Polyethylene Glycol Solution Research Articles

Nonaqueous amino-phenolic dual-functionalized ionic liquid absorbents for reversible CO2 capture: Phase change behaviors and mechanism

In order to improve the recycling capacity, regenerability and energy efficiency of ionic liquid (IL) based CO2 capture technology, a series of nonaqueous phase change solvents comprising amino-phenolic dual-functionalized ILs and polyethylene glycols (PEGs) were proposed for CO2 capture in this research. The capture performance results demonstrated that the 20 wt% diethylenetriamine-2-bromophenolate(D2Br)-PEG200 and diethylenetriamine-4-bromophenolate(D4Br)-PEG200 solutions with slight phase change could realize high CO2 loading of 1.923 and 1.859 mol/mol IL and CO2-rich phase constituted volume fractions lower than 70%. The absorption ability kept stable at relatively high temperature and the two systems could be rapidly regenerated at 363 K with cyclic regeneration rate above 85% after ten consecutive cycles. The weak thermal stability of the absorption products was proved by TG-DSC analysis, contributing to improved regeneration performance. ATR-IR and 13C NMR analysis confirmed that the amino groups of IL reacted with CO2 to form carbamates, and phenol groups through 1:1 mechanism to form alkyl carbonates, guaranteeing enhanced recycling capacity and regenerability. Spectroscopic analysis and theoretical calculation results revealed the different phase change behaviors presented in PEGs solutions were mainly derived from the product-solvent interaction, which was more influenced by hydroxyl content. The interactions between the product ion pairs could be the main cause of the unstable state of the solutions and phase separation. The different patterns of hydrogen bonding established between IL and PEG molecules could maintain a relatively strong product-solvent interaction in the reacted solution, which would partially overcome the interactions between protonated amine and carbamate, thus delaying the phase transition formation and forming a slight solid–liquid phase change, potentially beneficial for CO2 capture. The two systems experienced a low reaction heat of 1.315 and 0.782 GJ/t CO2, which could significantly reduce regeneration heat load. Therefore, the amino-phenolic dual-functionalized IL solutions are proposed to be a competitive and reversible CO2 trapping agent.

Macroscale superlubricity induced by film-forming polymer brush-grafted colloidal additives

HypothesisModifying surfaces with concentrated polymer brushes (CPBs) is an effective way to reduce friction of tribo-pairs lubricated with liquids. We investigate the hypothesis that colloids grafted with CPBs (hybrid colloids) can deposit onto tribo-substrates by varying the solvent quality with respect to the polymer, in order to obtain ultra-low coefficients of friction (CoFs), so-called superlubricity. ExperimentsHybrid colloids are synthesized and characterized, and a dynamic light scattering compares their swellings in aqueous solutions of glycerol or polyethylene glycol. A mini-traction machine with viscoelastic tribo-pairs is used for lubrication experiments. Adsorption of colloids and film structures are tested using a quartz crystal microbalance and an atomic force microscope. FindingsThe solvent controls whether hybrid colloids spontaneously adsorb to the substrate under quiescent conditions or require contact forces to enable (tribo-)deposition. In both cases, the friction in the boundary-mixed lubrication regimes is lower upon increasing the degree of swelling of CPBs and upon increasing coverage of deposited colloids. The greatest lubrication enhancement and surface coverage occur for the spontaneously adsorbed colloids, with ultra-low CoFs of order 10-3 over a large range of speeds. The results demonstrate the potential for hybrid colloids to be used as solvent dispersible “friction modifier additives”.

A multicenter randomized phase 4 trial comparing sodium picosulphate plus magnesium citrate vs. polyethylene glycol plus ascorbic acid for bowel preparation before colonoscopy. The PRECOL trial.

