One‐pot synthesis of cobalt‐incorporated polyglycerol ester as an antimicrobial agent for polyurethane coatings

Cobalt‐incorporated poly(glycerol ester) (Co–PGE) was synthesized by the polycondensation of glycerol and adipic acid followed by the reaction with cobalt(II) hydroxide under solvent‐free and noncatalyzed one‐pot synthesis conditions. The reaction was monitored through the acid value and hydroxyl value determination. The chemical structure and molecular weight of the poly(glycerol ester) (PGE) and Co–PGE were characterized by Fourier transform infrared spectroscopy, ¹³C‐NMR, gel permeation chromatography, and inductively coupled plasma mass spectrometry. Co–PGE with a 59.3% degree of branching was incorporated with up to 5.0% w/w cobalt, and it exhibited antimicrobial inhibition against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans in a broth microdilution study. Polyurethane (PU) coatings were prepared by the blending of 0.5–35% w/w Co‐PGE containing with 5% w/w of cobalt with blank PGE, poly(ethylene glycol) with a molecular weight of 6000, poly(caprolactone diol) with a molecular weight of 2000, and additives to react with isophorone diisocyanate. The prepared PUs demonstrated mild to high antimicrobial activities against E. coli, S. aureus, Bacillus subtilis, and C. albicans strains in a disc diffusion test. PU prepared with 0.5% w/w Co–PGE showed a mild inhibition activity against S. aureus, and PU prepared with 10% w/w Co–PGE demonstrated a high inhibition activity against C. albicans. This study demonstrated that value‐added Co–PGE synthesized from glycerol has the potential as an antimicrobial agent for polymer coatings in biomedical devices. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46045.     

Experimental design of the kinetic resolution of a key precursor of high‐value bioactive myo‐inositols by an immobilized lipase

BACKGROUND: The response surface methodology was successfully applied to the optimization of the reaction variables for the kinetic resolution of a precursor of high‐value myo‐inositols, ( ± )‐1,2‐O‐isopropylidene‐3,6‐di‐O‐benzyl‐myo‐inositol (( ± )‐1), by Novozym 435. The resolutions were run separately, with two acylating agents, ethyl acetate and vinyl acetate, in a solvent‐free system. The variables analyzed were reaction temperature, substrate concentration, water concentration and enzyme activity. A statistical model was employed for the evaluation of the influence of the variables on conversion and enantiomeric excess (ee). RESULTS: The optimal conditions for this resolution using vinyl acetate as acylating agent were 45 °C, 5 mg mL^?1 of substrate, 71 U of enzyme activity and 0%w/w of water concentration. The high conversion (49.2 %) and ee (>99%) reached in the chemoenzymatic synthesis of acylated product, L‐(?)‐5‐O‐Acetyl‐3,6‐di‐O‐benzyl‐1,2‐O‐isopropylidene‐myo‐inositol, secure the efficient synthesis of the D enantiomorph present in the original racemic mixture (( ± )‐1) as well. CONCLUSIONS: The use of the experimental design strategy was productive, leading to a 14‐fold increase in the productivity of the reaction compared with the non‐optimized conditions. Both derivative L‐(?)‐2 and remaining substrate D‐(+)‐1 were obtained at high ee. © 2012 Society of Chemical Industry     

Potential application of aqueous two‐phase systems for the fractionation of RNase A and α‐Lactalbumin from their PEGylated conjugates

