Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 680
1.
Epidemiol Health ; : e2024048, 2024 Apr 30.
Article En | MEDLINE | ID: mdl-38697860

The Korea Nurses' Health Study (KNHS) is an ongoing, large-scale, prospective cohort study of female nurses, focusing on the effects of occupational, environmental, and lifestyle factors on the health of women. The first KNHS survey was performed in 2013-2014 (n=20,613). As of December 2023, 11 follow-up surveys have been conducted. Participants who were pregnant were asked to participate in the early pregnancy survey (n=2,179) and postpartum survey after giving birth (n=2,790). The main variables included sociodemographic, work-related, lifestyle, physical, mental, and women's health factors. Blood, urine, and toenail samples were collected from a participant subgroup of the first survey (n=1,983). The subgroups of the second survey completed a food frequency questionnaire in 2019 (n=300) and 2021 (n=871). In 2020, a subgroup of the first survey answered a coronavirus disease 2019 (COVID-19)-related survey (n=975). To examine various health-related factors in young adults, new participants were added to the KNHS cohort in the 11th (n=1,000) and 12th (n=1,002) surveys. The KNHS cohort will help identify health and illness determinants in Korean women. Data can be accessed at https://coda.nih.go.kr/frt/index.do.

2.
Article En | MEDLINE | ID: mdl-38629850

OBJECTIVES: Childhood abuse has been extensively studied in relation to later-life health, yet relatively little attention has been given to understanding the nuanced dynamics across victim-perpetrator relationships. This study addresses this gap by identifying typologies of familial perpetrators of childhood abuse in a national sample and examining their associations with various health outcomes, including physical and mental health as well as substance abuse. METHODS: We used two waves of data from the Midlife in the US Study (n=6,295, mean age=46.9 at baseline). The analysis was completed in three stages. Using Latent Class Analysis (LCA), we identified subpopulations of victims with distinct familial perpetrator histories. With assigned LCA memberships and propensity score weighting, we investigated the extent to which specific victim-perpetrator relationships are associated with health outcomes measured at baseline and a 10-year follow-up adjusting for other early-life risks. We evaluated whether the observed associations differ across the waves. RESULTS: Parental and sibling abuse commonly co-occur, surpassing the occurrence of single perpetrators. While minimal health disparities are evident between sibling-only abuse and no/little abuse groups at baseline, parent-only abuse is associated with compromised health outcomes. Severe abuse from both siblings and parents is linked to the most adverse health outcomes. At the follow-up survey, the associations between familiar abuse and health outcomes weakened, particularly for substance abuse. DISCUSSION: This study, delving into family relationships, family violence, and health disparities, provides new evidence to augment our comprehension of the enduring link between childhood abuse and health within the family context.

4.
Adv Sci (Weinh) ; : e2402156, 2024 Apr 22.
Article En | MEDLINE | ID: mdl-38647410

Lithium metal anode (LMA) emerges as a promising candidate for lithium (Li)-based battery chemistries with high-energy-density. However, inhomogeneous charge distribution from the unbalanced ion/electron transport causes dendritic Li deposition, leading to "dead Li" and parasitic reactions, particularly at high Li utilization ratios (low negative/positive ratios in full cells). Herein, an innovative LMA structural model deploying a hyperporous/hybrid conductive architecture is proposed on single-walled carbon nanotube film (HCA/C), fabricated through a nonsolvent induced phase separation process. This design integrates ionic polymers with conductive carbon, offering a substantial improvement over traditional metal current collectors by reducing the weight of LMA and enabling high-energy-density batteries. The HCA/C promotes uniform lithium deposition even under rapid charging (up to 5 mA cm-2) owing to its efficient mixed ion/electron conduction pathways. Thus, the HCA/C demonstrates stable cycling for 200 cycles with a low negative/positive ratio of 1.0 when paired with a LiNi0.8Co0.1Mn0.1O2 cathode (areal capacity of 5.0 mAh cm-2). Furthermore, a stacked pouch-type full cell using HCA/C realizes a high energy density of 344 Wh kg-1 cell/951 Wh L-1 cell based on the total mass of the cell, exceeding previously reported pouch-type full cells. This work paves the way for LMA development in high-energy-density Li metal batteries.