Adequate bowel preparation before colonoscopy is crucial. Unfortunately, 25% of colonoscopies have inadequate bowel cleansing. From a patient perspective, bowel preparation is the main obstacle to colonoscopy. Several low-volume bowel preparations have been formulated to provide more tolerable purgative solutions without loss of efficacy. Investigate efficacy, safety, and tolerability of Sodium Picosulphate plus Magnesium Citrate (SPMC) vs. Polyethylene Glycol plus Ascorbic Acid (PEG-ASC) solutions in patients undergoing diagnostic colonoscopy. In this phase 4, randomized, multicenter, two-arm trial, adult outpatients received either SPMC or PEG-ASC for bowel preparation before colonoscopy. The primary aims were quality of bowel cleansing (primary endpoint scored according to Boston Bowel Preparation Scale) and patient acceptance (measured with six visual analogue scales). The study was open for treatment assignment and blinded for primary endpoint assessment. This was done independently with videotaped colonoscopies reviewed by two endoscopists unaware of study arms. A sample size of 525 patients was calculated to recognize a difference of 10% in the proportion of successes between the arms with a two-sided alpha error of 0.05 and 90% statistical power. Overall 550 subjects (279 assigned to PEG-ASC and 271 assigned to SPMC) represented the analysis population. There was no statistically significant difference in success rate according to BBPS: 94.4% with PEG-ASC and 95.7% with SPMC (P = 0.49). Acceptance and willing to repeat colonoscopy were significantly better for SPMC with all the scales. Compliance was less than full in 6.6 and 9.9% of cases with PEG-ASC and SPMC, respectively (P = 0.17). Nausea and meteorism were significantly more bothersome with PEG-ASC than SPMC. There were no serious adverse events in either group. SPMC and PEG-ASC are not different in terms of efficacy, but SPMC is better tolerated than PEG-ASC. SPMC could be an alternative to low-volume PEG based purgative solutions for bowel preparation. [ClinicalTrials.gov], Identifier [NCT01649674 and EudraCT 2011-000587-10].

All-Aqueous Bicontinuous Structured Liquid Crystal Emulsion through Intraphase Trapping of Cellulose Nanoparticles.

Here, we describe the all-aqueous bicontinuous emulsions with cholesteric liquid crystal domains through hierarchical colloidal self-assembly of nanoparticles. This is achieved by homogenization of a rod-like cellulose nanocrystal (CNC) with two immiscible, phase separating polyethylene glycol (PEG) and dextran polymer solutions. The dispersed CNCs exhibit unequal affinity for the binary polymer mixtures that depends on the balance of osmotic and chemical potential between the two phases. Once at the critical concentration, CNC particles are constrained within one component of the polymer phases and self-assemble into a cholesteric organization. The obtained liquid crystal emulsion demonstrates a confined three-dimensional percolating bicontinuous network with cholesteric self-assembly of CNC within the PEG phase; meanwhile, the nanoparticles in the dextran phase remain isotropic instead. Our results provide an alternative way to arrest bicontinuous structures through intraphase trapping and assembling of nanoparticles, which is a viable and flexible route to extend for a wide range of colloidal systems.

Efficiency Analysis of Fuel Cell Components with Ionic Poly-Arylether Composite Membrane.

We use polyethylene glycol as an additive to explore how the hydrogen bonding of this additive changes the properties of SA8 blended sulfonated polyetheretherketone (SPEEK) composite films. We mixed a 5%wt polyethylene glycol solution into a 12.5%wt SA8 solution, and then prepared a film with a total weight of 40 g at a ratio of 1:99. The SA8 (PEG) solution was prepared and then mixed with 5%wt SPEEK solution, and a film-forming solution with a total weight of 8g in different mixing ratios was created. Polyethylene glycol (PEG) was mixed into the sulfonated polyarylether polymer SA8 to form physical cross-linking. Therefore, the sulfonated polyether ether ketone SPEEK was mixed in, and it exhibited good thermal stability and dimensional stability. However, there was some decrease in proton conductivity as the proportion of SPEEK increased. Although SPEEK mixed with sulfonated polymer reduces the proton conductivity, the physical cross-linking of PEG can improve the proton conductivity of the composite membrane, and adding SPEEK can not only solve the problem of the high sulfonation film swelling phenomenon, it can also improve the dimensional stability of the film through the hydrogen bonding force of PEG and obtain a composite film with excellent properties.