BACKGROUND: PEGylation reactions often result in a heterogeneous population of conjugated species and unmodified proteins that presents a protein separations challenge. Aqueous two‐phase systems (ATPS) are an attractive alternative for the potential fractionation of native proteins from their PEGylated conjugates. The present study characterizes the partition behaviors of native RNase A and α‐Lac and their mono and di‐PEGylated conjugates on polyethylene glycol (PEG)—potassium phosphate ATPS. RESULTS: A potential strategy to separate unreacted native protein from its PEGylated species was established based upon the partition behavior of the species. The effect of PEG molecular weight (400–8000 g mol^?1), tie‐line length (15–45% w/w) and volume ratio (V_R; 0.33, 1.00 and 3.00) on native and PEGylated proteins partition behavior was studied. The use of ATPS constructed with high PEG molecular weight (8000 g mol^?1), tie‐line lengths of 25 and 35% w/w, and V_R values of 1.0 and 3.0 allowed the selective fractionation of native RNase A and α‐Lactalbumin, respectively, from their PEGylated conjugates on opposite phases. Such conditions resulted in an RNase A bottom phase recovery of 99%, while 98% and 88% of mono and di‐PEGylated conjugates, respectively were recovered at the top phase. For its part, α‐Lac had a bottom phase recovery of 92% while its mono and di‐PEGylated conjugates were recovered at the top phase with yields of 77% and 76%, respectively. CONCLUSIONS: The results reported here demonstrate the potential application of ATPS for the fractionation of PEGylated conjugates from their unreacted precursors. Copyright © 2010 Society of Chemical Industry     

Characteristics of poly(AAc5‐co‐HPMA3‐cl‐EGDMA15) hydrogel‐immobilized lipase of Pseudomonas aeruginosa MTCC‐4713

Four series of noble networks were synthesized with acrylic acid (AAc) copolymerized with varying amount of 2‐hydroxy propyl methacrylate or dodecyl methacrylate (AAc/HPMA or AAc/DMA; 5:1 to 5:5, w/w) in the presence of ethylene glycol dimethacrylate (EGDMA; 1, 5, 10, 15, and 20%, w/w) as a crosslinker and ammonium per sulfate (APS) as an initiator. Each of the networks was used to immobilize a purified lipase from Pseudomonas aeruginosa MTCC‐4713. The lipase was purified by successive salting out with (NH₄)₂SO₄, dialysis, and DEAE anion exchange chromatography. Two of the matrices, E_15a, i.e. [poly (AAc₅‐co‐DMA₁‐cl‐EGDMA₁₅)] and I_15c, i.e. [poly (AAc₅‐co‐HPMA₃‐cl‐EGDMA₁₅)], that showed relatively higher binding efficiency for lipase were selected for further studies. I_15c‐hydrogel retained 58.3% of its initial activity after 10th cycle of repetitive hydrolysis of p‐NPP, and I_15c was thus catalytically more stable and efficient than the other matrix. The I_15c‐hydrogel‐immobilized enzyme showed maximum activity at 65°C and pH 9.5. The hydrolytic activity of free and I_15c‐hydrogel‐immobilized enzyme increased profoundly in the presence of 5 mM chloride salts of Hg²⁺, NH₄⁺, Al³⁺, K⁺, and Fe³⁺. The immobilized lipase was preferentially active on medium chain length p‐nitrophenyl acyl ester (C:8, p‐nitrophenyl caprylate). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4636–4644, 2006     

Quality characteristics of olive leaf‐olive oil preparations

Olive leaf‐olive oil preparations were obtained by vigorous mixing at various levels of addition (5, 10, 15%w/w) of new or mature leaves. After removal of the plant material via centrifugation, quality and sensory characteristics of the preparations were determined. Oxidative stability (120°C, 20 L/h) and DPPH radical scavenging were increased ～2–7 fold depending on the level of leaves used due to enrichment with polar phenols, mainly oleuropein, and a‐tocopherol. The extraction process affected the chlorophyll content and organoleptic traits as indicated by acceptability and preference tests (n = 50). Forty‐four % of the panelists identified a strong pungency in preparations with 15% w/w new leaves. Fifty‐four % of them identified a bitter taste in those with 15% w/w mature leaves, which was attributed to high levels of oleuropein (～200 mg/kg oil). Olive leaf‐olive oil preparations had interesting properties regarding antioxidants present that can attract the interest of a functional product market. Practical applications: The wider use of olive oil and derived products is highly desirable. In this sense, the current study presents data that support introduction to the market of a new specialty olive oil based solely on olive tree products (olive oil and leaves). Thus, in addition to olive oil and olive paste, a new product, that is an olive oil enriched with olive leaf antioxidants, especially oleuropein produced via a “green” technique (mechanical means instead of extraction with organic solvent) can be made available for consumers.     

