Performance Analysis of Public Safety Cognitive Radio MANET for Diversified Traffic.

This paper presents properties of a mobile ad hoc network (MANET) with dynamic spectrum management (DSM) and is devoted to the concept and implementation of the new traffic engine that is used in a High-Fidelity simulator of MANET with cognitive nodes for special applications. The communication traffic generated by each node is defined according to its role in the hierarchical structure of the operational scenario, determining its priorities, permission to use particular real time and non-real time services. The service usage is a source based model, defined in the user's profile containing its statistical properties, describing periodicity, duration and randomness of traffic generation. The overall traffic generated by the node is a combination of traffics related to specific services. Their statistical parameters are based on real exercises results. The model was defined in the Matlab environment and next verified using the MAENA simulator for complex, operational scenarios. The achieved results show that use of both central and distributed DSM provides a better performance of the MANET network with complex traffic.

Design, Fabrication and Analysis of Magnetorheological Soft Gripper.

The magnetorheological elastomer is promising material for applications in soft robotics. Its properties like reactive to external magnetic field and softness allow to construct an attractive devices. This work presents a construction of soft gripper assembled with magnetorheological elastomers. The work describes the detailed molding process of magnetorheological elastomers. Further, the electromechanical properties of magnetorheological elastomers are shown using a simple beam. Finally, the soft gripper is constructed and analyzed with the series of experiments.

Cognitive Radio MANET Waveform Design and Evaluation.

The problem of waveform construction for mobile ad hoc networks with cognitive radio (MANET-CR) is discussed. This is the main limitation to widely use this very attractive technique, which does not need the deployment of expensive communication infrastructure. Two main questions correspond to MANET-CR effectiveness: spectrum sensing and spectrum sharing. The paper presents the structure of CR nodes that enables Opportunistic Spectrum Sharing. Procedures for advanced Dynamic Spectrum Management together with the concept of policy-based radio and a sensing method are presented. In the proposed system, the basic policy is to avoid interference generated by other users or jammers. The experiments were performed in a real environment, using the elaborated testbed. The results show that the use of sensing and cognitive management mechanisms enable more efficient use of the spectrum while maintaining reasonable overhead values related to the management procedures.

Ionogels Obtained by Thiol-ene Photopolymerization-Physicochemical Characterization and Application in Electrochemical Capacitors.

Flexible ionogels with good mechanical properties were obtained in situ by thiol-ene photopolymerization of trimethylolpropane tris(3-mercaptopropionate) (TMPTP) and 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TATT) (with C=C: SH ratio 1:1) in four imidazolium ionic liquids (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide-EMImNTf2, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate-EMImOTf, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide-BMImNTf2, and 1-butyl-3-methylimidazolium trifluoromethanesulfonate-BMImOTf) used in the range 50 to 70 wt.%. The mechanical and electrochemical properties of obtained ionogels were examined. Ionogels with ionic liquids (ILs) with NTf2- anion are more puncture resistant than with OTf⁻ anion. Moreover, ionogels with the NTF2- anion have better electrochemical properties than those with the OTf⁻ anion. Although it should be noted that ionogels with the EMIm+ cation have a higher conductivity than the BMIm+. This is connected with intermolecular interactions between polymer matrix and IL related to the polarity of IL described by the Kamlet-Taft parameters. These parameters influence the morphology of the polymer matrix (as shown by the SEM micrograph), which is formed by interconnected polymer spheres.

Asymmetric Hydrogenation of 3-Substituted Pyridinium Salts.

The use of an equivalent amount of an organic base leads to high enantiomeric excess in the asymmetric hydrogenation of N-benzylated 3-substituted pyridinium salts into the corresponding piperidines. Indeed, in the presence of Et3 N, a Rh-JosiPhos catalyst reduced a range of pyridinium salts with ee values up to 90 %. The role of the base was elucidated with a mechanistic study involving the isolation of the various reaction intermediates and isotopic labeling experiments. Additionally, this study provided some evidence for an enantiodetermining step involving a dihydropyridine intermediate.

