Solvent Removal Research Articles

Gas Evolution from Sulfide-Based All-Solid-State Batteries

The demand for high-performance batteries for electrical vehicles (EV) and large-scale energy storage systems have accelerated the development of all-solid-state batteries. Switching from organic liquid electrolyte to solid electrolyte (SE) ensures, not only the high energy density (Wh/L), but also an intrinsic improvement to safety from the removal of flammable solvent in the liquid electrolyte. However, for the development of all-solid-state batteries, still many problems exist toward commercialisation. One challenge is their chemical/electrochemical stability. In case of Li6PS5Cl argyrodite, their electrochemical decomposition was proposed as following reaction. [1]Li6PS5Cl → Li4PS5Cl + 2Li+ + 2e → Li3PS4 + Sx + LiCl → P2Sx + Sx + LiCl + 3Li+ + 3e (1) However, this proposed reaction is bulk electrochemical decomposition of argyrodite. To understand the decomposition in actual cell, layered oxide cathode/argyrodite composite were analysed by in situ Raman microscopy, X-ray photoelectron spectroscopy and Time-of-flight secondary ion mass spectrometry. [2, 3] This research reports actual solid decomposition product formed by active material and solid electrolyte such as POx or (S2)2- compound. Not only for solid decomposition product, but also gaseous decomposition product can be generated from the interface between cathode materials and SE. Previously, much work has demonstrated that O2 and CO2 gases are released from the positive electrode material within the lithium-ion cell. [4] These exothermic surface reactions are important not only for cell swelling in the long-term usage, but also for cell combustion. However, the gas releasing behaviour of positive electrode mixture in all-solid-state batteries are still not well recognised. In this research, we focused on the gas releasing behaviour of all-solid-state batteries. LiNi0.6Mn0.2Co0.2O2 was selected for cathode materials in this research. For the solid electrolyte itself and LiNi0.6Mn0.2Co0.2O2/SE mixture were analysed by Differential Electrochemical Mass Spectroscopy (DEMS). Furthermore, to understand the importance of surface chemistry, air stored LiNi0.6Mn0.2Co0.2O2 and Al2O3 coated LiNi0.6Mn0.2Co0.2O2were prepared. Since air contamination (H2O and CO2) is detrimental for Ni-rich cathode and battery [5], we propose role of surface chemistry in all-solid-state batteries by comparing different LiNi0.6Mn0.2Co0.2O2 composites. As shown in Figure 1, CO2 and O2 gas evolution is observed within an all-solid-state cell as it is charged up to 5 V, with evolution beginning at ca. 4 V highlighting the requirement of stabilising interfaces even when a solid-state electrolyte is used.Figure 1. Comparison of O2 and CO2 gas evolution from (a) Li6PS5Cl and (b) LiNi0.6Mn0.2Co0.2O2/ Li6PS5Cl composite when charged to 5 V vs. Li/Li+.[1] L. Zhou, N. Minafara, W. G. Zeier, L. F. Nazar, Innovative Approaches to Li-Argyrodite Solid Electrolytes for All-Solid-State Lithium Batteries, Acc. Chem. Res., 54, (2021) 2717–2728[2] Y. Zhou, C. Doerrer, J. Kasemchainan, P. G. Bruce, M. Pasta, L. J. Hardwick, Observation of Interfacial Degradation of Li6PS5Cl against Lithium Metal and LiCoO2 via In Situ Electrochemical Raman Microscopy, Batter. & Supercaps, 3, (2020) 647 –652[3] F. Walther, R. Koerver, T. Fuchs, S. Ohno, J. Sann, M. Rohnke, W. G. Zeier, J. Janek, Visualization of the Interfacial Decomposition of Composite Cathodes in Argyrodite-Based All-Solid-State Batteries Using Time-of-Flight Secondary-Ion Mass Spectrometry, Chem. Mater, 31, (2019), 3745-3755[4]S. Sharifi-Asl, J. Lu, K. Amine, R. Shahbazian-Yassar, Oxygen Release Degradation in Li-Ion Battery Cathode Materials: Mechanisms and Mitigating Approaches, Adv. Energy Mater., 9, (2019) 1900551[5] H. Kim, A. Choi, S. W. Doo, J. Lim, Y. Kim, K. T. Lee, Role of Na+ in the cation disorder of [Li1-xNax] NiO2 as a cathode for lithium-ion batteries, J. Electrochem. Soc., 165, (2018), A201 Figure 1

