Styrene-divinylbenzene Copolymer Research Articles

#2799 Myoglobin removal by hemadsorption: ex-vivo adsorption kinetics

Abstract Background and Aims Myoglobin, due to its molecular weight of 17 kDa and a Einstein-Stoke radius greater than expected, is classed as a middle molecular weight uremic toxin and presents a two-compartment model of distribution in the body. Rhabdomyolysis is a condition in which muscle cell content including myoglobin, are released into blood circulation due to severe injury to the muscle. Circulating myoglobin induces renal injury with several mechanisms: reduced concentration of nitric oxide in medullary renal arterioles, production of free radicals with oxidative stress, tubular necrosis as a consequence of tubular obstruction by myoglobin and cellular debris. A possible therapeutic option is the use of High Cut-off membranes but with the risk of significant loss of albumin and other proteins. The use of adsorption can overcome these limitations. The aim of our study is to assess the adsorption of myoglobin with neutral microporous styrene-divinylbenzene copolymer sorbent (e.g., HA330/380, Jafron Biomedical CO, Lts, Zhuhai City, China). Method Using a downscaled module of HA380 Cartridge, we set up an ex-vivo circulation experiment in which 1 liter of plasma containing 0.1 mg of myoglobin was pumped through the cartridge. We collected samples (3 mL) at different timepoints to measure Myoglobin concentration. We calculated the removal ratio (RR) and mass adsorbed at a given timepoints. Results Initial myoglobin concentration was 99.3 ng/ml. Final myoglobin concentration after 4 hours of experiment was 30.6 ng/ml. Removal Ratio at 4 hour was 69 % and mass adsorption of 0.068 mg of myoglobin. Conclusion To our knowledge, this is the first experiment that assessed the adsorption capacity of polystyrene-divinylbenzene sorbent. Our study, demonstrated high adsorption capacity in the first 4 hours of treatment therefore, confirming the possibility to use adsorption as an effective treatment option in rhabdomyolysis and avoiding complications associated to current dialytic treatment.

Superhydrophobic/ superoleophilic polystyrene-based porous material with superelasticity for highly efficient and continuous oil/water separation in harsh environments

Three-dimensional separation materials with robust physical/chemical stability have great demand for effective and continuous separation of immiscible oil/water mixtures and water-in-oil emulsions, resulting from chemical leakages and discharge of industrial oily wastewaters. Herein, a superelastic polystyrene-based porous material with superhydrophobicity/superoleophilicity was designed and prepared by high internal phase emulsion polymerization to meet the aforementioned requirements. A flexible and hydrophobic aminopropyl terminated polydimethylsiloxane (NH2-PDMS-NH2) segment was introduced into the rigid styrene-divinylbenzene copolymer through 1, 4-conjugate addition reaction with trimethylolpropane triacrylate. The addition of NH2-PDMS-NH2 simultaneously improved the mechanical and hydrophobic properties of the porous material (the water contact angle from 141.2° to 152.2°). The material exhibited outstanding reversible compressibility (80% strain, even in liquid N2 environments) and superhydrophobic stability, even after being repeatedly compressed 100 times, water contact angle still remained above 150°. Meanwhile, the as-prepared material had outstanding hydrophobic stability in corrosive solutions (strong acidic, alkaline, high-salty, and even strong polar solvent), presence of mechanical interference, strong UV radiations, and high/low temperature environments. More importantly, the material could continuously and efficiently separate immiscible oil/water mixture and water-in-oil emulsions under the above conditions, showing huge potential for the large-scale remediation of complex oily wastewaters.

Separation of rhenium(VII) from nuclear wastewater using N-methyl-glucosamine functionalized exchange resin

Selective separation of 99TcO4− from nuclear wastewater can reduce discharge of 99Tc into the environment, reducing the threat to human health. However, it presents a huge challenge due to the extreme conditions combining strong alkalis, high ionic strength and strong radiation. Here, we describe an effective adsorbent prepared by anchoring N-methyl-glucosamine on styrene-divinylbenzene copolymer spheres (N-resins). N-resins retains their original properties and exhibits excellent stability in highly alkaline solutions with β radiation. Its adsorption of 99TcO4− was investigated in a non-radioactive experiment using ReO4− as an analogue for 99TcO4−. Adsorption was considered as a function of alkali solution concentration, contact time and initial concentration, and in the presence of competing anions. Results demonstrate that N-resins presents a remarkable ability to remove ReO4− from alkaline conditions. The high adsorption capacity and fast kinetics are attributed to the abundant active groups including -OH and -NH on the N resin surface. Notably, N-resins can selectively remove ReO4− from mixed solutions with high concentrations of other anions, even with a molar ratio of NO3− to ReO4−of 10,000. Moreover, N-resins can be regenerated at least 6 times without significant reduction in ReO4− adsorption, indicating that N-resins has good durability. Its excellent properties suggest it to be a promising highly effective low-cost adsorbent for removal of 99TcO4− from alkaline wastewater.

