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Seawater electrolysis is a promising but challenging strategy to generate carbon-neutral hydrogen. A grand challenge for hydrogen evolution reaction (HER) from alkaline seawater electrolysis is the development of efficient and stable electrocatalysts to overcome the limitation of sluggish kinetics. Here, a 3D nanorod hybrid catalyst is reported, which comprises heterostructure MoO2@NiMoO4 supported Ru nanoparticles (Ru/ MoO2@NiMoO4) with a size of ≈5 nm. Benefitting from the effect of strongly coupled interaction, Ru/MoO2@NiMoO4 catalyst exhibits a remarkable alkaline seawater hydrogen evolution performance, featured by a low overpotential of 184 mV at a current density of 1.0 A cm-2, superior to commercial Pt/C (338 mV). Experimental observations demonstrate that the heterostructure MoO2@NiMoO4 as an electron-accepting support makes the electron transfer from the Ru nanoparticles to MoO2, and thereby implements the electron redistribution of Ru site. Mechanistic analysis elucidates that the electron redistribution of active Ru site enhances the ability of hydrogen desorption, thereby promoting alkaline seawater HER kinetics and finally leading to a satisfactory catalysis performance at ampere-level current density of alkaline seawater electrolysis.
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Li2CO3 is the most tenacious parasitic solid-state product in lithium-air batteries (LABs). Developing suitable redox mediators (RMs) is an efficient way to address the Li2CO3 issue, but only a few RMs have been investigated to date, and their mechanism of action also remains elusive. Herein, we investigate the effects of the central metal ion in binuclear metal phthalocyanines on the catalysis of Li2CO3 decomposition, namely binuclear cobalt phthalocyanine (bi-CoPc) and binuclear cobalt manganese phthalocyanine (bi-CoMnPc). Density functional theory (DFT) calculations indicate that the key intermediate peroxydicarbonate (*C2O62-) is stabilized by bi-CoPc2+ and bi-CoMnPc3+, which is accountable for their excellent catalytic effects. With one central metal ion substituted by manganese for cobalt, the bi-CoMnPc's second active redox couple shifts from the second Co(II)/Co(III) couple in the central metal ion to the Pc(-2)/Pc(-1) couple in the phthalocyanine ring. In artificial dry air (N2-O2, 78:22, v/v), the LAB cell with bi-CoMnPc in electrolyte exhibited 261 cycles under a fixed capacity of 500 mAh g-1carbon and current density of 100 mA g-1carbon, significantly better than the RM-free cell (62 cycles) and the cell with bi-CoPc (193 cycles).
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The conformation of 36 kDa polyethylene oxide (PEO) dissolved in three glyme-Li(+) solvate ionic liquids (SILs) has been investigated by small angle neutron scattering (SANS) and rheology as a function of concentration and compared to a previously studied SIL. The solvent quality of a SIL for PEO can be tuned by changing the glyme length and anion type. Thermogravimetric analysis (TGA) reveals that PEO is dissolved in the SILs through Li(+)-PEO coordinate bonds. All SILs (lithium triglyme bis(trifluoromethanesulfonyl)imide ([Li(G3)]TFSI), lithium tetraglyme bis(pentafluoroethanesulfonyl)imide ([Li(G4)]BETI), lithium tetraglyme perchlorate ([Li(G4)]ClO4) and the recently published [Li(G4)]TFSI) are found to be moderately good solvents for PEO but solvent quality decreases in the order [Li(G4)]TFSI â¼ [Li(G4)]BETI > [Li(G4)]ClO4 > [Li(G3)]TFSI due to decreased availability of Li(+) for PEO coordination. For the same glyme length, the solvent qualities of SILs with TFSI(-) and BETI(-) anions ([Li(G4)]TFSI and [Li(G4)]BETI) are very similar because they weakly coordinate with Li(+), which facilitates Li(+)-PEO interactions. [Li(G4)]ClO4 presents a poorer solvent environment for PEO than [Li(G4)]BETI because ClO4(-) binds more strongly to Li(+) and thereby hinders interactions with PEO. [Li(G3)]TFSI is the poorest PEO solvent of these SILs because G3 binds more strongly to Li(+) than G4. Rheological and radius of gyration (Rg) data as a function of PEO concentration show that the PEO overlap concentrations, c* and c**, are similar in the three SILs.
