Discipline: Chemistry and Chemical Sciences
Subcategory: Materials Science
José Luis Ramírez Colón - University of Puerto Rico- Rio Piedras Campus
Co-Author(s): José A. Lasalde, University of Puerto Rico- Rio Piedras, Puerto Rico Jairo Herrera, University of Puerto Rico- Rio Piedras, Puerto Rico
Phenolic compounds and their recurrent derivatives are useful compounds for the fabrication of plastics, adhesives and other commodities. These compounds find their way into aquatic environments through the usual degradation of organic matter and also due to discharge of effluents from industrials wastewaters, and percolation and runoffs from agricultural activities and landfills. Once here, they undergo degradation and/or transformations due to physical, chemical and biological factors that may eventually interfere in the metabolism and growth of aquatic species. Therefore, the removal of such compounds from the environment may serve as a sustainability model through remediation and reutilization of the compounds. Thus, this study intended to identify and operate a distinctive method to recover polyphenolic compounds from water environments by using the membrane?based separation method. Pursuing this objective, this work achieved the fabrication of an electrospun microporous polymer suitable for the removal of polyphenolic compounds in aqueous solutions. The technique of Electrospinning (ES), used for film development, contributed to the formation of interconnected pore structures and high surface area permeable structures, as evidenced by Scanning Electron Microscopy (SEM) and Contact Angle analysis. The electrospinning of Cellulose Acetate (CA) granted hydrophilicity, toughness, and biocompatibility to the produced fibers. The further addition of polyethylene oxide-b-4 vinyl pyridine (PEO-b-P4VP) onto the films served as a selective agent and pH responsive adsorption material towards the phenolic compounds. It is hypothesized, that this self-assembling compound, will retain the phenolic compounds via ?-? interactions between the PEO-b-P4VP?s pyridine rings and the phenyl groups of the targeted compounds. A later aggregation of alkoxysilane trimethoxy(2-phenylethyl)silane (TMPES) onto the composites, boosted by thermal heating, provided the necessary stability to avoid minimal damage of mechanical strength of the films. The presence of PEO-b-P4VP and TMPES onto the support membranes was confirmed by EDS and FTIR analysis. Batch absorption experiments, along with the use of Isotherm and kinetics adsorption models were performed with targeted compounds, to evaluate the adsorption of the phenolic compounds. Later, the films will be subjected to wastewater samples from a local wetland, formerly analyzed by GC-MS, to measure adsorption of pollutants. Preliminary results present an optimal biomaterial suitable for the recovery of phenolic compounds from aquatic environments.
Funder Acknowledgement(s): This work was supported by the NASA EPSCoR Program, grant #NNX14AN18A and NSF-CREST Center for Innovation, Research, and Education in Environmental Nanotechnology Grant #HRD-1736093.
Faculty Advisor: Eduardo Nicolau, firstname.lastname@example.org
Role: I went through all the process of fabrication of the electrospun microfibers and characterization of them following my mentor's recommendations and discussions. This includes the use of the following instruments: Electrospinning, Contact Angle, Energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and Scanning Electron Microscopy. The wastewater sample analysis of the local wetland, carried out by the Gas Chromatographer- Mass Spectrometer, was realized by other fellow researchers in the laboratory.