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[Display omitted] • NF-like iTFC FO membrane was paired with a high-valence food additive. • C 6 H 5 K 3 O 7 was identified as the optimal draw solute for pre-concentrating fruit juice. • MgSO 4 was found to be suitable for further concentration of fruit juice. • One dual-stage and dual-cycle FO was proposed without the need of DS recovery. • A hybrid system can establish a relationship between fruit and juice production. The technology of forward osmosis (FO) has garnered increasing research interest for its excellent advantages in producing high-quality concentrated juice. However, the practical application of FO to concentrate juice is hindered by the lack of an appropriate FO membrane and matched draw solution. To address this challenge, several additives containing high-valence ions were investigated to improve the feasibility of the FO process for juice concentration, using a nanofiltration(NF)-like FO membrane with an interlayer constructed by MOFs-based nanoparticles. The prepared NF-like FO membranes exhibited negative potential, superior hydrophilicity, and uneven crosslinking, which matched well with five selected additives (C 6 H 8 O 7 , K 2 SO 4 , C 6 H 5 K 3 O 7 , MgSO 4 , and KH 2 PO 4), potentially preventing bacterial growth on the membrane surface during the concentration process and contributing to the growth of plants. A comprehensive comparison of selected five additives indicated that, with the exception of MgSO 4 , these additives at their saturated concentration exhibited marginally higher osmotic pressure than that of the fresh juice, indicating their limited suitability for further concentration of the fresh juice. However, during the pre-concentration phase of the fresh juice, the juice concentration is lower than that of the fresh juice due to the additional water incorporated during the juice production process. C 6 H 5 K 3 O 7 was the optimal draw solution for pre-concentrating apple juice, while MgSO 4 was better suited for further concentrating fresh juice. The concentrations of C 6 H 5 K 3 O 7 and MgSO 4 in the final juice were well below their limit value. Based on these results, a proposal for a dual-stage and dual-cycle FO process has demonstrated to achieve highly efficient concentration of fruit juice and seamless integration of juice production and fertigation of fruit trees, without the need to consider draw solution recovery. [ABSTRACT FROM AUTHOR]

Osmotic dilution (OD) has been integrated with mainstream seawater reverse osmosis (SWRO) desalination technology to eliminate the worry about the draw solution regeneration and simultaneously lower the desalination cost. In this study, we further optimize the OD design with regard to mitigated water flux decline by introducing the concentration-dependent hydraulic pressure and developing one module-level techno-economic model. Analysis of the module-scale model firstly indicates that simply increasing the flowrate ratio of the feed solution stream to the draw solution stream is not economically applicable to mitigate the inherent water flux behavior in OD, potentially highlighting the significance of concentration-dependent hydraulic pressure. Accordingly, one-stage or multi-stage pressure-assisted forward osmosis (PAFO) followed by OD is evaluated its techno-economic advantage compared to the original OD process, respectively. Simulation results show that, for applied commercial FO membrane, OD combined with one-stage PAFO is the optimal design that balances the mitigated water flux decline with maximum saving and strongly depends on the permeate flow. But, future improved FO membranes necessitate the systematic exploration due to the fact that the optimal OD design is also affected by the membrane transport parameters. Therefore, this work can provide a protocol to optimize the OD design in seawater desalination. Unlabelled Image • Systematic techno-economic model is well-established at module level. • Simply increasing the flowrate ratio of FS to DS is not economically applicable. • OD with multi-stage PAFO lowers the membrane demand, sacrificing economic benefit. • OD with one-stage PAFO is most cost-effective under current conditions. • Optimal OD design must refer to the membrane properties and the permeate flow. [ABSTRACT FROM AUTHOR]

Preparation of porous cement-based materials via freeze casting is a process with great potential. However, freeze-drying and steam curing complicate the preparation process and increase the preparation period. To simplify the process, heat-dry curing was used for replacing freeze-drying and steam curing during operation. The new preparation method combined freeze casting and heat-dry curing possesses characteristics of low-energy, simplicity, and time-saving. Compared with the traditional preparation method of porous cement-based materials, the novel preparation process can shorten preparation time by at least 16 % and retrench energy consumption by at least 18 %. As the improvement condition, temperature of heat-drying curing has great influence on the structure and performance of the samples. Therefore, it is of great significance to discuss the relationship between heat-dry temperatures and structural parameters by SEM, N 2 -adsorption/desorption, TG, and ATR-FTIR. Lamellar pores of membranes can be easier observed at low temperatures than that at 100 °C. The separation performance of oil-water is generally improved with the increase of temperature. Meanwhile, the molecular dynamics simulation was operated to illustrate the reaction mechanism of hydration with three temperatures. This study probably provides more theoretical basis for expanding the application of porous silicate cement membranes. [Display omitted] • Novel coupled method simplifies the fabricating process complexity of cement-based samples. • Influences of heat-dry curing temperatures on porous silicate cement membranes are discussed. • Silicate cement membranes own excellent permeation, oil-water separation and mechanical strengths. • Influences of heat-dry curing temperatures are illustrated by using molecular dynamics. [ABSTRACT FROM AUTHOR]