Enhanced optical trapping of ZrO2@TiO2 photonic force probe with broadened solvent compatibility.

Optical trapping and manipulating nanoparticles are essential tools for interrogating biomedicine at the limits of space and time. Typically, silica or polystyrene microspheres are used as photonic force probes. However, adapting those probes to organic solvents is an ongoing challenge due to the limited solvent compatibility and low refractive index mismatch. Here we report on the optical force enhancement and solvent compatibility that utilizes ZrO2@TiO2 core-shell nanoparticles. We experimentally demonstrate that the 450-nm-diameter ZrO2@TiO2 core-shell nanoparticles achieve the lateral and axial trap stiffness up to 0.45 pN µm-1 mW-1 and 0.43 pN µm-1 mW-1 in water, showing more than fivefold and ninefold improvement on the ordinary SiO2 particle of the same size. In addition, ZrO2@TiO2 core-shell nanoparticles can realize stable three-dimensional trapping in both polyethylene glycol and glucose solutions. This optical trapping enhancement property, coupled with solvent compatibility, expands the range of feasible optical trapping experiments and will pave the way toward more advanced biological applications.

Water as Veneering Modeling Liquid Affects Microhardness of Glassy Matrix Veneering Ceramic.

To evaluate the effect of different veneering liquids used for modeling on microhardness, fracture toughness and biaxial flexural strength of a glass-veneering ceramic. The manufacturer recommended modeling liquid (ML), distilled water (DW), isopropyl alcohol (IA), 0.5% (P05), 1% (P1), and 2% (P2) polyethylene glycol solutions were mixed with feldspathic ceramic powder to form disc-shaped samples (n=20, 15 mm × 1.2 mm). After sintering, samples were mirror-polished and subjected to Vickers indentation (n=5) for measurement of microhardness and fracture toughness. The remaining 15 samples from each group were subjected to biaxial flexural strength. Data were subjected to one-way ANOVA and Weibull analysis. The microhardness was affected by veneering liquid (p=0.002): DW promoted higher microhardness values than ML and IA. Fracture toughness (p=0.301) and flexural strength (p=0.930) were not affected by the veneering liquid but Weibull parameters were affected. All groups presented surface pores under high magnification. Even though the use of DW led to higher values of surface microhardness than the ML, all obtained values are inside the range of enamel microhardness values reported in the literature. Such parameters may affect antagonist wear and should be reported in clinical trials.

Tribological properties of bis(2-hydroxyethyl)ammonium oleate in glycerol and polyethylene glycol aqueous solutions

The use of eco-friendly water-based lubricants can benefit manufacturing processes and the health of operating personnel while reducing environmental pollution. This study investigates the tribological properties of bis(2-hydroxyethyl)ammonium oleate protic ionic liquid (PIL) as a potential additive to enhance tribological properties in aqueous solutions of glycerol and polyethylene glycol. The studied concentration of bis(2-hydroxyethyl)ammonium oleate was in the range of 0.1 to 1.5 wt%. The base fluids contained 50 wt% glycerol and 12 wt% polyethylene glycol, respectively. The physicochemical properties, wettability, and corrosion-prevention ability were evaluated. Lubricity was investigated using a ball-on-plate configuration in reciprocation mode and a four-ball tribometre. The wear scars were analysed using optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The introduction of PIL into the base fluids enhanced their wettability and ability to prevent corrosion. Furthermore, the PIL improved the wear and reduced the friction coefficient of both fluids. Moreover, their load-carrying ability was enhanced. Based on the observed results, friction and wear reduction mechanisms were suggested.

Enabling Solution Processable COFs through Suppression of Precipitation during Solvothermal Synthesis.

