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The ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) can form nonaqueous microemulsions with benzene by the aid of nonionic surfactant TX-100. The effect of water on ionic liquid-in-oil (IL/O) microemulsions was studied, and it was shown that the addition of small amount of water to the IL microemulsion contributed to the stability of microemulsion and thus increased the amount of solubilized bmimBF4 in the microemulsion. The conductivity measurements also showed that the attractive interactions between IL microdroplets were weakened, that is, the IL/O microemulsion becomes more stable in the present of some water. Fourier transform IR was carried out to analyze the states of the added water, and the result showed that these water molecules mainly behaved as bound water and trapped water, indicating that the water molecules are located in the palisade layers of the IL/O microemulsion. Furthermore, 1H NMR and 19F NMR spectra suggested that the added water molecules built the hydrogen binding network of imidazolium cations and H2O, BF4- anion and H2O, and at the same time the electronegative oxygen atoms of the oxyethylene units of TX-100 and water in the palisade layers, which made the palisade layers more firm and thus increased the stability of the microemulsion. The study can help in further understanding the formation mechanism of microemulsions. In addition, the characteristic solubilization behavior of the added water can provide an aqueous interface film for hydrolysis reactions and therefore may be used as an ideal medium to prepare porous or hollow nanomaterials.

The ionic liquid (IL) 1‐butyl‐3‐methylimidazolium tetrafluoroborate (bmimBF4) forms nonaqueous microemulsions with p‐xylene, with the aid of the nonionic surfactant TX‐100. The phase behavior of the ternary system is investigated, and three microregions of the microemulsions—ionic liquid‐in‐oil (IL/O), bicontinuous, and oil‐in‐ionic liquid (O/IL)—are identified by conductivity measurements, according to percolation theory. On the basis of a phase diagram, a series of IL/O microemulsions are chosen and characterized by dynamic light scattering (DLS). The size of aggregates increases on increasing the amount of added polar component (bmimBF4), which is a similar phenomenon to that observed for typical water‐in‐oil (W/O) microemulsions, suggesting the formation of IL/O microemulsions. The microstructural characteristics of the microemulsions are investigated by FTIR and 1H NMR spectroscopy. The results indicate that the interaction between the electronegative oxygen atoms of the oxyethylene (OE) units in TX‐100 and the electropositive imidazolium ring may be the driving force for the solubilization of bmimBF4 into the core of the TX‐100 aggregates. In addition, the micropolarity of the microemulsions is investigated by using methyl orange (MO) as a UV/Vis spectroscopic probe. A relatively constant polarity of the microemulsion droplets is obtained in the IL microemulsion. Finally, a plausible structure for the IL/O microemulsion is presented.

Covalent organic frameworks (COFs) have attracted great attention across diverse research fields. However, only a few reports about the biomedical application of COFs are found in the literature. Attributed to the highly porous and tunable structure, as well as good thermal stability, COFs show great potential as drug carriers for chemotherapy. In this work, doxorubicin (DOX) was successfully in situ loaded into a COF by a one‐pot method for the first time. The resultant DOX@COF platform exhibited high drug‐loading capacity (32.1 wt %) and pH‐responsive release property. In vitro and in vivo experiments demonstrated its good biocompatibility and enhanced antitumor efficacy.