Target-Specific Capture of Relevant Gaseous Compounds Using Natural and Synthetic Nano and Micro Materials
By definition, volatile organic compounds (VOCs) are organic compounds that easily become vapor or gases. Many VOCs are hazardous air pollutants and often known for their low, often unpleasant, threshold odor, which can be below parts per billion in some cases. Nanotechnology-based materials for the remediation of gaseous pollutants has been the focus of many researchers due to their unique chemical and physical properties and enhanced reactivity when compared to bulkier materials. Among the many challenges preventing the global use of nanomaterials are the high costs of fabrication, on-site recovery, limited scale-up, potential toxicity since many of them rely on metallic nanomaterials, the low off-targeting specificity responsible for decreasing the effectiveness of the material and the limited applicability to few classes of contaminants. Here, the development of synthetic and natural materials for environmental remediation of significant gaseous contaminants, such as VOCs, was explored using poly(d,l-lactic acid)-poly(ethylene glycol)-carboxylic acid (PDLLA-PEG-COOH) (synthetic) and cellulose (natural) as the scaffold materials. Through the use of a simple and easy to scale up synthesis approach, and the use of a biodegradable or natural material, we overcome costs of fabrication and the need for the material to be recovered. An analysis of the different compounds present in a rendering plant allowed for determination of relevant compounds to be studied and provided information on the chemistry of these molecules. A variety of gaseous compounds were detected at a rendering plant area, in different sites of the plant, with the majority of the compounds belonging to carboxylic acid and aldehyde functionality. These findings were fundamental for the determination of the functional groups that to be conjugated into the materials to be used for the gas capture. Using appropriate chemistry approaches, it was possible to attach different functionalities to the synthesized PDLLA-PEG-COOH nanoparticles, tuning their properties so they can specifically target and capture different gaseous compounds. Consequently, different properties of the synthesized material were explored and investigated in an effort to determine the most efficient and facile approach to the gaseous capture, but also to better determine the possible applications of the material as well as the feasibility of scaling up the material synthesis. Results demonstrated a wide array of gaseous chemical compounds present in the air of an industrial site. While all detected concentrations were below the regulation limits, the obnoxious malodor associated with these compounds contributes to the difficulty in finding a location for new sites due to the annoyance caused to the population surrounding the area. Furthermore, the results showed that synthetic and natural materials could be tailored for the specific capture of said compounds. Preliminary results exploring the scale up of the materials synthesis provided promising results. These findings are expected to provide sufficient and strong theoretical and methodological evidence for the development of a large-scale process for the synthesis of amine-functionalized nano materials to be used for environmental remediation of relevant gaseous compounds.