Covalent organic frameworks (COFs) are crystalline, nanoporous materials of interest for various applications, but current COF synthetic routes lead to insoluble aggregates which precludes processing for practical implementation. Here, we report a COF synthesis method that produces a stable, homogeneous suspension of crystalline COF nanoparticles that enables the preparation of COF monoliths, membranes, and films using conventional solution-processing techniques. Our approach involves the use of a polar solvent, diacid catalyst, and slow reagent mixing procedure at elevated temperatures which altogether enable access to crystalline COF nanoparticle suspension that does not aggregate or precipitate when kept at elevated temperatures. On cooling, the suspension undergoes a thermoreversible gelation transition to produce crystalline and highly porous COF materials. We further show that the modified synthesis approach is compatible with various COF chemistries, including both large- and small-pore imine COFs, hydrazone-linked COFs, and COFs with rhombic and hexagonal topologies, and in each case, we demonstrate that the final product has excellent crystallinity and porosity. The final materials contain both micro- and macropores, and the total porosity can be tuned through variation of sample annealing. Dynamic light scattering measurements reveal the presence of COF nanoparticles that grow with time at room temperature, transitioning from a homogeneous suspension to a gel. Finally, we prepare imine COF membranes and measure their rejection of polyethylene glycol (PEG) polymers and oligomers, and these measurements exhibit size-dependent rejection and adsorption of PEG solutes. This work demonstrates a versatile processing strategy to create crystalline and porous COF materials using solution-processing techniques and will greatly advance the development of COFs for various applications.

One-step on-chip microfluidic synthesis of the hybrid capsules using aqueous two-phase system

Hydrogel capsules synthesized by conventional water-in-oil emulsion systems are the less preferred choice for biomedical applications due to the use of oils and surfactants. An aqueous two-phase system (ATPS), which allows the formation of water-in-water emulsion, is considered a green alternative and therefore has been explored a lot for its application in the biomedical field. Herein, we present the synthesis of hydrogel capsules using a set-up consisting of a pneumatic valve integrated with the ATPS microfluidic system. In this arrangement, at first, a pneumatic valve facilitates the generation of the droplets of one aqueous system i.e. sodium alginate (SA) containing dextran solution into another aqueous phase comprising polyethylene glycol solution. The present approach allows good control over droplet generation by tuning the pressure of the pneumatic valve and the flow rates of the core and middle phases. The synthesis of hybrid capsules within the microfluidic device is carried out mainly by using the interfacial complexation of oppositely charged polyelectrolytes, chitosan with SA via electrostatic interactions. The interfacial complexed SA and chitosan hydrogel capsules were collected via the settling collection method, which ensures the retaining of the shape of the hybrid capsules. The morphological properties of as-synthesized droplets and hybrid capsules were examined via optical microscopy. The hydrogel capsules show good encapsulation capability for the magnetic particles. Even though this study mainly focuses on the synthesis part, we anticipate that the proposed approach will enable the encapsulation of cells within the hybrid capsules as well as enhance the cell adhesion on the surface of the hydrogel capsules hence, these hydrogel capsules can find the potent application in the biomedical engineering.

Indicators of Immunity in Associated Mycotoxicosis of Cows

The issue of cattle reproduction was and still is one of the main tasks in cattle breeding. Losses of farms from infertility of cows are quite significant and range within 3.19-5.41 per 1 day of infertility. Mycotoxins produced by fungi of the Fusarium family, namely deoxynivalenol (DON) and zearalenone (ZEN) adversely affect not only the functioning of all organs and systems of the cow’s body, but also produce an immunosedative effect. The purpose of this study was to establish the effect of the DON and ZEN complex on the main indicators of the immune response of cows and its correction in a comparative aspect using a feed additive based on zeolite and organic acids and recombinant α-, g-interferons. The study material was the blood of cows (serum and stabilized) sick with mycotoxicosis caused by the association of DON and ZEN. Methods used: photonephelometric using E. coli test culture, spontaneous rosette formation with sheep red blood cells according to M. Jondal, modified method of rosette formation according to M. Wansbrough-Jones, R. Limatibul’s method, simple radial immunodiffusion in gel according to G. Mancini, precipitation in a polyethylene glycol solution according to M. Digeon. Experimental studies were performed on black-spotted cows in farms of the Sumy Oblast. The dynamics of the immune indicators of cows during the development of mycotoxicosis and upon treatment with products zeolite-based, organic acids, and an aqueous solution of recombinant α-, g-interferons were studied. It was found that the indicator of bactericidal, lysozyme, complementary, and phagocytic activity of cow blood serum under treatment increased to the indicator inherent in healthy animals. The dynamics of immunoglobulins in the treatment with zeolite and organic acids and recombinant α-, g-interferons was investigated, and an increase to the level of intact cows was established. It was proved that the indicators of the immune response of cows upon using a feed additive based on zeolite and organic acids at a dose of 2.5 kg per tonne of fodder and a preparation based on an aqueous solution of recombinant α-, g-interferons at a dose of 3 ml per animal were significantly higher

