William L. Poteat Professor of Chemistry
Office:Wake Downtown, Rm. 3811
Phone: (336) 702-1953
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.
Organic Synthesis/Synthetic Methods/Medicinal Chemistry/Molecular Electronics
1) Modification of Naturally Occurring Polysaccharides for Use in Regenerative Medicine (collaborator Emmanuel Opara)
Alginate is a naturally occurring polysaccharide which can be chemically modified to change its properties. The Welker lab has been modifying alginate by oxidation, reductive amination and amidation. These modifications are 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.
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.
(89) Cobaloxime Complex Mediated Organic Chemistry. Mark E. Welker, Invited book chapter for “The Chemistry of Organocobalt Compounds” in Patai’s Chemistry of Functional Groups Series published by Wiley Press, 2021, submitted.
(88) Boron and Silicon-Substituted 1,3-Dienes and Dienophiles and Their Use in Diels-Alder Reactions. Mark E. Welker, Invited review article for a special journal edition on Diels-Alder Reactions in Organic Synthesis, Molecules 2020, 25, 3740; doi:10.3390/molecules25163740
(87) Chemical Modifications of Alginates for Use in Drug Delivery and Regenerative Medicine Applications. Mark E. Welker, Invited book chapter for “Controlled Drug Delivery Systems”, edited by Emmanuel C. Opara CRC Press-Taylor & Francis, Boca Raton, FL 2020, Chapter 2, pp. 3-28, ISBN-13: 978-0367187170.
(86) Development of a Novel Oral Delivery Vehicle for Probiotics. Kevin Enck, Surya R. Banks, Hariom Yadav, Mark E. Welker, Emmanuel C. Opara, Current Pharmaceutical Design, 2020, 26, 3134-3140; doi: 10.2174/1381612826666200210111925.
(85) 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
Awards and Accomplishments
WFU College Board of Visitors Faculty Leadership Award, 2020 Graduate Student Association Faculty Excellence Award, 2016 Elected AAAS Fellow, 2008 William L. Poteat Professor of Chemistry, 2005-present
WFU Award for Excellence in Research, 1991