Primary cardiac angiosarcoma - a review.

Primary cardiac neoplasms are extremely rare. Angiosarcoma is the most commonly seen histological subtype and is characterized by its permeating and destructive nature. Unfortunately, primary cardiac angiosarcoma is often overlooked as an initial diagnosis because of its rarity. Since the time it was first identified in 1934, little progress has been made in improving survival outcome. Complete or partial surgical resection is still the best option for palliation, with little hope for cure. Improvements have been made in the ability to view and distinguish tumors. Echocardiography is one of the most useful diagnostic tools because of its high sensitivity; therefore, CT and MR images are often used to detect sites of metastatic disease. Immunohistochemistry staining can also be employed as an adjunctive diagnostic tool. CD31, CD34, FLI-1, and von Willebrand factor are the most commonly used markers in detecting tumors of endothelial origin. However, due to the vast heterogeneity within a tumor, immunohistochemistry staining can be quite variable. Surgical resection remains the standard modality of treatment. Primary cardiac angiosarcoma is largely resistant to chemotherapy and/or radiation. However, the exact benefit and its place in a multimodality treatment regimen are still under investigation.

Validation of Becton Dickinson Barricor™ tubes for use with Abbott Alinity™ and Siemens Atellica® highly sensitive cardiac troponin I measuring systems.

BACKGROUND: BD Barricor™ tubes have been proposed to decrease laboratory turnaround time (TAT). We analytically validated and then clinically verified these tubes for use with Abbott Alinity™ and Siemens Atellica® highly sensitive cardiac troponin I (hs-cTnI) assays. METHODS: hs-cTnI measurements were undertaken in paired Barricor™ and in-use PSTII™ tubes on both systems. 359 matched samples with hs-cTnI levels between 3 and 15,000 ng/L (Atellica® values) were used to assess the hemolysis rate and make method comparisons. 599 paired patient samples were collected on emergency department (ED) admission to compare the performance of the rapid acute myocardial infarction (AMI) rule-out strategy based on hs-cTnI concentrations lower than recommended thresholds (<4 ng/L Alinity™; <5 ng/L Atellica®) when different tubes and systems were employed. RESULTS: No between-tube differences in hemolysis rate were seen when free hemoglobin concentrations in plasma samples were ≥0.25 g/L, even if PSTII™ showed a significant increase of hemolysis rate vs. Barricor™ (31% vs. 22%, p=0.007) when a lower cut-off for hemolysis (≥0.11 g/L) was employed on the Atellica® detection system. The alternate use of these tubes did not influence the hs-cTnI results obtained from either of the two assays, which remained markedly biased (~40%) irrespective of the tube used. The expected optimal ability of very low hs-cTnI values on ED admission for ruling out AMI was confirmed by using both systems regardless of the tube type. CONCLUSIONS: Barricor™ and PSTII™ tubes can provide analytically equivalent hs-cTnI results when used on either Alinity™ or Atellica® hs-cTnI assays.

Effectiveness of remote pulmonary artery pressure estimating in heart failure: systematic review and meta-analysis.

Heart failure (HF) poses a significant challenge, often leading to frequent hospitalizations and compromised quality of life. Continuous pulmonary artery pressure (PAP) monitoring offers a surrogate for congestion status in ambulatory HF care. This meta-analysis examines the efficacy of PAP monitoring devices (CardioMEMS and Chronicle) in preventing adverse outcomes in HF patients, addressing gaps in prior randomized controlled trials (RCTs). Five RCTs (2572 participants) were systematically reviewed. PAP monitoring significantly reduced HF-related hospitalizations (RR 0.72 [95% CI 0.6-0.87], p = 0.0006) and HF events (RR 0.86 [95% CI 0.75-0.99], p = 0.03), with no impact on all-cause or cardiovascular mortality. Subgroup analyses highlighted the significance of CardioMEMS and blinded studies. Meta-regression indicated a correlation between prolonged follow-up and increased reduction in HF hospitalizations. The risk of bias was generally high, with evidence certainty ranging from low to moderate. PAP monitoring devices exhibit promise in diminishing HF hospitalizations and events, especially in CardioMEMS and blinded studies. However, their influence on mortality remains inconclusive. Further research, considering diverse patient populations and intervention strategies with extended follow-up, is crucial for elucidating the optimal role of PAP monitoring in HF management.

