Ned B. Bowden



  • Organic chemistry
  • Polymers
  • Materials
  • Fertilizers

Focus areas

  • Environmental/atmospheric
  • Materials/polymer
  • Synthesis

Research interests

We are focused on addressing challenges in a range of different fields using our expertise in nanomaterials and the synthesis of small molecules and polymers. We work in research areas where we can be unique and can bring our synthetic and materials experience to tackle problems in unexpected ways.  Our research is currently focused on organic solvent nanofiltration membranes, growth promoters to increase the harvest yields of agricultural crops, and investigating the effects of hydrogen sulfide on human cells. In each of these areas we develop novel approaches to solve problems and are keen to develop solutions that can be used in industry. We have an interest in launching start-up companies and have already formed two start-ups.

We have a long history of fabricating organic solvent nanofiltration membranes using polydimethylsiloxane, polydicyclopentadiene, polyepoxies, and carbon nanotubes. Research in this field is concerned with how to separate organic chemicals with molecular weights from approximately 100 to 2,000 grams per mole. This is a challenging field because the chemicals to be separated may have similar shapes and sizes, and these shapes change as bonds within the chemicals rotate. The opportunities for success are large in this field because much of the chemical industry uses chemicals in this molecular weight range and developing an inexpensive, membrane-based method to separate them would have an important impact. We focus on the synthesis of new membranes and have recently synthesized highly selective membranes based on polyepoxies.  We are bringing an understanding of how the molecular structure of membranes can change their nanometer and macro properties.  We have developed highly selective membranes that can separate chemicals with only small differences in their molecular weights.

We are actively synthesizing new growth promoters to increase the growth of many of the key crops grown in the U.S. The population of the world is continuing to grow and will exceed 10B by 2050, but the amount of farmland is shrinking worldwide. To feed the growing population the productivity of current farmland needs to increase. We are using our synthetic and materials expertise to synthesize and fabricate a next generation of growth promoters for agricultural plants. We have already doubled the weight of radishes and increased the weight of a head of lettuce by 86%.  We are working to develop methods to use this technology in greenhouses, indoor farms, and in outdoor farms. 

We are also investigating the effects of hydrogen sulfide on human cells. Hydrogen sulfide is the third known gasotransmitter. It is made by enzymes in our bodies and has been implicated in a wide range of diseases and cellular cycles. Hydrogen sulfide in medicine is a relatively new area of science, and we are synthesizing new chemicals to slowly or rapidly release it in vivo.  This work will, we hope, result in new treatments for ocular diseases and cancer. 

Recent publications

Bowden, N. B. Nanomaterials-based membranes increase flux and selectivity to enable chemical separation. ACS Applied Nano Materials, 2020, 4, 9538-9541.

Wafa, E. I.; Wilson-Welder, J. H.; Hornsby, R. L.; Nally, J. E.; Geary, S. M.; Bowden, N. B.; Salem, A. K. Poly(diaminosulfide) microparticle-based vaccine for delivery of leptospiral antigens. Biomacromolecules, 2020, 21, 534-544.  

Do, A.-V., Smith, R., Tobias, P., Carlsen, D., Pham, E., Bowden, N. B., Salem, A. K. Sustained release of H2S from poly(lactic acid) functionalized 4-hydroxythiobenzamide microparticles to protect from oxidative damage. Annals of Biomedical Engineering, 2019, 47, 1691-1700.

Carter, J. M., Brown, E. M., Irish, E. E., Bowden, N. B. Characterization of dialkyldithiophosphates as slow hydrogen sulfide releasing chemicals and their effect on the growth of maize. Journal of Agriculture and Food Chemistry, 2019, 67, 11883-11892.

Schumacher, A. L., Gilmer, C. M., Atluri, K., Lee, J., Jugessur, A. S., Salem, A. K., Bowden, N. B., Raghavan, M. L., Hasan, D. M. Development and evaluation of a nanometer-scale hemocompatible and antithrombotic coating technology platform for commercial intracranial stents and flow diverters. ACS Applied Nano Materials, 2018, 1, 344-354. 

