SusChEM: Collaborative Research: Identification of the critical length scales and chemistries responsible for the anti-fouling properties of heterogeneous surfaces

Stanford University, Stanford CA

Investigators

Abstract

In this project funded by the Environmental Chemical Sciences Program in the Chemistry Division at the National Science Foundation, Professors Meagan S. Mauter of Carnegie Mellon University and Ayse Asatekin of Tufts University characterize the fundamental mechanisms of foulant adhesion to surfaces with self-assembled chemical heterogeneity. This research leads to a novel class of fouling resistant surfaces that enable energy savings and the use of membrane desalination in highly fouling environments, such as wastewater reclamation. The fundamental insights also inform approaches to fouling prevention in biomedical and marine applications. This work involves polymer synthesis, colloidal force and deposition experiments, and modeling to evaluate the relative importance of domain size, domain hydrophobicity/hydrophilicity contrast, and domain chemistry in determining foulant adsorption. A library of copolymer films with surface heterogeneity on the length scale of 1 to 10 nm are synthesized and characterized. The material properties are used to model the attachment efficiency of colloids to these heterogeneous surfaces using three models of increasing complexity. These models are validated using colloidal force microscopy and mass-based deposition measurements using a quartz crystal microbalance with dissipation monitoring. Finally, this project explores the role of nanopatterning on colloidal release as a function of shear velocity. Two graduate and several undergraduate students involved in this research gain interdisciplinary knowledge and skills, and disseminate their work through publications and presentations. Both Professors Meagan S. Mauter and Ayse Asatekin are active advocates of broadening the participation of women in STEM fields, and incorporate this research into their teaching, which covers classes on environmental policy, polymer science, and separations.