Physiotherapy in asthma--seeking consensus.

OBJECTIVE: The evidence base for or against physiotherapy interventions in asthmatic adults remains ambiguous, and there are discrepancies between different clinical practice guidelines. We evaluated the level of agreement between the recommendations about physiotherapy for adults with asthma in two major clinical practice guidelines: the Global Initiative for Asthma (GINA 2011) and the British Thoracic Society and the Association of Chartered Physiotherapists in Respiratory Care (BTS/ACPRC 2009). METHODS: We used the Appraisal of Guidelines for Research & Evaluation (AGREE II) instrument to assess the methodological rigor of the guideline development, the Assessment of Multiple Systematic Reviews (AMSTAR) tool and the Physiotherapy Evidence Database (PEDro) scale to assess the methodological quality of systematic reviews and clinical trials included in the analyzed documents. Additionally, we compared the reference lists of the analyzed sections to establish the overlap in included primary and secondary studies. RESULTS: We observed no agreement between the two guidelines in the choice of source research articles. Only two studies out of 18 used in BTS guidelines were used in the GINA. The reason why GINA developers did not use the body of evidence included in BTS is that it is not clear. Three independent investigators indicated higher scores in all domains of the AGREE II in the BTS/ACPRC document in comparison with the GINA guidelines. CONCLUSIONS: The significant differences in the content and in the development processes of the examined sections of the two guidelines suggest the need for more frequent and careful updating or directing the readers of the GINA to the BTS/ACPRC, a guideline addressing specifically and more comprehensively physiotherapy interventions in asthma.

Hydrogel Polymer Electrolytes: Synthesis, Physicochemical Characterization and Application in Electrochemical Capacitors.

Electrochemical capacitors operating in an aqueous electrolyte solution have become ever-more popular in recent years, mainly because they are cheap and ecofriendly. Additionally, aqueous electrolytes have a higher ionic conductivity than organic electrolytes and ionic liquids. These materials can exist in the form of a liquid or a solid (hydrogel). The latter form is a very promising alternative to liquid electrolytes because it is solid, which prevents electrolyte leakage. In our work, hydrogel polymer electrolytes (HPEs) were obtained via photopolymerization of a mixture of acrylic oligomer Exothane 108 with methacrylic acid (MAA) in ethanol, which was later replaced by electrolytes (1 M Na2SO4). Through the conducted research, the effects of the monomers ratio and the organic solvent concentration (ethanol) on the mechanical properties (tensile test), electrolyte sorption, and ionic conductivity were examined. Finally, hydrogel polymer electrolytes with high ionic conductivity (σ = 26.5 mS∙cm-1) and sufficient mechanical stability (σmax = 0.25 MPa, εmax = 20%) were tested using an AC/AC electrochemical double layer capacitor (EDLC). The electrochemical properties of the devices were investigated via cyclic voltammetry, galvanostatic charge/discharge, and impedance spectroscopy. The obtained results show the application potential of the obtained HPE in EDLC.

Safety, Feasibility of Controllable Decrease of Vena Cava Pressure by Doraya Catheter in Heart Failure.

