Magnetic sorting using magnetic beads has become a routine methodology for the separation of key cell populations from biological suspensions. Due to the inherent ability of magnets to provide forces ...at a distance, magnetic cell manipulation is now a standardized process step in numerous processes in tissue engineering, medicine, and in fundamental biological research. Herein we review the current status of magnetic particles to enable isolation and separation of cells, with a strong focus on the fundamental governing physical phenomena, properties and syntheses of magnetic particles and on current applications of magnet-based cell separation in laboratory and clinical settings. We highlight the contribution of cell separation to biomedical research and medicine and detail modern cell-separation methods (both magnetic and non-magnetic). In addition to a review of the current state-of-the-art in magnet-based cell sorting, we discuss current challenges and available opportunities for further research, development and commercialization of magnetic particle-based cell-separation systems.
Magnetic nanobeads have been widely used for magnetic separation, target labeling and signal amplification in the development of various biosensors. This review summarized (1) the basic knowledge of ...magnetic nanobeads, including physical structure, chemical characteristics and surface modification; (2) the development and applications of magnetic separation, from the earliest conventional magnetic separation, to high gradient magnetic separation, then to magnetophoretic separation and magnetic continuous-flow separation, finally to the latest magnetic grid separation; and (3) recent advances and applications of magnetic nanobead based biosensors, where the magnetic nanobeads work as either detection signal for electromagnetic biosensors, magnetic lateral flow biosensors and magnetic relaxation switching biosensors, or signal amplifying tag for electrochemical biosensors, QCM biosensors and SPR biosensors, or both. Besides, the important issues and future trends for magnetic nanobead based separation and biosensor were also discussed and summarized.
•Basic knowledge of magnetic nanobeads were summarized.•Recent advances on MNBs for magnetic separation were reviewed.•Recent advances on MNBs for target label were reviewed.•Recent advances on MNBs for signal amplification were reviewed.
Cell separation is at the core of current methods in experimental biology and medicine. Its importance is illustrated by the large number of physical and biochemical principles that have been ...evaluated for application to cell separation. The development of cell separation methods is driven by the needs of biological and medical research, and the ever-increasing demands for sensitivity, selectivity, yield, timeliness and economy of the process. The interdisciplinary nature of research in this area and the volume of information available in research publications and conferences necessitates a basic description of the fundamental processes involved in magnetic cell separation that may help the user in navigating this wealth of information available online and in scientific publications. This book will appeal to researchers in many areas utilizing this technique, including those working in cell biology, clinical research, inorganic chemistry, biochemistry, chemical engineering, materials science, physics and electrical engineering. * Provides examples of how to calculate the volume magnetic susceptibility, a fundamental quantity for calculating the magnetic force acting on a cell, from various types of magnetic susceptibilities available in literature * Introduces the elements of magnetostatics as they apply to cell magnetization and the magnetization of magnetic micro- and nano- particles used for cell separation * Describes the parameters used to determine cell magnetophoresis
The development of low‐pressure or pressureless self‐driven membranes is important for saving energy and overcoming the critical trade‐off effect in membrane separation processes. However, ...conventional self‐driven membranes rely on gravity, which is effective in the separation of large‐sized materials but is still ineffective in the fine separation of small molecules. Herein, inspired by the capillary effect that exists in nature, a capillary force‐induced membrane‐driving strategy for fine separation at ultra‐low pressures is demonstrated. Hydrophilic nanoparticles are prepared by a cross‐linking reaction between tannic acid and 3‐aminopropyltriethoxysilane and then introduce them into membrane pores to simulate sand accumulation with an aim to generate the capillary force. The membrane is then used in ultra‐low pressure membrane separation. Interestingly, it is found that the membrane has excellent performance in the separation of dye/salt mixtures (dye rejection > 99%, salt rejection < 10%) and a high permeate flux (160 L m−2 h−1) under near “zero pressure” conditions. Moreover, the structural stability of the membrane is verified. Introducing capillary forces into membranes as an autonomous driving force can be a promising universal approach that can be added up to the toolbox for the efficient preparation of separation membranes.
Inspired by the capillary phenomenon in nature, such as tree roots transporting water to the stem and leaves against gravity, the membrane achieves fine separation of dye/salt at ultra low pressure by introducing a large number of hydrophilic nanoparticles into the membrane pores to simulate sand accumulation with an aim to generate the capillary force.
