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In the processing of carbon nanotube/polymer composites, the interactions between the nanotube and polymer matrix will occur at the molecular level. Understanding their interactions before curing is crucial for nanocomposites processing. In this study, molecular dynamics (MD) simulations were employed to reveal molecular interactions between (10, 10) single-walled nanotube and two kinds of epoxy resin systems. The two kinds of resin systems were EPON 862/EPI-CURE W curing agent (DETDA) and DGEBA (diglycidylether of bisphenol A)diethylenetriamine (DETA) curing agent. The MD simulation results show that the EPON 862, DETDA and DGEBA molecules had strong attractive interactions with single-walled nanotubes and their molecules changed their conformation to align their aromatic rings parallel to the nanotube surface due to π-stacking effect, whereas the DETA molecule had a repulsive interaction with the single-walled nanotubes. The interaction energies of the molecular systems were also calculated. Furthermore, an affinity index (AI) of the average distance between the atoms of the resin molecule and nanotube surface was defined to quantify the affinities between the nanotubes and resin molecules. The MD simulation results show that the EPON 862/EPI-CURE W curing agent system has good affinities with single-walled nanotubes.

When a drug enters an organism, interactions between the drug and proteins in the organism play a vital role in the storage, transport and metabolism of the drug and also affect its nonspecific toxicity, targeting and pharmacodynamic activity. However, monitoring the interaction process is a great challenge in the research of the absorption, transport and metabolic processes of drugs. In this study, we used reflectometric interference spectroscopy (RIfS) and silica colloidal crystal (SCC) film as a sensing platform to detect the binding affinity between human serum albumin (HSA) and indomethacin. SCC films composed of three silica nanospheres with different diameters were fabricated using the vertical evaporation method. HSA was immobilized covalently on SCC film using a very simple approach, and optical thickness was used as a parameter to evaluate the process of drug absorption and desorption. Finally, the optimal SCC film was selected, and three drugs other than indomethacin (i.e., warfarin, salicylic acid and quinine) were used for the validation of this sensing platform. The results verified that SCC film using RIfS is a simple and real-time sensing platform for detecting the affinity between HSA and drugs, which may be widely used in drug development and clinical testing in the future.