Lowering elevated central venous pressure may reduce renal dysfunction in acute heart failure (AHF) patients. The Doraya catheter lowers renal venous pressure by creating a gradient in the inferior vena cava below the renal veins. Here, we present a first-in-human feasibility study of the Doraya catheter performed on 9 AHF patients. We assessed the safety, feasibility, and acute clinical (hemodynamic and renal) effects of transient Doraya catheter deployment when added to the standard diuretic-based regimen in AHF patients with a poor diuretic response. The procedures decreased central venous pressure from 18.4 ± 3.8 mm Hg to 12.4 ± 4.7 mm Hg (P < 0.001) and improved mean diuresis and clinical signs of congestion. No device-related serious adverse events were observed. Thus, Doraya catheter deployment was safe and feasible in AHF patients. (First In Human Study of the Doraya Catheter for the Treatment of AHF Patients; NCT03234647).

A Pilot Study on Standardized In-hospital Education About Heart Failure Conducted During the First Days After Decompensation.

INTRODUCTION: Education addressed to heart failure (HF) patients constitutes an important element of modern comprehensive treatment programs. The present article demonstrates a novel method of standardized in-hospital education addressed to patients admitted due to decompensation in HF. METHODS: This pilot study was conducted among 20 patients [19 men, age 63 ± 16 years, NYHA (Classification according to New York Heart Association) on admission (II/III/IV): 5/25/70%]. Five-day education was based on individual sessions conducted using colorful boards demonstrating selected, highly practical elements of the knowledge about HF management, prepared by experts in HF management (medical doctors, a psychologist, and a dietician). The level of knowledge about HF was measured before and after education, based on a questionnaire prepared by the authors of the boards. RESULTS: All patients experienced an improvement of their clinical status (confirmed by reduced New York Heart Association class and body mass, both P < 0.05). Mini Mental State Exam (MMSE) confirmed that no one demonstrated cognitive impairment. The score reflecting the level of knowledge about HF improved significantly after 5 days of in-hospital treatment accompanied by education (P = 0.0001). CONCLUSIONS: We showed that the proposed model of education addressed to patients with decompensated HF, conducted using colorful boards demonstrating selected, highly practical elements of the knowledge about HF management, prepared by experts in HF management lead to significant increase of HF-related knowledge.

Sex-stratified patterns of emergency cardiovascular admissions prior and during the COVID-19 pandemic.

The COVID-19 pandemic has had a significant impact on global public health, with long-term consequences that are still largely unknown. This study aimed to assess the data regarding acute cardiovascular hospital admissions in five European centers before and during the pandemic. A multicenter, multinational observational registry was created, comparing admissions to the emergency departments during a 3-months period in 2020 (during the pandemic) with the corresponding period in 2019 (pre-pandemic). Data on patient demographics, COVID-19 test results, primary diagnosis, comorbidities, heart failure profile, medication use, and laboratory results were collected. A total of 8778 patients were included in the analysis, with 4447 patients in 2019 and 4331 patients in 2020. The results showed significant differences in the distribution of cardiovascular diseases between the two years. The frequency of pulmonary embolism (PE) increased in 2020 compared to 2019, while acute heart failure (AHF) and other cardiovascular diseases decreased. The odds of PE incidence among hospitalized patients in 2020 were 1.316-fold greater than in 2019. The incidence of AHF was 50.83% less likely to be observed in 2020, and the odds for other cardiovascular diseases increased by 17.42% between the 2 years. Regarding acute coronary syndrome (ACS), the distribution of its types differed between 2019 and 2020, with an increase in the odds of ST-segment elevation myocardial infarction (STEMI) in 2020. Stratification based on sex revealed further insights. Among men, the incidence of AHF decreased in 2020, while other cardiovascular diseases increased. In women, only the incidence of STEMI showed a significant increase. When analyzing the influence of SARS-CoV-2 infection, COVID-positive patients had a higher incidence of PE compared to COVID-negative patients. COVID-positive patients with ACS also exhibited symptoms of heart failure more frequently than COVID-negative patients. These findings provide valuable information on the impact of the COVID-19 pandemic on acute cardiovascular hospital admissions. The increased incidence of PE and changes in the distribution of other cardiovascular diseases highlight the importance of monitoring and managing cardiovascular health during and post pandemic period. The differences observed between sexes emphasize the need for further research to understand potential sex-specific effects of COVID-19 on cardiovascular outcomes.

