EAGER: A Novel Approach to Fabricate Biomimetic Membranes Embedded with AquaporinZ

University Of Toledo, Toledo OH

Investigators

Abstract

1308095 Escobar Combining the efficient functioning of biological molecules with the productivity of synthetic membranes is the basis of this project. Aquaporin, a highly selective water channel protein, has received increasing attention because of its potential to form biomimetic membranes with high flux in water reuse and desalination applications; however, a proof-of-concept that aquaporins can be used to make biomimetic membranes has not been successfully demonstrated. The overarching objective of this project is to fabricate a biomimetic membrane from aquaporin dispersed in a membrane-selective layer, capable of operation under high hydraulic pressure. The hypothesis is that by incorporating aquaporin Z (AqpZ) into a membrane, AqpZ will act as a molecular water channel to significantly increase water permeability. Because of its high selectivity and permeability, the incorporation of this protein could give rise to a biomimetic membrane that can provide pure water. The first challenge is to attach aquaporin to the membrane without chemically altering or damaging the aquaporin. The PI will treat AqpZ with gum arabic (GA) and then disperse the AqpZ-GA in a matrix of amphiphilic polyvinyl alcohol carrying alkyl side chains (PVA-alkyl). GA is hypothesized to protect AqpZ from damaging covalent or ionic interactions with PVA-akyl. PVA-alkyl is amphiphilic and has the high hydrophilicity of PVA combined with the hydrophobicity of the long alkyl side chains, good film-forming properties, and outstanding physical and chemical stability. The second challenge of the current study is to design and prepare an assembly that will allow artificial biomimetic membranes with embedded aquaporin proteins to sustain hydraulic water pressure gradients without losing their integrity and performance. The PI expects that the GA and the PVA-alkyl will protect AqpZ from flattening. The attachment of the PVA-alkyl matrix with AqpZ-GA to hydrophilized polybenzimidizole (PBI) is expected to produce membranes able to withstand high hydraulic pressures. Broader Impacts Membrane technologies are expected to be increasingly competitive for water purification. In addition to reducing disinfection byproducts (DBPs), membranes can be effective in removing taste, odor, iron, manganese, synthetic organic compounds, pharmaceutical organic compounds, and endocrine disruptors. These issues are becoming increasingly important as a result of population growth and water shortages, especially in the southwestern part of the United States, where treated wastewater comprises a large fraction of the drinking water intake sources. Membranes with pores or channels specifically engineered to maximize water transport or ion selectivity would offer the potential for dramatically more efficient operation compared to conventional polymer membranes. Biomimetic membranes with structure and function similar to membranes of living organisms may offer the ultimate breakthrough for low-energy desalination. Overall, this research has the potential to demonstrate a novel biomimetic membrane, useful for water purification and other applications.