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Atomic force microscope (AFM) force curves and images are used to characterize the adsorbed layer structure formed by a series of diblock copolymers with solvophilic poly(ethylene oxide) (PEO) and solvophobic poly(ethyl glycidyl ether) (PEGE) blocks at silica-water and silica-ethylammoniun nitrate (EAN, a room temperature ionic liquid (IL)) interfaces. The diblock polyethers examined are EGE109EO54, EGE113EO115, and EGE104EO178. These experiments reveal how adsorbed layer structure varies as the length of the EO block varies while the EGE block length is kept approximately constant; water is a better solvent for PEO than EAN, so higher curvature structures are found at the interface of silica with water than with EAN. At silica-water interfaces, EGE109EO54 forms a bilayer and EGE113EO115 forms elongated aggregates, while a well-ordered array of spheres is present for EGE104EO178. EGE109EO54 does not adsorb at the silica-EAN interface because the EO chain is too short to compete with the ethylammonium cation for surface adsorption sites. However, EGE113EO115 and EGE104EO178 do adsorb and form a bilayer and elongated aggregates, respectively.
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The conformation of 38 kDa PEO in a solvate ionic liquid (SIL), lithium tetraglyme bis(trifluoromethane-sulfonyl)amide ([Li(G4)]TFSI) from dilute to concentrated solution regimes has been determined by small angle neutron scattering and rheology. SANS analysis reveals that [Li(G4)]TFSI is better than a theta solvent (theta-good) for PEO. The variation of the radius of gyration (Rg) and viscosity as a function of polymer concentration allow the overlap concentrations, c* and c**, to be identified at 13 mg mL(-1) and 50 mg mL(-1), respectively, which are similar to values reported previously for conventional ionic liquids. Unlike water and conventional ionic liquids, [Li(G4)]TFSI cannot form hydrogen bonds with PEO. Thermal gravimetric analysis indicates that the solvation of PEO by [Li(G4)]TFSI is a consequence of PEO forming coordinate bonds with the lithium by displacing the anion, but without displacing the glyme molecule.
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A crystalline Ti2O1.3(PO4)1.6/TiO2 carbon-coated composite was synthesized by a glucose-modified hydrothermal method. It shows the highest reversible capacities, excellent rate properties and remarkable cycling performances compared to its counterpart prepared without glucose modification, particularly maintaining a capacity of 233.9 mA h g-1 after 200 cycles at 1000 mA g-1.
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MXene-reinforced composite coatings have recently shown promise for metal anticorrosion due to their large aspect ratio and antipermeability; however, the challenges of the poor dispersion, oxidation, and sedimentation of MXene nanofillers in a resin matrix that are often encountered in the existing curing methods have greatly limited practical applications. Herein, we reported an efficient, ambient, and solvent-free electron beam (EB) curing technology to fabricate PDMS@MXene filled acrylate-polyurethane (APU) coatings for anticorrosion of 2024 Al alloy, a common aerospace structural material. We showed that the dispersion of MXene nanoflakes modified by PDMS-OH was dramatically improved in EB-cured resin and enhanced the water resistance through the additional water-repellent groups of PDMS-OH. Moreover, the controllable irradiation-induced polymerization enabled a unique high-density cross-linked network, presenting a large physical barrier against corrosive media. The newly developed APU-PDMS@MX1 coatings achieved excellent corrosion-resistance with the highest protection efficiency of 99.9957%. The coating filled with uniformly distributed PDMS@MXene promoted the corrosion potential, corrosion current density, and corrosion rate to be -0.14 V, 1.49 × 10-9 A/cm2, and 0.0004 mm/year, respectively, and the impedance modulus was increased by 1-2 orders of magnitude compared to that of APU-PDMS coating. This work combining 2D material with EB curing technology broadens the avenue for designing and fabricating composite coatings for metal corrosion protection.
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Approximate partial phase diagrams for nine amphiphile-protic ionic liquid (PIL) systems have been determined by synchrotron source small angle X-ray scattering, differential scanning calorimetry and cross polarised optical microscopy. The binary phase diagrams of some common cationic (hexadecyltrimethyl ammonium chloride, CTAC, and hexadecylpyridinium bromide, HDPB) and nonionic (polyoxyethylene (10) oleyl ether, Brij 97, and Pluronic block copolymer, P123) amphiphiles with the PILs, ethylammonium nitrate (EAN), ethanolammonium nitrate (EOAN) and diethanolammonium formate (DEOAF), have been studied. The phase diagrams were constructed for concentrations from 10 wt% to 80 wt% amphiphile, in the temperature range 25 °C to >100 °C. Lyotropic liquid crystalline phases (hexagonal, cubic and lamellar) were formed at high surfactant concentrations (typically >50 wt%), whereas at <40 wt%, only micelles or polydisperse crystals were present. With the exception of Brij 97, the thermal stability of the phases formed by these surfactants persisted to temperatures above 100 °C. The phase behaviour of amphiphile-PIL systems was interpreted by considering the PIL cohesive energy, liquid nanoscale order, polarity and ionicity. For comparison the phase behaviour of the four amphiphiles was also studied in water.