Adsorption Removal Characteristics of Hazardous Metalloids (Antimony and Arsenic) According to Their Ionic Properties

Antimony and arsenic, which have a high carcinogenicity, should be removed depending on their ionic charge in water. Therefore, we attempted to confirm the adsorption characteristics of antimony and arsenic considering ionic charge to improve removal efficiency. We used palm-based activated carbon (PAC), coal-based activated carbon (CAC), modified activated carbon (MAC), styrene-divinylbenzene copolymer (SP825), activated alumina (AA), and zeolite as adsorbents for antimony and arsenic. Negatively charged adsorbents (CAC, PAC, MAC, and zeolite) with similar zeta potentials showed better removal efficiency as the surface area increased. However, SP825, which is almost neutral, and AA, which is positively charged, exhibited a high removal efficiency (100%) for arsenic and Sb(V), which are anions, regardless of surface area. However, due to the price, coal-based activated carbon or palm-based activated carbon is considered more advantageous than using AA or SP825. Last, during the arsenic adsorption process, As(III) was oxidized to As(V) due to Fe(II) contained in activated carbon. The addition of activated carbon can improve oxidation efficiencies of As(III) before coagulation and precipitation, in which As(V) is easier to remove than As(III).

Reaction of Partially Methylated Polygalacturonic Acid with Iron(III) Chloride and Characterization of a New Mixed Chloride-Polygalacturonate Complex.

We have described a new route for the preparation of partially methylated polygalacturonic acid containing hydrolyzed (acidic) and unhydrolyzed (methyl esterified) carboxylate groups in a ratio of 1:1 (PGA, compound 1), and one of its basic FeIII-salts (compound 2) with a ~1:2 FeIII:GA stoichiometry (GA means galacturonic acid and methylated galacturonic acid units). The partially hydrolyzed pectin was transformed into compound 1 with the use of double ion exchange with a strongly acidic macroreticular sulfonated styrene-divinylbenzene copolymer as a hydrogen ion source. The reaction of compound 1 with FeCl3 resulted in compound 2. Compound 2 has a polymeric nature and contains binuclear FeIII(µ-O)(µ-OH)FeIII core units with two kinds of distorted octahedral iron geometries. The salt-forming acidic and methylated GA units of compound 1 are coordinated to FeIII centers in asymmetric bidentate-chelating and -bridging (via C=O group and glycosidic oxygen) modes, respectively. Two kinds of outer-sphere chloride anions were also detected by XPS in various chemical environments fixed by different sets of hydrogen bonds. We also observed a partial reduction of FeIII into FeII due to the ring-opening of the chain-end GA units of compound 1. This reaction provides a new route to determine the number of chain-ends in compound 2, and with the use of the number of GA units calculated from charge neutrality, the average length of these chains and the average molecular weight were also determined. The average molecular weight of the partially methylated polygalacturonic acid used in the industrial-scale production of commercial anti-anemic iron-polygalacturonate agents was ~50,000 g/mol. Compound 2 was also characterized by IR, Mössbauer, and X-ray photoelectron spectroscopy, and magnetic susceptibility measurements. These results on the structure and average molecular weight of basic iron(III) polygalacturonate provide a tool to design Fe-PGA complexes with tuned iron-releasing properties.

Fabrication of PS-DVB@Cu core-shell microsphere for anisotropic conductive adhesives by electroless plating with copper nanoparticles as seeds

Polymer@metal core-shell microspheres are widely used in anisotropic conductive adhesives (ACAs). Styrene-divinylbenzene copolymer (PS-DVB) copper core-shell microspheres (PS-DVB@Cu) with high conductivity and anti-oxidation performance were successfully prepared by combining copper nanoparticles (Cu NPs) and electroless plating copper. The Cu NPs served as catalytic seeds, substituting noble metals to promote electroless deposition. Using environmentally benign ammonia borane as the reductant to replace toxic formaldehyde, the dense copper film was deposited on the surface of PS-DVB microspheres. The thickness of the Cu layer and bulk electrical resistivity of PS-DVB@Cu were tuned by controlling the concentration of the reducing agent. The minimum resistivity of PS-DVB@Cu was 3.27×10−6 Ω·m and merely slightly changed in the air for two months. The prepared PS-DVB@Cu-based ACAs could be effectively applied to anisotropic conductive connections in small-scale circuits with satisfactory anisotropic conductivity.