How does Poly(ethylene glycol) with varied chain length affect the thermo-responsive behavior of methyl cellulose in aqueous solutions?

In this study, by using a set of narrowly distributed polyethylene glycol (PEG) samples with varied average molar mass (PEGn, 9 <n < 454), we have systematically studied how PEG molar mass and solution concentration influence the thermal response behavior of methyl cellulose (MC) aqueous solutions (Mw = 4.3 × 105 g/mol, <Rg> = 71 nm) by a combination of isothermal titration calorimetry (ITC), rheometer, UV–vis spectroscopy, laser light scattering (LLS) and atomic force microscopy (AFM). At room temperature, ITC result clarifies the existence of extremely weak hydrophobic interactions between MC and PEG chains. In addition, for MC/PEG mixed solution with shorter PEGs (PEG22 and PEG90), experimentally measured zero-shear viscosity (ηexp) is confirmed to be 5–10% higher than the theoretical values (ηcalc), further supporting the interchain association. Whereas for MC/PEG454, insoluble aggregates are formed, which results in ηexp < ηcalc. Further, dynamic laser scattering (DLS) results further reveal how the percentage of peak area of aggregates depends on the chain length of PEG. During the heating process from T = 20 to 70 °C, a combination of UV, LLS and AFM results clearly illustrates that the shorter PEG chains can effectively stabilize the formed MC fibers and prevent the fiber extension; whereas for longer PEG chains, they can not only promote the nucleation process, but also destabilize the formed fibers and promote the fiber extension. Our result unambiguously reveals the macromolecular effect of PEGs on the thermal response behavior of MC in solutions.

Hemolymph osmolality in mollusk Lymnaea stagnalis during acute experimental hyperglycemia

It has been established that the development of hyperglycemia, accompanied by a multiple increase in the hemolymph glucose content (up to 4.0 – 4.5 mmol/L), doesn’t lead to any significant changes in Lymnaea’ s hemolymph osmolality. Incubation of mollusks in 100 mmol/L aqueous solution of polyethylene glycol 200 for 2 h causes a 1.4-fold increase in hemolymph osmolality (up to 210 mosmol/kg) compared to the control level.

Drug-preloadable methacrylated gelatin microspheres fabricated using an aqueous two-phase system

Gelatin microspheres (GMS) can retain biomolecules and be incorporated into artificial tissues and organs for tissue regeneration. However, the inactivation of biomolecules during the conventional fabrication process of GMS requires postloading of biomolecules to prefabricated GMS. Herein, a novel method for fabricating drug-preloaded GMS using a water-in-water (w/w) emulsification technique, is reported. A highly concentrated gelatin methacrylate (Gm) solution containing fibroblast growth factor 2 (FGF2), a model drug, was emulsified in a highly concentrated polyethylene glycol solution, and the mixture was irradiated with ultraviolet light. The obtained water-in-water gelatin methacrylate microspheres (w/w GmMS) were superior to conventional GMS in terms of stability, FGF2-loading efficiency, and sustained release of FGF2. The FGF2-loaded w/w GmMS efficiently activated the proliferation of adipose tissue-derived mesenchymal stem cells (ASCs). In addition, FGF2-loaded w/w GmMS incorporated into multicellular spheroids of ASCs increased the viability of ASCs in the spheroids. The therapeutic efficacy of ASC spheroids in a wound healing mouse model was significantly improved by the incorporation of FGF2-loaded w/w GmMS. These results indicate that drug-preloadable w/w GmMS can be widely applied in tissue engineering and regenerative medicine strategies.