5.
J World Fed Orthod ; 2024 Apr 22.
Article En | MEDLINE | ID: mdl-38653656

Orthodontic uprighting or traction of an impacted mandibular second molar often necessitates invasive interventions. This report aims to illustrate the utilization of nickel-titanium wire segments inserted into small, simple tubes for uprighting mesially impacted mandibular second molars and also for scissor bite correction. The term "simple tube" refers to a tube without a bonding base attached to a tooth surface by covering it with flowable composite resin. Due to the absence of a bonding base, the simple tube is characterized by its diminutive size and minimal profile height, facilitating placement on partially exposed second molars and unconventional positioning to adjust the force geometry. In this case study, mesially-impacted mandibular second molars with scissor bite were uprighted in a 21-year-old male utilizing simple tubes. Simple tubes can be used for molar uprighting and scissor bite correction buccally and lingually.

6.
Res Sq ; 2024 Mar 29.
Article En | MEDLINE | ID: mdl-38585893

Background: Viscoelastic hemostatic assays (VHA) provide more comprehensive assessments of coagulation compared to conventional coagulation assays. While VHAs have enabled guided hemorrhage control therapies, improving clinical outcomes in life-threatening hemorrhage, the role of VHAs in intracerebral hemorrhage (ICH) is unclear. If VHAs can identify coagulation abnormalities relevant for ICH outcomes, this would support the need to investigate the role of VHAs in ICH treatment paradigms. Thus, we investigated whether VHA assessments of coagulation relate to long-term ICH outcomes. Methods: Spontaneous ICH patients enrolled into a single-center cohort study receiving admission Rotational Thromboelastometry (ROTEM) VHA testing between 2013 and 2020 were assessed. Patients with prior anticoagulant use or coagulopathy on conventional coagulation assays were excluded. Primary ROTEM exposure variables were coagulation kinetics and clot strength assessments. Poor long-term outcome was defined as modified Rankin Scale ≥ 4 at 6 months. Logistic regression analyses assessed associations of ROTEM parameters with clinical outcomes after adjusting for ICH severity and hemoglobin concentration. Results: Of 44 patients analyzed, mean age was 64, 57% were female, and the median ICH volume was 23 mL. Poor 6-month outcome was seen in 64%. In our multivariable regression models, slower, prolonged coagulation kinetics (adjusted OR for every second increase in clot formation time: 1.04, 95% CI: 1.00-1.09, p = 0.04) and weaker clot strength (adjusted OR for every millimeter increase of maximum clot firmness: 0.84, 95% CI: 0.71-0.99, p = 0.03) were separately associated with poor long-term outcomes. Conclusions: Slower, prolonged coagulation kinetics and weaker clot strength on admission VHA ROTEM testing, not attributable to anticoagulant use, were associated with poor long-term outcomes after ICH. Further work is needed to clarify the generalizability and the underlying mechanisms of these VHA findings to assess whether VHA guided treatments should be incorporated into ICH care.

7.
ACS Omega ; 9(15): 17533-17540, 2024 Apr 16.
Article En | MEDLINE | ID: mdl-38645326

Epoxy resin is extensively applied in the electronics and electrical fields because of its outstanding comprehensive performance. However, the low thermal conductivity (TC) limits its application in thermal interface materials. In the present work, epoxy-based hybrid composites with high TC were prepared by using expanded graphite (EG) and copper (Cu) nanoparticles as thermally conductive hybrid fillers via hot blending and compression-curing processes. Additionally, the influence of the Cu content on the thermal properties, mechanical properties, and morphology of each epoxy/EG/Cu composite was investigated. According to the results, the epoxy/EG/Cu composite showed a maximum TC of 9.74 W/(m·K) at a fixed EG content of 60 wt % owing to the addition of 10 wt % Cu. After the addition of 10 wt % Cu, the flexural strength, flexural modulus, and impact strengths of epoxy/EG/Cu composites were improved from 27.9 MPa, 9.72 GPa, and 0.81 kJ/m2 to 37.5 MPa, 10.88 GPa, and 0.91 kJ/m2, respectively. Hence, this study offers a feasible strategy for the design of epoxy hybrid composites with excellent TC that can be applied to thermal interface materials.

