Smart membranes with tunable permeability and selectivity have drawn widespread attention because of their unique biomimetic characteristics. Constructed by incorporating various stimuli-responsive materials into membrane substrates, smart membranes could self-adjust their physical/chemical properties (such as pore size and surface properties) in response to environmental signals such as temperature, pH, light, magnetic field, electric field, redox and specific ions/molecules. Such smart membranes show great prospects in biomedical applications ranging from controlled drug release to bioseparation and tissue engineering. In this review, three controlled release models realized by different designed smart membranes are emphatically introduced, and then smart membranes for biological separation and controlled cell culture are introduced and discussed respectively. At last, the existing challenges of smart membranes for biomedical applications are briefly summarized, and future research topics are suggested.

In the face of human society's great requirements for health industry, and the much stricter safety and quality standards in the biomedical industry, the demand for advanced membrane separation technologies continues to rapidly grow in the world. Nanofiltration (NF) and reverse osmosis (RO) as the high-efficient, low energy consumption, and environmental friendly membrane separation techniques, show great promise in the application of biomedical separation field. The chemical compositions, microstructures and surface properties of NF/RO membranes determine the separation accuracy, efficiency and operation cost in their applications. Accordingly, recent studies have focused on tuning the structures and tailoring the performance of NF/RO membranes via the design and synthesis of various advanced membrane materials, and exploring universal and convenient membrane preparation strategies, with the objective of promoting the better and faster development of NF/RO membrane separation technology in the biomedical separation field. This paper reviews the recent studies on the NF/RO membranes constructed with various materials, including the polymeric materials, different dimensional inorganic/organic nanomaterials, porous polymeric materials and metal coordination polymers, etc. Moreover, the influence of membrane chemical compositions, interior microstructures, and surface characteristics on the separation performance of NF/RO membranes, are comprehensively discussed. Subsequently, the applications of NF/RO membranes in biomedical separation field are systematically reported. Finally, the perspective for future challenges of NF/RO membrane separation techniques in this field is discussed.

The past few decades have witnessed rapid gains in our demands of antifouling membranes such as water purification membranes and hemodialysis membranes. A variety of methodologies have been proposed for improving the antifouling performance and the hemocompatibility of the membranes. In this study, a series of copolymers (PSF-PESSB) containing polysulfone (PSF) and poly(arylene ether sulfone) bearing pendant zwitterionic sulfobetaine groups (PESSB) were prepared via one-pot polycondensation. Subsequently, the ultrafiltration (UF) membranes were prepared from different zwitterion-containing copolymers. The prepared membranes showed high thermal stability and mechanical properties. Besides, it also displayed attractive antifouling performance and blood compatibility. Compared with the original PSF membrane, the amount of protein absorption on the modified membrane was reduced; the flux recovery ratio and the resistance to blood cells were significantly improved. The results of this work suggest that PSF-PESSB membranes are expected to be applied in blood purification. The introduction of zwitterion-containing polymers to membranes paves ways for developing advanced hemodialysis technologies for crucial process.

The protein-bound uremic toxins, represented by indoxyl sulfate (IS), have been associated with the progression of chronic kidney disease and the development of cardiovascular disease in the presence of impaired renal function. Herein, we proposed a novel strategy of thin-film nanofibrous composite (TNFC) dialysis membrane combined with reduced graphene oxide (rGO) aerogel adsorbents for clinical removal of IS as well as high retention of proteins. The TFNC membrane was prepared by electrospinning in conjunction with coating-reaction method and proved to have good selectivity and permeability. To further improve the removal rate of toxins, we used a medium hydrothermal method following by freeze-drying treatment to obtain the rGO aerogel adsorbents. It exhibited excellent adsorption for IS with a maximum adsorption capacity of 69.40 mg·g^-1 through π-π interaction and hydrogen bonding interaction based on Langmuir isotherm models. Time-dependent absorption experiments showed that it reached adsorption equilibrium within 4 h, which was matched with the hemodialysis time. The coordination was significantly exhibited by introducing rGO aerogel blocks into the dialysate for absorbing the diffused free IS during hemodialysis. Taking the advantages of the TFNC dialysis membrane and the rGO aerogel, the volume of dialysate for hemodialysis was only one-tenth of that without adsorbent blocks but with very comparable dialysis performance (the clearance of IS at 51.8% and the retention of HSA over 98%), which could lighten conventional hemodialysis effectively and be benefit to realize the miniaturization of the hemodialysis equipment. Therefore, the coordination of the TFNC dialysis membrane and rGO aerogel adsorbents would open a new path for the development of portable artificial kidney.

