Revealing the spatiotemporal dynamics of protein fouling on micropatterned ultrafiltration membranes by in-situ visualization

• Microscale herringbone patterns effectively reduce early-stage protein fouling. • Confocal microscopy enables in situ imaging of protein deposition dynamics. • Fluorescent labeling provides spatiotemporal resolution of fouling processes. • Surface pattern geometry influences fouling behavior and filtration performance. This study is the first to directly visualize and quantify the spatiotemporal dynamics of protein fouling on micropatterned ultrafiltration membranes using in situ confocal laser scanning microscopy (CLSM). In it, we investigated the effectiveness of adding microscale herringbone patterns to ultrafiltration membrane surfaces for reducing protein fouling. Patterns with different geometries were introduced to membrane surfaces by embossing with woven mesh fabrics. Having found earlier that CLSM can provide greater detail for the early (pre-monolayer) stage of fouling, we used CLSM in situ to investigate the protein fouling profiles on as-received and patterned membranes. Labeling the proteins and membranes with different fluorescent probes allowed the spatiotemporal imaging of protein deposition at the early stages of fouling. CLSM images were compared with filtration data to reveal the effect of pattern geometry on protein fouling. Extending the approach to other patterns and multi-component solutions can inform surface modification strategies to control protein fouling in pressure-driven membrane operations.