Institutional Repository of Institute of Process Engineering, CAS (IPE-IR）
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A self-healing polyacrylic acid-based hydrogel electrolyte for flexible quasi-solid-state electrochromic device
No full textDue to the demand for healing damages caused during applications, it is desired to develop self-healing hydrogel electrolytes for flexible electrochromic device (ECD). A hydrogel electrolyte with remarkable self-healing ability, outstanding stretchability, and high ionic conductivity is presented in this work. Non-covalent interactions such as ionic connections between Ca2+ and-COO-, as well as numerous hydrogen bonds between PAA and HPMC, form dynamically cross-linked PAA-HPMC-Ca hydrogel electrolytes. Owing to the exceptional reversibility of non-covalent interactions, the hydrogel electrolyte exhibits remarkable self-healing and durability. Fracture strain and stress in the self-healed PAA-HPMC-Ca hydrogel can reach 429% and 240 KPa, respectively. In addition, a flexible ECD based on PAA-HPMC-Ca hydrogel electrolyte and a WO3 electrochromic layer was assembled and evaluated. The flexible quasi-solid-state ECD possesses excellent modulation transmittance range (approximately 66%), high coloration efficiency and steady response time. Thanks to the stability of the PAA-HPMC-Ca hydrogel electrolyte, the flexible ECD exhibits a great stability over 1000 cycles. This study may pave the way for self-healing electrolyte gels to be used in ECDs, supercapacitors, and batteries, among other flexible electrochemical devices
Dual-site eutectic ionic liquids based microemulsion for boosting selective dimerization of isobutene
No full textOligomerization is one of the efficient routes for making use of C4 olefins to produce high value-added chemicals. However, high reagent conversion is usually accompanied by low dimer product selectivity, and vice versa. Ionic liquids (ILs) with intense interaction between Lewis and Bronsted acidic sites were demonstrated to be excellent catalysts for butene oligomerization. Furthermore, it was found that eutectic IL could be formed by strong hydrogen bond when alcohol was added to the IL, which exhibited enhanced butene solubility and thus improved catalytic performance. Moreover, microemulsion could be constructed by adding an IL emulsifier into the IL catalyst, and the improved interfacial area further enhanced efficient contact between butene and catalyst. Combining the strategies of employing dualsite eutectic IL as the catalyst and microemulsion formation, butene conversion could reach 98%, while dimer selectivity was 91%, resolving the contradiction that high conversion and target product selectivity cannot be achieved simultaneously
Pretreatment of membrane dye wastewater by CoFe-LDH-activated peroxymonosulfate: Performance, degradation pathway, and mechanism
No full textWhen a membrane is used to treat dye wastewater, dye molecules are continually concentrated at the membrane surface over time, resulting in a dramatic decrease in membrane flux. Aside from routine membrane cleaning, the pretreatment of dye wastewater to degrade organic pollutants into tiny molecules is a facile solution to the problem. In this study, the use of layered double hydroxide (LDH) to activate peroxymonosulfate (PMS) for efficient degradation of organic pollutant has been thoroughly investigated. We utilized a simple two-drop co-precipitation process to prepare CoFe-LDH. The transition metal components in CoFe-LDH effectively activate PMS to create oxidative free radicals, and the layered structure of LDH increases the number of active sites, and thereby considerably enhancing the reaction rate. It was found that the reaction process produced non-free and free radicals, including singlet oxygen (O-1(2)), sulfate radicals (SO4 center dot-), and hydroxyl radicals (center dot OH), with O-1(2) being the dominant reactive species. Under the optimal conditions (pH 6.7, PMS dosage 0.2 g/L, catalyst loading 0.1 g/ L), the degradation of Acid Red 27 dye in the CoFe-LDH/PMS system reached 96.7% within 15 min at an initial concentration of 200 mg/L. The CoFe-LDH/PMS system also exhibited strong resistance to inorganic ions and pH during the degradation of organic pollutants. This study presents a novel strategy for the synergistic treatment of dye wastewater with free and non-free radicals produced by LDH-activated PMS in a natural environment
Pretreatment of deep-sea bacteria for reverse flotation of magnesite tailings: Cleaner production, behavior and mechanism
No full textAccording to the principle of cleaner production, strengthening the selectivity and separation effect of dode-cylamine (DDA) as a conventional reverse flotation agent is an effective way to realize the re-enrichment of magnesite tailings, reduce the cost of agents, recover valuable elements, improve the quality of products and industrialize high value-added utilization. In this study, we designed the technology of microbial pretreatment -reverse flotation of magnesite tailings, and used the deep-sea silicate bacteria SiBY-2 to pretreat magnesite tailings, which enhanced the separation efficiency of magnesite from silicon bearing gangues in the reverse flotation process. The results show that the SiBY-2 enhances the desilication effect of magnesite tailings mainly by secreting organic acids, polysaccharides and proteins, and intensifies the interaction between silicon bearing gangues and the collectors (DDA). Compared with the conventional reverse flotation, the concentrate grade and recovery of the SiBY-2 pretreatment-reverse flotation process is increased by 2.04% and 5.93% respectively, while the utilization rate of DDA is reduced by 9.0%. It is estimated that the production cost of magnesite can be reduced by 900-1350 yen /t, which achieves the purpose of clean production of magnesite high quality products
Lanthanide complexes functionalized carbon dot nanocomposites as lubricant additives for improving tribological performance
No full textA novel nanocomposite, CDs-La-EDTA, was synthesized by bonding carbon dots to the functional sites of rare earth complexes, and its tribological characteristics were evaluated as lubricant additives. The results showed that the mean friction coefficient and the wear scar diameter of lubricating oil containing 0.15 wt% CDs-La-EDTA were reduced by 14% and 22%, respectively, compared with those of the base oil. Furthermore, the dual lubrication mechanism of the nanocomposite was proposed. The rolling or sliding effect of rare earth nanofibrous rods and the mending effect of carbon dot particles contributed to excellent lubrication performance
The simultaneous removal of NO and SO2 over MnO2 material via the multi-stage fluidized bed process at low temperatures
No full textTo overcome the easy poisoning and deactivation of denitrification catalysts by SO2 at low temperatures, the bench-scale multi-stage fluidized bed (MSFB) process with the active MnO2 medium (feeding rate of 0.3-1.2 kg/ h) is designed and applied to simultaneously remove the NO and SO2 from flue gas of medium/small industrial boilers in the low-temperature range of 100 - 200 degrees C, which demonstrates excellent and stable removal efficiency of both NO and SO2 even in the presence of 10 vol% water. In the MSFB system, the fluidized MnO2 particles in different layers flow against the simulated flue gas stage by stage, and the deactivated MnO2 will be continuously discharged and replaced with fresh MnO2 to keep the system effective and steady. The MnO2 medium acts as both denitrification (DeNOx) catalyst and desulfurizer, and the limited backmixing and layered arrangement of the MSFB system ensure the high removal capacity and sufficient utilization of MnO2 material. The multiple structural characterizations further reveal that the active MnO2 is gradually consumed by SO2 to form MnSO4 stage by stage with decreased specific surface and pore volume, accounting for its gradually decreased removal efficiency of both NO and SO2 stage by stage. And the deactivated MnO2 can be easily regenerated by aqueous ammonia with the conversion of MnSO4 to active MnO2. The demonstrated advantages of the MSFB system with MnO2 will provide a promising technical route for the simultaneous removal of NO and SO2 from low-temperature flue gas in industry