Optimal design of a simulated-moving-bed separation process for economical production of xylitol from bamboo-hydrolysis byproducts

Xylitol, which is one of industrially useful sugar-alcohols, has received constant attention from various industries. For the eco-friendly and economical production of xylitol, the byproducts from bamboo hydrolysis treatments for bioethanol-production purposes can be utilized as the source for xylitol. Since such bamboo-hydrolysis byproducts were reported to consist of several polyols such as xylitol, xylose, and glycerol, one essential requirement for ensuring a large-scale production of xylitol will be to secure a highly-efficient process for separation of xylitol from the above-mentioned polyol mixture. To address this issue, we aimed to establish an optimal simulated-moving-bed (SMB) process that can accomplish the xylitol-separation task of interest in a continuous mode while maintaining the best performances. It was found first that the use of an ion-exchange resin of styrene–divinylbenzene copolymer in lanthanum form at 60 °C was most suitable as the adsorbent conditions of the xylitol-separation SMB. Under such adsorbent conditions, the intrinsic parameters of the polyol mixture components were determined and then applied to the optimization of the xylitol-separation SMB with a standard type of configuration (2–2–2–2), which was carried out based on the standing wave design method. It was confirmed that the optimized process was successful in keeping the front and rear of each solute band within their corresponding zones under the maximized degree of adsorbent utilization, which suggested that the yield of xylitol and the removal rates of non-products could be maintained at sufficiently high levels while maximizing the SMB throughput. Further comprehensive optimizations revealed that compared to the standard configuration-based SMB, the 5–2–7–2 configuration-based SMB can more than double the xylitol product concentration as well as almost halve the desorbent usage, while maintaining the same throughput and separation capability.

Vancomycin and Gentamicin Removal with the HA380 Cartridge during Experimental Hemoadsorption

Introduction: Hemoadsorption has emerged as an adjunctive therapy for sepsis, but its impact on antibiotic levels remains poorly defined. We conducted an in vivo experimental study to investigate the removal of vancomycin and gentamicin during hemoadsorption using the HA380 cartridge, a novel styrene-divinylbenzene copolymer cartridge. Methods: Six surgically prepared sheep were administered 2 g of vancomycin and 400 mg of gentamicin over 30 min, followed by a continuous infusion of vancomycin (20 mg/h). Hemoadsorption was implemented with a styrene-divinylbenzene copolymer HA380 cartridge at a blood flow of 120 mL/min. The removal ratio, sorbent-based clearance, and the mass removal rate were calculated for each time point. Results: The mean 10-min vancomycin removal ratio exceeded 90% and declined to 68.0% at 30 min; 52.8% at 60 min, and 28.0% by 4 h. Due to constant plasma flow, clearance varied proportionally with the removal ratio. Over 4 hours, the total mass removal was 556 mg (SD 106.3). For gentamicin, the mean 10-min removal ratio was 96.9% and the final ratio at 4 h remained 53.0%, with clearances changing proportionately. The total mass removal of gentamicin was 138 mg (SD 26.6) over 4 h. The sorbent-based clearance of vancomycin was significantly lower than that of gentamicin (P_group < 0.0001). Conclusion: The novel HA380 sorbent cartridge appears safe and achieves significant vancomycin and gentamicin removal over a four-hour period. This information can be used by clinicians to guide their prescription and consider the additional dosing of at least an extra 25–35% amount in patients receiving HA380 hemoadsorption therapy during sepsis.