Partitioning behaviour of cephalexin and 7‐aminodeacetoxicephalosporanic acid in PEG/ammonium sulfate aqueous two‐phase systems

In order to develop an aqueous two‐phase system (ATPS) for cephalexin synthesis with extractive bioconversion, the partitioning behaviour of cephalexin and 7‐aminodeacetoxicephalosporanic acid (7‐ADCA) in poly(ethylene glycol) (PEG)/salt ATPS were examined. Parameters such as PEG size, salt type and tie line length were investigated to find a primary extraction system. In PEG400/ammonium sulfate and PEG400/magnesium sulfate systems, the partition coefficient of cephalexin (K_C) was larger than 1 while that of 7‐ADCA (K_A) deviated about 1.5. Addition of neutral salts, surfactants and water‐miscible solvents were also investigated in the primary ATPS in order to improve the separation efficiency. K_C greatly increased when neutral salts and surfactants were added to the PEG400/ammonium sulfate primary systems whereas K_A was only slightly higher than that of the additive‐free ATPS. In an improved ATPS for extractive bioconversion, consisting of PEG400 (20% w/w), ammonium sulfate (17.5% w/w), methanol (5% w/w) and NaCl (3% w/w), a K_C value of up to 15.2 was achieved; K_A was 1.8; K_P (partition coefficient of phenylglycine methyl ester) was 1.2 and the recovery yield of cephalexin was 94.2%. The results obtained from the extractive bioconversion of cephalexin in the improved ATPS showed that it is feasible to perform such an enzymatic process in an ATPS and the system offers the potential as a model for enzymatic synthesis of some water soluble products. © 2001 Society of Chemical Industry     

Temperature‐responsive alginate‐g‐poly(N,N‐diethylacrylamide) copolymer: Synthesis,characterization, and swelling behavior

Temperature‐responsive polymers have recently gained importance due to their applications in drug delivery. Herein, temperature‐responsive graft copolymer (Alg‐g‐PDEAAm) of alginate and N,N‐diethylacrylamide was synthesized by microwave‐assisted copolymerization using potassium persulfate/N,N,N′,N′‐tetramethylethylenediamine initiator system. The reaction conditions for the best grafting (331%) have been optimized by changing microwave irradiation time, temperature, N,N‐diethylacrylamide, and alginate concentrations. The spectroscopic characteristic, thermal properties, and surface morphology of the copolymers were investigated by FTIR, ¹H‐NMR, DSC/TGA, XRD, gel permeation chromatography, and SEM. Furthermore, low critical solution temperatures of Alg‐g‐PDEAAm copolymers were detected by UV spectroscopy. Swelling ratio of graft microspheres was carried out at 25, 32, and 37 °C, and microspheres were found exhibiting temperature‐responsive property. Cytotoxicity test indicated the Alg‐g‐PDEAAm copolymer and its microsphere were biocompatible. Therefore, based on the results the synthesized temperature‐responsive copolymer could be considered as a promising biomaterial. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46688.     

Thermal analysis of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) irradiated under vacuum

Poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) was irradiated by ⁶⁰Co γ‐rays (doses of 50, 100 and 200 kGy) under vacuum. The thermal analysis of control and irradiated PHBV, under vacuum was carried out by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The tensile properties of control and irradiated PHBV were examined by using an Instron tensile testing machine. In the thermal degradation of control and irradiated PHBV, a one‐step weight loss was observed. The derivative thermogravimetric curves of control and irradiated PHBV confirmed only one weight‐loss step change. The onset degradation temperature (T_o) and the temperature of maximum weight‐loss rate (T_p) of control and irradiated PHBV were in line with the heating rate (°C min^?1). T_o and T_P of PHBV decreased with increasing radiation dose at the same heating rate. The DSC results showed that ⁶⁰Co γ‐radiation significantly affected the thermal properties of PHBV. With increasing radiation dose, the melting temperature (T_m) of PHBV shifted to a lower value, due to the decrease in crystal size. The tensile strength and fracture strain of the irradiated PHBV decreased, hence indicating an increased brittleness. Copyright © 2004 Society of Chemical Industry     