Helium (He) is commercially produced from natural gas by low-temperature condensation. The process is energy extensive because of the extremely low He concentration (<0.3%) and the operation at cryogenic temperature. Herein we demonstrated DD3R zeolite membrane was efficient to extract He from natural gas at atmosphere temperature. The membrane performance was evaluated in terms of temperature, pressure and molar fractions. The overall membrane performance was dominated by the diffusivity selectivity. The single He permeance and ideal He/CH₄ selectivity were 5.8×10^-9 mol·m^-2·s^-1·Pa^-1 and 79 under a feed pressure of 1.3 MPa. Even though He concentration was as low as 0.22%, the He permeance and He/CH₄ mixture selectivity were 3.0×10^-9 mol·m^-2·s^-1·Pa^-1 and 44 at 0.7 MPa. During the long-term operation (～130 h) the membrane performance was stable even the feed mixture containing 3.6% ethane as contaminations. The results approved the feasibility of DD3R zeolite membranes for He extraction from natural gas.

Precluding the excessive lipoproteins from plasma rapidly and effectively is highly needed for biomedical detection and reducing plasma product scrap in blood donation stations. The current centrifugation procedure is high-cost and time-consuming. Herein, we fabricated an anionic microfiltration polyethersulfone (PES) membrane modified by interface swelling and implanting of acrylic acid (AA) for screening out large particle lipoprotein chylomicron (CM) and adsorbing cationic very low-density lipoproteins (VLDL). To improve the separation efficiency, a two-stage filtration through carboxylated polyethersulfone microfiltration membranes with the mean pore size of 0.45 and 0.22 μm respectively were conducted. Attenuated total reflection Fourier transform infrared technique (ATR-FTIR), water contact angle (WCA), Zeta potential and scanning electron microscope (SEM) were employed to characterize the modified membrane. To test the effectiveness of this membrane, plasma flux and concentration variation of plasma components were examined to study the purification effectiveness. Furthermore, the hemocompatibility of modified membranes was tested to confirm its practicability on blood-contacting materials. The carboxylated polyethersulfone microfiltration membrane shows its promising potential application to purify chylous plasma.

The design of membrane pore is critical for membrane preparation. Polyvinylidene fluoride (PVDF) membrane exhibits outstanding properties in the water-treatment field. However, it is a huge challenge to prepare PVDF macro-pore plasma separation membrane by non-solvent induced phase separation (NIPS). Herein, a facile strategy is proposed to prepare PVDF macro-pore plasma separation membrane via macromolecular interaction. ATR-FTIR and ¹H NMR showed that the intermolecular interaction existed between polyethylene oxide (PEO) and polyvinylpyrrolidone (PVP). It could significantly affect the PVDF macro-pore membrane structure. The maximum pore of the PVDF membrane could be effectively adjusted from small-pore/medium-pore to macro-pore by changing the molecular weight of PEO. The PVDF macro-pore membrane was obtained successfully when PEO-200 k existed with PVP. It exhibited higher plasma separation properties than the currently used plasma separation membrane. Moreover, it had excellent hemocompatibility due to the similar plasma effect, hemolysis, prothrombin time, blood effect and complement C_3a effect with the current utilized plasma separation membrane, implying its great potential application. The proposed facile strategy in this work provides a new method to prepare PVDF macro-pore plasma separation membrane by NIPS.

Adsorptive recovery of valuable components from industrial wastewater is highly desirable for avoiding resource wastage but remains a challenge. Herein, we develop an efficient continuous adsorption process for recovering aromatic compounds in wastewater from styrene monomer and propylene oxide co-production (SMPO) plant. Based on our insight into the potential of bio-based porous materials for adsorption application, starch-graft-polystyrene (SPS) and aryl-modified β-cyclodextrin (ACD) were prepared, and novel hypercrosslinked porous polymers combined SPS with ACD (HSPS-ACDs) were synthesized through external crosslinking approach. In a binary-component system, the best-performing one HSPS-ACD(H) with high ACD content and large specific surface area possessed superior capacities for the representative aromatic compounds, acetophenone (AP, 2.81 mmol·g^-1) and 1-phenylethanol (1-PE, 1.35 mmol·g^-1) compared with the previously reported materials. Further, the adsorption properties of aromatic compounds on HSPS-ACD(H) were investigated in batch mode. For practical application, continuous adsorption experiments were conducted in a HSPS-ACD(H)-packed fixed bed, where the target aromatic components in wastewater were effectively retained and further released by elution. Besides showing the reversible adsorption and efficient enrichment effect, the HSPS-ACD(H)-packed fixed bed also maintained great stability in multiple cycles. Moreover, quantum chemical calculations were performed to elucidate the potential mechanism of adsorption of AP and 1-PE onto HSPS-ACD(H).