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BACKGROUND: Gestational diabetes mellitus affects millions of pregnant women. Lifestyle intervention is recommended as the first-line treatment, in which exercise plays an important role. Effective and safe exercise is required to facilitate glycaemic control and improve delivery outcomes. OBJECTIVE: To investigate the efficacy and safety of the original Gymnastics for Pregnant Women program for glycaemic control and delivery outcomes improvement in gestational diabetes mellitus women. DESIGN: The study was a two-arm parallel randomized controlled clinical trial. SETTING: The study was conducted in a tertiary specialized maternity hospital in Hangzhou, China. PARTICIPANTS: Totally 131 eligible pregnant women were enrolled from June to December 2020. METHODS: Participants were randomly allocated to the control group (conventional intervention) or experimental group that engaged in the original Gymnastics for Pregnant Women program. The primary outcomes included glycaemic control during pregnancy and postpartum. Secondary outcomes included adverse events, maternal and neonatal outcomes. RESULTS: Participants showed a significant improvement in glycaemic control after engaging in the intervention for 2â¯weeks; the improvement was most significant in terms of the 2-h postprandial plasma glucose (Pâ¯<â¯0.05). The fasting blood glucose and 2-h postprandial plasma glucose data indicated a higher glycaemic control rate in the experimental than control group (86.16% vs. 66.67%, Pâ¯=â¯0.008; and 84.62% vs. 36.36% [6.09⯱â¯0.79 vs. 6.96⯱â¯1.06â¯mmol/L], Pâ¯<â¯0.001, respectively). After delivery, the 2-h oral glucose tolerance test results indicated better glycaemic control in the experimental than control group (75.44% vs. 57.41% [6.93⯱â¯1.44 vs. 7.79⯱â¯2.03â¯mmol/L], Pâ¯=â¯0.047). Additionally, the 2-h oral glucose tolerance test in the experimental group with reasonable exercise frequency (≥10 times per week) had the best glucose level (6.81⯱â¯1.30â¯mmol/L), followed by the experimental group with a lower exercise frequency (<10 times per week) (7.35⯱â¯1.83â¯mmol/L) and the control group (7.79⯱â¯2.03â¯mmol/L). No statistical differences in maternal or neonatal outcomes were observed between the control and experimental groups (Pâ¯>â¯0.05). In addition, there were no adverse events in the experimental group; however, in the control group, two cases experienced at least one hypoglycaemic episode and two cases received insulin during the study period. CONCLUSIONS: The original Gymnastics for Pregnant Women was associated with greater improvements in blood glucose levels during pregnancy and postpartum compared with a conventional intervention for women with gestational diabetes mellitus. REGISTRATION: ChiCTR2000033963 (2020-06-22). TWEETABLE ABSTRACT: The original Gymnastics for Pregnant Women program improves glycaemic control in GDM women but does not affect delivery outcomes.
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Diabetes Gestacional , Glicemia , Diabetes Gestacional/terapia , Feminino , Controle Glicêmico , Ginástica , Humanos , Recém-Nascido , Gravidez , GestantesRESUMO
Named entity recognition (NER) systems are often realized by supervised methods that require large hand-annotated data. When the hand-annotated data is limited, distantly supervised (DS) data and cross-domain (CD) data are usually used separately to improve the performance. The distantly supervised data can provide in-domain dictionary information, and the hand-annotated cross-domain information can be provided by cross-domain data. These two types of information are complemental. However, there are two problems required to be solved before using directly. First, the distantly supervised data may contain a lot of noise. Second, directly using cross-domain data may degrade performance due to the distribution mismatching problem. In this paper, we propose a unified model named PARE (PArtial learning and REinforcement learning). The PARE model can simultaneously use distantly supervised data and cross-domain data as external data. The model uses the partial learning method with a new label strategy to better handle the noise in distantly supervised data. The reinforcement learning method is used to alleviate the distribution mismatching problem in cross-domain data. Experiments in three datasets show that our model outperforms other baseline models. Besides, our model can be used in the situation where no hand-annotated in-domain data is provided.
