Accurate Prediction of the Diffusion Coefficients of Organic Compounds in Water by Multimodal Learning

The aqueous diffusion coefficients of organic compounds are among the most important topics of interest for chemical research and engineering, particularly for the dispersal of organic pollutants in water environments. The experimental determination of the diffusion coefficients is time-consuming, and the experimental data are lacking for most newly synthesized chemicals. Our study developed a multimodal deep learning model incorporating molecular images, molecular descriptors, and temperatures to predict aqueous diffusion coefficients at varying temperatures. The deep learning model made accurate predictions on the test set (R² = 0.986) and had a considerably lower error than previous empirical equations. Besides, the model interpretation indicated that the deep learning model correctly captured the effects of molecular features and temperature on the prediction of diffusion coefficients. Thus, our study provided a valuable tool for the rapid and accurate prediction of organic compounds diffusion coefficients in water at varying temperatures and also facilitated a better understanding of how different molecular features and water temperatures influence diffusion-controlled processes in both the environmental and engineered systems.