Preparation of porous cement-based materials via freeze casting is a process with great potential. However, freeze-drying and steam curing complicate the preparation process and increase the preparation period. To simplify the process, heat-dry curing was used for replacing freeze-drying and steam curing during operation. The new preparation method combined freeze casting and heat-dry curing possesses characteristics of low-energy, simplicity, and time-saving. Compared with the traditional preparation method of porous cement-based materials, the novel preparation process can shorten preparation time by at least 16 % and retrench energy consumption by at least 18 %. As the improvement condition, temperature of heat-drying curing has great influence on the structure and performance of the samples. Therefore, it is of great significance to discuss the relationship between heat-dry temperatures and structural parameters by SEM, N 2 -adsorption/desorption, TG, and ATR-FTIR. Lamellar pores of membranes can be easier observed at low temperatures than that at 100 °C. The separation performance of oil-water is generally improved with the increase of temperature. Meanwhile, the molecular dynamics simulation was operated to illustrate the reaction mechanism of hydration with three temperatures. This study probably provides more theoretical basis for expanding the application of porous silicate cement membranes. [Display omitted] • Novel coupled method simplifies the fabricating process complexity of cement-based samples. • Influences of heat-dry curing temperatures on porous silicate cement membranes are discussed. • Silicate cement membranes own excellent permeation, oil-water separation and mechanical strengths. • Influences of heat-dry curing temperatures are illustrated by using molecular dynamics. [ABSTRACT FROM AUTHOR]

To help resolve issues associated with reverse osmosis (RO) brine handling for inland water reuse plants, RO brine treatment and recovery from NEWater factory was demonstrated in a laboratory using a low cost, less footprint and low energy consumption pretreatment method of inline coagulation–ultrafiltration (UF). Polyaluminum chloride (PACl), aluminum chlorohydrate (ACH) and ferric chloride (FeCl 3 ) were chosen as the coagulants. PACl and ACH attained dissolved organic carbon (DOC) removal of 31% and 27% respectively at the optimal dosage (0.556 mM as Al), while FeCl 3 outperformed PACl and ACH at this molar dosage, reaching up to 60% of DOC removal. At the optimal pH (pH7), FeCl 3 was again more superior with the highest DOC removal efficiency of 55%. FeCl 3 also presented the highest phosphate (> 99%) and silica removals (14%) at its optimum dosage and pH. Liquid chromatography-organic carbon detector (LC-OCD) and fluorescence excitation–emission matrix (EEM) were used to characterize the DOC fractions removed by inline coagulation-UF. For LC-OCD, FeCl 3 revealed higher removal efficiency for almost all the DOC fractions ranging from low to high molecular weight. These results suggest that the inline-coagulation (FeCl 3 )-UF pretreatment is potential in reducing the fouling tendency of downstream RO because of its high DOC and phosphate removal efficiency. [ABSTRACT FROM AUTHOR]

A bench-scale submerged membrane bioreactor (SMBR) was employed to treat vegetable oil plant wastewater with complete sludge retention. Treatment performance and membrane fouling of the SMBR were investigated. The system stably removed high amounts of total organic carbon, oil, and ammonia from vegetable oil wastewater and reduced the chemical oxygen demand, demonstrating the great potential of the SMBR in removing pollutants. The membrane fouling layer was not only governed by deposition of organic substances composed of extracellular polymeric substances like proteins, polysaccharides etc., and oil substances but also by inorganic elements. Organic foulants coupled to inorganic precipitation enhanced the formation of a gel layer and triggered severe membrane fouling in the SMBR. [ABSTRACT FROM AUTHOR]

The fouling mechanism of the anion exchange membrane (AEM) induced by natural organic matter (NOM) in the absence and presence of calcium ions was systematically investigated via the extended Derjaguin–Landau–Verwey–Overbeek (xDLVO) approach. Sodium alginate (SA), humic acid (HA), and bovine serum albumin (BSA) were utilized as model NOM fractions. The results indicated that the presence of calcium ions tremendously aggravated the NOM fouling on the anion exchange membrane because of Ca-NOM complex formation. Furthermore, analysis of the interaction energy between the membrane surface and foulants via xDLVO revealed that short-range acid–base (AB) interaction energy played a significant role in the compositions of interaction energy during the electrodialysis (ED) process. The influence of NOM fractions in the presence of calcium ions on membrane fouling followed the order: SA > BSA > HA. This study demonstrated that the interaction energy was a dominating indicator for evaluating the tendency of anion exchange membranes fouling by natural organic matter. [ABSTRACT FROM AUTHOR]

Abstract: This study aimed to investigate the effect of temperature variation on membrane fouling and microbial community in a membrane bioreactor (MBRs). The results indicated that extracellular polymer substances (EPS) and soluble microbial products (SMPs) increased due to decreasing temperature, which triggered membrane fouling as evidenced by the trans-membrane pressure (TMP) increase rate. Moreover, fluorescent intensity variations in the excitation–emission matrix (EEM) fluorescence spectroscopy of SMPs were closely related to rapid increase in TMP, suggesting that they might be used to monitor SMPs variations and indicate membrane performance. In addition, 16S rRNA clone library and sequence analyses results demonstrated the predominant phyla were always Proteobacteria, Nitrospira and Bacteroidetes. However, at lower temperature, α-proteobacteria and some filamentous bacteria such as Actinobacteria, Haliscomenobacteria and Thiothrix were relatively rich. At higher temperature, Zoogloea showed its presence. Detrended correspondence analysis (DCA) and Mantel test results also demonstrated that temperature had strongly influence on microbial community. [Copyright &y& Elsevier]