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Aprendizagem , Aprendizado de Máquina , Reconhecimento PsicológicoRESUMO
OBJECTIVE: Many women experience pelvic floor dysfunction (PFD) during the perinatal period. Knowledge of PFD among women is poor, which may reflect inadequate provision of information by healthcare workers. The aim of this study was to explore obstetrical healthcare workers' knowledge, attitude, and practice regarding PFD. MATERIAL AND METHODS: This study had a cross-sectional design. We developed a 65-question survey to explore obstetrical healthcare workers' knowledge, attitude, and practice regarding PFD. An electronic version of the questionnaire was distributed to healthcare workers from 31 provinces in the People's Republic of China by convenience sampling in July and August 2019. This research complied with the guidelines of the Strengthening of the Reporting of Observational Studies in Epidemiology checklist. RESULTS: In total, 1545 valid questionnaires were collected. The mean scores for the knowledge, attitude, and practice of obstetrical healthcare workers were 23.67 ± 4.70 out of 30, 31.91 ± 6.68 out of 40, and 47.88 ± 9.17 out of 65, respectively. Approximately 50 % of the respondents reported providing practical pelvic floor muscle training (PFMT) guidance and evaluation of its correct performance only "sometimes" or even "never". Nearly 30 % of respondents denied asking patients about PFD-related symptoms. Respondents' PFD-related practice were affected not only by their knowledge and attitude but also by their age, treatment or nursing experience of PFD, own PFD history and that of relatives or friends, and the PFD-related departmental setup of their hospital (P < 0.001). CONCLUSION: Most obstetrical healthcare workers have knowledge of PFD and hold a positive attitude but fail to routinely provide PFD counseling and mentoring to patients. Many factors affect the respondents' PFD-related practice.
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Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde/psicologia , Distúrbios do Assoalho Pélvico/diagnóstico , Adolescente , Adulto , China , Estudos Transversais , Feminino , Pessoal de Saúde/estatística & dados numéricos , Humanos , Pessoa de Meia-Idade , Obstetrícia/métodos , Distúrbios do Assoalho Pélvico/terapia , Gravidez , Inquéritos e QuestionáriosRESUMO
Electrocatalytic oxygen evolution reaction (OER), an important electrode reaction in electrocatalytic and photoelectrochemical cells for a carbon-free energy cycle, has attracted considerable attention in the last few years. Metal oxides have been considered as good candidates for electrocatalytic OER because they can be easily synthesized and are relatively stable during the OER process. However, inevitable structural variations still occur to them due to the complex reaction steps and harsh working conditions of OER, thus impending the further insight into the catalytic mechanism and rational design of highly efficient electrocatalysts. The aim of this review is to disclose the current research progress toward the structural variations of metal oxide-based OER electrocatalysts. The origin of structural variations of metal oxides is discussed. Based on some typical oxides performing OER activity, the external and internal factors that influence the structural stability are summarized and then some general approaches to regulate the structural variation process are provided. Some operando methods are also concluded to monitor the structural variation processes and to identify the final active structure. Additionally, the unresolved problems and challenges are presented in an attempt to get further insight into the mechanism of structural variations and establish a rational structure-catalysis relationship.
