The recovery of gasoline vapor is still a major challenge in the petrochemical industry. In this study, a zeolitic imidazolate frameworks (ZIFs) membrane has been developed and first applied to gasoline vapor recovery. Zeolitic imidazole framework (ZIF-8) membranes were fabricated by a facile solvothermal seed growth method on ZrO2 supports. X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis measurements were conducted to study the morphologies, structure, and physical and chemical properties of ZIF-8 membranes. The effects of trans-membrane pressure drop, operating temperature, feed concentration, and stage cut on the separation performances of ZIF-8 membranes were systematically investigated. At 293 K, the ZIF-8 membrane showed an optimum n-hexane (n-C6H14) permeance of 7.16 × 10–8 mol/(m2·s·Pa) with the corresponding separation factor of 2.46 for the nitrogen/n-hexane model mixtures at a trans-membrane pressure drop of 0.05 MPa, a stage cut of 0.293, and a n-hexane volume fraction of 30%. Moreover, the separation factor for the multicomponent alkanes decreased with increasing the number of n-alkanes because of competitive adsorption of the n-alkanes in membrane pores. Experimental results indicated that the ZIF-8 membrane is a fairly promising candidate for the application in gasoline vapor recovery.

•The introduction of BTESE into PDMS led to a simultaneous improvement of membrane permeance and sulfur selectivity.•The PDMS/BTESE hybrid membrane showed better swelling resistance.•The hybrid membrane exhibited superior durability under a continuous pervaporative desulfurization process.A promising new polydimethylsiloxane (PDMS)/organosilica hybrid membrane has been developed and applied to the removal of sulfur from model gasoline by pervaporation. The introduction of organosilicas derived from bis(triethoxysilyl)ethane (BTESE) into the PDMS matrix led to a simultaneous improvement of permeance and selectivity of the resultant membrane. The dual role of BTESE-derived organosilica networks as crosslinking agent and transport channel endowed the membrane with enhanced chain rigidity, appropriate free volume property and facilitated transport of permeating molecules. Swelling measurements confirmed that the PDMS/BTESE-derived organosilica hybrid membrane had a lower swelling degree than that of the PDMS control membrane. Moreover, effects of operational variables such as operating temperature, feed sulfur concentration, permeate pressure and feed flow rate on the desulfurization performances of the membranes were investigated. The PDMS/BTESE hybrid membrane exhibited superior durability in a continuous pervaporation operation of 80 h, showing the potential for the application in gasoline desulfurization.

A promising new ethenylene-bridged organosilica membrane has been developed for pervaporative desalination of water. Due to the introduction of polarizable and rigid ethenylene bridges in the silica networks, the membrane exhibited an improved water affinity and superior hydrothermal stability. The ethenylene-bridged organosilica membrane delivered a high water flux of up to 14.2 kg m–2 h–1 with a high NaCl rejection of 99.6% for pervaporative desalination 70 °C. Moreover, the membrane was highly applicable and stable for desalination of saline water under a wide range of salt concentrations. The rapid permeation of water molecules through the membrane was attributed to the open pore structure and the water–pore wall interactions, while the transport of hydrated salt ions was explained by the relatively broad pore size distribution of the ethenylene-bridged silica networks.

•A novel strategy for thiol functionalization of HSQ was demonstrated via an in-situ reaction between Si–H groups and H2S.•Tailoring surface and structural properties of HSQ was achieved via this strategy.•Thiol functionalized silsesquioxanes will have potential areas of applications.In this study, a novel strategy has been proposed for thiol functionalization of hydrogen silsesquioxane (HSQ) via an in-situ reaction between Si–H groups and H2S at high temperatures. Compared to conventional strategies with long chain alkane thiols, the in-situ thiol functionalization with H2S can effectively maintain the open and accessible pore structure of the resultant networks. Water sorption measurements confirmed that the pore networks of thiol functionalized silsesquioxane (HS-SQ) had a higher affinity to water than that of HSQ. A continuous and crack-free HS-SQ film with low roughness was obtained on the support. The new strategy and materials show great promise for versatile applications in adsorption, catalysis and separation based on both the structure and surface superiorities.

The compact ZIF-69 membranes have been prepared by seeded growth method for the recovery of gasoline vapor which is a major challenge in the petrochemical industry. The membrane performances for separating N2/n-alkane mixtures at various operating conditions (e.g. trans-membrane pressure difference, operating temperature, feed concentration, and stage cut) were systematically investigated. The highest separation factor was 2.60 with the corresponding permeance of 5.02 × 10−8 mol/(m2 s Pa) for the N2/n-C6H14 model mixtures. Moreover, the effects of n-alkane components (n-C5H12, n-C6H14, and n-C7H16) on the separation performances were studied, and the separation factors followed α(N2/n-C7H16) > α(N2/n-C6H14) > α(N2/n-C5H12), due to the different adsorption capacities of n-alkanes on ZIF-69 materials. The present work demonstrates that the ZIF-69 membrane is a highly promising candidate for the application in gasoline vapor recovery.