Abstract: Two types of amorphous, silica nanoparticles have been produced and used as surface assisting agents during laser desorption/ionisation time-of flight-mass spectrometry (SALDI-TOF-MS). The first is hydrophilic possessing surface aminopropyl groups and the second hydrophobic containing surface phenyl groups. Each particle type acts as a solid phase adsorbent, adsorbing analytes according to their charge and hydrophobicity. The adsorbed analytes can be directly analysed on the particles using SALDI-TOF-MS. Intrinsically magnetisable versions of the hydrophobic particles act as magnetic solid phase extraction (MSPE) materials which are used to selectively adsorb analytes within a mixture deposited onto a surface, transfer the adsorbed components using a magnetic wand and to deposit the particles at a site adjacent to that of the original mixture. Non-adsorbed components remain at the original site. The extracted and residual analytes are then directly analysed on the surface by SALDI-TOF-MS. Using fingerprints as an example of a complex biological matrix, this new approach has been used to separate polar (amino acids) and non-polar constituents (squalene and fatty acids) within latent fingerprints deposited on a surface and for their subsequent direct analysis on the surface by SALDI-TOF-MS. Alanine, ornithine, lysine and aspartic acid which were undetected or poorly detected prior to separation showed improved signal detection after separation. [Copyright &y& Elsevier]

Abstract: Two rod-like pyrene–perylene bisimide triads with different linkers were synthesized and characterized. Their photophysical properties were investigated by UV–vis absorption, both steady-state and time-resolved emission. According to fluorescence excitation and time-resolved emission spectroscopic studies, efficient intramolecular resonance energy transfer was observed in both triads. Furthermore, the influence of the molecular structure on the energy transfer rates was also studied and discussed. To gain insights into the intramolecular interactions and the electronic structures, the electronic structures of both triads were investigated through theoretical calculation. [Copyright &y& Elsevier]

Abstract: A series of benzothiadiazole-based (BT) hyperbranched polyfluorene copolymers with various branching degrees (5–40%) were designed and synthesized. TGA and film annealing tests showed the substantial thermal stability of these highly branched polymers. The optical performance of the polymers in solutions and as films, and their electrochemical properties were characterized. The energy transfer (ET) processes in these hyperbranched conjugated polymers, both in solutions and in the solid state, were also investigated. With the change of the solution concentration and the branching degree, the energy transfer efficiency of the polymers varied in solutions and the main photoluminescence (PL) peaks changed from blue to green region. As films, only green light emitted from BT units. In addition, the PL efficiency of the films decreased dramatically with the increase of branching degrees. All these features demonstrated that highly branched structure would effectively impede the intra- and interchain energy migration, especially in solutions, and remarkably influence the ET process in the solid state, which resulted in low PL efficiency. [Copyright &y& Elsevier]

Minimizing the release of highly saline mine wastewater is crucial in order to meet the zero liquid discharge requirement of the coal chemical industry. However, the inorganic salts produced, such as NaCl and Na 2 SO 4 , have low value and are difficult to consume locally, particularly in western China. Therefore, this study proposes the multi-stage membrane integrated system with the aim of achieving low discharge of mixed salts in high-salinity mining wastewater. Two different combinations of reverse osmosis (RO), nanofiltration (NF), electrodialysis (ED), and bipolar membrane electrodialysis (BMED) are proposed for the integrated system, specifically designed for treating Bulianta coal mining wastewater ZLD projects in Inner Mongolia, western China. To compare the effectiveness of these combinations, experimental tests were conducted using ED to concentrate pure solutions of NaCl and Na 2 SO 4 separately. The results indicated that, in terms of energy consumption for transferring the same charge across the membrane, Na 2 SO 4 solution was more suitable to be concentrated than NaCl solution under low feed concentration (cation concentration<1.0 M) in ED, and the corresponding energy saving to transfer on unit charge significantly decreased from 6.15 × 10−3 kWh/mol charge to 1.60 × 10−4 kWh/mol when cation concentration ranged from 0.2 M to 1.0 M. Then, the production of acid and base in BMED was experimentally investigated using Na 2 SO 4 solution and a mixed solution of NaCl and Na 2 SO 4. Results revealed that the energy consumption decreased from 150.62 Wh/[H++OH-]mol to 97.88 Wh/[H++OH-]mol when the Na 2 SO 4 solution increased from 0.2 M to 1.4 M, meanwhile the energy consumption for mixed solution of NaCl and Na 2 SO 4 is strongly related to the mole ratio of Na 2 SO 4 to NaCl. Thus, the utilization of NF membranes with high selectivity for Na 2 SO 4 over NaCl in the NF stage, combined with high feed concentrations in the ED stage, is crucial for achieving lower energy consumption in BMED. Based on experimental results and analyses, the NF concentrate is more effectively treated in ED and BMED when dealing with mining wastewater with a high mole ratio of Na 2 SO 4 to NaCl (>1). [Display omitted] • Low-mixed-salt-discharge treatment of high-salinity mining wastewater was studied. • Membrane integrated systems were designed for reducing mixed salt production. • System configuration was related to mole ratio of Na 2 SO 4 to NaCl in wastewater. [ABSTRACT FROM AUTHOR]