8.
Intensive Care Med ; 50(5): 646-664, 2024 May.
Article En | MEDLINE | ID: mdl-38598130

Aneurysmal subarachnoid haemorrhage (aSAH) is a rare yet profoundly debilitating condition associated with high global case fatality and morbidity rates. The key determinants of functional outcome include early brain injury, rebleeding of the ruptured aneurysm and delayed cerebral ischaemia. The only effective way to reduce the risk of rebleeding is to secure the ruptured aneurysm quickly. Prompt diagnosis, transfer to specialized centers, and meticulous management in the intensive care unit (ICU) significantly improved the prognosis of aSAH. Recently, multimodality monitoring with specific interventions to correct pathophysiological imbalances has been proposed. Vigilance extends beyond intracranial concerns to encompass systemic respiratory and haemodynamic monitoring, as derangements in these systems can precipitate secondary brain damage. Challenges persist in treating aSAH patients, exacerbated by a paucity of robust clinical evidence, with many interventions showing no benefit when tested in rigorous clinical trials. Given the growing body of literature in this field and the issuance of contemporary guidelines, our objective is to furnish an updated review of essential principles of ICU management for this patient population. Our review will discuss the epidemiology, initial stabilization, treatment strategies, long-term prognostic factors, the identification and management of post-aSAH complications. We aim to offer practical clinical guidance to intensivists, grounded in current evidence and expert clinical experience, while adhering to a concise format.


Critical Care , Intensive Care Units , Subarachnoid Hemorrhage , Humans , Subarachnoid Hemorrhage/complications , Subarachnoid Hemorrhage/therapy , Subarachnoid Hemorrhage/physiopathology , Critical Care/methods , Critical Care/standards , Intensive Care Units/organization & administration , Prognosis , Aneurysm, Ruptured/complications , Aneurysm, Ruptured/therapy , Aneurysm, Ruptured/physiopathology
9.
Nat Commun ; 15(1): 3459, 2024 Apr 24.
Article En | MEDLINE | ID: mdl-38658566

Establishing dependable, cost-effective electrical connections is vital for enhancing device performance and shrinking electronic circuits. MXenes, combining excellent electrical conductivity, high breakdown voltage, solution processability, and two-dimensional morphology, are promising candidates for contacts in microelectronics. However, their hydrophilic surfaces, which enable spontaneous environmental degradation and poor dispersion stability in organic solvents, have restricted certain electronic applications. Herein, electrohydrodynamic printing technique is used to fabricate fully solution-processed thin-film transistors with alkylated 3,4-dihydroxy-L-phenylalanine functionalized Ti3C2Tx (AD-MXene) as source, drain, and gate electrodes. The AD-MXene has excellent dispersion stability in ethanol, which is required for electrohydrodynamic printing, and maintains high electrical conductivity. It outperformed conventional vacuum-deposited Au and Al electrodes, providing thin-film transistors with good environmental stability due to its hydrophobicity. Further, thin-film transistors are integrated into logic gates and one-transistor-one-memory cells. This work, unveiling the ligand-functionalized MXenes' potential in printed electrical contacts, promotes environmentally robust MXene-based electronics (MXetronics).