Tuning the porosity of hypercrosslinked styrene-divinylbenzene copolymers for efficient adsorption of rifampicin from aqueous media

Tuning the porosity of hypercrosslinked styrene-divinylbenzene copolymers for efficient adsorption of rifampicin from aqueous media

Ultrastable emissive perovskite nanocomposite via dual protection of polymer-grafted TS-1 zeolite for backlight display application

Instability of all-inorganic perovskite quantum dots (PQDs) driven by the inherent ionic nature poses a grand challenge towards their long-term stability in optoelectronic devices. Herein, we report the crafting of a highly stable dual-protected CsPbBr3 perovskite nanocomposite by capitalizing on the encapsulation of a hydrophobic Styrene-Divinylbenzene (St-Dvb) copolymer grafted hierarchical titanium silicalite-1 (TS-1) zeolite shell. Firstly, an optimal hot injection method was used to accommodate CsPbBr3 PQDs into hierarchical TS-1 zeolite. After the modification of terminated Si-OH groups on the surface of TS-1 by phenyltriethoxysilane (PTES), a subsequent polymerization of St and Dvb was implemented using azobisisobutyronitrile (AIBN) as initiator to result in the highly emissive CsPbBr3-TS@St-Dvb nanocomposite, exhibiting outstanding luminescent stability against heat, polar solvents, and UV light irradiation. The as-prepared CsPbBr3-TS@St-Dvb nanocomposite also showed strongly suppressed anion exchange and high compatibility in polymer matrix, enabling improved applicability for versatile lighting and optical display applications. Ultimately, a white light-emitting diode (WLED) composed of green-emitting CsPbBr3-TS@St-Dvb and red-emitting K2SiF6:Mn4+ phosphor onto a commercial blue InGaN LED chip with wide color gamut and excellent stability is demonstrated. This work highlights a judiciously-designed and hard-soft dual-protected strategy to produce ultrastable perovskite nanomaterials with high brightness and durability for backlight display application.

Carbonization of Zr-Loaded Thiourea-Functionalized Styrene-Divinylbenzene Copolymers: An Easy Way to Synthesize Nano-ZrO2@C and Nano-(ZrC, ZrO2)@C Composites

Thermal processing of Zr-loaded ion-exchangers is a facile route to synthetize (ZrO2, ZrC)@C composites. In the present paper, furnace and RF-thermal plasma processing of ZrOCl2 loaded thiourea-functionalized styrene-divinylbenzene copolymer was investigated and led to composites containing ZrO2 and ZrC. Different ZrO2@C composites were formed between 1000 and 1400 °C in 2 h, whereas the composite containing ZrC was created at 1400 °C in 8 h. The ratio of ZrO2/ZrC, the prevailing ZrO2 modifications, and the crystallite sizes strongly depend on the synthesis conditions. The ZrC-containing composites formed only at 1400 °C in 8 h and by the plasma treatment of the ZrO2@C sample prepared in the furnace, resulting in 8 and 16% ZrC content, with 44 and 41 nm ZrC crystallite sizes, respectively. The ZrO2-containing composites (tetragonal, monoclinic, and cubic modifications with 65–88 nm ZrO2 crystallite sizes and 15–43 m2/g BET surface areas) formed in a tube furnace between 1000 and 1400 °C in 2 h. All ZrO2@C composites had both amorphous carbon and graphite, and their ratio is temperature dependent. The carbonaceous compounds were characterized by Raman spectroscopy with analysis of the G and D band intensities. XPS studies showed the surface oxidation of ZrC.

Enhancing solar photothermal conversion and energy storage with titanium carbide (Ti3C2) MXene nanosheets in phase-change microcapsules

We propose to enhance photothermal conversion via doping titanium carbide (Ti3C2) MXene nanosheets on the surfaces of phase-change microcapsules consisted of the n-Octadecane core and styrene divinylbenzene copolymer shell. Detected by scanning electron microscopy, the microcapsules showed a usually circular form with an appropriate dispersion. The thermal properties of the microcapsules were characterized using the differential scanning calorimetry and thermal conductivity instruments, realizing an excellent phase-change enthalpy of around 140 J/g, high encapsulation ratio of over 64 %, good heat transfer of 0.294 ± 0.003 W/(m·K), and great thermal reliability. More importantly, the microcapsules doped with Ti3C2 MXene nanosheets reach a solar-to-heat conversion efficiency of 85 ± 7 %, a substantial enhancement by 240 % in comparison with non-doping sample. The Ti3C2 MXene-doped microcapsules with excellent heat storage and solar-to-heat conversion capabilities offer great potential for high-efficiency solar energy utilization and can be applied to thermal energy storage systems and direct absorption solar collectors.