Response surface methodology was employed to model and optimize the electrodialysis process for Reverse osmosis concentrate (ROC) reclamation in coal-fired power plants. Predictive models were developed for simulation of different input parameters and responses of ED process. The model for responses was statistically verified by analysis of variance which generated a high coefficient of determination value. Moreover, regression analysis showed a good repeatability and agreement of the experimental data to a quadratic model. The optimum operating parameters were found to be 5.9 V of operational voltage, 1.19 m/s of flow rate and 74 min of time. And the corresponding energy consumption and desalination rate were 0.11 Wh/L and 75.3%, respectively. [ABSTRACT FROM AUTHOR]

The adverse effects of high concentration of phenolic compounds in wastewater on aquatic organisms are a major environmental issue. In recent years, treating organic wastewater by algae has attracted attention because this treatment is economic, efficient and eco-friendly. Here we review the use of algae in removing phenol and phenolic derivatives. We discuss phenolic wastewater treatment, mechanisms of adsorption and degradation, and effects of excessive phenols on algal cells. [ABSTRACT FROM AUTHOR]

During an oceanographic campaign in the western Pacific Ocean from 12 August to 3 October 2014, the concentrations of five non-methane hydrocarbons (NMHCs) were measured in marine atmosphere and seawater. The average mixing ratios of ethane, ethylene, propane, propylene, and isoprene were 1.109 ± 0.359, 0.658 ± 0.137, 0.711 ± 0.377, 0.429 ± 0.139, and 0.255 ± 0.201 ppbv, respectively. In general, atmospheric concentrations of ethane and propane showed significant decrease from the inshore area to the open ocean, while ethylene and propylene exhibited decreasing trends from low latitudes to high latitudes. The results suggested that atmospheric ethane and propane with long lifetimes were more likely influenced by the air mass transported from continent, while ethylene, propylene and isoprene with short lifetimes were mainly derived from the surface seawater. The average concentrations of ethane, ethylene, propane, propylene, and isoprene in the surface seawater were 6.6 ± 5.8, 51.9 ± 23.5, 15.4 ± 4.3, 17.2 ± 3.8, and 23.5 ± 8.6 pmol L−1, respectively. A significant positive correlation was observed between ethane and propane (R 2 = 0.45, n = 39, p < 0.001), implying that their production and removal pathways in the surface seawater were similar. High concentrations of isoprene were observed in the waters with high Chl- a values, suggesting that the biological process was a controlling factor. The estimated sea-to-air fluxes of ethane, propane, ethylene, propylene, and isoprene were in the range of 0.1–24.9, 4.2–235, 1.0–43.8, 1.5–90.2, and 2.1–149 nmol m−2 d−1, respectively. This study is of great importance to the contribution to the atmospheric NMHCs from the western Pacific Ocean and provides data supporting for global NMHCs emission estimates. Unlabelled Image • Light C 2 -C 3 NMHCs and isoprene were measured in the seawater and atmosphere of the western Pacific Ocean. • High isoprene concentrations occurred in the highly productive waters. • The oceanic emissions in the surface seawater were main sources of atmospheric alkenes. [ABSTRACT FROM AUTHOR]

Membrane desalination has become an important solution to global water problems. Graphene-based materials have excellent advantages in the desalination process due to their intriguing features, including single atomic layer structure, large specific surface area, hydrophobic property, rich modification approaches, etc. After an introduction of membrane, graphene and graphene oxide (GO), this review systematically summarizes the current progress and gives an insight into the graphene-based separation membranes (GBSMs). The applications of the pressure-driven graphene-based membranes are introduced and their performances are listed and analyzed. By molecular dynamics simulation (MDS), the researchers predict the excellent performances of GBSMs, including high water flux, good salt rejection, etc. which have been verified in subsequent experiments. We believe that the application of graphene-based materials in pressure-driven membrane is worthy of further exploration. Several researchers have prepared electric-driven membranes with graphene-based materials, since their good stabilities and water-retention. However, graphene is not efficient in forward osmosis membrane area for now. In spite of the shortcomings like weak mechanical strength of single layer graphene, difficult to prepare nanopores on graphene film and hard to integrate with polymer, we hold the opinion that graphene-based films still have great research value especially in the membrane separation technology. [ABSTRACT FROM AUTHOR]

Hierarchical porous silicate cements with lamellar/dendritic morphology were prepared by combination of ice-templating and hydration reaction routes. The macropores with multimodal pore distributions are found to be interconnected through intrinsic mesopores resulting from ice crystals growth and hydration products generation. As the slurry concentration increased from 40 to 60 wt%, the BET surface area decreased from 86.744 m 2  g −1 to 70.707 m 2  g −1 , the porosity decreased from 61.8% to 47.62%, whilst the compressive strength increased from 10.76 Mpa to 16.67 Mpa. Low-cost starting material and eco-friendly technique probably endow ordered porous cement with potential in a variety of applications including membrane separation and adsorption process. [ABSTRACT FROM AUTHOR]

