Ram Kannappan

Current Research

My current research involves using redox active biopolymers to remove hazardous metals from water.  Heavy metal contamination is a notable environmental concern because even very small amounts of certain metals have human health effects.  Metals also represent a recirculating problem because they cannot be broken down like organics.  These metals must be removed to meet drinking water and wastewater discharge standards.  Many existing treatment processes move the metals from one waste stream to another more concentrated, but harder to treat waste stream.

As part of an effort to improve on existing metals removal, our research group has studied metal binding peptides.  Several
biopolymers consisting of small amino acid chains, such as poly-L-cysteine, have shown good binding capacity for various metals
in addition to specificity for certain metals.  Cysteine is redox active and can be oxidized or reduced to modify binding capacity.
Placing the peptide on to an electrically conductive substrate allows for change of binding capacity by application of a potential to the
substrate.  A system which takes advantage of this electrically activated binding switch can be used to remediate a waste stream and
then release the contaminants on demand without the need for additional chemicals, unlike ion exchange.  I am specifically looking
at the fundamental science involved in the Electronically Switchable Ion Exchange (ESIE) process and what factors affect how it might scale to practical size. Several engineering constraints such as power usage, service lifetime, treatment effectiveness, and ultimately cost factor into the feasibility of the ESIE system in practice.

Undergraduate Research

I worked under Dr. Grant Willson in Chemical Engineering and Chemistry and was involved the development of a hydrogel sensor array system. The purpose of the project was to develop a scalable sensor system which was limited in density only by lithography. Individual sensing elements were indexed by shape patterned through photolithography. The elements were then assembled into a larger array which can be scanned optically. The hydrogel matrix which comprised the elements and matrix allowed for a variety of sensing mechanisms centered on DNA, enzymes, or even live cells. I worked on the materials aspect of the project and looked specifically at the hydrogel formulation, ability to pattern the hydrogel, and response of the hydrogel a variety of environmental conditions

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Publications

Meiring, Jason E.; Schmid, Matthew J.; Grayson, Scott M.; Rathsack, Benjamin M.; Johnson, David M.; Kirby, Romy; Kannappan, Ramakrishnan; Manthiram, Kalpana; Hsia, Benjamin; Hogan, Zachary L.; Ellington, Andrew D.; Pishko, Michael V.; Willson, C. Grant.  Hydrogel Biosensor Array Platform Indexed by Shape. Chemistry of Materials  (2004), 16(26),  5574-5580