Microstructure Characterization of Catalysis Layers during Ink Drying Process for Polymer Electrolyte Membrane Fuel Cells

A catalyst ink for proton exchange membrane fuel cells (PEMFCs) is generally prepared by various mixing methods by dispersing platinum or platinum alloy nanoparticles supported on carbon blacks with ionomers in a specific solvent or solvent combination. The catalyst ink is deposited on the surface of the membrane or diffusion media and is typically subjected to elevated temperatures to facilitate rapid removal of solvent. Large carbon agglomerates resulting from sub-optimal ink dispersion and drying conditions can limit catalyst utilization, inhibit mass transport in the catalyst layer, and damage the membrane and possibly also the gas diffusion media [1, 2]. Micro-structural evolution of the catalyst ink can be controlled by interactions of the ionomer in the catalyst-ionomer ink and by the effect of ink solvent composition on those interactions during the ink drying process. This presentation will describe the results of in-situ/ex-situ X-ray scattering studies of the evolution of the cathode catalyst layer during the ink drying process to determine the impact of solvent removal rates and solvent identity on the structural evolution of the cathode catalyst layer. These studies also included operando ink drying at room temperature, under an atmosphere containing the solvent, and a high temperature. Ultra-small angle X-ray scattering (USAXS) was used to measure the agglomerate size distribution during the ink drying. A small environmental chamber was used to examine drying phenomena of high solid-content inks and dispersions to determine structural evolution during ink drying. The effects of ionomer concentration, catalyst concentration, and solvent composition on the microstructure of the catalyst inks and electrode are correlated with the MEA performance and operando diagnostic data. The goal of these studies is to guide the MEA fabrication process to optimize MEA performance and durability.

Hierarchical 3D Printed Porous Silicones with Porosity Derived from Printed Architecture and Silicone-Shell Microballoons

A method is reported to prepare siloxane microballoons that can be loaded into a direct ink write siloxane ink for 3D printing. The resulting structure is subjected to a solvent removal and supercritical drying process to provide a final printed siloxane having both macroscopic and microscopic porosity. Core-shell particles are generated by an emulsion template and phase separation process. Intra-strand closed-cell porosities can be achieved between 10 and 40 vol% thus facilitating additional compressive strain before lockup. Short term compression set testing highlights the excellent shape retention properties of these elastomers, which have less than 8% relative compression set under load.

Carbonated 3D-Printable Polymer Composite for Thermo-Mechanically Stable Applications

In this report, we investigate the infusion of carbon dioxide into a 3D-printable photosensitive polymer. The result is a carbonated polymer composite material. In use, polymer composite materials expect to succeed where ordinary polymers and metals fail. This is due to the tailorability of composite materials for specific applications. Usually, micro/nano-particulates are embedded as fillers within a polymer matrix, enhancing the overall material properties. Here, carbon dioxide (CO2) microbubbles serve as the filler within a nylon-like polymer matrix. Additive manufacturing by stereolithography (SLA) of the carbonated polymer composite proved possible using the digital light projection (DLP) 3D printing technique. Post-heat treatment using thermogravimetric analysis of the samples at elevated temperatures resulted in a 33% mass reduction, indicative of nearly complete solvent removal and curing. An initial increase in polymer carbonation duration showed a 16% increase in porosity, more stable thermal profiles, and a 40% decrease in specific heat capacity. Thermo-mechanical compressive tests on an optimal carbonated sample revealed a 70% increase in compressive strength over its neat counterpart and a peak modulus at 50 °C of 60 MPa. Such 3D-printable carbonated polymer composites may find use in applications requiring high strength-to-weight ratio thermally stable polymers and applications requiring a versatile and convenient storage medium for on-demand CO2 deposition or supercritical fluid phase transformation.

Efficient aqueous remote loading of peptides in poly(lactic-co-glycolic acid).

