Chemical Modification of Kombucha-Derived Living Filtration Membranes

Presenter: Autumn Voyer

Faculty Sponsor: Jessica Schiffman

School: UMass Amherst

Research Area: Chemical and Biomolecular Engineering

Session: Poster Session 6, 4:15 PM - 5:00 PM, Auditorium, A1

ABSTRACT

Commercial polymer membranes used for water purification involve complex production equipment and toxic solvents, and many end up in landfills. We propose a sustainable alternative using kombucha-derived bacterial cellulose (BC). BC is produced from a symbiotic culture of Komagataeibacter rhaeticus bacteria and Saccharomyces cerevisiae yeast (SCOBY) that forms a mechanically strong nanocellulose network which can self-repair and act as a filter for removing harmful bacteria or large molecules/particles from water sources. To further explore the applications of BC in water filtration, wound dressings, and food packaging, in this study, we treated the membranes with polydopamine, glycerol, polyvinyl alcohol (PVA), or sodium hydroxide (NaOH). PDA coatings decreased the surface energy compared with cellulose controls by 2.9% (61.17 mN*m-1), which potentially would be beneficial for reduced adhesion of foulants in biomedical applications. PVA formed a distinct hydrogel surrounding the cellulose after full integration, and glycerol caused no significant mechanical or visual change. Dead-end filtration using a BC membrane requires pretreatment with NaOH, which decreased ultimate tensile strength by up to 50% after 20 hours, but it successfully removed lingering microbes as demonstrated by agar plate assessment. We determined the minimum amount of time required to remove microbes (starting with 5 minutes) to minimize reductions in mechanical strength while maintaining sterility for producing potable water. Assessing the chemical and physical impacts of varied chemical modifications will provide a basis for future research with a focus on self-healing, highly specific, and accessible water filtration membranes treated with NaOH.

RELATED ABSTRACTS