IDENTIFICATION OF DROUGHT-TOLERANT KABULI CHICKPEA (CICER ARIETINUM L.) GENOTYPES AT THE EARLY SEEDLING STAGE

Chickpea (Cicer arietinum L.) is negatively affected by drought stress at all the growth stages, including germination and seedling emergence. The recent study aimed to investigate the drought-tolerant Kabuli chickpea genotypes at the seedling stage under osmotic stress conditions. An in vitro screening technique evaluated the 120 different genotypes of Kabuli chickpea for drought tolerance by using different concentrations of polyethylene glycol (8000) solution, viz., T0: Control, T1: -0.19 MPa, and T2: -0.47 MPa, arranged in a completely randomized design. Data were recorded on germination percentage, root length, shoot length, seedling length, root/shoot ratio, dry matter, seedling vigor index, and proline content. The results of a pooled analysis of variance revealed significant variability among genotypes, different polyethylene glycol treatments, as well as, between genotypes and treatments. The increase of polyethylene glycol levels negatively affected most of the parameters under study, except for proline content, which increased with an increase in polyethylene glycol concentration. The study results indicated that the advanced lines, 15KCC-106, 13KCC-114, 6KCC-103, GP-37, FS-10, and 12KCC-106, performed better under different osmotic stress conditions and gained selection as drought-tolerant advanced lines at early seedling stage. These advanced lines suitably combine with their desirable traits to cope with the drought condition and can serve as a baseline for the improvement of Kabuli chickpea breeding material for drought tolerance.

Seed priming with ascorbic acid improves response of Medicago polymorpha L. seedlings to osmotic stress induced by NaCl and PEG solutions

This study assessed to which extent seed priming with ascorbic acid (0.2 mM) may improve Medicago polymorpha L. performance under water shortage induced by irrigation with either 50 mM NaCl or 100 g/L polyethylene glycol (PEG). Parameters related to plant morphology, CO2/H2O leaf gas exchanges, osmotic adjustment, pigment content, and proline accumulation were specifically determined. Both NaCl and PEG solutions induced osmotic stress and reduced plant biomass (−30% and −40%, respectively), number of leaves and ramifications, stem length, net CO2 assimilation (−31% and 63%, respectively), and leaf water content. However, both treatments and especially PEG led to increased root/shoot ratios and leaf proline content. Interestingly, seed priming using ascorbic acid improved CO2/H2O gas exchange and plant biomass production (+66%, +100%, and +92% in control, NaCl-, and PEG-treated plants, respectively). It also improved the water relations as reflected by the decrease of leaf osmotic potential and higher leaf proline accumulation (+67% and +120% in PEG- and NaCl-treated plants, respectively) and water content (especially under PEG treatment). Besides, seed priming with ascorbic acid increased leaf carotenoid and chlorophyll contents (+65 and +45%, respectively, for chlorophyll a and chlorophyll b), thereby contributing to the better photosynthetic activity, and hence plant performance under salinity. We conclude that seed priming with ascorbic acid is an easy, cost-effective and promising approach to mitigate the impact of osmotic stresses like drought and salinity, by especially improving plant water relations and photosynthetic activity.