Oxo‐biodegradability of high‐density polyethylene films containing limited amount of isotactic polypropylene

Limited amount of isotactic polypropylene (iPP) is added to high‐density polyethylene (HDPE) containing 1% w/w an oxo‐biodegradable additive and extruded and converted to films. The films are put under UV irradiation for different periods of time. Irradiation of the films for 6 weeks imposes remarkable effects on viscosity average molecular weight (M_v) and carbonyl index (CI) of them. M_v decreases from 3.4 × 10⁵ to 4.7 × 10⁴ g mol^?1 for neat HDPE films; from 3.1 × 10⁵ to 3.3 × 10⁴ g mol^?1 for the films containing oxo compound, and from 1.5 × 10⁵ to 2.6 × 10⁴ g mol^?1 for the films containing oxo compound and 1% w/w iPP. Carbonyl index of the neat HDPE films increases from 4 to 8.7 while for the sample containing only the oxo compound it increases from 4.5 to 7.3 and for the sample containing both oxo compound and iPP it decreases from 12.0 to 8.8. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) indicate more cracks and uniform degradation in the samples containing iPP and oxo compound. Thermogravimetric analysis (TGA/DTG) of the samples shows that the samples containing iPP and oxo compound have lower decomposition temperature after UV irradiation. Finally, it can be said that the presence of iPP in HDPE matrix containing oxo compound can improve HDPE oxo‐biodegradablity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45843.     

Solution behavior of water‐soluble poly(acrylamide‐co‐sulfobetaine) with intensive antisalt performance as an enhanced oil‐recovery chemical

In the process of oilfield development, salt tolerance is an important property for enhanced oil‐recovery (EOR) chemicals. In this study, we synthesized two acrylamide‐based sulfobetaine copolymers containing 2‐hydroxy‐3‐[(3‐methacrylamidopropyl)dimethylammonio]propane sulfonate (SHPP) or 3‐(4‐acry‐loyl‐1‐methyl‐piperazinio)‐2‐hydroxypropane sulfonate (SHMP). The interactions between these two copolymers and inorganic salts were compared, and the apparent viscosity (η_app) behaviors of copolymer–salt solutions at different shear rates and temperatures were investigated. We found that the η_app of PAPP and PAMP showed intensive antisalt performance, exhibiting an excellent antipolyelectrolyte effect. The η_app retention value of 30,000 mg/L PAMP in brine was 86.47 mPa s at 510 s^?1, and when the temperature was increased to 90 °C, it was 99.73 mPa s; this was better than that of PAPP under the same conditions. Therefore, PAMP was more applicable as an EOR chemical that have outstanding salt tolerance and temperature resistance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46235     

Melt‐electrospun fibers obtained from polypropylene/poly(ethylene‐co‐vinyl alcohol)/polypropylene three‐layer films

Production of polypropylene (PP) nanofibers below 1 μm in average diameter is difficult with conventional melt‐spinning. A nozzle‐free melt‐type electrospinning (M‐ESP) system with a line‐like CO₂ laser beam melting device were used to produce PP nanofibers. To achieve the purpose, core [poly(ethylene‐co‐vinyl alcohol) (EVOH)]–clad (PP) nanofibers (average diameter, 0.88 μm) were fabricated from PP/EVOH/PP three‐layer films using the M‐ESP. The core–clad structure was formed by a wrapping phenomenon caused by the difference in the melt flow rates (MFRs) of PP and EVOH melts. Hollow PP nanofibers were obtained from the core–clad nanofibers by extraction of EVOH. Nanofiber diameter and hollow wall thickness could be altered by changing the MFR of the PP melt. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46393.     

