Characteristics of Spectral Properties and Morphological Aspects in Thiacarbocyanine J-aggregates

The study investigated the aggregation behavior of TCC dye in aqueous solutions and polymer films using optical spectroscopy and microscopy techniques. The findings revealed that the dye forms two distinct types of aggregates in water: H-aggregates and J-aggregates. As the dye concentration increases, J-aggregates become more dominant. Notably, unlike J-aggregates with a “herringbone” pattern revealing both H - and J -bands, no interactions were observed between the H - and J-aggregates in this case. Microscopy images displayed rod-shaped structures associated with both aggregate types. The addition of salt (NaCl) or increased solution acidity favored J-aggregation. Inthin polymer films created using a layer-by-layer (LbL) assembly method, J-aggregation predominated over H -aggregation. The highest concentration of J-aggregates was observed in LbL films formed from a salt solution.