Effective extraction and regeneration of radioactive iodide is one of urgent concerns for the safe utilization of nuclear energy. As a novel environmentally benign ion separation technique, electrochemically switched ion extraction (ESIE) process can be applied for effective capture and recovery of iodide ions (I^-). Herein, a novel kelp seaweed-like core/shell I^- imprinted polypyrrole@bismuth oxyiodide (PPy/I^-@BiOI) composite film is successfully prepared for the selective I^- capture in the ESIE system. It is found that the I^- can be easily trapped in the PPy/I^-@BiOI film after I^- is in situ desorbed from the film by an electrochemical reduction process since it offers particular electroactive binding sites for I^- extraction. The I^- imprinted PPy/I^-@BiOI film displays an extraction capacity as high as 325.2 mg·g^-1 for I^- with favorable stability. In particular, the extraction and desorption of I^- is achieved by adjusting the redox potential and the pristine PPy/I^-@BiOI film can be regenerated and reused for multiple times without decrease in extraction capacity. It is expected that such a PPy/I^-@BiOI film would be useful as an electrochemically switched renewable extractor that could capture and regenerate I^- from radioactive water.

Harvesting water from the atmosphere is an important process to solve the extreme lack of water resources in arid regions. Adsorption-based atmospheric water harvesting (AWH) takes advantage of solar thermal energy to harvest water from air. This technique is particularly suitable for arid regions characterized by low humidity and an abundance of sunshine. Nonetheless, under low humidity conditions, AWH is highly dependent on water-adsorbing materials exhibiting excellent performance. In this work, a metal–organic framework (MOF), namely [Zn₂(bpy)(btec)(H₂O)₂]·2H₂O, also denoted as MWH-1, was investigated for application in water harvesting under low humidity conditions (<20%). Notably, MWH-1 displayed outstanding water and thermal stability. At temperatures of 293–333 K and low pressure, activated MWH-1a exhibited competitive water uptake (relative humidity (RH) = 5%, uptake>200 cm³·cm^-3; RH = 10%, uptake>250 cm³·cm^-3). This ensured effective water harvesting at high temperatures during the day. In situ powder X-ray diffraction and Fourier-transform infrared analyses confirmed the sensitive water adsorption process of MWH-1a. The X-ray single-crystal study further demonstrated that single-crystal structures could be completely restored following water harvesting. MWH-1 showed good structural stability and enabled water harvesting under low humidity and high temperature conditions. Thus, it has the potential for application in round-the-clock water harvesting in extremely arid regions.

As the core component of the rotating packing bed, packing is a place for efficient gas–liquid mixing and mass transfer. In this paper, a 3D structured packing composed of a mesh structure and a support structure was designed. The mesh structure is a ring-shaped mesh surrounded by triangular meshes, which is stable in structure and can achieve a high degree of dispersion and aggregation of the liquid phase. The support structure is composed of ring-shaped structural units arranged at a certain angle along the axial direction, which can enhance the turbulence of the airflow while constructing regular gas-phase channels. Circumferential steel meshes of different diameters and supporting structures are alternately combined to form 3D packing, which is loaded in a layered cross-flow rotating packing bed. The results show that under the same operating conditions, the mass transfer performance of 3D packing and wire mesh packing are equivalent, and both are better than pall ring packing. Moreover, the pressure drop of 3D packing is significantly lower than that of pall ring packing and wire mesh packing. The design and implementation of packing the development presented in this paper can be used to develop special structured packing for rotating bed, which can further improve the performance of rotating packed bed (RPB).

The Ni-Nb₂O₅ nanocatalysts have been prepared by the sol–gel method, and the catalytic hydrodeoxygenation (HDO) performance of anisole as model compound is studied. The results show that Nb exists as amorphous Nb₂O₅ species, which can promote Ni dispersion. The addition of Nb₂O₅ increases the acidity of the catalyst. However, when the content of niobium is high, there is an inactive Nb-Ni-O mixed phase. The size and morphology of Ni grains in catalysts are different due to the difference of Nb/Ni molar ratio. The Ni_0.9Nb_0.1 sample has the largest surface area of 170.8 m²·g^-1 among the catalysts prepared in different Nb/Ni molar ratios, which is mainly composed of spherical nanoparticles and crack pores. The HDO of anisole follows the reaction route of the hydrogenation HYD route. The Ni_0.9Nb_0.1 catalyst displayed a higher HDO performance for anisole than Ni catalyst. The selectivity to cyclohexane over the Ni_0.9Nb_0.1 sample is about 10 times that of Ni catalyst at 220 ℃ and 3 MPa H₂. The selectivity of cyclohexane is increased with the increase of reaction temperature. The anisole is almost completely transformed into cyclohexane at 240 ℃, 3 MPa H₂ and 4 h.

