner: Sunny Ogbmo |
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Aging in polymer nanocomposites
Viscoelastic materials show a significant creep response with respect bo both temperature and stress changes imposed on the material over time. We model the creep response, correlate it to changes in molecular relaxation times, breadth of relaxations and use constitutive relations to probe multiparameter (stress and temperature simultaneously) effects.
Student partner: Ali Shaito |
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