•Silica nanoparticles in sol were twined by silicate polymers with chemical bonds.•The twined structure vastly improved the abrasion-resistance of nanoparticle film.•The addition of template into sols succeeded in optimizing antireflection.•The hydrophobicity of composite AR film was greatly improved after TMCS treatment.Antireflective (AR) films were prepared by the sol–gel method and dip-coating process by using tetraethylorthosilicate (TEOS) as silica precursor. Silica nanoparticle (SiO2-NP) sol was first synthesized via classical Stöber method, and then SiO2-NPs in sol were chained in series by linear silicate polymers (SiO2-LPs) to improve the film abrasion-resistant property. To further increase the transmittance of the SiO2-LP/NP composite film, the template agent CTAB was introduced into the SiO2-LP/NP composite sol. The experimental results revealed that the abrasion-resistant property had been enhanced with the increase of SiO2-LPs addition and the pencil hardness of the composite film had reached 6H when the mole ratio of SiO2-LPs to SiO2-NPs was 0.7:1. Meanwhile, the transmittance was optimized when nCTAB:nLPs was equal to 0.15:1 in the composite sol, and at this mole ratio the average transmittance of the glass substrate coated with AR film was about 98.5% in the wavelength range of 400–800 nm, while that of the bare glass substrate was just 91.5%. Trimethylchlorosilane (TMCS) treatment was finally used to provide AR films with hydrophobicity. The water contact angle was significantly increased from 6° to 120° after TMCS treatment, affording the AR films excellent environmental resistance.

Time-Dependent Density Functional Theory (TDDFT) method was used to investigate the substituent effect of fluorine ligand on geometrical structures, electronic properties, electroluminescent properties, absorption and emission spectra of six tridentate cyclometalated Pt(II) complexes. M062X hybrid functional was proved to be suitable for calculating the lowest triplet excited state (T1) characters in TDDFT calculations. The energies of d–d transitions both in absorption and emission were larger than HOMO–LUMO energy gaps, so d–d transitions did not easily occur. With the introduction of fluorine ligand, the energy levels did not show regularity changes, while the IP (ionization potentials) values and EA (electron affinities) values increased correspondingly. The phosphorescence emissions of the complexes were all assigned as 3ILCT mixed with 3MLCT. In addition, one dimeric form of cyclometalated Pt(II) complexes have also been investigated.Graphical abstractHighlights► d–d Transitions did not easily occur. ► The energy levels did not show regularity changes. ► One dimeric form of cyclometalated Pt(II) complexes have also been investigated.

Time-dependent density functional theory (TDDFT) method was used to investigate the effect of arylacetylide chain length on the geometrical structures, electronic properties, electroluminescent properties, absorption and emission spectra of four cyclometalated Pt(II) complexes [Pt(tBu)3(tpy){CC(C6H4CC)n−1}C6H5]+ (n = 1–4). The ωB97XD functional which includes long range corrections and empirical dispersion proved to be suitable for calculating the characters of the lowest singlet excited state (S1) and the lowest triplet excited state (T1) in TDDFT calculations. With the arylacetylide chain increasing, the energy levels of the occupied molecular orbitals could be raised orderly, while the unoccupied molecular orbitals had little changes. Moreover, both the absorption and emission wavelengths were red-shifted with the arylacetylide introduction. The difficulties of hole and electron injection gradually decreased. When there were four arylacetylide ligand, the complex had the best performance for electron and hole transport.Highlights► The energy levels of occupied molecular orbitals could be raised orderly. ► The unoccupied molecular orbitals have little changes. ► The hole injection become harder while the electron injection become easier.

•19-Channel ZrO2 microfiltration membrane was used in pretreatment of DMF wastewater.•0.2 μm ZrO2 membrane can effectively remove fine particles in DMF wastewater.•Combined flushing, ultrasonic and chemical cleaning was effective for flux recovery.Three kinds of 19-channel ZrO2 micro-filtration membranes with different pore size were used for pretreatment of dimethylformamide (DMF) wastewater from the polyurethane (PU) synthetic leather factories, which would enter the distillation column for further purification. The effects of membrane pore size, cross flow velocity (CFV) and transmembrane pressure (TMP) on ceramic membrane filtration performances were investigated. Experimental results indicated that the optimum membrane pore size, CFV and TMP were 0.2 μm, 3 m·s− 1 and 0.2 MPa, respectively, with the corresponding liquid turbidity removal rate of 99.62% and suspended solid content retention rate of 99.99%. The membrane fouling mechanism was analyzed by resistance in series model. The main resistance derived from the particle adsorption and sedimentation on the membrane surface. The ratio of particle adsorption and sedimentation resistance to total resistance was above 70% for the 0.2 μm membrane. The backflushing technology was applied and the effect of backflushing on the permeate flux was studied. The permeate flux eventually increased by 50% with the optimum backflushing pressure of 0.6 MPa, backflushing time of 5 s and backflushing interval of 20 min. A combination cleaning method was used to regenerate the ZrO2 micro-filtration membrane. The pure water flux recovered to 608.2 L·m− 2·h− 1 and flux recovery rate was 96.8% which indicated that the combination cleaning method was effective.