Poly(lactic-co-glycolic acid) (PLGA) long-acting release depots are effective for extending the duration of action of peptide drugs. We describe efficient organic-solvent-free remote encapsulation based on the capacity of common uncapped PLGA to bind and absorb into the polymer phase net positively charged peptides from aqueous solution after short exposure at modest temperature. Leuprolide encapsulated by this approach in low-molecular-weight PLGA 75/25 microspheres slowly and continuously released peptide for over 56 days in vitro and suppressed testosterone production in rats in an equivalent manner as the 1-month Lupron Depot®. The technique is generalizable to encapsulate a number of net cationic peptides of various size, including octreotide, with competitive loading and encapsulation efficiencies to traditional methods. In certain cases, in vitro and in vivo performance of remote-loaded PLGA microspheres exceeded that relative to marketed products. Remote absorption encapsulation further removes the need for a critical organic solvent removal step after encapsulation, allowing for simple and cost-effective sterilization of the drug-free microspheres before encapsulation of the peptide.

Zirconium diboride assisted superhydrophobic/superoleophilic surface modification of polyurethane sponge for continuous oil-water separation and emulsion purification

BackgroundWith rapid industrialization, water pollution by accidental oil spills and industrial wastes dumping into water bodies has become a severe threat to the marine ecosystem. In this regard, usage of superhydrophobic/superoleophilic sorbent is forecasted perhaps one of the best solution to recover oil and natural solvents from contaminated water owing to its high absorption capacity, and recyclability. MethodsHerein, we report zirconium diboride modified polyurethane sponge (ZrB2@PUS) prepared by facile dip coating technique at ambient condition for selective oil/water removal. The ZrB2@PUS was further functionalized using octadecyl trichlorosilane (OTS) in presence of toluene to impart superhydrophobicity. Significant findingsMicrostructural analysis revealed that ZrB2 platelets anchored onto smooth struts of PUS thereby increasing surface roughness, whereas, OTS helps in decreasing the surface tension and enhancing the non-wettability. The ZrB2@PUS exhibited a contact angle ∼166° and ∼0° for a sessile water and oil droplet, respectively. Moreover, ZrB2@PUS was found suitable for removal of various oil and organic solvents from oil-water mixture with absorption capacity reaching ∼83–129 g/g and capacity retention ∼92–97% after 20 cycles in static and dynamic conditions. OTS-functionalized ZrB2@PUS also successfully explored for separating SDS stabilized diesel-in-water and toluene-in-water emulsion, demonstrating feasibility for wastewater treatment containing oil and organic solvents.

Reclaimed Asphalt Pavement Binder Extraction and Recovery Evaluation and Their Effects on the Recycling Agent Assessment

The use of reclaimed asphalt pavement (RAP) has proved to be an advantageous alternative for the restoration and construction of new roads, with regard to the economical and environmental performance of the recycled material. However, one of the concerns about the use of RAP in the production of new asphalt mixtures is related to its inherent variability, manifested mainly in the asphalt binder. Some procedures to recover the aged binder are commonly used, such as extraction with solvents and recovery applying distillation techniques. These methods might change the intrinsic properties of the asphalt binder (e.g., rheological and chemical characteristics), which may lead to flaws in the dose of the recycling agent. The present study evaluated the variability of the techniques of asphalt binder extraction-recovery from a RAP source, and its effects on the final assessment of binder blend between RAP binder and a softer binder for recycled hot mix asphalt. The results show that automated extraction provided statistically satisfactory values for determination of the RAP binder content. The recovery method conditions, however, were not efficient with regard to solvent removal for 40% of the analyzed RAP samples. Pearson’s coefficients indicated a weak correlation between RAP binder aging indices and its rheological behavior, probably because of the presence of solvent. Tetrachlorethylene (TCE) spectrum band at wavelengths of 903 to 915 cm−1 tends to affect binder stiffness more than wavelengths of 771 to 783 cm−1, underestimating high temperature continuous performance grade ([Formula: see text]) and consequently the binder blend results.

Supercritical Carbon Dioxide Extraction of Vegetable Oils: Retrospective and Prospects