Gel Polymer Electrolytes with Mixture of Triazolium Ionic Liquids and Propylene Carbonate.

This study is focused on the structural influence of 1,2,4-triazolium ionic liquid (IL), that is, the effect of the length of the substituent and the type of substitution (1-methyl-4-alkyl or 1-alkyl-4-methyl) used in the mixture with propylene carbonate (PC) on the properties of thiol-ene polymer ionogels and on the preparation of an ionogel with satisfactory mechanical and conductive properties. PC allows for higher conductivity but also causes electrolyte leakage from the gel. When using triazolium IL (instead of the imidazolium one), because of the stronger interactions between components of the system, the ionogels do not leak. In this study, 1,4-dialkyl-1,2,4-triazolium ILs were successfully synthesized by the alkylation of 1,2,4-triazole. Subsequently, gel polymer electrolytes were obtained by one-pot thiol-ene photopolymerization reactions of tetrafunctional thiols with different chemical structures: pentaerythritol tetra(3-mercaptopropionate) (PETMP) or pentaerythritol tetra(3-mercaptobutyrate) (PETMB) and trifunctional ene (TATT) in the presence of a mixture of 1,4-dialkyl-1,2,4-triazolium IL with PC. Measurements made by electrochemical impedance spectroscopy showed that all ionogels with TATT+PETMB as a polymer matrix presented smaller relative ionic conductivity compared to ionogels containing TATT+PETMP. The puncture resistance and elongation at puncture, measured by the puncture resistance method, were higher for ionogels with poly(TATT+PETMB) than for those with poly(TATT+PETMP). Moreover, ILs containing a methyl group in position N1 of the 1,2,4-triazole ring presented lower puncture resistance than ionogels with ILs containing a methyl group in position N4, especially for shorter alkyl chains. Additionally, the photo-differential scanning calorimetry method was employed to characterize the course of photopolymerization. The compositions and their constituents were characterized by UV and IR spectroscopy.

Influence of Initiator Concentration on the Polymerization Course of Methacrylate Bone Cement.

Background: The amount of oxidant (initiator) and reductant (co-initiator) and their ratio have a significant effect on the properties of polymethacrylate bone cement, such as maximum temperature (Tmax), setting time (tset) and compressive strength (σ). The increase in the initiating system concentration causes an increase in the number of generated radicals and a faster polymerization rate, which shortens the setting time. The influence of the redox-initiating composition on the course of polymerization (rate of polymerization and degree of double bond conversion) and the mechanical properties of bone cement will be analyzed. Methods: Bone cements were synthesized by mixing a powder phase composed of two commercially available methacrylate copolymers (Evonic) and a liquid phase containing 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA), and triethylene glycol dimethacrylate (D3). As an initiating system, the benzoyl peroxide (BPO) as an oxidant (initiator) in combination with a reducing agent (co-initiator), N,N-dimethylaniline (DMA), was used. Samples were prepared with various amounts of peroxide BPO (0.05%, 0.1%, 0.2%, 0.3%, 0.5% and 0.7% by weight) with a constant amount of reducing agent DMA (0.5 wt.%), and various amounts of DMA (0.25%, 0.35% and 0.5% by weight) with a constant amount of BPO (0.3 wt.%). The polymerization kinetics were studied by differential scanning calorimetry (DSC). Doughing time and compressive strength tests were carried out according to the requirements of the ISO 5833:2002 standard. Results: The increase in polymerization rate was due to the increase in the amount of BPO. In addition, the curing time was shortened, as well as the time needed to achieve the maximum polymerization rate. The final conversion of the double bonds in the studied compositions was in the range 74-100%, and the highest value of this parameter was obtained by the system with 0.3 wt.% of BPO. The doughing times for each BPO concentration were in the range of 90-140 s. The best mechanical properties were obtained for the cement following the initiating system concentrations: 0.3 wt.% of BPO and 0.5 wt.% of DMA. Nevertheless, all tested cements met the requirements of the ISO 5833:2002 standard. Conclusions: Based on the conducted polymerization kinetic studies, the best reaction conditions are provided by an initiating system containing 0.3 wt.% of BPO oxidant (initiator) and 0.5 wt.% of DMA reductant (co-initiator). A decrease in the DMA amount caused a decrease in the polymerization rate and the amount of heat released during the reaction. The change in BPO and DMA concentrations in the composition had little effect on the doughing time of the studied bone cement. The cements showed similar doughing times, ranging from 90-225 s, which is comparable to the bone cement available on the market.

