Mark Welker

Education

B.S. Chemistry with Highest Honors, University of North Carolina at Chapel Hill (1981);
Ph.D., Florida State University (L.S. Liebeskind) (1985);
Postdoctoral Fellow (Exxon & NIH), University of California-Berkeley (K.P.C. Vollhardt) (1985-86).
Elected a Fellow in the American Association for the Advancement of Science (AAAS) 2008. Dreyfus Foundation Henry Dreyfus Teacher-Scholar Awardee (1994-99).
Program Officer, Division of Chemistry, Organic and Macromolecular Chemistry Program, National Science Foundation, 2001-2002 and 2005 (off site).
Associate Provost for Research 2003-2008, Associate Provost for Research and Faculty Affairs 2008-2010, Vice Provost 2010-2011, Interim Provost 2011-2012.

Research Description

Organic Synthesis/Synthetic Methods/Medicinal Chemistry/Molecular Electronics

1) Modification of Naturally Occurring Polysaccharides for Use in Regenerative Medicine (collaborators Aleks Skardal and Emmanuel Opara)

Hyaluronic acid and alginate are naturally occurring polysaccharides which can be chemically modified to change their properties. The Welker lab has been modifying these polysaccharides by converting their carboxylic acid functional groups into amides. In the case of alginate, this modification is being performed to alter the acid-base stability of alginate pellets used for drug delivery. Preliminary work shows that modified alginate is stable to acid environments similar to what one would find in the stomach and that these pellets disintegrate readily in a basic environment similar to what one would find in the small intestine. The Welker lab is also modifying the chemical structure of naturally occurring hyaluronic acid (HA) with the goal of improving HA’s adhesive properties and its rigidity thereby improving its performance as a wound healing aid. The Welker lab is also simultaneously synthesizing small molecules which could be used as modular additives to existing HA with hopefully similar improved performance outcomes for patients.

3) High Performance Organic Thin Film Transistors and Molecular Rectifiers (collaborator Oana Jurchescu)

Organic thin film transistors (OTFTs) could enable the development of next generation low cost, flexible electronics but they suffer from inadequate performance and high- power requirements. We are preparing novel self-assembled monolayer (SAM) dielectrics to simultaneously control film microstructure and induce a high charge density in the device channel. Some of the small molecules we are preparing also self assemble and function as molecular rectifiers (rectifiers are one way conductors of electric current). Synthetic organic chemistry reactions are used to prepare small molecules which are then self-assembled and tested on silica surfaces.

Publications

Link to Google Scholar Publications for Mark E. Welker

(86) Chemical Modification of Alginate for Controlled Oral Drug Delivery.  Surya R. Banks, Kevin Enck, Marcus W. Wright,  Emmanuel C. Opara, and Mark E. Welker, J. Agricultural and Food Chemistry, 2019, 67, 10481-10488, DOI: 10.1021/acs.jafc.9b01911.

(84) Synthesis of Sulfur and Silicon SAM Precursors for Molecular Electronics Applications.  Mark E. Welker, Phosphorus, Sulfur, and Silicon, 2019, 1563, DOI: 10.1080/10426507.2019.1653871

(83) Molecular Rectifiers on Silicon: High Performance by Enhancing Top-Electrode/Molecule Coupling.  Zachary A. Lamport, Angela D. Broadnax, Ben Scharmann, Robert W. Bradford III, Andrew DelaCourt, Noah Meyer, Hui Li, Scott M. Geyer, Timo Thonhauser, Mark E. Welker, and Oana D. Jurchescu, ACS Applied Materials & Interfaces  2019, 11, 18564-18570; DOI: 10.1021/acsami.9b02315

(82) Synthesis and PI3 Kinase Inhibition Activity of a Wortmannin-Leucine Derivative. William Cantrell, Yue Huang, Antonio A. Menchaca, George Kulik, and Mark E. Welker, Molecules 2018, 23(7), 1791; doi: 10.3390/molecules23071791.

(81) Synthesis and PI3 Kinase Inhibition Activity of Some Novel Trisubstituted Morpholinopyrimidines.  Emily W. Wright, Ronald A. Nelson, Jr., Yelena Karpova, George Kulik and Mark E. Welker, Molecules 2018, 23(7), 1675; doi: 10.3390/molecules23071675.

(80) Synthesis and PI3 Kinase Inhibition Activity of Some Novel 2,4,6-Trisubstituted 1,3,5-Triazines.  Ronald A. Nelson, Jr., Taylor Schronce, Yue Huang, , Alanoud Albugami, George Kulik, and Mark E. Welker, Molecules 2018, 23(7), 1628; doi: 10.3390/molecules23071628.

(79) Ferrocenes as Building Blocks in Molecular Rectifiers and Diodes.  Mark E. Welker, Molecules 2018, 23, 1551;  http://dx.doi.org/10.3390/molecules23071551.

(78) Ferrocenealkylsilane Molecular Rectifiers.  Zachary Lamport, Angela Broadnax, Ben Scharmann, Oana Jurchescu, and Mark E. Welker Journal of Organometallic Chemistry, 2018, 856, 23; https://doi.org/10.1016/j.jorganchem.2017.12.019.

(77) Fluorinated Benzalkylsilane Molecular Rectifiers.  Zachary Lamport, Angela Broadnax, David Harrison, Katrina Barth, Lee Mendenhall, Clayton Hamilton, Martin Guthold, Timo Thonhauser, Mark E. Welker, and Oana Jurchescu, Scientific Reports, 2016, 6, 38092; doi: 10.1038/srep38092, open access doi: http://em.rdcu.be/m5Lf

Awards and Accomplishments

William L. Poteat Professor of Chemistry, 2005-present
Elected AAAS Fellow, 2008