10.
Small ; : e2401426, 2024 Apr 30.
Article En | MEDLINE | ID: mdl-38686686

The current high-capacity lithium-ion batteries (LIBs), reliant on flammable liquid electrolytes (LEs) and nickel-rich cathodes, are plagued by safety hazards, especially the risk of hazardous gas release stemming from internal side reactions. To address these safety concerns, an electron beam (E-beam)-induced gel polymer electrolyte (E-Gel) is introduced, employing dipentaerythritol hexaacrylate (DPH) as a bi-functional cross-linkable additive (CIA). The dual roles of DPH are exploited through a strategically designed E-beam irradiation process. Applying E-beam irradiation on the pre-cycled cells allows DPH to function as an additive during the initial cycle, establishing a protective layer on the surface of the anode and cathode and as a cross-linker during the E-beam irradiation step, forming a polymer framework. The prepared E-Gel with CIA has superior interfacial compatibility, facilitating lithium-ion diffusion at the electrode/E-Gel interface. The electrochemical assessment of 1.2 Ah pouch cells demonstrates that E-Gel substantially reduces gas release by 2.5 times compared to commercial LEs during the initial formation stage and ensures superior reversible capacity retention even after prolonged cycling at 55 °C. The research underscores the synergy of bifunctional CIA with E-beam technology, paving the way for large-scale production of safe, high-capacity, and commercially viable LIBs.

11.
ACS Appl Mater Interfaces ; 16(17): 21367-21382, 2024 May 01.
Article En | MEDLINE | ID: mdl-38631339

Recent advances in paper-based microsupercapacitors (p-MSCs) have attracted significant attention due to their potential as substrates for flexible electronics. This review summarizes progress in the field of p-MSCs, discussing their challenges and prospects. It covers various aspects, including the fundamental characteristics of paper, the modification of paper with functional materials, and different methods for device fabrication. The review critically analyzes recent advancements, materials, and fabrication techniques for p-MSCs, exploring their potential applications and benefits, such as flexibility, cost-effectiveness, and sustainability. Additionally, this review highlights gaps in current research, guiding future investigations and innovations in the field. It provides an overview of the current state of p-MSCs and offers valuable insights for researchers and professionals in the field. The critical analysis and discussion presented herein offer a roadmap for the future development of p-MSCs and their potential impact on the domain of flexible electronics.

13.
J Stroke Cerebrovasc Dis ; 33(5): 107678, 2024 May.
Article En | MEDLINE | ID: mdl-38479493

BACKGROUND AND PURPOSE: Non-O blood types are known to be associated with thromboembolic complications (TECs) in population-based studies. TECs are known drivers of morbidity and mortality in intracerebral hemorrhage (ICH) patients, yet the relationships of blood type on TECs in this patient population are unknown. We sought to explore the relationships between ABO blood type and TECs in ICH patients. METHODS: Consecutive adult ICH patients enrolled into a prospective observational cohort study with available ABO blood type data were analyzed. Patients with cancer history, prior thromboembolism, and baseline laboratory evidence of coagulopathy were excluded. The primary exposure variable was blood type (non-O versus O). The primary outcome was composite TEC, defined as pulmonary embolism, deep venous thrombosis, ischemic stroke or myocardial infarction, during the hospital stay. Relationships between blood type, TECs and clinical outcomes were separately assessed using logistic regression models after adjusting for sex, ethnicity and ICH score. RESULTS: Of 301 ICH patients included for analysis, 44% were non-O blood type. Non-O blood type was associated with higher admission GCS and lower ICH score on baseline comparisons. We identified TECs in 11.6% of our overall patient cohort. . Although TECs were identified in 9.9% of non-O blood type patients compared to 13.0% in O blood type patients, we did not identify a significant relationship of non-O blood type with TECs (adjusted OR=0.776, 95%CI: 0.348-1.733, p=0.537). The prevalence of specific TECs were also comparable in unadjusted and adjusted analyses between the two cohorts. In additional analyses, we identified that TECs were associated with poor 90-day mRS (adjusted OR=3.452, 95% CI: 1.001-11.903, p=0.050). We did not identify relationships between ABO blood type and poor 90-day mRS (adjusted OR=0.994, 95% CI:0.465-2.128, p=0.988). CONCLUSIONS: We identified that TECs were associated with worse ICH outcomes. However, we did not identify relationships in ABO blood type and TECs. Further work is required to assess best diagnostic and prophylactic and treatment strategies for TECs to improve ICH outcomes.