Construction of phase change n-Octadecane microencapsulated in carbon nanotubes-modified polymer for thermal management applications of finned heat sinks

The low thermal conductivity of organic shell-based phase change microcapsules severely limits their practical applications in thermal management of high-power-density electronic components. A novel microencapsulated phase change material (MPCM) was synthesized via suspension polymerization with n-Octadecane core shelled by aminated multiwalled carbon nanotubes-doped styrene–divinylbenzene copolymer (SDB/MWCNT-NH2). The chemical structure and micromorphology of the new microcapsules (MPCM/CNT) with various amounts of doped aminated multiwalled carbon nanotubes (MWCNT-NH2) were identified by the Fourier transform infrared spectroscopy and scanning electron microscopy. The thermal properties of various MPCM/CNT samples were analyzed based on the measurements of thermogravimetric analyzer, differential scanning calorimeter and thermal conductivity meter. The results indicated that the microcapsules with MWCNT-NH2 had good thermal stability, heat storage capacity and heat transfer properties. The thermal performance of the microcapsule samples in the low and medium temperature finned heat sink (FHS) was investigated and their thermal performance with that of bare FHS at four constant thermal loads of 5 W, 7 W, 10 W and 15 W was compared. The thermal performance was evaluated based on the time to setpoint temperature, heat dissipated and heat dissipation factors. Compared with the bare FHS, the FHS with the MPCM/CNT-2.5 sample (i.e., 2.5 wt% MWCNT-NH2) exhibited 17.70% longer operation time, 33.01% more heat dissipated, and 16.53% higher heat dissipation factor during heating at 10 W. This study aims to apply the phase change microcapsules modified with high thermal conductivity MWCNT-NH2 in medium and low temperature heat sinks to optimize the thermal management of high power density electronic components and improve the heat dissipation performance of heat sinks. The microcapsules with MWCNT-NH2 showed great potential for applications in thermal management of electronic components.

Study on molten salt oxidation process of simulated Co doped cation exchange resins

Cation exchange resins (CERs) are widely applied to purify waste liquids generated during the operation of nuclear reactors. The radioactive nuclides 60Co and 58Co are important corrosion activation products in reactor cooling water. In this study, the simulated Co doped CERs were oxidized with ternary carbonate. According to the thermogravimetric analysis (TG), the decomposition of Co doped CERs includes three processes: 1. Elimination of the osmotic water; 2. Pyrolysis of sulfonic acid group; 3. Destruction of styrene–divinylbenzene copolymer. The X-Ray Diffraction (XRD) patterns indicate that sulfur mainly exists in the form of sulfate in waste salt. The Co2+ undergoes the path of CoS2 → Co3O4 with the increase of temperature and the transition point is 650 °C. Combined with Fourier Transform Infrared Spectrometer (FT-IR) spectra and X-ray Photoelectron Spectroscopy (XPS) analysis, sulfonic acid groups begin to decompose at 350 °C. During the molten salt oxidation process, most of the sulfur in sulfonic acid groups is entrapped by carbonate as the form of sulfate, and a little of which remains as sulfone group, sulfoxide group and sulfur bridge in residue. When the resins are oxidized at 800 °C, the retention rate of Co2+ is 97.3%, indicating that the molten salt oxidation can effectively remain Co2+ and convert it into a more stable substance.

Phase change n-Octadecane microencapsulated in titanium dioxide nanoparticle-doped polymer for photothermal conversion and photocatalysis

We microencapsulated the n-Octadecane (ODE) with titanium dioxide (TiO2) nanoparticle-doped styrene–divinylbenzene copolymer (SDB) via the suspension polymerization. The TiO2 was grafted with 3-Glycidoxypropyltrimethoxysilane (KH560) to obtain amphiphilic properties in order to enhance their anchoring capability at the oil-aqueous interface. Emphasis is placed on analyzing how the TiO2 nanoparticles affect the multiple functions of the prepared microcapsules for heat storage, photothermal conversion, and photodegradation. Under scanning electron microscope, the microcapsules show generally spherical shapes with rough surface and good dispersibility. The thermophysical property of the microcapsules was examined via the differential scanning calorimetry and thermogravimetric analyzer. The microcapsules prepared with 4.0 wt% TiO2 had the highest thermal storage capacity with molten andcrystallized enthalpies of 105.3 ± 0.3 and 102.4 ± 0.7 J/g, respectively. The microcapsules with 4.0 wt% TiO2 achieved 48.0 ± 0.4% encapsulation. The doped-TiO2 nanoparticles improved the thermal stability of microcapsule samples. The initial decomposition temperature of the microcapsule sample with 4.0 wt% TiO2 is increased to 167.6 °C as compared to 115.1 °C for pure ODE. In the solar thermal conversion and photocatalytic tests, the microcapsule sample with 4.0 wt% TiO2 exhibited the best performance as well, with 42.80% photothermal conversion efficiency and 90.92% degradation rate. The multifunctional phase change microcapsules have broad application prospects as heat storage and depollution materials.