Hexavalent chromium is one of the main heavy metal pollutants. As the environmental legislation becomes increasingly strict, seeking new technology to treat wastewater containing hexavalent chromium is becoming more and more important. In this research, a novel modified ultrafiltration membrane that could be applied to adsorb and purify water containing hexavalent chromium, was prepared by polyvinylidene fluoride (PVDF) blending with 2-aminobenzothiazole via phase inversion. The membrane performance was characterized by evaluation of the instrument of membrane performance, infrared spectroscopy (FTIR), scanning electron microscope (SEM), and water contact angle measurements. The results showed that the pure water flux of the PVDF/2-aminobenzothiazole modified ultrafiltration membrane was 231.27 L/m2·h, the contact angle was 76.1°, and the adsorption capacity of chromium ion was 157.75 μg/cm2. The PVDF/2-aminobenzothiazole modified ultrafiltration membrane presented better adsorption abilities for chromium ion than that of the traditional PVDF membrane. [ABSTRACT FROM AUTHOR]

This article examines the use of doped amorphous silica nanoparticles for surface-assisted laser desorption/ionisation-time of flight-mass spectrometry (SALDI-TOF-MS) of hydrophilic and hydrophobic compounds. A range of particles with surface aliphatic carboxylic, aminophenyl, phenyl or aminopropyl groups have been produced and these have been doped with carbon black, polyaniline or graphite. The effects of surface groups and dopants on the laser desorption/ionisation process were studied. The key factor in effective LDI was the presence of carbon black dopant carrying carboxyphenyl or phenyl residues for positive and negative ion formation. The second key factor was the presence of hydrophilic surface functional groups for hydrophilic amino acid analytes for their detection in positive or negative mode as protonated or de-protonated species respectively whereas hydrophobic surfaces were need for ionisation viacationisation for the hydrophobic analyte squalene. The mechanism for LDI of these particles appears to involve initial adsorption of the analyte onto the surface of the particle, formation of primary ions viaadsorption of laser UV irradiation by carboxyphenyl residues attached to the carbon black network which act in an equivalent way to the matrix in matrix-assisted LDI. This is followed by reaction of the primary ions with neighbouring adsorbed analyte molecules. The latter are then released possibly viathermal desorption following proton donation or acceptance from/to viasurface residues such carboxylate groups associated with the carbon black within the dopant. Alternatively in the absence of such proton donor/acceptor residues as with hydrophobic particles, the primary ions are released from the particles during desorption and form cation adducts as sodiated and potassiated species in the gas phase above the surface. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the surface charged and structural information of sulfonated polyethersulfone nanofiltration membrane are acquired through the analysis on the relevant electrochemical impedance spectroscopies (EIS) expressed in terms of dispersions of the impedance with frequency (1KHz–1MHz). The measurements are performed in the different electrolyte solutions (NaCl, MgCl2, LaCl3, KCl, K2SO4, and K3PO4) with different concentrations ranging from 1×10−4 mol/L to 6×10−3 mol/L. After that, the corresponding equivalent circuit as a theoretical model is set up. Experimental results indicate that the resistance of active layer is influenced by the concentration and ion species of electrolytes, while the capacitance is independent of them. For different cations and anions，the corresponding resistances of the active layer take on a sequence of SO4 2− >Cl− >PO4 3- and Na+ >La3+ >Mg2+，respectively, which is in well agreement with the variation trend of ion retention, especially for monovalent and divalent ions. Furthermore, the thickness of the active layer in the working state is estimated from the capacitance values and compared with the result obtained by SEM. On the basis of the above, it is reasonable to think that EIS can be used for online analysis in membrane process. [Copyright &y& Elsevier]

Abstract: A novel series of soluble hyperbranched polyfluorenes P1−P6 with various branching degrees and contents of kinked carbazole units were successfully synthesized with good yields and high molecular weight via a facile “A2+B2+C3+D2” approach. The thermal, optical, and electrochemical properties as well as thermal spectral stability of the resulting hypberbranched polymers were investigated. All polymers exhibited good thermal stabilities and bright blue emission in both solutions and solid-states. Hyperbranched polyfluorenes (P3 and P6) exhibited improved spectral stability upon annealing at 200°C in air, in sharp contrast to the linear poly(9,9-dihexylfluorene) (PDHF) that showed significant additional green emission at ca. 530nm within minutes. In particular, outstanding spectral stability was observed with carbazole-incorporating hyperbranched polyfluorene P6. Electrochemical characterization indicated that the presence of carbazole also effectively raised the HOMO level with respect to that of polyfluorene homopolymer, suggesting better hole-injection properties. Hence, the incorporation of kinked carbazole unit into hyperbranched polyfluorenes could provide a new methodology for preparing blue light-emitting polymers with improved optoelectronic characteristics. [Copyright &y& Elsevier]

New monodisperse starburst oligofluorene derivatives, which contain 5,5′,10,10′,15,15′-hexahexyltruxene as the central core linked with oligo(9,9′-dihexylfluorene) as the arms through ethynylene bridge are presented. All these compounds were prepared via Sonogashira reaction. Their molecular structures were confirmed by NMR, MALDI-TOF MS spectrometry and elementary analysis. The fluorescence spectra showed that introduction of ethynylene linker showed that the optical properties of the starburst oligofluorenes were modified. Both the absorption and the fluorescence peaks were found to be red-shifted. [ABSTRACT FROM AUTHOR]