Objective of this study is to elucidate relationship with aerodynamic properties and vortex shedding from suction surface and wake of wind turbine blade at low Reynolds numbers. Force measurement of ...NACA 4412 airfoil was conducted at various angles of attack and Reynolds numbers. Furthermore, smoke-wire experiment was performed to clearly visualize flow patterns such as flow separation or laminar separation bubble (LSB) over the airfoil. Also, velocity measurements at near wake region were done to highlight coactions among LSB and trailing edge vortices. Hot-film experiment was performed to obtain more information with regards to progress and formation of LSB. Experiments indicated that location and formation of LSB were affected by variety of both Reynolds number and angle of attack. Besides, mean and rms velocities showed that flow characteristics near wake were influenced by LSB and trailing-edge separation. At lower angles of attack, short bubble occurred, and frequency of vortex shedding due to short bubble were high whereas shedding frequency of long bubble at moderate angles of attack were low. The bubbles can cause vibration and noise at the wind turbine blade, hence they should be better known and eliminated, which aerodynamic performance and energy efficiency of turbine can be increased.
•Vortex shedding from suction surface and wake of aerofoil at low Reynolds numbers.•Strouhal number of vortices due to bubble and trailing edge varies with incidence.•Separation bubble physically changes as Reynolds number and angle of attack vary.•Strouhal number of vortex shedding due to bubble changes at low angles of attack.
•MIL-53-Al and MIL-101 beads were synthesized using alginate as a binder.•MIL-53-Al and MIL-101 beads show good crushing strength values of 18.17 and 16.45 N which is comparable to commercial zeolite ...adsorbents.•MIL-53-Al beads show good CH4/N2, CO2/CH4 and CO2/N2 selectivity than MIL-101 beads.
Metal-organic frameworks (MOF) are promising materials for gas storage and separation. The formulation and shaping of MOFs in mechanically stable bead forms is an essential requirement for their practical application as an adsorbent for gas and liquid mixture separations. In this work, MIL-53-Al and MIL-101 MOF beads are synthesized using sodium alginate as a binder, and calcium chloride as a gelling agent. The synthesized MIL-53-Al and MIL-101 MOF beads are characterized by powder X-ray diffraction (PXRD), BET surface area, porosity analysis from N2 uptake data at 77 K, FTIR, TGA, and scanning electron microscopy (SEM). The isothermal equilibrium adsorption uptake of CH4 and N2 gases is measured up to 10 bar pressure while the CO2 equilibrium uptake is measured up to 1 bar at 298 and 313 K respectively. The isotherm data of all adsorbates are fitted in Dual Site Langmuir (DSL) isotherm equations. The adsorption selectivity for CH4/N2, CO2/CH4, and CO2/N2 binary systems are predicted using the Ideal Adsorbed Solution Theory (IAST) method. The dynamic column breakthrough experiments are carried out on MIL-53-Al beads for CH4/N2 (30:70 and 50:50 v/v), CO2/CH4 (45:55 v/v) and CO2/N2 (15: 85 v/v) feed mixtures. The IAST selectivity and breakthrough time obtained under the same superficial velocity, pressure, and temperature conditions follow the order CO2/N2 > CO2 /CH4 > CH4/N2. The MIL-53-Al beads show higher CH4/N2, CO2/CH4, and CO2/N2 selectivity for the targeted mixtures than MIL-101 beads.
The fractal velocity pattern in symmetric kink-antikink collisions in ϕ4 theory is shown to emerge from a dynamical model with two effective moduli: the kink-antikink separation and the internal ...shape mode amplitude. The shape mode usefully approximates Lorentz contractions of the kink and antikink, and the previously problematic null vector in the shape mode amplitude at zero separation is regularized.
•High pressure CO2/CH4 separation of the optimized MMMs with CO2-philic MOFs.•Simulating an actual natural gas separation condition (pressure, feed, temperature).•At highest pressure, the effect of ...H2S (50,000 ppm) in feed was investigated.•MMMs showed CO2- and H2S-induced plasticization suppression.•Revealed reversible competitive sorption, also increased total acid gas selectivity.
