Fig. 3 Demulsification efficiencies of MIL-100(Fe) at different time (a ), pH (b ) and salinity (c ), and that of the used MIL-100(Fe) (d )
Above investigation for demulsification performance suggested that MIL-100(Fe) can demulsify perfectly, especially at the acid and hyperhaline environment, which exactly was the conditions of exploiting for the oil 33,34. Therefore, the MIL-100(Fe) is suitable for demulsification in the area of the petroleum industry.
Furthermore, the dehydration for crude oil emulsion was carried out to investigate the practical demulsification performance of MIL-100(Fe). Shocking drastically about 10 s following adding 0.50 g of MIL-100(Fe) into 50 ml of crude oil emulsion with a water content of 90%, the crude oil and water separated spontaneously within 5 min at room temperature without any other assistive technologies (Fig. S5 ). The dehydration efficiency for crude oil emulsion using MIL-100(Fe) was 79%. Particularly, the time for the dehydration of crude oil emulsion was very short, compared with the conventional demulsifier (~hour) 35-37and some loading type heterogeneous demulsifier (exceed 30 min)38,39. It should be noted that the dehydration efficiency for crude oil emulsion using MIL-100(Fe) might be further improved through the optimization of dehydration conditions and the combination with other assistive technologies.