mixtures of oil and water are classified based on the size of oil droplet (doil) – free oil if doil > 150 μm, dispersed oil if 20 μm < doil < 150 μm and emulsified oil if doil < 20 μm. we have developed a novel solution for the separation of free oil, dispersed oil, and oil-water emulsions based on the design of hygro-responsive (from the greek word ‘hygra’ meaning liquid) membranes. these membranes, counter-intuitively, are wet by water, but are still able to repel low surface tension oils like rapeseed oil or hexadecane. this makes these porous surfaces ideal for gravity-based separation of oil and water as they allow the higher density liquid (water) to flow through while preventing the flow of the lower density liquid (oil). as the separation is solely gravity driven, it is expected to be one of the most energy efficient technologies for oil-water separation. we have developed a setup based on these membranes that allows for the continuous separation of oil–water emulsions for over 100 hours without a decrease in flux, using only gravity. the demonstrated separation methodology is expected to have numerous applications, including the clean-up of oil spills, wastewater treatment, fuel purification and the separation of numerous commercially relevant emulsions.

this video won the doe people’s choice contest. http://www.energyfrontier.us/videos/results.

primack wanted to know how evolutionary relationships influence plant species’ susceptibility to climate change. he and his students surveyed thoreau’s woods for flowering-time responses and abundance of the same plants thoreau and other botanists counted a century and a half earlier. thoreau’s woods, located in the town of concord, massachusetts, are ideal for such studies because up to 60 percent of concord land is protected or undeveloped. primack’s 2003-2007 data, along with temperature data, were combined with a historic data set from alfred hosmer, a concord storekeeper. hosmer picked up thoreau’s careful observations thirty years later, between 1888 and 1902. charles davis of the university of michigan contributed a phylogenetic tree, from a previous nsf-funded project, that illustrates how concord plant species are related to one another. the combined data sets and phylogeny were analyzed together to reveal evolutionary patterns in plant responses to climate change.

primack and colleagues discovered that changes in abundance and flowering-time responses of plants in thoreau’s woods are more similar among closely related species than expected by chance. more specifically, there was a correlation between flowering-time tracking of seasonal temperatures and changes in abundance, indicating that plant species that did not track temperatures have experienced greater declines than species that do track temperature. this pattern was found in plant families such as dogwood, mint, orchids and roses. the study is notable because it shows that climate change-induced species loss is happening and does not occur randomly. entire lineages, encompassing many closely related species, are being lost completely.