Dr. Stephen C. Dexter Professor University of Delaware College of Marine Studies 700 Pilottown Rd. Lewes, Delaware 19958 phone: (302) 645-4261 fax: (302) 645-4007 dexter@udel.edu

• Professor of Marine Biology-Biochemistry

Education

• B.S., Mechanical & Aerospace Engineering, University of Delaware, 1965
• Ph.D., Applied Science, Metallurgy, University of Delaware, 1971

Research Interests

Marine corrosion. Influence of microorganisms and microbial films on corrosion electrochemistry. Factors affecting bioattachment and adhesion. Cathodic protection, calcareous deposition, marine corrosion and biofouling control. Professional Society Activities.

Current Projects

• Measuring the chemistry within thin films of microorganisms and their extracellular polymeric materials that form on metallic, nonmetallic and composite materials immersed in natural aqueous environments. Development, in cooperation with Dr. George Luther, of solid state microelectrodes for use in making these measurements.

• Determing and modeling the mechanisms by which the chemical changes within such biofilms on metal surfaces affect the electrochemistry of marine corrosion.

• Determining the sequence of biological and electrochemical events that results in initiation of localized corrosion at or near the welds of stainless steel structures used in fresh and marine industrial waters.

• Measuring the effect of microbial biofilms on initiation and propagation of galvanic corrosion and crevice corrosion in seawater.

• Materials Science Program

Teaching

I currently teach graduate level courses on "Biological Interactions at Surfaces" and "Corrosion Measurements and Mechanisms." I also teach a beginning course on "Corrosion and Corrosion Control," which may be taken for either undergraduate or graduate credit. I advise a population of 2 to 4 graduate students and one undergraduate summer intern. Information for Prospective Graduate Students.

Current Research Group

• Kunming Xu, Ph.D. student (B.S., Xiamen University, People's Republic of China, 1987) - Development of microelectrodes and measurement of chemisty within thin biofilms .

• David Ruppel, M.S. student (B.S., Chemistry and B.A., Government, University of Notre Dame, 1991) - Do Mn and Fe cycling in biofilms support greater corrosion rates in galvanic couples?

• Malayappan Eashwar, Postdoctoral fellow (Ph.D., Marine Biology, Madurai University, India, 1996) - Effect of marine biofilms on corrosion of stainless alloys and stainless steel weldments.

Selected Publications

Author or co-author of over 80 technical papers, reports and books in the fields of marine corrosion and biofouling including:

Dexter, S. C. 1979. Handbook of Oceanographic Engineering Materials, Wiley-Interscience, New York, 315 pp.

Dexter, S. C. and G. Y. Gao. 1988. "Effect of seawater biofilms on corrosion potential and oxygen reduction of stainless steel," Corrosion, Vol. 44, No. 10, p. 717.

Dexter, S. C., O. W. Siebert, D. J. Duquette and H. A. Videla. 1991. "Use and limitations of electrochemical techniques for investigating microbiological corrosion," Corrosion, Vol. 47, No. 4, p. 308.

Dexter, S. C. and S-H. Lin. 1992. "Effect of marine biofilms on cathodic protection," International Biodeterioration and Biodegradation, Vol. 29, p. 231.

Dexter, S. C. and S-H. Lin. 1992. "Calculation of seawater pH at polarized metal surfaces in the presence of surface films," Corrosion, Vol. 48, No. 1, p. 50.

Dexter, S. C. 1993. "Role of microfouling organisms in marine corrosion," Biofouling, Vol. 7, p. 97.

Zhang, H-J and S. C. Dexter. 1995. "Effect of biofilms on crevice corrosion of stainless steels in coastal seawater," Corrosion, Vol. 51, No. 1, 1995, pp. 56-66.

Dexter, S. C. 1995. "Effect of biofilms on marine corrosion of passive alloys," in Bioextraction and Biodeterioration of Metals, C. Gaylarde and H. Videla, Eds., Cambridge University Press, pp. 129-168.

Dexter, S. C. 1995. Section V, Chapter 43, "Microbiological Effects," in Corrosion Tests and Standards, Application and Interpretation, R. Baboian, Ed., ASTM Manual Series: MNL 20, American Society for Testing and Materials, Philadelphia, pp. 419-429.

Hansen, D. C., S. C. Dexter and J. H. Waite. 1995. "The inhibition of corrosion of S30403 stainless steel by a naturally occurring catecholic polymer," Corrosion Science, Vol. 37, No. 9, pp. 1423-41.

Dexter, S. C. and P. Chandrasekaran. 1996. "Chemical changes at the metal surface under biofilms, effect on localized corrosion," in Critical Factors in Localized Corrosion II, P. M. Natishan et al., eds., The Electrochemical Society, Pennington, NJ, pp. 188-200.

Dexter, S. C. 1996. "Effect of biofilms on crevice corrosion," Proc. COR/96 Topical Research Symposium on Crevice Corrosion, NACE, Houston, TX, pp. 367-383.

dexter@udel.edu

Graduate College of Marine Studies

University of Delaware