Dr. Vijay John at Tulane University was awarded an RFP-I grant at $10,338,000 to lead the GoMRI Consortium for the Molecular Engineering of Dispersant Systems (C-MEDS) that consisted of 22 collaborative institutions and 188 research team members. The goals of C-MEDS were to understand the role of dispersants and related chemical compounds in mitigating the effects of deep-sea hydrocarbon releases and to develop new and improved dispersants, particularly suited for deep-sea application, through the evaluation of physiochemical aspects of new dispersants and detailed research on physiochemical properties, fate, and transport mechanisms. Researchers with C-MEDS conducted lab-based experiments to support sophisticated modeling, and development work was accompanied by detailed characterizations of the molecular phenomena occurring at the oil-water interface.
C-MED investigators are extremely grateful for the opportunity given to them by GoMRI. We hope that the results of our research will be useful in understanding oil spills and in developing technologies for the remediation of oil spills.
Over its award period (3 years, plus a 12-month no-cost extension), C-MEDS organized over 90 outreach activities or products, including but not limited to:
- In partnership with others, C-MEDS hosted a forum at Our Lady of Holy Rosary Church in Houma, LA, entitled: “Is it safe? The oil spill dispersants and frequently asked questions,” which provided the Vietnamese fishing/shrimping community with an opportunity to ask questions from researchers.
- C-MEDS designed, coordinated, and facilitated a 1-day Summer Science Academy for approximately 20 elementary students from St. James Methodist Church of New Orleans Summer Camp. Campers were engaged in a “round-robin” rotation of 6 miniature, age-appropriate, scientific experiments.
- C-MEDS partnered with the Metcalf Institute for Marine & Environmental Reporting to develop and implement a one-day science seminar for journalists to focus on the science and technology of deep-sea dispersants.
As of August 6th, 2017, C-MEDS research has resulted in 118 peer-reviewed publications, 110 scientific presentations and 141 datasets being submitted to the GoMRI Information and Data Cooperative (GRIIDC), which are/will be available to the public. C-MEDS engaged 136 students over its award period. Significant outcomes of C-MEDS research according to GoMRI Research Theme are highlighted below.
- Understanding that concepts of particles and polymers at interfaces have significant implications for the understanding of oil-mineral aggregates and marine snow, C-MEDS researchers studied and subsequently found that tubular natural clays, known as halloysites, can be used as hosts for the surfactants used in dispersant formulations. This discovery will allow for the development of particle-based dispersants that, in addition to stabilizing oil droplets, reduce interfacial tension and generate droplets that are small enough to be dispersed through the water column for improved response and mitigation.
- C-MEDS explored the fundamental interfacial science (both thermodynamic and rate/transport factors) of marine oil dispersants to provide guidance on the development of novel dispersants. In 2014, C-MEDS found that dioctyl sodium sulfosuccinate (DOSS), in the formulation of Corexit 9500A, can be replaced by the use of the plant-based phospholipid, soybean lecithin, which is an environmentally benign material. C-MEDS researchers also worked to translate this discovery into practice, thereby offering improved spill response and mitigation methods.
- C-MEDS research showed that the surfactant components of Corexit 9500 have distinct adsorption characteristics at the oil-water interface with Tween-80 showing virtually irreversible adsorption. The conformation of the various surfactant components at the interface was further understood using molecular simulations.
- C-MEDS research was also the first to show that gas bubbles rising through the ocean surface containing a thin layer of oil would result in the creation of aerosol droplets that could be carried significant distances. The entrainment of air upon wave action could also result in bubbles that led to aerosol formation. In the presence of dispersants, aerosol droplets containing dispersant components could be generated. Molecular simulations again contributed to the understanding of the partitioning of surfactants to the aerosol droplet – air interface. C-MEDS research also showed that secondary droplets formed from bubbles bursting through an oil layer over water would result in a stable emulsion when the droplets fell back into the liquid.
- As stated above, a very distinctive aspect of C-MEDS research was the use of molecular scale computation and simulation to understand surfactant anchoring and conformation at the oil-water interface.
Project Research Overview (2015):
An overview of the project research activities from the GoMRI 2015 Meeting in Houston.
Direct link to the Research Overview presentation.
Proposed Research Overview (2011):
For an overview of the proposed research, see the Proposed Research Overview presentation from the GoMRI Fall 2011 Meeting in New Orleans.