A combined strategy to enhance phytosterols biotransformation to 22-hydroxy-23,24-bisnorchol-4-ene-3-one by Mycobacterium neoaurum

A combined strategy for the overexpression of cholesterol oxidase M2 (ChoM2) and in situ removal of inhibitory intermediates was applied to promote the production efficiency of 22-hydroxy-23,24-bisnorchol-4-ene-3-one (HBC) from phytosterols (PS) biotransformation by Mycobacterium neoaurum (M. neoaurum). Firstly, the rate-limiting step of PS to phytostenones was overcome by increasing the activity of ChoM2. Under this condition, PS transformation period was reduced from 84 h to 72 h, and the productivity of HBC was increased by 17%, in g/L/d from 9.36 (84 h) to 10.92 (72 h). Meanwhile, the overexpressed ChoM2 caused an excessive accumulation of the inhibitory intermediates, phytostenones, which hindered PS biotransformation. Accordingly, in situ removal of the inhibitory intermediates through adding 5 g/L of resin D101 (a macroporous styrene-divinylbenzene copolymer resin) at the beginning of the biotransformation further reduced the PS transformation time to 60 h, and the productivity was increased by 41% from 9.36 to 13.21 g/L/d.

Size exclusion chromatography and stable carbon isotopes reveal the limitations of solid phase extraction with PPL to capture autochthonous DOM production

The study of the elemental and carbon isotopic composition of dissolved organic matter (DOM) is of great interest in deciphering the origin and transformations of organic matter in estuarine and coastal environments. Styrene-divinylbenzene copolymer (PPL) sorbent is currently the most commonly used material for the isolation of DOM from environmental samples. It is notably used for the development of molecular formula-based indices used to study DOM reactivity. However, any extraction procedure (including with PPL) will fractionate the DOM. If this fractionation is not well constrained it can lead to biased interpretations of the biogeochemical processes affecting DOM. In this work we investigate the fractionation effects of the PPL sorbent on the size class distribution of DOM and the carbon isotopic composition of the PPL retentate. The use of size exclusion chromatography, that does not require a pre-concentration step, allows a precise study of the fractionation of DOM (including aromaticity) by the PPL resin. Extractions performed on two types of humic substances dissolved in artificial seawater, using the PPL resin, showed high extraction yield (> 85%) and the stable isotopic carbon composition (δ13C) of these compounds was successfully recovered. These results indicate that salinity is not a parameter affecting extraction yield on PPL sorbent. For a hydrophilic compound (atropine) the extraction efficiency was low (33%) and δ13C signature was underestimated. Size exclusion chromatography measurements, in samples collected along a salinity gradient, demonstrate that the PPL sorbent strongly fractionates DOM. Although the DOM size class distributions in freshwaters and marine waters were initially different, their retentates were marked by similar size class distributions. This work demonstrates that PPL resin captures DOM compounds with less nitrogenous content and it seems to have a lower affinity for aromatic compounds of marine origin than of terrigenous origin. The study of DOM distribution in a macro-tidal estuary demonstrated the limitations of PPL resin extraction in capturing an internal N-rich DOM production event at the time of sampling. Futhermore, the isotopic composition of the PPL resin retentate appears to depend on the extraction efficiency of the more hydrophobic compounds which changed along the salinity gradient. This study recommends careful interpretations of data that only rely on PPL extractions, particularly for works tracking the origin of DOM in estuaries and comparing DOM composition across ocean biogeochemical domains.