Early Hemodynamic Changes following Surgical Ablation of the Right Greater Splanchnic Nerve for the Treatment of Heart Failure with Preserved Ejection Fraction.

BACKGROUND: Permanent ablation of the right greater splanchnic nerve (GSN) has previously been demonstrated to improve quality of life and functional outcomes, as well as reduce abnormally high intracardiac filling pressures, in patients with heart failure with preserved ejection fraction (HFpEF) at 1, 3 and 12 months following the procedure. We hypothesize that hemodynamic changes that ensue from surgical right GSN ablation would be apparent as early as 24 h after the medical intervention. METHODS AND RESULTS: This is a prespecified analysis of a single-arm, two-center, open-label study evaluating the effects of right GSN ablation via thoracoscopic surgery in HFpEF patients with pulmonary capillary wedge pressure (PCWP) ≥15 mmHg at rest or ≥25 mmHg with supine cycle ergometry. A total of seven patients (median age 67 years, 29% female) underwent GSN removal followed by invasive right heart catheterization within 24 h. GSN ablation resulted in a significant reduction in PCWP 24 h after the procedure compared to baseline for both 20 W exercise (baseline (28.0 ± 4.3 mmHg) to 24 h (19.6 ± 6.9 mmHg); p = 0.0124) and peak exercise (baseline (25.6 ± 2.4 mmHg) to 24 h (17.4 ± 5.9 mmHg); p = 0.0025). There were no significant changes in resting or leg-up hemodynamics. CONCLUSIONS: Permanent right GSN ablation leads to a reduction in intracardiac filling pressures during exercise, apparent as early as 24 h following the procedure.

Novel Phenotyping for Acute Heart Failure-Unsupervised Machine Learning-Based Approach.

Acute heart failure (AHF) is a life-threatening, heterogeneous disease requiring urgent diagnosis and treatment. The clinical severity and medical procedures differ according to a complex interplay between the deterioration cause, underlying cardiac substrate, and comorbidities. This study aimed to analyze the natural phenotypic heterogeneity of the AHF population and evaluate the possibilities offered by clustering (unsupervised machine-learning technique) in a medical data assessment. We evaluated data from 381 AHF patients. Sixty-three clinical and biochemical features were assessed at the admission of the patients and were included in the analysis after the preprocessing. The K-medoids algorithm was implemented to create the clusters, and optimization, based on the Davies-Bouldin index, was used. The clustering was performed while blinded to the outcome. The outcome associations were evaluated using the Kaplan-Meier curves and Cox proportional-hazards regressions. The algorithm distinguished six clusters that differed significantly in 58 variables concerning i.e., etiology, clinical status, comorbidities, laboratory parameters and lifestyle factors. The clusters differed in terms of the one-year mortality (p = 0.002). Using the clustering techniques, we extracted six phenotypes from AHF patients with distinct clinical characteristics and outcomes. Our results can be valuable for future trial constructions and customized treatment.

COVID-19 Related Myocarditis in Adults: A Systematic Review of Case Reports.