Abstract: A series of novel hybrid organic–inorganic light-emitting materials, polyhedral oligomeric silsesquioxane-tethered poly(fluorenyleneethynylene)s, were successfully synthesized via Sonagashira coupling reaction. The chemical structures of these copolymers were determined by 1H NMR and FT-IR spectra. The morphologies of these copolymers were studied in details using TEM and WAXD. The WAXD data showed that POSS formed aggregation instead of crystallization in the polymer matrix, indicating the significant effect of the backbone constraint on POSS crystallization. Furthermore, it also revealed that the interchain interaction weakened and the interchain distance increased after introducing POSS groups. The TEM data indicated that POSS aggregates were well dispersed in polymer matrix. In accordance with the morphological investigation, the results of UV–vis absorption and photoluminescence emission spectra of these copolymers showed that the tendency toward planar conformation of conjugated backbones reduced to a certain extent due to weakened interchain interaction. Accordingly, these copolymers exhibited the enhanced quantum yields in the solid state. In addition, owing to the thermal and oxygen stability of hybrid POSS, the thermal spectral stability of these polymers was also improved greatly. [Copyright &y& Elsevier]

[Display omitted] • T-PRO was experimentally validated in the lab-scale setup. • T-PRO powered by solar energy was not feasible under current conditions. • T-PRO powered by solar energy can be combined with thermal desalination processes. Temperature-enhanced PRO (T-PRO) has been demonstrated to enhance the PRO performance via one system/module-scale mathematical model, but its techno-economic availability is still uncertain. As such, T-PRO was experimentally investigated in the lab-scale setup and its economic benefit was evaluated via utilizing solar energy as the thermal source. The experimental investigation showed that both optimal operating pressure and corresponding water flux increased from 12 bar and 3.74 LMH to 16 bar and 7.94 LMH when the operating temperature increased from 20 to 30 °C, thereby rendering an increase in power density from 1.25 to 3.53 W/m2 by 1.82 times and validating that the contribution of high operating temperature on energy generation was derived from increased operating pressure and water flux. Furthermore, the economic feasibility of T-PRO was assessed via one developed economic evaluation model based on solar linear Fresnel collectors. Evaluation results showed that the economic benefit of T-PRO could not cover the expenditure of thermal power, thus a standalone T-PRO system powered by solar energy was not feasible under current conditions. But, if these high-temperature and low-salinity solutions discharging from T-PRO can enter some thermal desalination systems, additional thermal power in T-PRO would reduce the thermal input in a further thermal desalination system. Therefore, T-PRO powered by solar energy must be integrated with thermal desalination technologies under the high cost of solar energy. [ABSTRACT FROM AUTHOR]

Copper phthalocyanine can assemble along PPE backbones into molecular arrays and 2D assemblies with structural parameters different from its intrinsic 2D crystal. The template effect depends on the match between the size of phthalocyanine and the repeating period of the PPE backbone. [ABSTRACT FROM AUTHOR]

Highlights • The entrainers p -xylene, butyl propionate and isobutyl acetate were selected. • The VLE data for (DMC + entrainers) and (ethanol + isobutyl acetate) were measured. • The measured VLE data were correlated by the NRTL, UNIQUAC and Wilson models. • The extractive distillation process for separating DMC and ethanol was proposed. Abstract Dimethyl carbonate and ethanol can form an azeotrope with the minimum boiling point. To separate the azeotrope (dimethyl carbonate + ethanol) by extractive distillation, p -xylene, butyl propionate, and isobutyl acetate were chosen as entrainers, and the isobaric vapour-liquid equilibrium (VLE) data for the binary systems of (dimethyl carbonate + p -xylene), (dimethyl carbonate + butyl propionate), (dimethyl carbonate + isobutyl acetate) and (ethanol + isobutyl acetate) were measured at 101.3 kPa using a modified Rose type recirculating still. The thermodynamic consistency of the VLE experimental data for the four binary mixtures was tested by the Herington and van Ness methods. Furthermore, the measured VLE data were correlated by the NRTL, UNIQUAC and Wilson thermodynamic models and the binary interaction parameters of the three models were regressed. Based above, an extractive distillation process with the entrainer of p -xylene was proposed and simulated to separate the azeotrope (dimethyl carbonate + ethanol). [ABSTRACT FROM AUTHOR]

Highlights • GO dispersions do have good antimicrobial activity. • GO nanosheets lost their antimicrobial activity once they were assembled into GO membranes. • Layered GO membranes exhibit excellent stability in a 14-day test. • Antifouling properties of GO membranes need to be improved. Abstract GO is of great interesting for membrane materials due to its unique properties including antimicrobial activity and antifouling property. However, the differences between GO nanosheets and layered GO membranes gained little attention. Herein, we fabricated GO membranes that have a thickness of around 30 nm and a void d-spacing of 0.67 nm (wet state) with single layer GO nanosheets of 10–75 nm in lateral size and investigated their antimicrobial and antifouling potential for practical use. It exhibits typical nanofiltration performance, with the rejections of 65.23%, 17.79%, 42.10% and 12.47% to Na 2 SO 4 , NaCl, Mg 2 SO 4 and MgCl 2 , respectively. The antimicrobial test demonstrated that GO nanosheets lose their antimicrobial activity after they stacked together. A 14-day test showing that GO membrane has excellent resistance for organic fouling, with reversible fouling of more than 98%. But when it comes to tapwater, the proportion of irreversible fouling is surging to more than fifty percent even after cleaning with 2000 mg/L of sodium hypochlorite. Thus, we suggested that there are more details should be investigated before put layered GO membrane into practical use. Surprisingly, GO membrane exhibits excellent mechanical stability during the 14-day test, showing its exciting potential in water treatment. [ABSTRACT FROM AUTHOR]