Исследование новых макропористых катализаторов в процессе алкилирования фенола олигомерами этилена

The features of phenol alkylation by higher alpha-olefins in order to obtain mono-substituted alkylphenols (o-AF and p-AF) using commercial industrial samples of sulfocationites: Hydrolite ZG CD552, ND-102 and the line of catalysts Purolite CT275DR/4503, CT275DR/4883, CT151DR, CT169DR, which belong to macroporous and are in different price categories. A feature of these cationites is a particularly strong matrix of regularly cross-linked divinylbenzene styrene copolymer. The structure of the granules combines the increased rigidity of the polymer mesh with a highly developed surface of the pores for exchange, which provides a large concentration of available exchange groups and high diffusion permeability of the granules. A comparative analysis of the catalytic activity of alkylation catalysts was carried out, which showed that, despite the high activity of all the studied catalysts in the reaction of alkylation of phenol with ethylene oligomers (OE) of the C16-C18 fraction, most of the studied catalysts showed low thermal stability and showed a tendency to rapid mechanical destruction. During the research, optimal technological parameters for each catalyst were established, including temperature and molar ratio of reagents, providing maximum yields of the target monoalkylphenol at the level of 97-98 %.

The Early Use of Selective Hemoadsorption Based on a Hyper-Crosslinked Styrene-Divinylbenzene Copolymer in Patients with Toxic Rhabdomyolysis Complicated by Acute Kidney Injury (Multicenter Randomized Clinical Trial)

Rhabdomyolysis (RM) is a clinical and laboratory syndrome with the underlying destruction of myocytes and the release of intracellular debris into the systemic circulation. In more than 55% of cases, RM is complicated by acute kidney injury (AKI), which necessitates various methods of extracorporeal detoxification and currently is a controversial issue.Aim: to improve the results of treatment of patients with RM of toxic origin complicated by AKI by using early selective hemoadsorption (SH).Material and methods. The study included 36 patients divided into 2 groups. Group 1 included 24 patients who received standard therapy and hemodiafiltration (HDF) as a life-saving intervention. Group 2 comprised 12 patients who underwent early SH to prevent the progression of AKI. We performed a comparative analysis of clinical and laboratory parameters and treatment outcomes in the groups.Results. The use of SH was associated with reduced level of myoglobin on day5 of therapy from 384.1 to 112.4 gg/l (70.7%) vs 335.15 to 219.1 gg/l (34.6%) reduction in the conservative therapy group. By day 7, this parameter was 18.8 (95.1%) and 142.4 (57.5%), respectively (7=0.012). The level of cystatin-C decreased on day 5 from 17.3 to 3.2 mg/l (81.5%) in group 2 and from 14.9 to 11.7 mg/l (21.5%) in group 1. By day 7, this parameter decreased to 2.5 (85.6%) and 14.1 (5.3%) mg/l, respectively (7=0.001). The length of ICU stay in group 2 was 7 (6; 9) days, while in the conservative therapy group it was 12 (7; 13) days (7=0.04). The hospital stay was 12 (10; 16) and 22 (14,5; 24,5) days, respectively (7=0.028).Conclusion. The early use of SH in the intensive therapy helped decrease the levels of markers of endogenous intoxication, AKI severity, improve the filtration capacity of the kidneys, and reduced the length of stay in the ICU and hospital.

Functionalized graphene modified styrene-divinylbenzene copolymer as a superhydrophobic catalyst carrier for hydrogen-water liquid phase catalytic exchange

Styrene-divinylbenzene (SDB) catalyst carrier is the key material for hydrogen-water liquid phase catalytic exchange (LPCE) reaction. However, currently available SDB generally has drawbacks such as low hydrophobicity, small particle size, and poor strength. Therefore, it is interesting to obtain SDB carriers with large particle size, superhydrophobicity and high strength. Herein, modification of graphene with hexadecyltrimethoxysilane (HDTMS) and γ-methylallyl oxypropyl (KH570) respectively gave KH570-GNS and HDTMS-GNS with a good lipophilicity and a uniform dispersity. Then, terpolymerization of KH570-GNS with styrene and divinylbenzene provided KH570-GNS-SDB; In-situ polymerization of HDTMS-GNS with styrene and divinylbenzene in oil phase gave HDTMS-GNS-SDB. Data show that catalyst carriers KH570-GNS-SDB and HDTMS-GNS-SDB have a suitable particle size (up to 3.5–4.5 mm), as well as a higher strength and a better hydrophobicity (152.36°) than reported for SDB. Interestingly, the hardness of the modified SDBs with a graphene-content of 1% is 189% greater than that of normal SDB with the same diameter, according to particle hardness test. Furthermore, KH570-GNS-SDB exhibits a high stability more than 11 h at 80 °C.Generally, the modified SDB carriers have excellent properties such as superhydrophobicity, high strength and high specific surface area. Hence, they have certain application prospects in the treatment of tritium-containing wastewater.