Progress 10/01/12 to 09/30/15

Outputs
Target Audience: Nothing Reported Changes/Problems:Major challenges including explosions that resulted in destruction of two electrospinning devices, turnover of staff (2 technicians and a postdoc came and went during the course of the project) and students (three different undergraduates participated, but there was no overlap since the second one (who had been trained by the first)decided not to continue with the project. We also faced major challenges obtaining sufficient quantities of small biochar particles from traditional grinding devices, and in keeping the biochar suspended in the electrospinning solvents.We had to narrow the scope of the project away from multiple pollutants, biochars, and particular sizes because of the difficulty in milling and suspending biochar in the solvents used during electrospraying. We have, however, made significant process on the electrospinning side, including the development of an explosion-proof electrospinner and the production of vicious co-solvents that serve to keep the biochar particles suspended and dispersed during electrospinning. What opportunities for training and professional development has the project provided?Over the course of the 3 years threesenior staff (technicians/post docs)and three undergraduates received training in electrospinning, milling, and size fractionation as well training in the use and detection of radioisotope tracers used to quantify pollutant deposition on the biochar fabrics. How have the results been disseminated to communities of interest?The results are still preliminary and not yet ready for publication. We are continuing with the project using volunteer undergraduate research assistants who hope to be able to build on the hard won methodologicaladvances obtained during the funding period. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? In year one our main focus was on getting the biochar ready for suspension in the solvents caring the dissolved polymers that would eventually be electrospun. We tried numerous different commercial grinders and were able to producethe two larger sizes of particles (>100um and a 10-100um fraction), though we were notable to produce and separate enough of the smallerbiochar fraction (0.1-10um) to make it practical for it to be used in electrospinning. We also had to develop a new system for electrospinning since the biochar in the electrospinning solvent led to several explosions that destroyed two electrospinning units. We developed a simple remedy by enclosing the electrospinning setup in an air tight plexy-glass box with two gas ports andinto which high purity nitrogen was fed. This displaced the oxygen and prevented further combustion events. In year twowe produced one biochar containing fabric and a control fabric and tested themfor theirsorptive ability using semivolatile biphenyl as a model pollutant in a closed system:a 40 ml EPA vial with 10,000 dpm of 14C biphenl sorbed to the bottom of the vial. We found that it adsorbed approximately 10 times more biphenyl than the control fabric. We alsofound that biochar particles greater than 10-100um sizeproducedbrittle fabrics with numerous macrospores that were difficult to work with so these were not tested further. We also develop a multi-needle electropining device that increased the rate at which electrospun fabriccould be generated (though unfortunately, we still had problems with the biochar settling in the syringe during the spinning process and couldn't produce uniform fabric- i.e. char was more dense in some sections than others and therefore difficult to quantitively compare with controls). In year three we used filtration of acetone suspended biochar to obtained fractions that were less than 1um and wewere able to spin numerous biochar membranesbut still found that it was difficult of obtain thedistribution of biochar particles we had initially hoped to obtain because it would still sediment in the syringe during the spinning process.This was likely due to low viscosity of the acetone carrier solvent that was used to dissolvethe polymers used for electro spinning. We thereforepivoted towards testing many different solvent/polymer combinations in order to keep the biochar from settling and the electrospinning device from clogging. We eventually settled on using formic acid as the polymer solvent because its higher viscosity which kept the biochar suspended (and therefore more evenly distributed in the fabric).We ended up only being able to test the fabrics against one type of modelpollutant (biphenyl), but found that the biochar fabric wasmore effective at sorbing this compound than the control fabric.

Publications

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Nothing Reported Changes/Problems: A major challenge was the departure of the post doc coordinating the project and training the undergraduate. In addition, one of the undergraduates graduated in May. It took time for the technician to receive the radiation safety training needed to perform the adsorption tests. It also took time for her to master the adsorpting testing procedure. What opportunities for training and professional development has the project provided? Two undergraduate students were given cross disciplinary training in materials science and environmental chemistry via one on one interaction with Drs. Hay and Hinestrosa (collaborator). How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? We will produce additional fabrics and test them against additional volatile and semivolatile model pollutants.

Impacts
What was accomplished under these goals? We tested one biochar containing fabric for its sorptive ability using semivolatile biphenyl as a model pollutant. We found that it adsorbed approximately 10 times morebiphenyl than the control fabric. We found that biochar particles in the 10-100um size range produce brittle fabrics with numerous macropores that were difficult to work with so these were not tested further.

Publications

Progress 10/01/12 to 09/30/13

Outputs
Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The undergraduates and a part time post doc worked on the project in a multidisciplinary fashion with the PD and Dr. Juan Hinestrosa in the department of Fiber Science at Cornell. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Additional testing of existing char-fabrics will be performed and additional fabrics with chars obtained at different temperatures will be produced and tested.

Impacts
What was accomplished under these goals? The grinding technology was put in place to allow us to produce the two larger sizes of particles, though production of the biochar that is 0.1-10um in sufficient quantities for electro-spinning does not appear too practical.

Publications