Abstract Resolution of the global fresh-water crisis requires advanced separation systems and hence the search for perfect separation materials is being undertaken vigorously. The ideal membrane material should be capable of being easily fabricated and modified to obtain a controllable performance. Graphene oxide (GO) is a graphene-based material with oxygen-containing functional groups. In recent years, GO-based separation membranes have received a lot of attention in the field of separation technology. In this review, we discuss the methods to fabricate or modify multilayered GO membranes. GO membranes and conventional separation membranes are compared and discussed. Further, we compared the molecular dynamics simulation results and the applications of GO membranes. Finally, we summarize the challenges and point out possible future research directions. This review is expected to help researchers obtain a quick idea of multilayered GO membranes and aid in future research for designing and fabricating multilayered GO membranes. Graphical abstract The graphical abstract includes some vary representative schematic views for permeation route in multilayered GO membrane [1–2], a new structure of multilayered GO membrane [3], and three kinds of crosslinked GO nanosheets [4]. Image [ABSTRACT FROM AUTHOR]

Freeze casting liquid dispersions of solid particles is an effective method for preparing porous composites, thus creating strong and lightweight materials with “designed” microstructures for various applications. This work illuminates that tert-butyl alcohol (TBA)/water (H 2 O) mutually miscible system can be used as template to prepare aligned porous silicate cement supports with unique pore structures via directional freezing. The resulting pore morphology of porous cement substrates changes from prismatic to needle-like, dendritic, coralline, graininess and lamellar structure with the increasing of TBA-H 2 O ratio in cement slurry. Pore size distributions (macropores and mesopores) demonstrate the hierarchical pore structure of porous cement. The BET surface area ( S BET ) of porous cement support increases with the decreasing TBA content in cement slurry, until the pore forming agent was pure water. Porous cement that are fabricated from mixed slurries with relatively high TBA-H 2 O ratio show better mechanical strength. Porous cement support prepared from cement slurry with 90 wt% TBA exhibits the best permeation performance due to its well-distributed and oriented pore structure. These findings demonstrate how an aligned and hierarchical porous inorganic support with desirable properties can be prepared, under mild conditions, with the combination of advanced casting technique and most ancient construction material on earth. [ABSTRACT FROM AUTHOR]

Abstract: A series of novel blue light-emitting copolymers PCC-1, PCC-2, and PCC-3, composed of different ratios of electron-withdrawing segments (spirobifluorene substituted with cyanophenyl groups) and electron-donating segments (carbazole-triphenylamines), has been synthesized and characterized. In order to investigate the effect of hole/electron charge transporting segments, two reference polymers PSF and PCF, containing only one charge transporting moiety in the polymer backbone, were also synthesized. Incorporation of the rigid spirobifluorene units substituted with cyanophenyl groups into the polymer backbone improved not only the thermal stabilities but also the photoluminescence efficiencies. The polymers except PSF possess similar hole injection barriers but different hole transporting abilities. With the device configuration of ITO/PEDOT:PSS/polymers:PBD/CsF/Ca/Al, PCC-2 showed the best performance with the lowest turn-on voltage of 3.1 V, the highest luminance of 6369 cd/m2, the highest current efficiency of 1.97 cd/A, and the best power efficiency of 1.40 lm/w. [Copyright &y& Elsevier]

• Energy-saving separation of methyl alcohol - methyl ethyl ketone – tert -butanol azeotropic system is studied. • A few extractive distillation processes with ionic liquid are proposed and parametrically optimized. • The best one greatly reduces energy consumption, investment and CO 2 emission. • An efficient simulated annealing based optimization strategy is designed. Several new extractive distillation configurations using green and highly selective ionic liquid (IL) as extractant are proposed as an alternative to the conventional extractive distillation (CED) and conventional extractive dividing wall column (CEDWC) configuration to separate methyl alcohol (MeOH)-methyl ethyl ketone (MEK)-tert butyl alcohol (TBA) azeotropic mixture, including direct and indirect extractive distillation (direct-ED, indirect-ED), azeotropic extractive distillation (AED), and extractive dividing wall column (EDWC). These schemes are optimized with the objective of total annual costs (TAC) by simulated annealing based optimization method. Among these schemes, EDWC is undoubtedly the best due to the benefits of IL and dividing wall column. As compared with the CED process, it can reduce TAC by 22.19%, total capital cost by 31.47%, total operating cost by 8.35%, CO 2 emission by 7.7%. In addition, the computation shows that the used optimization method is very practical for the optimal design of complex distillation systems with the advantages of direct, efficient, robust and global optimal. [ABSTRACT FROM AUTHOR]