Gilmer, C. M., Bowden, N. B. Reactive epoxy nanofiltration membranes with disulfide bonds for the separation of multicomponent chemical mixtures. ACS Omega, 2018, 3, 10216-10224.

Carter, J. M., Brown, E. M., Grace, J. P., Irish, E. E., Bowden, N. B. Improved growth of pea, lettuce, and radish plants using the slow release of hydrogen sulfide from GYY-4137. PLoS ONE, 2018, 13, e0208732. 

Gilmer, C. M., Zvokel, C., Vick, A., Bowden, N. B. Separation of saturated fatty acids and fatty acid methyl esters with epoxy nanofiltration membranes. RSC Advances, 2017, 7, 55626-55632.

Gilmer, C. M., Bowden, N. B. Highly cross-linked epoxy nanofiltration membranes for the separation of organic chemicals and fish oil ethyl esters. ACS Applied Materials & Interfaces, 2016, 8, 24104-24111. 

Geary, S. M.; Hu, Q.; Joshi, V. B.; Bowden, N. B.; Salem A. K. “Diaminosulfide based polymer microparticles as cancer vaccine delivery systems” Journal of Controlled Release, 2015, 220, 682-690. 

Long, T. R.; Wongrakpanich, A.; Do, A.-V.; Salem, A. K.; Bowden, N. B. “Long-term release of a thiobenzamide from a backbone functionalized poly(lactic acid)”  Polymer Chemistry, 2015, 6, 7188-7195.

D’Mello, S. R.; Yoo, J.; Bowden, N. B.; Salem, A. K. “Microparticles prepared from sulfenamide-based polymers” Journal of Microencapsulation, 2014, 31, 137-146.

Kitano, H.; Ramachandran, K.; Bowden, N. B.; Scranton, A. B. “Unexpected visible-light-induced free radical photopolymerization at low light intensity and high viscosity using a titanocene photoinitiator” J. Appl. Polym. Sci. 2013, 128, 611-618.

Gupta, A.; Bowden, N. B. “Separation of cis-fatty acids from saturated and trans-fatty acids by nanoporous polydicyclopentadiene membranes” ACS Appl. Mater. Interfaces, 2013, 5, 924-933.


  • A review of this article was published in Chemical & Engineering News. See Chemical & Engineering News, 2013, 91, issue 6
  • This article was also reviewed in Inform which is the magazine published by the American Oil Chemists Society.
  • This article was highlighted in the magazine Tribology & Lubrication Technology that is published by the Society of Tribologists and Lubrication Engineers ( It is read by 4,000 professionals worldwide on a monthly basis.
  • This article was highlighted in Advances in Engineering in March of 2013.

Graf, T. A.; Yoo, J.; Brummett, A. B.; Lin, R.; Wohlgenannt, M.; Quinn, D.; Bowden, N. B. “New polymers possessing a disulfide bond in a unique environment” Macromolecules, 2012, 45, 8193-8200.  

Note: A review of this article and articles 55 and 54 appeared in Chemical & Engineering News. See Chemical & Engineering News, 2012, 90, issue 35.

Yoo, J.; Kuruvilla, D. J.; D’Mello, S. R.; Salem, A. K.; Bowden, N. B. “New class of biodegradable polymers formed from reactions of an inorganic functional group” Macromolecules, 2012, 45, 2292-2300.

Note: This article was reviewed in Synfacts. Synfacts is a journal to describe important trends and results in organic chemistry.  Swager, T. M.; Mirica, K. A. “First synthesis of polysulfenamidies” Synfacts, 2012, 8, 611.

Yoo, J.; D’Mello, S. R.; Graf, T.; Salem, A. K.; Bowden, N. B. “Synthesis of the first poly(diaminosulfide)s and an investigation of their applications as drug delivery vehicles” Macromolecules, 2012, 45, 688-697. 

View CV

Research areas
  • Organic chemistry
Ned B. Bowden portrait
Postdoctoral Research Associate, Stanford University
PhD, Harvard University
BS, California Institute of Technology

University of Iowa
W425 Chemistry Building (CB)
230 N. Madison Street
Iowa City, IA 52240
United States