AbstractSupercritical carbon dioxide (SC‐CO2) extraction is projected as one of the most viable alternatives to conventional hexane extraction due to its density‐dependent solvent power, low viscosity, moderately high diffusion coefficient, and low‐temperature operative conditions. Demands for retention of bioactive compounds in oils like wheat germ oil, rice bran oil, almond oil, etc., are increasing and that can be easily met up by this alternative solvent. Solvent extraction of oils rich in polyunsaturated fatty acid, like flaxseed oil, microbial oil, etc., is highly sensitive. Prolonged heating during removal of solvent often leads to degradation of essential fatty acids. As the phase change is done by changing the pressure, the use of SC‐CO2 overcomes such issues. It is quite evident that degumming, one of the processing steps in refining of vegetable oils, will not be required if SC‐CO2 is used for extraction. Moreover, in some other cases, bioactive compounds will be retained in the de‐fatted meal and can be recovered with better purity. All these factors will add to the overall economy. A detailed review of the application of SC‐CO2 for the extraction of vegetable oils—the initial reports, current status, and future prospectsis presented in this paper.Practical applications: In recent years, the oils and fats industry has gone through several technological advancements and the most important of them was shifting to physical refining process from highly polluting chemical process. The industry may see another major change in the extraction process in the near future. Hexane has been enlisted as a hazardous air pollutant as per the Clean Air Act, 1990. Recent reports show that hexane may have some role even in ozone layer depletion. Scientists are looking forward to alternatives. SC‐CO2 has emerged as one of the most suitable alternatives. The large capital investment required for the installation of SC‐CO2‐based extraction plants was a major drawback. However, ready availability of critical machineries and advancements in terms of automation has brought down the capital expenditure significantly. The utilization of superior quality by‐products generated by the process of SC‐CO2 extraction may be an added advantage for the overall economy of the process.

Light Scattering of Electrospinning Jet with Internal Structures by Flow-Induced Phase Separation.

Herein, the direct morphological evidence of the extension-induced phase-separated structures in the electrospinning jet observed by high-speed video imaging and by light scattering technique is reported. Model solutions of poly(vinyl alcohol) (PVA)/water are electrospun. Two types of internal structures, that is, long strings and short ellipsoids, are found. A light scattering model is derived for the Vv scattering configuration to account for the scattered intensities contributed from the liquid jet itself and those from the internal structures. For the severely stretching jet of PVA/water, the Vv intensity profile is dominant by the internal structures to mask the scattering contribution from the jet itself. Moreover, the Hv intensity profile reflects the anisotropy of the oriented chains parallel to the jet axis. For the 7 wt% solution, the derived extension rate in the vicinity of the Taylor cone apex is about 3420 s-1 , which is higher than the Rouse relaxation rate measured by rheometer. It is concluded that extension-induced phase separation of the single-phase PVA solution is likely to occur in Taylor-cone apex to trigger the self-assembly process for producing strings (and/or bulges) in the flowing jet, which eventually transform to become the nanofibers, after solvent removal, to be collected on the grounded collector.

Kinetics of CO2 gas bubbling for the separation of residual solvent from waste solids: Effects of bubble size

Solvent loss in the residual solids has been considered as a major challenge during the solvent extraction processes of unconventional oil ores (oil sands, asphalt rocks, etc.) or similar liquid-solid extraction. Meanwhile, the residual solvent in the solvent-extracted solids also causes serious environmental problems. The gas (CO2) bubbling process is proved to be an effective method for the removal and recovery of residual solvents from solvent-extracted solids. Herein, the kinetic model of the solvent removal by the gas bubbling has been built after considering the bubbling process as quasi vapor-liquid equilibrium. It is found that the solvent removal by gas bubbling matches well with the first-order kinetic model. Based on the fitting of gas bubbling experimental data under different water volumes, the quasi Henry’s constant and separation rate constant were obtained. At this time, all the related parameters of gas bubbling kinetic model were determined. Then the effect of bubble size on the gas bubbling kinetics was systematically analyzed, a potential strengthening method of connecting micro-nano bubbles and large bubbles is proposed for improving the solvent removal from the residual solids. Finally, the molecular dynamic (MD) simulation and gas bubbling experiments combined with large bubbles and micro-nano bubbles prove micro-nano could well accelerate the solvent removal in the residual solids. This work provides the fundamental basis for the industrialization of the gas bubbling process for the solvent removal from residual solids, which also provides a new idea for the treatment of environmental problems, such as the treatment of solvent-containing waste solids.

Glassy-like Metal Oxide Particles Embedded on Micrometer Thicker Alginate Films as Promising Wound Healing Nanomaterials.