Hierarchical N‐doped carbons from designed N‐rich polymer: Adsorbents with a record‐high capacity for desulfurization

The removal of 4,6‐dimethyldibenzothiophene is quite challenging in petroleum refining process. Adsorptive desulfurization is an efficient technique but the capacities and/or poor stability of current adsorbents need to be improved. Here, the fabrication of hierarchical N‐doped carbons (NCs) derived from carbonizing the polymerization of 2,4,6‐tris(chloromethyl)mesitylene and p‐phenylenediamine is reported. The results show that the NCs have developed micropores (0.34–0.93 cm³ g^?1) and mesopores (0.15–0.47 cm³ g^?1), and their surfaces have abundant pyrrole‐like/graphitic N and topological defects and vacancies, and high cycle stability (6 cycles). The typical adsorbent NC‐700 shows a record‐high capacity of 2.91 mmol g^?1 under ambient conditions. The computational results show that the doped N is capable of promoting adsorptive strength by 0.055–0.178 eV. In conclusion, the obtained materials exhibit excellent performance for deep desulfurization, and this work may open up new avenues for the development of efficient adsorbents. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3786–3793, 2018     

Morphology,mechanical properties and electromagnetic shielding effectiveness of poly(styrene‐b‐ethylene‐ran‐butylene‐b‐styrene)/carbon nanotube nanocomposites: effects of maleic anhydride,carbon nanotube loading and processing method

Nanocomposites based on poly(styrene‐b‐ethylene‐ran‐butylene‐b‐styrene) (SEBS) and carbon nanotubes (CNTs) (SEBS/CNT) as well as SEBS grafted with maleic anhydride (SEBS‐MA)/CNT were successfully prepared for electromagnetic shielding applications. Both SEBS/CNT and SEBS‐MA/CNT nanocomposites were prepared by melt compounding and were post‐processed using two different techniques: tape extrusion and compression moulding. The different nanocomposites were characterized by Raman spectroscopy and rheological analysis. Their mechanical properties, electrical properties (10^-2–10⁵ Hz) and electromagnetic shielding effectiveness (8.2–12.4 GHz) were also evaluated. The results showed that the CNT loading amount, the presence of MA in the matrix and the shaping technique used strongly influence the final morphologies and properties of the nanocomposites. Whilst the nanocomposite containing 8 wt% CNTs prepared by compression moulding presented the highest electromagnetic shielding effectiveness (with a value of 56.73 dB, which corresponds to an attenuation of 99.9996% of the incident radiation), the nanocomposite containing 5 wt% CNTs prepared by tape extrusion presented the best balance between electromagnetic and mechanical properties and was a good candidate to be used as an efficient flexible electromagnetic interference shielding material. © 2018 Society of Chemical Industry     

Measurements of horizontal three‐phase solid‐liquid‐gas slug flow: Influence of hydrate‐like particles on hydrodynamics

Gas hydrate formation is a main flow assurance concern in oil and gas production. Understanding the effects of the introduction of solid particles in the slug flow is essential to improve the efficiency and safety of multiphase production. The purpose of the present work is the experimental characterization of solid‐liquid‐gas slug flow with the presence of dispersed hydrate‐like particles. Experimental tests were carried out with inert polyethylene particles of 0.5‐mm diameter with density similar to gas hydrates (938 kg/m³). The test section comprised a 26‐mm ID, 9‐m length horizontal duct of transparent Plexiglas. High Speed Imaging and resistivity sensors was used to analyze the slug flow unit cell behavior due to the introduction of the solid particles and to measure the unit cell translational velocity, the slug flow frequency, the bubble and slug lengths, and the phase fractions. Two distinct concentrations of solid particles were tested (6 and 8 g/dm³). © 2018 American Institute of Chemical Engineers AIChE J, 64: 2864–2880, 2018     

Preparation of high‐performance zeolite NaA membranes in clear solution by adding SiO2 into Al2O3 hollow‐fiber precursor

