Ethyl cellulose was grafted with ionic liquids in optimal yields (62.5–64.1%) and grafting degrees (5.93–7.90%) by the esterification of the hydroxyl groups in ethyl cellulose with the carboxyl groups in ionic liquids. In IR spectra of the ethyl cellulose derivatives exhibited C=O bond stretching vibration peaks at 1760 or 1740 cm⁻¹, confirming the formation of the ester groups and furnishing the evidence of the successful grafting of ethyl cellulose with ionic liquids. The ethyl cellulose grafted with ionic liquids could be formed into membranes by using the casting solution method. The resulting membranes exhibited good membrane forming ability and mechanical properties. The EC grafted with ionic liquids-based membranes demonstrated PCO₂/PCH₄ separation factors of up to 18.8, whereas the PCO₂/PCH₄ separation factor of 9.0 was obtained for pure EC membrane (both for CO₂/CH₄ mixture gas). The membranes also demonstrated an excellent gas permeability coefficient PCO₂, up to 199 Barrer, which was higher than pure EC (PCO₂ = 46.8 Barrer). Therefore, it can be concluded that the ionic liquids with imidazole groups are immensely useful for improving the gas separation performances of EC membranes.

The preparation, characterization and gas separation properties of mixed matrix membranes (MMMs) were obtained from polyimide capped with ionic liquid and blended with metal-organic frameworks (MOFs). The synthesized MOF was amine functionalized to produce UiO-66-NH₂, and its amino group has a higher affinity for CO₂. Mixed matrix membranes exhibited good membrane forming ability, heat resistance and mechanical properties. The polyimide membrane exclusively capped by ionic liquid exhibited good permselectivity of 74.1 for CO₂/CH₄, which was 6.2 times that of the pure polyimide membrane. It is worth noting that MMM blended with UiO-66-NH₂ demonstrated the highest ideal selectivity for CO₂/CH₄ (95.1) with a CO₂ permeability of 7.61 Barrer, which is close to the 2008 Robeson upper bound. The addition of UiO-66-NH₂ and ionic liquid enhanced the permselectivity of MMMs, which may be one of the promising technologies for high performance CO₂/CH₄ gas separation.

Corn straw is an agricultural waste. The system for extracting cellulose from corn straw at a high temperature has been widely reported by researchers. However, the system for extracting cellulose from corn straw at a low temperature has been rarely reported. In this paper, a new system for extracting cellulose from corn straw at a low temperature was reported for the first time. This new system is designated as the low temperature laccase system (LTLS). Cellulose was successfully extracted from corn straw by the LTLS, and the used solution could be recycled. Therefore, the low temperature laccase system is an environmentally-friendly system. The cellulose content in corn straw is 30–40%. The yield of cellulose extracted by LTLS was 33%. The obtained cellulose product was creamy white. The extracted cellulose samples were characterized by using infrared spectroscopy (IR), thermogravimetry (TG), and X-ray diffraction (XRD). The results were consistent with that of standard cellulose. We confirmed that the LTLS extracted cellulose from corn straw with high purity.

In this paper, superhydrophilic polyimide (PI) membranes were prepared using the electrostatic spinning method, capped with a hydrophilic ionic liquid (IL), and blended with polyvinylpyrrolidone (PVP). Using this preparation, the surface of the fiber membranes was coated in polydopamine (PDA) by means of an in-growth method. Scanning electron micrographs showed prepared blend films can form continuous fibers, for whom the distributions of diameter and pore were uniform. Post-modification (carried out by adding hydrophilic substances), the ability of the membrane surface to adhere to water was also significantly improved. The water contact angle was reduced from 128.97 ± 3.86° in unmodified PI to 30.26 ± 2.16°. In addition, they displayed a good separation effect on emulsified oil/water mixtures. The membrane flux reached a maximum value of 290 L·m⁻²·h⁻¹, with a maximum separation efficiency reached of more than 99%. After being recycled 10 times, the separation efficiency maintained a level exceeding 95%. The purpose of this study is to demonstrate the simplicity and efficiency of this experiment, thereby providing new ideas for the future application of membrane separation technology in wastewater treatment.

The waste oil emulsion liquid membrane produced by waste oil from oil refineries (WELM) is used to separate the phenol in purified water from the sour water stripper in oil refinery facilities, and the stability of WELM was studied. It is verified that waste refinery oil can be produced into emulsion liquid membrane with good stability and high removal rate for the first time. The WELM stability models were established by response surface methodology (RSM) and artificial neural network (ANN), respectively. The principle and mechanism of various parameters, as well as the interaction effects on the stability of WELM, are proposed. The effects of parameters, including the ratio of Span-80, liquid paraffin, the ratio of internal and oil, and the rotational speed of the homogenizer, were investigated. Under the optimal operating parameters, the WELM had a demulsification percentage of just 0.481%, and the prediction results of RSM and ANN were 0.536% and 0.545%, respectively. Both models demonstrate good predictability. The WELM stability model has a high application value in the treatment of phenol-containing wastewater in the oil refining industry, and provides a green method of resource recovery.