Micrometer-thicker, biologically responsive nanocomposite films were prepared starting from alginate-metal alkoxide colloidal solution followed by sol-gel chemistry and solvent removal through evaporation-induced assembly. The disclosed approach is straightforward and highly versatile, allowing the entrapment and growth of a set of glassy-like metal oxide within the network of alginate and their shaping as crake-free transparent and flexible films. Immersing these films in aqueous medium triggers alginate solubilization, and affords water-soluble metal oxides wrapped in a biocompatible carbohydrate framework. Biological activity of the nano-composites films was also studied including their hemolytic activity, methemoglobin, prothrombin, and thrombine time. The effect of the films on fibroblasts and keratinocytes of human skin was also investigated with a special emphasis on the role played by the incorporated metal oxide. This comparative study sheds light on the crucial biological response of the ceramic phase embedded inside of the films, with titanium dioxide being the most promising for wound healing purposes.

Zirconium Metal-Organic Cages: Synthesis and Applications.

ConspectusFor the last two decades, materials scientists have contributed to a growing library of porous crystalline materials. These synthetic materials are typically extended networks, including metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), or discrete materials like metal-organic cages (MOCs) and porous organic cages (POCs). Advanced porous materials have shown promise for various applications due to their modular nature and structural tunability. MOCs have recently garnered attention because of their molecularity that bestows them with many unique possibilities (e.g., solution-processability, structural diversity, and postsynthetic processability).MOCs are discrete molecular assemblies of organic ligands coordinated with either metal cations or metal oxide clusters of different nuclearities, resulting in architectures with inherent porosity. Notably, the molecular nature of MOCs endows them with easy solution-processability unattainable with traditional framework materials. To date, a number of stable MOCs have been reported, such as those based on Rh (Rh-O bond energy: 405 ± 42 kJ/mol), Fe (Fe-O bond energy: 407.0 ± 1.0 kJ/mol), Cr (Cr-O bond energy: 461 ± 8.7 kJ/mol), Ti (Ti-O bond energy: 666.5 ± 5.6 kJ/mol), and Zr (Zr-O bond energy: 766.1 ± 10.6 kJ/mol). Paddle-wheel MOCs have also shown great stability in aqueous environments due to their rigid backbones. The zirconium MOC (Zr-MOCs) family emerges as a class of very robust cages for which their high bond energy endows them with high hydrothermal stability.In 2013, we reported the first four zirconocene tetrahedrons assembled from trinuclear zirconium oxide clusters with ditopic or tritopic organic ligands. Since then, significant progress in the rational design of Zr-MOC has led to an assortment of structures dedicated to meaningful applications.In this Account, we highlight the recent progress in synthesizing Zr-MOCs and Zr-MOC-based higher dimensional frameworks and their applications dedicated in our laboratories and beyond. The general Zr-MOC synthetic strategy involves assembling Zr trinuclear clusters with organic ligands (rigid or flexible) containing various functional groups. This chemistry has afforded cages with structural versatility and active sites, e.g., amino groups, for postsynthetic modifications (PSMs). Since the extrinsic porosity of cage-based frameworks is relatively weak, the resulting frameworks are susceptible to structural rearrangement after solvent removal. To circumvent this limitation, increasing the hydrogen bond ratio and strength between interlinked cages and conducting in situ catalytic polymerizations have been reported to afford permanently porous structures amenable to host-guest reactions.To expand their potential applications, multifunctional Zr-MOCs are highly desired. Such multivariate MOCs can be attained by either employing the isoreticular expansion strategy to create MOCs with high surface areas or using mixed-ligand approaches to afford heterogeneous MOCs. In addition, amorphous MOCs, flexible organic ligands, new functionalities, and MOC-based extended networks are exciting new approaches to developing materials with structural versatility and enhanced characteristics. Thereby, we believe the stability and versatility of the Zr-MOC family hold great potential in expanding and addressing challenging applications.

LED-Based Photo-CIDNP Hyperpolarization Enables 19F MR Imaging and 19F NMR Spectroscopy of 3-Fluoro-DL-tyrosine at 0.6 T