Despite the progress of its management, COVID-19 maintains an ominous condition which constitutes a threat, especially for the susceptible population. The cardiac injury occurs in approximately 30% of COVID-19 infections and is associated with a worse prognosis. The clinical presentation of cardiac involvement can be COVID-19-related myocarditis. Our review aims to summarise current evidence about that complication. The research was registered at PROSPERO (CRD42022338397). We performed a systematic analysis using five different databases, including i.a. MEDLINE. Further, the backward snowballing technique was applied to identify additional papers. Inclusion criteria were: full-text articles in English presenting cases of COVID-19-related myocarditis diagnosed by the ESC criteria and patients over 18 years old. The myocarditis had to occur after the COVID-19 infection, not vaccination. Initially, 1588 papers were screened from the database search, and 1037 papers were revealed in the backward snowballing process. Eventually, 59 articles were included. Data about patients' sex, age, ethnicity, COVID-19 confirmation technique and vaccination status, reported symptoms, physical condition, laboratory and radiological findings, applied treatment and patient outcome were investigated and summarised. COVID-19-related myocarditis is associated with the risk of sudden worsening of patients' clinical status, thus, knowledge about its clinical presentation is essential for healthcare workers.

The Influence of Monomer Structure on the Properties of Ionogels Obtained by Thiol-Ene Photopolymerization.

The influence of ene and thiol monomer structure on the mechanical and electrochemical properties of thiol-ene polymeric ionogels were investigated. Ionogels were obtained in situ by thiol-ene photopolymerization of 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TATT), 2,4,6-triallyloxy-1,3,5-triazine (TAT), diallyl phthalate (DAP), and glyoxal bis(diallyl acetal) (GBDA) used as enes and trimethylolpropane tris(3-mercaptopropionate) (TMPTP), pentaerythritol tetrakis(3-mercaptopropionate) (PETMP), and pentaerythritol tetrakis(3-mercaptobutyrate) (PETMB) used as thiols in 70 wt.% of ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMImNTf2). The mechanical strength of ionogels was studied by puncture resistance and ionic conductivity by electrochemical impedance spectroscopy. The course of photopolymerization by photo-DSC method (differential scanning calorimetry) as well as characterization of compositions and its components (by IR and UV spectroscopy-Kamlet-Taft parameters) were also studied. The resulting ionogels were opaque, with phase separation, which resulted from the dispersion mechanism of polymerization. The mechanical and conductive properties of the obtained materials were found to be largely dependent on the monomer structure. Ionogels based on triazine monomers TAT and TATT were characterized by higher mechanical strength, while those based on aliphatic GBDA had the highest conductivity. These parameters are strongly related to the structure of the polymer matrix, which is in the form of connected spheres. The conductivity of ionogels was high, in the range of 3.5-5.1 mS∙cm-1.

Optimization of the Properties of Photocured Hydrogels for Use in Electrochemical Capacitors.

In this work, hydrogel polymer electrolytes (HPEs) were obtained by the photopolymerization of a mixture of two monomers: Exothane 8 (Ex8) and 2-hydroxyethylmethacrylate acid phosphate (HEMA-P) in an organic solvent N-methyl-2-pyrrolidone (NMP), which was replaced after polymerization with water, and then with the electrolyte. The ratio of monomers as well as the concentration of NMP was changed in the composition to study its influence on the properties of the HPE: conductivity (electrochemical impedance spectroscopy, EIS) and mechanical properties (puncture resistance). Properties were optimized using a mathematical model to obtain a hydrogel with both good mechanical and conductive properties. To the best of our knowledge, it is the first publication that demonstrates the application of optimization methods for the preparation of HPE. Then, the hydrogel with optimal properties was tested as a separator in a two-electrode symmetric AC/AC pouch-cell. The cells were investigated by cyclic voltammetry galvanostatic charge/discharge with potential limitation and EIS. Good mechanical properties of HPE allowed for obtaining samples of smaller thickness while maintaining very good dimensional stability. Thus, the electrochemical capacitor (EC) resistance was reduced and their electrochemical properties improved. Moreover, photopolymerization kinetics in the solvent and in bulk by photo-DSC (differential scanning calorimetry) were performed. The great impact on the polymerization of HEMA-P and its mixtures (with Ex8 and NMP) have strong intermolecular interactions between reagents molecules (i.e., hydrogen bonds).