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BACKGROUND: Stress urinary incontinence is a distressing and burdensome condition affecting approximately one third of pregnant women and pelvic floor muscle training is recommended as the first-line treatment. Convenient and cost-effective regimen of pelvic floor muscle training is required to facilitate the treatment of stress urinary incontinence and improve the adherence to treatment in pregnant women. OBJECTIVE: To determine the effectiveness of app-based audio guidance pelvic floor muscle training on the treatment of stress urinary incontinence in primiparas. DESIGN: The study was a two-arm, parallel, randomized controlled clinical trial. SETTING: The study was conducted in the obstetric clinic of a tertiary maternity hospital in Hangzhou, China. PARTICIPANTS: A total of 108 eligible primiparas were enrolled from January to April 2018. METHODS: Participants were randomly allocated (1:1) to the audio group or the control group. Primary outcomes included severity of stress urinary incontinence and adherence to pelvic floor muscle training assessed by the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form and the Broome Pelvic Muscle Self-Efficacy Scale, respectively. Secondary outcomes included pelvic floor muscle strength, bladder neck mobility and sexual function measured by vaginal palpation and pelvic floor muscle surface electromyography, perineal ultrasound and Female Sexual Function Index, respectively. Data analysis followed the intention-to-treat principle. Generalized estimation equation model, t-test and chi-square test were used to examine intervention effect on primary outcomes and secondary outcomes, respectively. RESULTS: Participants showed significant improvement in symptom severity across the study, which was most significant at 6 weeks postpartum (ß = -4.245, p < 0.001). No significant difference was found in symptom severity between groups (ß = -0.344, p = 0.168). The interaction effect between intervention and time on adherence was significant. Compared with the control group, greater self-efficacy was shown in the audio group at 6 weeks (ß = 4.425, p = 0.009), 3 months (ß = 3.204, p < 0.001) and 6 months (ß = 4.457, p < 0.001) postpartum. Participants in the audio group indicated less bladder neck descent (16.5 vs. 19.5, p = 0.020) at 6 weeks postpartum, better pelvic floor muscle strength (12.5% vs. 34.0%, p = 0.012; 4.2% vs. 18.0%, p = 0.030) and sexual function (22.2 vs. 17.3, p = 0.007) at 6 months postpartum. CONCLUSIONS: The app-based audio guidance pelvic floor muscle training was more effective and much easier to comply for treatment of stress urinary incontinence in primiparas than the conventional home-based pelvic floor muscle training.
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Aplicativos Móveis , Diafragma da Pelve/fisiopatologia , Incontinência Urinária por Estresse/terapia , Adulto , China , Terapia por Exercício , Feminino , Humanos , Período Pós-Parto , Gravidez , Inquéritos e Questionários , Resultado do Tratamento , Incontinência Urinária por Estresse/fisiopatologia , Adulto JovemRESUMO
HYPOTHESIS: The solvation characteristics of poly(ethylene oxide) (PEO) in nanostructured protic ionic liquids (PILs) are driven by polymer-solvent interactions in the polar domains of the PIL. This work hypothesises that the nanostructure of a PIL can be altered via halide addition, directly affecting the solvation of PEO. EXPERIMENTS: Small angle neutron scattering (SANS) is used to explore the conformation of 38â¯kDa PEO dissolved in the PIL propylammonium nitrate (PAN), a mol fraction of 10% propylammonium chloride (PACl) in PAN, and a mole fraction of 10% propylammonium bromide (PABr) in PAN. FINDINGS: Each of these solutions are shown to behave as a good solvent for PEO, as determined by their Flory exponents and Zimm plot analysis. The quality of solvation is reduced by the addition of the halide salt, with the order of solvation as follows: PANâ¯>â¯Br- additionâ¯>â¯Cl- addition. Our experimental observations are consistent with the recently reported solvation structure of PEO in these solutions (Stefanovic et al., 2018). The increased charge density from NO3- to Br- to Cl- results in greater net ionic interaction between the ionic charge centres. As PEO interacts with PAN primarily through the ammonium hydrogens of the cation, this increased ionic interaction effectively displaces the PEO, resulting in poorer solvation.
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A novel approach is developed to synthesize a nitrogen-doped porous Co3O4/anthracite-derived graphene (Co3O4/AG) nanocomposite through a combined self-assembly and heat treatment process using resource-rich anthracite as a carbonaceous precursor. The nanocomposite contains uniformly distributed Co3O4 nanoparticles with a size smaller than 8 nm on the surface of porous graphene, and exhibits a specific surface area (120 m2·g-1), well-developed mesopores distributed at 3~10 nm, and a high level of nitrogen doping (5.4 at. %). These unique microstructure features of the nanocomposite can offer extra active sites and efficient pathways during the electrochemical reaction, which are conducive to improvement of the electrochemical performance for the anode material. The Co3O4/AG electrode possesses a high reversible capacity of 845 mAh·g-1 and an excellent rate capacity of 587 mAh·g-1. Furthermore, a good cyclic stability of 510 mAh·g-1 after 100 cycles at 500 mA·g-1 is maintained. Therefore, this work could provide an economical and effective route for the large-scale application of a Co3O4/AG nanocomposite as an excellent anode material in lithium-ion batteries.