Pulmonary Embolism , Thromboembolism , Adult , Humans , Prospective Studies , Cerebral Hemorrhage/diagnosis , Thromboembolism/diagnosis , Thromboembolism/epidemiology , Thromboembolism/etiology , Logistic Models , Pulmonary Embolism/complications
14.
J Am Heart Assoc ; 13(7): e034032, 2024 Apr 02.
Article En | MEDLINE | ID: mdl-38533990

BACKGROUND: Intracerebral hemorrhage (ICH) is a major cause of maternal morbidity, but its pathophysiology is poorly characterized. We investigated characteristics of pregnancy-associated ICH (P-ICH), compared with ICH in similar aged nonpregnant adults of both sexes. METHODS AND RESULTS: We performed a retrospective analysis of 134 adults aged 18 to 44 years admitted to our center with nontraumatic ICH from January 1, 2012, to December 31, 2021. We compared ICH characteristics among 3 groups: those with P-ICH (pregnant or within 12 months of end of pregnancy); nonpregnant women; and men. We categorized ICH pathogenesis according to a modified scheme, SMASH-UP (structural, medications, amyloid angiopathy, systemic, hypertension, undetermined, posterior reversible encephalopathy syndrome/reversible cerebral vasoconstriction syndrome), and calculated odds ratios and 95% CIs for primary (spontaneous small-vessel) ICH versus secondary ICH (structural lesions or coagulopathy related), using nonpregnant women as the reference. We also compared specific ICH pathogenesis by SMASH-UP criteria and functional outcomes between groups. Of 134 young adults with nontraumatic ICH, 25 (19%) had P-ICH, of which 60% occurred postpartum. Those with P-ICH had higher odds of primary ICH compared with nonpregnant women (adjusted odds ratio, 4.5 [95% CI, 1.4-14.7]). The odds of primary ICH did not differ between men and nonpregnant women. SMASH-UP pathogenesis for ICH differed significantly between groups (P<0.001). While the in-hospital mortality rate was lowest in the P-ICH group (4%) compared with nonpregnant women (13%) and men (24%), 1 in 4 patients with P-ICH were bedbound and dependent at the time of discharge. CONCLUSIONS: In our cohort of young adults with ICH, 1 in 5 was pregnancy related. P-ICH differed in pathogenesis compared with non-pregnancy-related ICH in young adults, suggesting unique pathophysiology.


Hypertension , Posterior Leukoencephalopathy Syndrome , Pregnancy Complications , Male , Pregnancy , Humans , Female , Young Adult , Retrospective Studies , Posterior Leukoencephalopathy Syndrome/complications , Cerebral Hemorrhage/etiology , Hypertension/complications
15.
Glia ; 72(6): 1136-1149, 2024 Jun.
Article En | MEDLINE | ID: mdl-38406970

Sirtuin3 (Sirt3) is a nicotinamide adenine dinucleotide enzyme that contributes to aging, cancer, and neurodegenerative diseases. Recent studies have reported that Sirt3 exerts anti-inflammatory effects in several neuropathophysiological disorders. As epilepsy is a common neurological disease, in the present study, we investigated the role of Sirt3 in astrocyte activation and inflammatory processes after epileptic seizures. We found the elevated expression of Sirt3 within reactive astrocytes as well as in the surrounding cells in the hippocampus of patients with temporal lobe epilepsy and a mouse model of pilocarpine-induced status epilepticus (SE). The upregulation of Sirt3 by treatment with adjudin, a potential Sirt3 activator, alleviated SE-induced astrocyte activation; whereas, Sirt3 deficiency exacerbated astrocyte activation in the hippocampus after SE. In addition, our results showed that Sirt3 upregulation attenuated the activation of Notch1 signaling, nuclear factor kappa B (NF-κB) activity, and the production of interleukin-1ß (IL1ß) in the hippocampus after SE. By contrast, Sirt3 deficiency enhanced the activity of Notch1/NF-κB signaling and the production of IL1ß. These findings suggest that Sirt3 regulates astrocyte activation by affecting the Notch1/NF-κB signaling pathway, which contributes to the inflammatory response after SE. Therefore, therapies targeting Sirt3 may be a worthy direction for limiting inflammatory responses following epileptic brain injury.