In order to remove hexavalent chromium (Cr(VI)) from solutions efficiently, the mycelial pellets with a marine-derived fungus Aspergillus niger as a biosorbent were prepared. The effects of removal process parameters such as solution pH, initial Cr(VI) concentration and biomass concentration on Cr(VI) removal process were investigated. The results showed that Cr(VI) removal rate up to 100% could be achieved under optimized conditions, which indicated the excellent Cr(VI) removal performance of the Aspergillus niger pellets. As a more important point, the Cr(VI) removal mechanism was studied, and the results revealed that Cr(VI) removal was achieved in the adsorption-coupled reduction process. A little of Cr(VI) was reduced to less toxic trivalent chromium (Cr(III)) in solution, while some was absorbed on the surface of mycelial pellets. Then they may be reduced on the surface or transferred into cells and then be reduced. The marine-derived A. niger mycelial pellets show properties of easy preparation and separation and cost effectiveness, which are potential biosorbent and reductant in the treatment of trace chromate containing wastewater.

Electrolytic manganese metal residue (EMMR) harmless treatment has always lacked a low-cost and quick processing technology. In this study, surfactants, namely tetradecyl trimethylammonium chloride (TTC), sodium dodecyl benzene sulfonate (SDBS), sodium lignin sulfonate (SLS), and octadecyl trimethylammonium chloride (OTC), were used in the solidification of Mn²⁺ and removal of NH₄⁺-N from EMMR. The Mn²⁺ and NH₄⁺-N concentrations under different reaction conditions, Mn²⁺ solidification and NH₄⁺-N removal mechanisms, and leaching behavior were studied. The results revealed that the surfactants could enhance the Mn²⁺ solidification and NH₄⁺-N removal from EMMR, and the order of enhancement was as follows: TTC > SDBS > OTC > SLS. The NH₄⁺-N and Mn²⁺ concentrations were 12.3 and 0.05 mg·L^-1 with the use of 60.0 mg·kg^-1 TTC under optimum conditions (solid–liquid ratio of 1.5:1, EMMR to BRM mass ratio of 100:8, temperature of 20 ℃, and reaction duration of 12 h), which met the integrated wastewater discharge standard (GB8978-1996). Mn²⁺ was mainly solidified as Mn(OH)₂, MnOOH and MnSiO₃, and NH₄⁺-N in EMMR was mostly removed in the form of ammonia. The results of this study could provide a new idea for cost-effective EMMR harmless treatment.

The development of effective visible and near-infrared photocatalysts is highly promising in the current field of photocatalysis. Herein, carbon dots/ZnFe₂O₄ (CDs/ZFO) with coating zero dimensional (0D) CDs on the surface of three dimensional (3D) yolk-shell ZFO spheres was designed and synthesized via a self-templated solvothermal method. The as-prepared CDs/ZFO composites displayed outstanding visible and near-infrared photocatalytic degradation activity of tetracycline (TC), and the optimal 3% CDs/ZFO sample with loading 3% (mass) CDs displayed the highest photocatalytic TC degradation ability under visible light (79.5% within 120 min) and near-infrared light (41% within 120 min). The enhancement of photocatalytic activity for CDs/ZFO composite is mainly ascribed to the fact that 0D/3D yolk-shell CDs/ZFO structure not only effectively reflect the incident light to increase the utilization efficiency of solar light, but also utilize the up-conversion photoluminescence and electronic conductivity properties of CDs to broaden sunlight absorption range and promote separation and transfer of electron-hole pairs.

Economically separating 1-propanol (NPA) from water is an emergent issue for producing pharmaceutical intermediates such as n-propyl acetate, n-propylamine and so on. In this work, fourionic liquids (ILs) 1-ethyl-3-methylimidazolium thiocyanate ([EMIM][SCN]), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF₄]), 1,3-dimethylimidazolium methylsulfate ([MMIM][MS]), 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]) were introduced as potential entrainers for separating NPA–water azeotropic mixture. The results show that [MMIM][MS] is the most suitable entrainer compared with other ILs from the analysis of vapor–liquid equilibrium and relative volatilities. The extractive distillation process with the entrainer regeneration system of flash tank and stripper was employed and optimized by the two-step optimization method. The results show that total annual cost and energy consumption per product flow rate were reduced by 39.79% and 60.47% compared with literature. In addition, the efficiency indicator of extractive section, efficiency indicator of per tray in extractive section, carbon dioxide emissions were also selected as the evaluation index for selection of operating parameters and calculated for different cases. The CO₂ emissions of the optimal design can be reduced by 60.98% from environmental aspect.

