The desorption of heavy oil is one of the important indicators affecting the development efficiency of the remaining oil in nanopores. However, the study of the adsorption and diffusion mechanisms of heavy oil molecules in nanopores remains scarce. In this work, the influences of temperature on the adsorption and diffusion properties of the heavy oil four-fractions in quartz nanopore have been investigated via molecular dynamics simulations. Our results show that the heavy oil molecules will form a denser multilayer adsorption oil layer on the nanopore surface, and high temperature can alter the adsorption behaviors of the heavy oil four-fractions. As the temperature increases, the saturate molecules are desorbed from the nanopore surfaces, but the aromatic, resin, and asphaltene molecules maintain a tendency to aggregate towards the nanopore surface. In particular, the agglomeration behaviors of most saturate, aromatic and asphaltene molecules in nanopore can be suppressed by the confined space compared with the heavy oil molecules in oil droplet. In addition, the influence of temperature on the movement of heavy oil molecules in nanopore decreases compared with the oil molecules in a heavy oil droplet due to the confined space and adsorption effect. Interestingly, there is a competition phenomenon between the adsorption and diffusion of aromatic, resin, and asphaltene molecules in the nanopore, resulting in different adsorption behaviors with the increase in temperature. The results obtained in this paper will provide molecular-level theoretical guidance for understanding the adsorption and desorption mechanisms of heavy oil in nanopores.

Hygroscopic materials that capture water vapor across a wide humidity range are important for emerging applications including atmospheric water harvesting, moisture control, and thermal management. Hydrogel sorbents are attractive because they can store large amounts of water while remaining solid-like, yet common hydrophilic gels sorb little vapor at low relative humidity (RH) unless hygroscopicity is introduced by deliquescent salts. Here, we report intrinsically hygroscopic hydrogels (IHHs) assembled from inosine and Zn²⁺ through pH-controlled supramolecular coordination. The IHHs show a moisture-sorption onset near zero RH, reaching 0.17 g g^-1 at 30% RH while retaining swelling-amplified uptake at high RH (1.9 g g^-1 at 95% RH) and reversible cycling. Varying gelation pH reprograms the coordination microenvironment and network structure, reshaping early-stage sorption and shifting uptake onset. Experiments and simulations indicate that hydration-accessible Zn-centered motifs serve as important early hydration loci, while pH-dependent network structure further modulates hydration growth. These results provide a coordination-chemistry route to hygroscopic hydrogels without salt deliquescence.