• Efficient triple-side-stream quaternary extractive distillation is developed. • A computing-efficient simulated annealing optimization strategy is used. • The best one among side-stream flow control schemes is identified. • Side-stream flows dynamic responses to feed disturbances are examined. Dynamic control of extractive distillation process with multiple liquid side-streams is challenging although it has an energy-saving potential. In this work, the optimal design and control of a high-efficient triple-side-stream quaternary extractive distillation process (TSQED) is presented for separating acetone/methanol/butanone/tert‑butanol. All operating parameters are optimized by a simulated annealing based systematic method, resulting in the reduction of total annual costs by 9.37%, energy consumption by 18.76%, and CO2 emissions by 33.17% as compared with conventional extractive distillation process. Subsequently, three control structures (CS1, CS2, and CS3) are proposed and demonstrated according to different side-stream flowrate control strategy. In the CS1, the side-stream flowrate is proportional to feed flow. In the CS2, the side-stream flowrate is proportional to reboiler vapor flow. In the CS3, and temperature-sensitive plate in distillation column is identified and cascaded by side-stream flowrate. By contrast, CS3 is far better than CS1 and CS2 in terms of dynamic responses and integral performance criteria. This attributes to the virtuous effect of the inferential temperature control on side-stream flowrate in the whole process control of TSQED. Finally, the feedforward control of QR/F is added in the CS4 to further improve the effectiveness of CS3. [Display omitted] [ABSTRACT FROM AUTHOR]

The spacer geometries have a crucial effect on the hydrodynamics of spacer-filled channels in electrodialysis (ED) process, which are beneficial to mass transfer enhancement. Herein, a three-dimensional, isothermal, and steady flow model was developed by computational fluid dynamics (CFD) to illuminate the impacts of the spacer geometrical configurations on hydrodynamic behaviors in the spacer-filled channel for ED applications. Simultaneously, the finite element analysis method was employed to investigate the effects of spacer geometries on the velocity and pressure profiles. Furthermore, the normalized expenditure (NEXP) was introduced to acquire one comparable cost estimation index, which determined the optimal spacer geometries subserving the efficiency and economic competitiveness of ED process. Theoretical and techno-economic analysis validated that the optimal mesh parameters within the range of the test parameters were a cylindrical mesh, a filament diameter of 0.8 mm, a filament interval of 1.0 mm, a flow attack angle of 30°. Therefore, this work can provide a feasible strategy to visualize and quantitate the hydrodynamics in the spacer-filled channel and insight into the optimization of ED stack, potentially reducing the expenditure related to materials usage, energy consumption and test time. [ABSTRACT FROM AUTHOR]

• EDM was proposed to prepare high-purity TPAOH for the first time. • Techno-economic performance of EDM was systematically evaluated. • EDM showed technical advantages in energy consumption and product purity. • Considerable economic benefit could be obtained under current lab-scale tests. High-purity and low-cost tetrapropyl ammonium hydroxide, denoted by TPAOH, is of significance for industrial applications of high-performance Titanium-Silicalite-1 molecular sieve catalyst. For the first time, the electrodialysis metathesis, abbreviated to EDM, was proposed to prepare high-valued and high-purity TPAOH from its bromide and effects of operation conditions including initial feed concentration, operation voltage, and flowrate on the techno-economic availability of EDM were systematically investigated. Results showed that increasing initial feed concentration could result in higher production capacity and TPAOH purity, but lower current efficiency and higher energy consumption; higher feed initial concentration was more preferable concerning maximum economic benefit. The optimal operation voltage of 4.5 V was observed to achieve highest production capacity, current density, and product purity. Based on experimental results, estimated maximum economic benefit can also be obtained at the operation voltage of 4.5 V. The highest current efficiency, lowest energy consumption, and maximum economic benefit occurred at the flowrate of 100 ml/min under the current experimental scale. Meanwhile, the product purity can be enhanced by increasing the flowrate when product purity is in the first place. Compared to other technologies, preparing TPAOH via EDM showed lower energy consumption and higher product purity, thereby rendering superior techno-economic advantages. [ABSTRACT FROM AUTHOR]

This study describes the preparation and characterisation of MIL-53(Fe) and its effect on the performance of forward osmosis (FO) membranes. The cellulose acetate (CA)/MIL-53(Fe) hybrid membranes were fabricated using the method of phase inversion by dispersing MIL-53(Fe) in a CA casting solution. To improve the selectivity and permeability performance of FO membranes, the effects of MIL-53(Fe) content, casting solution temperature, coagulation bath temperature, and annealing temperature were studied. Results from scanning electron microscopy, membrane porosity, atomic force microscopy, and water contact angle tests of all the membranes show that the structural properties of the CA/MIL-53(Fe) hybrid membranes were optimised. The results of the FO performance tests, including the values of water flux and reverse salt flux, indicate improvement in the selectivity and permeability properties of the CA/MIL-53(Fe) hybrid membranes. Under the conditions of deionised water as the feed solution and 1 M NaCl solution as the draw solution, the water flux and reverse salt flux of the CA/MIL-53(Fe) hybrid membranes reached 34.9 L/(m2·h) and 2.02 g/(m2·h), respectively, in comparison with CA membranes. This study demonstrates that MIL-53(Fe) can improve the desalination performance and structural properties of FO membranes. • MIL-53(Fe) with high porosity was used to fabricate cellulose acetate (CA)/MIL-53(Fe) hybrid membranes for the first time. • Optimal experimental conditions of CA/MIL-53(Fe) hybrid membranes were conducted. • The water flux and reverse salt flux of CA/MIL-53(Fe) hybrid membranes were improved compared to CA membranes. • Effect of MIL-53(Fe) on structural properties of CA membranes was widely discussed. [ABSTRACT FROM AUTHOR]