Although 19F has high potential to serve as a background-free molecular marker in bioimaging, the molar amount of marker substance is often too small to enable 19F MR imaging or 19F NMR spectroscopy with a sufficiently high signal-to-noise ratio (SNR). Hyperpolarization methods such as parahydrogen-based hyperpolarization or dynamic nuclear polarization (DNP) can significantly improve the SNR, but require expensive and complex sample preparation and the removal of toxic catalysts and solvents. Therefore, we used the biologically compatible model of the fluorinated amino acid 3-Fluoro-DL-tyrosine with riboflavin 5ʹ-monophosphate (FMN) as a chromophore dissolved in D2O with 3.4% H2Odest., allowing to transform light energy into hyperpolarization of the 19F nucleus via photo-chemically induced dynamic nuclear polarization (photo-CIDNP). We used a low-cost high-power blue LED to illuminate the sample replacing traditionally used laser excitation, which is both potentially harmful and costly. For the first time, we present results of hyperpolarized 19F MRI and 19F NMR performed with a low-cost 0.6 T benchtop MRI system. The device allowed simultaneous dual-channel 1H/19F NMR. 19F imaging was performed with a (0.94 mm)2 in-plane resolution. This enabled the spatial resolution of different degrees of hyperpolarization within the sample. We estimated the photo-CIDNP-based 19F signal enhancement at 0.6 T to be approximately 465. FMN did not bleach out even after multiple excitations, so that the signal-to-noise ratio could be further improved by averaging hyperpolarized signals. The results show that the easy-to-use experimental setup has a high potential to serve as an efficient preclinical tool for hyperpolarization studies in bioimaging.

Time-Resolved SAXS Study of Polarity- and Surfactant-Controlled Superlattice Transformations of Oleate-Capped Nanocubes During Solvent Removal.

Structural transformations and lattice expansion of oleate-capped iron oxide nanocube superlattices are studied by time-resolved small-angle X-ray scattering (SAXS) during solvent removal. The combination of conductor-like screening model for real solvents (COSMO-RS) theory with computational fluid dynamics (CFD) modeling provides information on the solvent composition and polarity during droplet evaporation. Evaporation-driven poor-solvent enrichment in the presence of free oleic acid results in the formation of superlattices with a tilted face-centered cubic (fcc) structure when the polarity reaches its maximum. The tilted fcc lattice expands subsequently during the removal of the poor solvent and eventually transforms to a regular simple cubic (sc) lattice during the final evaporation stage when only free oleic acid remains. Comparative studies show that both the increase in polarity as the poor solvent is enriched and the presence of a sufficient amount of added oleic acid is required to promote the formation of structurally diverse superlattices with large domain sizes.

The Synthesis of Tris(silyl)silanides Revisited. A Study of Reactivity and Stability

AbstractIn this contribution, we investigated the stability of (H3Si)3SiLi (2a) in the presence of tetramethylethylenediamine (TMEDA) and 1,2‐bis(diphenylphosphino)ethane (DPPE). Moreover, the synthesis to obtain tris(silyl)silanides with alternated counter ions by the base mediated desilylation approach was described. Additionally, metal‐metal exchange reactions of 2 a with MgBr2, ZnCl2, HgCl2 were examined. Subsequently, we reacted 2 a with 1.0 and 0.5 equivalents of ZnCl2[TMEDA] and could obtain the isolable zinc substituted silanides 5 a,b. Finally, we reacted 2 a with equimolar amounts of [(MesNacnac)MgI(OEt2)] and [(DippNacnac)MgI(OEt2)] and found the selective transmetalation to the corresponding magnesium substituted silanides 6 a,b in good yields. Interestingly, for compounds 5 a,b and 6 a,b the removal of the reaction solvents did not induce a degradation. For compound 6 a crystals suitable for X‐ray analysis could be grown, which represents the first structural characterization of an isolable perhydrogenated hypersilanide.

Preparation and properties study of polylactic acid/bacterial cellulose composite scaffolds by solvent removal

Preparation and properties study of polylactic acid/bacterial cellulose composite scaffolds by solvent removal

Design of Superhydrophobic CoFe2O4 Solar Seawater Desalination Device and Its Application in Organic Solvent Removal.

Environmental pollution and clean water production are challenges to the development of human society. In this paper, devices consisting of a superhydrophobic Ni-CoFe2O4 foam layer (floating layer), a hydrophilic channel and a superhydrophilic Ni-CoFe2O4 foam layer (photothermal conversion layer) were designed. The light energy was converted into heat on the photothermal layer, for which the hydrophilic channel provided a small amount of water. The superhydrophobic layer ensured the floating and selective adsorption of organic solvents on the water surface, whose contact angle reached 157°, and the steam production rate reached 1.68 kg·m−2·h−1. Finally, the LSV curve demonstrated that the Ni-CoFe2O4 foam prepared had a minimum starting potential, achieving the multifunctionality of the Ni foam.