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A novel carboxymethyl cellulose (CMC)-supported graphene oxide aerogel (CGOA) was fabricated from a cost-effective and abundant bituminous coal by a mild hydrothermal process and freeze-drying treatment. Such an aerogel has cross-linked graphene oxide layers supported by CMC, and therefore, displays high mechanical strength while having ultra-low density (8.257 mg·cm-3). The CGOA has a 3D interconnected porous structure, beneficial graphene framework defects and abundant oxygen-containing functional groups, which offer favorable diffusion channels and effective adsorption sites for the transport and adsorption of dye molecules. The adsorption performance of rhodamine B by an optimized CGOA shows a maximum monolayer adsorption capacity of 312.50 mg·g-1, as determined by Langmuir isotherm parameters. This CGOA exhibited a better adsorption efficiency (99.99%) in alkaline solution, and satisfactory stability (90.60%) after three cycles. In addition, adsorption experiments on various dyes have revealed that CGOA have better adsorption capacities for cationic dyes than anionic dyes.
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Truly naked fluoride exists only in the gas phase. Fluoride can be stabilized by a complexing agent and an organic cation, resulting in anhydrous or dehydrated fluoride which is "partially naked." This partially naked fluoride enables fluorination reactions at much lower temperatures than hydrated fluorides. Here we show a simple method for preparing fluoride-based solvate ionic liquids (SILs) by mixing 1-alkyl-3-methylimidazolium (1-ethyl-3-methylimidazolium or 1-butyl-3-methylimidazolium) bromide, silver fluoride (AgF), and EG (1:1:1 in molar ratio) in dry methanol. Removal of the methanol produced anhydrous SILs, [C2C1im]F·EG and [C4C1im]F·EG. This is the first SIL reported that comprises fluoride. 1H NMR and infrared spectroscopy reveal fluoride hydrogen bonds with EG OH groups and cation aromatic H atoms but not cation tail group protons. Fluorination reactions on benzyl bromide show that [C2C1im]F·EG has high reactivity with reasonable yield under mild conditions, confirming the fluoride ion is partially naked.
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Deep eutectic solvents (DESs) have been prepared from mixtures of alkyl ammonium bromide salts (ethylammonium bromide, propylammonium bromide and butylammonium bromide) and glycerol at a 1: 2 M ratio. These DESs reveal the effect of cation alkyl chain length on interfacial structure at mica (a model anionic) surface. As the cation chain length is increased it becomes more amphiphilic and solvophobic, leading to stronger association of alkyl chains, as revealed by atomic force microscope force curve measurements. The effect of increasing cation alkyl chain length on phase transition and thermal decomposition temperatures, density, refractive index, viscosity, ionic and thermal conductivity and air liquid surface tension are also probed. Combined, these studies reveal the length of the cation alkyl chain weakly affects composition dependent properties (e.g. density, refractive index, thermal conduction, etc.) but has a stronger effect where intermolecular (ionic) forces play a role, such as on viscosity, and on surface tension and interfacial structure. To the authors knowledge, this is the first report of amphiphilic nanostructure in DESs and the first systematic study of the effect of cation alkyl chain length on physical properties.
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HYPOTHESIS: The conformation of poly(ethylene oxide) (PEO) in deep eutectic solvents (DESs) is determined by the polymer-solvent interactions, especially hydrogen bonding interactions. The hypothesis for this work is that the hydrogen bonding environment of a DES can be varied via changing the cation or hydrogen bond donor (HBD), and therefore the solvent quality for PEO; the anion species will also effect hydrogen bonding, but this is not examined here. EXPERIMENTS: Small angle neutron scattering (SANS) is used to probe the concentration dependent conformation of 36kDa PEO dissolved in DESs formed by mixing ethyl or butyl ammonium bromide with a molecular HBD (glycerol or ethylene glycol) in a 1:2 molar ratio. FINDINGS: The radius of gyration (Rg), Flory exponent and crossover concentration (c*) from the dilute to the semi-dilute regime of PEO in the DESs revealed by SANS and Zimm plot analysis show that these DESs are moderately good solvents for PEO. When the ammonium alkyl chain length is increased, the hydrogen bond density per unit volume decreases, and with it the solvent quality for PEO. The solvent quality is improved when the HBD is changed from glycerol to ethylene glycol due to differences in the hydrogen bonding environment for PEO.
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The melting point of a deep eutectic solvent formed from a ternary mixture of ethylammonium bromide (EABr), butylammonium bromide (BABr) and urea is 10 °C, which is almost 40 °C lower than the melting points of binary DESs formed from either EABr:urea or BABr:urea mixtures. This reveals a new route to prepare room temperature DESs via mixing different cations.