The high-purity distillation column system is strongly nonlinear and coupled, which makes it difficult to control. Active disturbance rejection control (ADRC) has been widely used in distillation systems, but it has limitations in controlling distillation systems with large time delays since ADRC employs ESO and feedback control law to estimate the total disturbance of the system without considering the large time delays. This paper designs a proportion integral-type active disturbance rejection generalized predictive control (PI-ADRGPC) algorithm to control the distillation column system with large time delay. It replaces the PD controller in ADRC with a proportion integral-type generalized predictive control (PI-GPC), thereby improving the performance of control systems with large time delays. Since the proposed controller has many parameters and is difficult to tune, this paper proposes to use the grey wolf optimization (GWO) to tune these parameters, whose structure can also be used by other intelligent optimization algorithms. The performance of GWO tuned PI-ADRGPC is compared with the control performance of GWO tuned ADRC method, multi-verse optimizer (MVO) tuned PI-ADRGPC and MVO tuned ADRC. The simulation results show that the proposed strategy can track reference well and has a good disturbance rejection performance.

Developing an efficient and selective catalyst for the dehydration of fructose to 5-hydroxymethylfurfural (HMF) is significant for biomass conversion. Herein, a metal-organic framework (MOF) with acidity and strong hydrophobicity is first reported by the condensation of amino-tagged MOFs with mercapto carboxylic acids and subsequent oxidation. The hydrophobic acidic MOFs possess acid densities ranging from 0.2-1.0 mmol·g^-1, H₂O contact angles of 114°-125°, and specific surface areas above 260 m²·g^-1. Compared to the methyl sulfo-functionalized MOF, the benzene sulfo-functionalized MOF with a strong hydrophobicity shows much higher activity and selectivity for the conversion of fructose to 5-hydroxymethylfurfural. In particular, 2.99% (mass) UiO-PhSO₃H shows the best catalytic performance with a 90.4% HMF yield due to its suitable hydrophobicity and abundant acidic sites. Moreover, the catalyst shows great stability after recycling for 5 runs. This work provides an interesting design strategy for the preparation of hydrophobic acidic MOFs and shows the powerful synergistic effect of acidity and hydrophobicity.

HZSM-5 zeolites with Si/Al ratios of 20, 35, 50 and 65 were prepared by the directing crystallization process of silicalite-1 seeds. The influence of Si/Al ratios on the production of benzene, toluene, xylene and naphthalene (BTXN) originated from asphaltenes catalytic pyrolysis was explored by adopting Py-GC/MS. Modified Z5-50 zeolites were prepared by various metal ions (Ni²⁺, Mo⁶⁺, Fe³⁺, and Co²⁺) with different loading rates (3% (mass), 5% (mass), 7% (mass), and 9% (mass)) and the physical and chemical properties of these zeolites were characterized by XRD, SEM, ICP-OES, XPS, NH₃-TPD, FTIR, Py-IR and N₂ adsorption-desorption isotherm. In addition, they were employed to catalyze the conversion of asphaltenes pyrolysis production to BTXN using Py-GC/MS. Results show that the highest relative content of aromatics has been obtained over HZSM-5 with Si/Al ratio of 50 (Z5-50), reaching 61.87%. Besides, the loading of Ni, Mo, Fe, and Co on Z5-50 leads to an increase of acid strength and provides new active sites. The relative content of BTXN increases by 3.17% over 3Ni-Z5, which may be ascribed to that Ni promoted the conversion of polycyclic aromatic hydrocarbons (PAHs) to monocyclic aromatics due to the cracking of aliphatic side chains of PAHs and the decrease of phenolic activation energy. While under the catalysis of 5Mo-Z5, the relative content of aromatics and BTXN augmented by 5.75% and 4.02%, respectively. In addition, the highest relative content of aromatics reaches 70.09% when the loading rate of Fe was 7% (mass), and the relative content of BTXN increases from 25.87% to 29.42%. The results demonstrate that the active sites provided by different metal species expressed diverse effects on BTXN. Although the Brønsted/Lewis acid ratios of HZSM-5 modified by metal decreased, the acid strength and the relative content of BTXN both increased, which illustrated that there is a synergistic catalysis with the Brønsted acid sites and Lewis acid sites provided by metal species. In general, the performance of the catalyst is affected by the pore structure, acidity and metal active sites. Moreover, the possible formation mechanism of BTXN derived from asphaltenes catalytic pyrolysis was proposed on the basis of structural features and catalytic performances of a series of zeolites.