Zeolite NaA membranes were prepared in a clear synthesis solution without the aid of nanoseeds. To improve the properties of the membranes formed in a clear solution, alumina hollow fibers were fabricated by adding silica powder to the conventional spinning slurry, resulting in hollow fibers with a mullite phase. Prior to the membrane synthesis, the hollow fibers were pretreated by dipping in an aged synthesis solution diluted with isopropanol. Dense zeolite NaA membranes on mullite‐containing alumina hollow fibers were successfully obtained at 100°C for 2 h without the aid of nanoseeds. The membranes have a good pervaporation performance with a high flux of 10.8 kg m^?2 h^?1 and a separation factor of over 10,000. The abundant mullite‐phase hydroxyl groups on the support surface promote the nucleation and growth of zeolite crystals on the support, resulting in dense membranes. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2679–2688, 2018     

Foaming of poly(ethylene‐co‐vinyl acetate) and poly(ethylene‐co‐vinyl acetate‐co‐carbon monoxide) and their blends with carbon dioxide

Poly(ethylene‐co‐vinyl acetate) (EVA‐25) and poly(ethylene‐co‐vinyl acetate‐co‐carbon monoxide) (EVACO‐2410) and their blends with EVACO:EVA ratios of 80:20, 60:40, 40:60, and 20:80 were foamed using CO₂. These foams are of interest for applications ranging from footwear to medical devices. Foaming experiments were carried out using 1 mm thick melt‐extruded films in CO₂ at a range of pressures (100, 200, and 300 bar) and temperatures (30, 40, 50, and 60 °C). Foamability of the polymers was explored both under isothermal and gradient temperature conditions. Foams of EVACO‐2410 displayed high initial expansions followed by postfoaming relaxation and shrinkage while foams generated from EVA‐25 showed more dimensional stability. Blending EVACO‐2410 with EVA‐25 was explored as an approach to reduce postfoaming relaxation and shrinkage. The surfaces of the foamed samples displayed blistering that was linked to CO₂ bubble entrapment and coalescence at the surface. Scanning electron micrographs of the foams generated from blends displayed distinct morphologies reflecting whether the sections were representing the machine‐ or cross‐machine direction of extruded films. In going from EVACO‐2410 to EVA‐25, the cell densities ranged from about 10⁶ to 10¹⁰ cells/cm³. Foams with low bulk densities of about 0.11 g/cm³ could be generated. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45841.     

Preparation of block copolymers via metal‐free visible‐light‐induced ATRP for the detection of lead ions

Polyacrylamide‐b‐poly(methacrylic acid) was prepared on the surface of Au electrode (Au/PAM/PMAA) for Pb²⁺ ion electrochemical sensing via metal‐free visible‐light‐induced atom transfer radical polymerization, which was very simple, convenient, and environmentally friendly. Au/PAM/PMAA was carefully examined by cyclic voltammetry, electrochemical impedance spectroscopy, and X‐ray photoelectron spectroscopy. Further, Au/PAM/PMAA was successfully used for the determination of Pb²⁺ ion by differential pulse anodic stripping voltammetry. Under the optimal conditions, a linear response from 1.0 × 10^?11 to 1.0 × 10^?4 mol/L with detection limit of 2.5 × 10^?12 mol/L (S/N = 3) was achieved from the results of experiments. Comparing with similar Pb²⁺ sensors, the broader linear range and lower detection limit suggested the promising prospect of Au/PAM/PMAA. In a word, the work of this article had an important significance for the polymer‐modified electrodes and the sensitive detection of Pb²⁺. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45863.     

