CAREER: Unlocking the potential of natural polymers for efficient removal of emerging contaminants from drinking water.

About This Grant

NON-TECHNICAL SUMMARY In this project, Dr. Maria Soledad Peresin aims to unlock the potential of certain components of plant or animal biomass to design biomaterials by advancing the fundamental understanding of naturally occurring systems to address critical issues of societal concern, such as the removal of emerging contaminants from drinking water. Polymers are natural or man-made chemicals that are composed of building blocks of smaller repeating molecules, as one would picture individual Legos® within a larger structure. Natural polymers, such as cellulose (from wood, soybean hulls, cotton, etc.), chitosan (from the outer shell of shellfish) and alginates (from algae) are sustainable and renewable resources that are an essential component of a circular economy, aimed at minimizing waste. Combining properties of different natural polymers is a way to develop a new generation of products that may replace traditional, non-renewable fossil fuel-based materials. This project will focus on understanding, developing and using renewable, natural polymers to design efficient and sustainable adsorbents, which are highly porous structures for the removal of contaminants. Dr. Peresin proposes an extensive study of a variety of polymer systems to maximize their potential adsorption capacity for removing contaminants from water bodies in different environmental conditions. Adsorption capacity of the polymers’ assemblies and their performance will be assessed using three model emerging aquatic contaminants, tetracycline (an antibiotic), ibuprofen (an analgesic) and sulfamethoxazole (an antibiotic). Dr. Peresin will use this research program as a platform for education with an impactful contribution to improving science literacy in the State of Alabama while contributing to local, national and global efforts to provide a sustainable method for cleaning drinking water. Younger generations have an increased environmental concern and awareness of the need to decrease our impact on the planet. Through her research and mentorship, Dr. Peresin hopes to advance career opportunities within the forest industry for environmentally conscience students with the development of novel processes and new products that contribute to the sustainable use of resources and economic benefit of society. This project is jointly funded by the Biomaterials Program in the Division of Materials Research, and the Established Program to Stimulate Competitive Research (EPSCoR).   TECHNICAL SUMMARY The overarching goals of this CAREER plan are 1) to uncover the principles that underlie the structure-property relationship between naturally occurring polysaccharides (PS) interactions, surface properties and their assembly for the design of macroscale adsorbents, 2) to use this platform to educate students on interfacial phenomena involved in cleaning water using natural resources, and 3) to contribute to global efforts to provide clean drinking water to society. Natural polymers are renewable resources, essential for the circular economy. Combining their properties is critical for developing the new generation of functional materials on lieu of traditional fossil-based materials. However, several challenges remain in order to deploy these materials, such as cost, performance and scale. The long-term research goal of this CAREER is to advance the knowledge that will enable the rational design of PS structures based on natural polymers for effective removal of emerging contaminants from drinking water. This CAREER proposal will provide a fundamental framework for elucidating the fine interplay between the composition, surface functionality, and the supramolecular structure of natural polymers, specifically PS such as cellulose and chitin, and their effect on interfacial interactions with emerging contaminants. Polymers self-assembly and their interfacial behavior have been extensively studied, however, more work is needed for understanding the correlation between the surface properties of natural PS assembly and their impact on the interfacial adsorption phenomena. During this five year CAREER award, the following hypotheses will be addressed: 1) PS interactions can be controlled by changing environmental conditions and macromolecules intrinsic properties, 2) entropic and enthalpic contributions to binding energy of PS assemblies will affect their swelling and adsorption capacity, 3) interfacial interactions resulting from the macromolecule assembly will determine the surface energy and chemistry of the PS structures, with a direct impact on the total sorption capacity. The majority of the work will be performed on cellulose and chitin (and their derivatives) as they are ideal for this project due to their abundancy, robust chemical structural, surface area and versatile surface functionality. To test the hypothesis the PI will use a combinatory approach that involves PS assemblies and adsorption studies on 2D model surfaces. These findings then will be translated to a 3D hydrogel system, produced through a bottom-up self-assembly approach. Adsorption capacity and performance will be assessed using three model of emerging contaminants namely, tetracycline (an antibiotic), ibuprofen (an analgesic) and 2,4-dichlorophenoxyacetic acid (an herbicide). These hypotheses will be tested with the following specific objectives 1) elucidate the nature of the PS interactions during their self-assembly; 2) understand the role of composition and surface functionality on PS assemblies swelling and supramolecular structure, 3) examine different routes for self-assembly of PS in 3D structures and 4) unveil the effects of supramolecular structure, composition and surface on the overall adsorption capacity of the PS assemblies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.