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Aggregation Dynamics of Colloids Under Diffusioelectrophoretic Levitation

Primary Investigators:
Carlos A. Silvera Batista
Brief Description of Project:
Control of the spatial arrangement of uniform and anisotropic colloids into 3D lattices is of scientific and technological interest to achieve materials with novel properties such as optical bandgaps and structural colors. Electric fields are a useful external input of energy that can help rapidly and controllably concentrate colloidal suspensions to the point of liquid/crystals transitions by creating gradients in osmotic pressure. Electric fields can also impart directionality to colloidal interactions through induced multipoles, while the large and easy-to-navigate parameter space provides versatility. Therefore, knowledge of the dynamics and forces that colloids experience under electric fields is essential for the fabrication and engineering of reconfigurable materials. A parameter space of interest is where electrokinetics becomes relevant and ions respond to fields. The electrokinetic behavior of anisotropic colloids in fields at low frequency shows emerging forms of transport processes (diffusioelectrophoresis) that manifest into unique levitation and aggregation behavior that can be exploited in separation and microfluidic operations. But most interestingly, while levitating, the colloids experience collective dynamics that results in clustering despite the particles holding similar charges. The objective of this project is to unravel the physical origins of such counterintuitive collective dynamics. Research tasks will include the fabrication and surface modification of uniform and anisotropic colloids, the characterization of surface properties, the application of DC and low frequency AC fields, visualization of individual and collective dynamics through confocal microscopy, image analysis and particle tracking.

Desired Qualifications:
- Basic programming skills
- Basic chemistry, physics and physical chemistry, calculus and differential equations
- Sophomore; Junior level preferred
- Chemical Engineering, Chemistry or Physics background
Nature of Supervision:
The student will mostly work under my direct supervision and at times will work alongside a graduate student. I will meet the student weekly to discuss progress and research goals. He/She will have a chance to improve his/her research skills and communication skills by presenting the work regularly in our group meetings. My travel throughout the summer will be minimal (less than a week), which will ensure that the student will always have either myself or the graduate student for assistance and guidance.
A Brief Research Plan (period is for 10 weeks):
- Training on confocal microscopy and surface characterization (Week 1-2)
- Synthesis of particles (Week 1-2)
- Particle tracking (Week 2-4)
- Electric field experiments (Week 3-7)
- Tracing of Flows and Particle Tracking Velocimetry (Week 8)
- Conclusion and Writing of final report (Week 9-10)
Number of Open Slots: 1
Contact Information:
Name: Carlos Silvera Batista
Title: Assistant Professor
Department: Chemical Engineering
Campus Address: ESB 352
Mailing Address: 2400 Highland Avenue, 107 Olin Hall
Nashville, Tn 37212
United States