Assessment of cold resistance in &lt;i&gt;Momordica charantia&lt;/i&gt; l. accessions according to pollen germination at low temperatures &lt;i&gt;in vitro&lt;/i&gt;

Background. Bitter melon (Momordica charantia L.) is a vegetable and medicinal crop new for Russia. Its high heat demand is the main factor limiting the possibilities of its cultivation in a temperate continental climate. Evaluation and selection of more cold-resistant accessions is required for breeding new cultivars and expanding production. Previously obtained data attest to a possibility of assessing cold hardiness in the mature male gametophyte phase in vitro.Materials and methods. Eight bitter melon accessions, including parent forms, F hybrids and cv. ‘Gosha’, were grown in the unheated film greenhouse of the Central Siberian Botanical Garden, Novosibirsk (54°49’ N, 83°06’ E) for evaluation and selection for cold resistance. The ratio of pollen germination in vitro on a 15% polyethylene glycol solution with a molecular weight of 6000 (PEG 6000) with the addition of boric acid (0.006%) at a temperature of 10°C for 24 h to the same indicator at 25°C / 3 h (in %) was used as a criterion of cold resistance.Results. The cultivar ‘Gosha’, the accession Okinawa green from Japan, and the F1 hybrid (Feng Guang × Okinawa green) had the highest cold resistance, with the values of 59.7; 53.8 and 48.2%, respectively. The inheritance of cold resistance in F , assessed by the pollen germination index, depending on the crossing combination, changed from intermediate in two hybrids [F1 Feng Guang × Gosha) and F1 Feng Guang × Okinawa green)] to overdominant (positive heterosis) in the hybrid F1 (Feng Guang × Okinawa white).

Inflammatory Bowel Disease and Pregnancy

Inflammatory Bowel Disease and Pregnancy

Desulfurization of natural gas condensate using polyethylene glycol and water intercalated activated γ-bauxite

Three different active γ-bauxite were developed from a low-grade raw boehmite ore, as a cheap and efficient adsorbent for the desulfurization of gas condensates. The first adsorbent (RBa) was developed directly through a two-stage thermochemical activation (thermal activation process followed by an acid treatment) of the boehmite ore. The other two adsorbents (PBa and WBa) were initially intercalated with polyethylene glycol (PEG) solution or water, respectively, at the optimum temperature and pressure followed by thermochemical activation to modify the pore size and active surface area. The process parameters such as pulp density and leaching time were optimized using response surface methodology (RSM) based on central composite design (CCD).Comparing the performance of prepared adsorbents to remove sulfur-containing compounds from natural gas condensate indicated the superior sulfur removal efficiency of PBa compared to WBa and non-intercalated adsorbents. Using PBa, the sulfur content was significantly reduced from 2821 ppm to <35 ppm. Characterization of the developed adsorbents indicated that after thermal activation, the pore size of the non-intercalated adsorbent was significantly reduced, which negatively affects its desulfurization efficiency. Nevertheless, the pore diameter of PBa was maintained similar to that of raw bauxite while its surface area was approximately 12-fold larger, which confirms the successful role of PEG as a lattice expansion element, improving its desulfurization efficiency.

Effects of sodium chloride addition on immunoglobulin G partitioning and solubility in polyethylene glycol/hydroxypropyl starch aqueous two-phase system

The effect mechanisms of sodium chloride (NaCl) addition on the partitioning and solubility of immunoglobulin G (IgG) in polyethylene glycol (PEG)/hydroxypropyl starch (HPS) aqueous two-phase system (ATPS) were studied. The influences of NaCl on PEG/HPS phase diagram and the hydrophobicity of IgG were investigated. The results indicated that the hydrophobicity difference between two phases and the IgG hydrophobicity were both enhanced with NaCl addition, so IgG preferred to partition into the top phase with more hydrophobicity. The solubilities of IgG in PEG and HPS solutions with or without NaCl were measured. It was found that NaCl addition could significantly reduce IgG precipitation in PEG solution. The effects of NaCl on the interaction between IgG and PEG was studied by Isothermal Titration Calorimetry (ITC). It was found that the main interactions between IgG and PEG changed from electrostatic force to hydrophobic interaction with NaCl addition. IgG would be wrapped by PEG molecules due to hydrophobic interaction so that the solubility of IgG in PEG solution was enhanced. The results reveal the mechanisms of NaCl addition on the partitioning and solubility of IgG in PEG/HPS systems, and PEG/HPS ATPS might be a promising alternative for IgG separation with good purity and yield.