The gas separation properties of 6FDA-DAM mixed matrix membranes (MMMs) with three types of zirconium-based metal organic framework nanoparticles (MOF NPs, ca. 40 nm) have been investigated up to 20 bar. Both NPs preparation and MMMs development were presented in an earlier publication that reported outstanding CO2/CH4 separation performances (50:50 vol% CO2/CH4 feed at 2 bar pressure difference, 35 °C) and this subsequent study is to demonstrate its usefulness to the natural gas separation application. In the current work, CO2/CH4 separation has been investigated at high pressure (2–20 bar feed pressure) with different CO2 content in the feed (10–50 vol%) in the temperature range 35–55 °C. Moreover, the plasticization, competitive sorption effects, and separation of the acid gas hydrogen sulfide (H2S) have been investigated in a ternary feed mixture of CO2:H2S:CH4 (vol% ratio of 30:5:65) at 20 bar and 35 °C. The incorporation of the Zr-MOFs in 6FDA-DAM enhances both CO2 permeability and CO2/CH4 selectivity of this polymer. These MMMs exhibit high stability under separation conditions relevant to an actual natural gas sweetening process. The presence of H2S does not induce plasticization but increases the total acid gas permeability, acid gas/CH4 selectivity and only causes reversible competitive sorption. The overall study suggests a large potential for 6FDA-DAM Zr-MOF MMMs to be applied in natural gas sweetening, with good performance and stability under the relevant process conditions.
Separation of inert nitrogen from natural gas by membranes is much more energy-saving than cryogenic distillation but very challenging because the size difference of both gas molecules is quite ...small. Herein, high-quality and N2-selective SSZ-13 membranes on α-alumina tubes were prepared using a novel synthesis approach called seeded-gel synthesis. Seeded-gel synthesis was more convenient and credible than the conventional secondary growth because a seeding step on the substrate was omitted for the former method. The effect of calcination atmosphere on the quality of membranes was also discussed. SSZ-13 membranes had the fewest defects when ozone calcination was used. The predicted values of single-component N2 and CH4 permeances by the Maxwell-Stefan equations agreed well with the experimental ones. The SSZ-13 membrane exhibited ultrahigh N2 permeance of 850 × 10−9 mol m−2 s−1 Pa−1 (equals 2500 GPU) and a high N2/CH4 selectivity of 13.5 at 298 K and 0.303 MPa feed pressure (absolute). Membrane preparation by seeded-gel method had good reproducibility. The effects of temperature, pressure drop and feed flow rate on membrane performances were investigated for N2/CH4 mixture separations. The membrane also displayed good separation performance in N2/CH4 system either at 2.6 MPa feed pressure or under humid conditions. The continuous SSZ-13 thin membranes prepared by the simple seeded-gel synthesis showed great potentials for energy-efficient N2 removal from unconventional gases.
Display omitted
•Highly N2-permeable SSZ-13 membranes were synthesized by novel seeded-gel synthesis.•The best membrane showed N2 permeance of 2500 GPU and N2/CH4 selectivity of 13.5.•Ozone calcination at low temperature reduced the formation of the defects.•The membrane had good separation performance for high-pressure and humid mixtures.
Lack of clean water is a major global challenge. Membrane separation technology is an ideal choice for the treatment of industrial, domestic sewage owing to its low energy consumption and cost. ...However, membranes are highly susceptible to contamination, particularly during wastewater treatment, which has limited their practical applications in this field. Similarly, the flux of the membrane decreases with prolonged use due to its reduced interlayer spacing. Preparation of membranes with anticontamination properties and stable flux is the key to addressing this problem. In this study, a 2D heterostructure membrane with visible‐light‐driven self‐cleaning performance is prepared via a self‐assembly process. Notably, the addition of palygorskite increases the interlayer spacing of the graphene and heterojunction structures, which increases the flux of the membrane and avoids a decrease of the interlayer spacing of the membrane under pressure. The presence of a heterojunction with visible light catalytic properties effectively avoids membrane fouling and avoids a sharp decrease of the permeation flux. Importantly, the prepared 2D membrane has excellent separation performance for oil–water emulsions with both high flux and efficiency. These features suggest great potential for the prepared 2D membrane in wastewater treatment applications.
A visible‐light‐driven self‐cleaning 2D heterojunction membrane for stable oil‐in‐water emulsion separation with stable flux is introduced. The 2D heterostructure membranes are successfully fabricated via a self‐assembly method. The prepared membranes have a high permeation flux for stable oil‐in‐water emulsion separation and they exhibit a high‐flux, stable flow rate after multiple cycles, and excellent self‐cleaning properties for stable oil‐in‐water emulsions.
PDF