Influences of the chain structure of PE‐b‐PEG on the properties of PE/PE‐b‐PEG blend membranes prepared by TIPS

In this article, a series of diblock copolymer polyethylene‐b‐ poly(ethylene glycol)s (PE‐b‐PEGs) with various molecular weight of polyethylene segment was blended with linear low‐density PE. The PE/PE‐b‐PEG blend porous membranes with high porosity were obtained by thermally induced phase separation (TIPS) process. The isothermal crystallization kinetics of PE/LP/PE‐b‐PEG blends indicated that the introduction of PE‐b‐PEG could inhibit the growth rate of polyethylene crystals which could increase the pore size and porosity of the membranes. The PE/PE‐b‐PEG blend membranes with PE₁₃₀₀‐b‐PEG₂₂₀₀ showed the largest pore size and porosity due to its crystallization behavior during TIPS. The surface of the membranes became smoother and the morphology of the membranes could be effectively tuned by introducing PE‐b‐PEG. Compared with the PE membrane, the PE/PE‐b‐PEG blend membranes exhibited higher hydrophilicity (the water contact angle decreased from 112° to 84°), water permeability (the permeation flux increased from 80 to 440 L/m² h under 0.1 MPa), rejection performance (completely reject carbon particles in the filtration of carbon ink solution), and fouling resistance (the value of protein adsorption dropped from 0.25 to 0.05 mg/cm²). The hydrophilicity and fouling resistance of PE/PE‐b‐PEG blend membranes increased as the length of PE segment in PE‐b‐PEGs decreased. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46499.     

Nanospace‐confined synthesis of coconut‐like SnS/C nanospheres for high‐rate and stable lithium‐ion batteries

Coconut‐like monocrystalline SnS/C nanospheres are developed as anode materials for lithium‐ion batteries by a micro‐evaporation‐plating strategy in confined nanospaces, achieving reversible capacities as high as 936 mAh g^?1 at 0.1 A g^?1 after 50 cycles and 830 mAh g^?1 at 0.5 A g^?1 for another 250 cycles. The remarkably improved electrochemical performances can be mainly attributed to their unique structural features, which can perfectly combine the advantages of the face‐to‐face contact of core/shell nanostructure and enough internal void space of yolk/shell nanostructure, and therefore well‐addressing the pivotal issues related to SnS low conductivity, sluggish reaction kinetics, and serious structure pulverization during the lithiation/delithiation process. The evolutionary process of the nanospheres is clearly elucidated based on experimental results and a multiscale kinetic simulation combining the microscopic reaction‐diffusion equation and the mesoscopic theory of crystal growth. Furthermore, a LiMn₂O₄//SnS/C full cell is assembled, likewise exhibiting excellent electrochemical performance. © 2018 American Institute of Chemical Engineers AIChE J, 64: 1965–1974, 2018     

13‐Hydroxy‐9Z,11E‐Octadecadienoic Acid Production by Recombinant Cells Expressing Burkholderia thailandensis 13‐Lipoxygenase

Linoleate 13‐lipoxygenase from Burkholderia thailandensis was expressed in Escherichia coli for the production of 13‐hydroxyoctadecadienoic acid (13‐HODE), an antiseptic emulsifier. Linoleate 13‐lipoxygenase in cells had higher thermal stability than the purified enzyme. To increase 13‐HODE production, recombinant cells were permeabilized by solvents, detergents, salts, and other chemicals. The enzymatic activity in cells was the highest for permeabilized cells treated with 0.5 M NaCl among the permeabilizers tested. The optimal reaction conditions for the production of 13‐HODE from linoleic acid by permeabilized cells treated with 0.5 M NaCl were at pH 7.5, 25 °C, 20 g/l linoleic acid, 15 g/l cells, 0.15 mM Cu²⁺, and 6 % (v/v) methanol in a 100‐ml baffled flask containing a 5‐ml working volume with agitation at 200 rpm. Under these conditions, permeabilized cells produced 15.8 g/l 13‐HODE after 30 min with a conversion yield of 79 % (w/w) and a productivity of 31.6 g/l/h. The conversion yield and productivity of permeabilized cells for 13‐HODE production were higher than those of purified and crude enzymes as well as nonpermeabilized cells. Therefore, permeabilized cells were efficient biocatalysts for 13‐HODE production. To the best of our knowledge, this is the first report of the production of 13‐HODE using cells.