Fabrication of non-fluorinated superhydrophobic and flame retardant porous material for efficient oil/water separation

Oil spill clean-up is a difficult process, and it is important to keep the spill contained by minimizing risk and collateral harm to natural resources. While there has been tremendous research and practical applications for the removal of oil and organic solvent from water, there are still a lot of disadvantages, such as the fabrication process being quite difficult, relatively expensive, and causing secondary contamination. This study aimed to find a more effective and environmentally friendly material for oil/water separation. We prepared simple, cost-effective, and environmentally friendly superhydrophobic activated carbon from leather trimming waste at 400 °C (LAC-400). The prepared activated carbon shows excellent water contact angle of 152 ± 2°. Superhydrophobic property of activated carbon without any other modification has never been reported to the best of our knowledge. This was coated on a melamine sponge (LACMS-400), which shows a water contact angle 158 ± 2°, which is higher than the activated carbon. This superhydrophobic activated carbon coated melamine sponge (LACMS-400) was used for oil/water separations and it demonstrated excellent absorption capacity ranging from 75.77 ± 0.83–141.24 ± 1.46 times higher than its mass for various types of oil and organic solvents. The quick absorption ability of LACMS-400 was studied at various soaking times and it absorbs oil and organic solvents very quickly. In 10 s, it absorbed silicone oil 60 times higher than its mass. Thus, LACMS-400 is an efficient, low-cost, environmentally friendly, and ideal candidate for the removal of oil and organic solvents from water.

Development of a colloidal gold immunochromatographic strip for the rapid detection of pefloxacin in grass carp with a novel pretreatment method

A rapid colloidal gold immunochromatography assay (GICA) for the detection of pefloxacin (PEF) was established and optimized. The anti-PEF monoclonal antibody (mAb) was used to target PEF as a colloidal gold-mAb conjugate. The mAb belonged to the IgG2b subtype, lambda light chain, the affinity constant (Ka) was 5.21 × 109 L·mol−1, and its half maximal inhibitory concentration (IC50) was 0.23 ng·mL−1. No obvious cross-reactivity (CR) was observed with other common fluoroquinolone antibiotics, including ciprofloxacin (CIP), norfloxacin (NOR), lomefloxacin (LOM) and ofloxacin (OFL). The visual limit of detection (vLOD) of the optimized GICA was 2 ng·g−1 under the conventional pretreatment method, and the assay was completed in 15 min. Liquid chromatography tandem-mass spectrometry (LC–MS/MS) was employed to confirm the performance of the strip. In addition, a novel pretreatment was established and compared with conventional pretreatment. Without the removal of organic solvents, the novel pretreatment method reduced the sample pretreatment time (more than 10 min). The vLOD of the optimized GICA was also 2 ng·g−1 when applying the novel pretreatment method. In conclusion, the proposed PEF-GICA could detect samples containing PEF rapidly and accurately, and the novel pretreatment method saved the time of sample pretreatment and improved the efficiency of detection.

Characterization of the integrated gas stripping-condensation process for organic solvent removal from model acetone-butanol-ethanol aqueous solution

During ABE fermentation, the bacterial toxicity of produced solvents, especially butanol at a high concentration, can cause low butanol productivity. This study aimed to characterize an integrated gas stripping and novel ABE recovery system using two-stage condensation equipped with an absorption unit for butanol recovery from the model ABE aqueous solution. The potential off-gas from ABE fermentation had 20–60% H2 balanced with CO2, along with low-cost inert N2 as stripping gas mix, at the volume of gas per volume of liquid per minute (vvm) set at 0.5, 1.0, and 1.5. The results showed that butanol was the most selective in the stripping, followed by acetone, ethanol, butyric, and acetic. The trend of stripping rate was opposite to the trend of condensation efficiency. Using 1.5 vvm nitrogen could achieve the highest stripping efficiency with butanol removal rate of 1.48 g/L·h, while the highest condensation efficiency of stripped ABE was obtained by using 20% H2 in gas mix at 0.5 vvm. The recovered butanol in condensate had high concentrations of 80–170 g/L. According to the results obtained, the integrated stripping process has potential to reduce butanol in fermentation broth and produce concentrated butanol in condensate that can be further purified at reduced energy cost.