Epilepsy , Sirtuin 3 , Status Epilepticus , Animals , Humans , Mice , Astrocytes/metabolism , Epilepsy/metabolism , Hippocampus/metabolism , NF-kappa B/metabolism , Signal Transduction , Sirtuin 3/metabolism , Status Epilepticus/chemically induced , Status Epilepticus/metabolism
16.
Article En | MEDLINE | ID: mdl-38364323

OBJECTIVES: Low-cost debt can potentially enhance wealth and indirectly benefit health, yet Black Americans disproportionately lack this type of debt, which may constrain their ability to accumulate wealth throughout their lives and across generations. Our objectives are to develop a novel debt-asset measure, use it to quantify the Black-White differential in debt-asset profiles, and estimate its contribution to the racial gap in cognition. METHODS: Using the Health and Retirement Study (1998-2020), we grouped individuals based on debt and asset information during the preretirement period of ages 55-61, including the absence of debt and the relative amount of debt compared to assets. Linear mixed models were used to examine the extent to which cognition in later life (ages 62-80) differs across these debt-asset profiles and its role in explaining the racial disparity in cognition. RESULTS: Compared with Whites, Blacks were more likely to fall into categories characterized by high debt-to-asset ratio (DAR) or limited asset ownership. Low-asset nonborrowers displayed the poorest cognition, followed closely by high-DAR borrowers. The Black-White differential in debt-asset profiles contributed to the racial gap in cognition. DISCUSSION: There were 2 unfavorable debt-asset profiles: high debt relative to assets and little or no debt due to a lack of assets, which was more prevalent among Blacks than Whites. We discuss how institutional and structural racism shapes Black-White disparities in debt-asset profiles, such as limited access to borrowing opportunities, thereby contributing to health inequalities, including cognition.


Black or African American , Cognition , Racial Groups , Aged , Humans , United States/epidemiology , Middle Aged , Aged, 80 and over , White
17.
Nanomicro Lett ; 16(1): 138, 2024 Feb 29.
Article En | MEDLINE | ID: mdl-38421464

Zinc-air batteries (ZABs) are gaining attention as an ideal option for various applications requiring high-capacity batteries, such as portable electronics, electric vehicles, and renewable energy storage. ZABs offer advantages such as low environmental impact, enhanced safety compared to Li-ion batteries, and cost-effectiveness due to the abundance of zinc. However, early research faced challenges due to parasitic reactions at the zinc anode and slow oxygen redox kinetics. Recent advancements in restructuring the anode, utilizing alternative electrolytes, and developing bifunctional oxygen catalysts have significantly improved ZABs. Scientists have achieved battery reversibility over thousands of cycles, introduced new electrolytes, and achieved energy efficiency records surpassing 70%. Despite these achievements, there are challenges related to lower power density, shorter lifespan, and air electrode corrosion leading to performance degradation. This review paper discusses different battery configurations, and reaction mechanisms for electrically and mechanically rechargeable ZABs, and proposes remedies to enhance overall battery performance. The paper also explores recent advancements, applications, and the future prospects of electrically/mechanically rechargeable ZABs.

18.
Small ; : e2311652, 2024 Feb 15.
Article En | MEDLINE | ID: mdl-38361217

Modern strides in energy storage underscore the significance of all-solid-state batteries (ASSBs) predicated on solid electrolytes and lithium (Li) metal anodes in response to the demand for safer batteries. Nonetheless, ASSBs are often beleaguered by non-uniform Li deposition during cycling, leading to compromised cell performance from internal short circuits and hindered charge transfer. In this study, the concept of "bottom deposition" is introduced to stabilize metal deposition based on the lithiophilic current collector and a protective layer composed of a polymeric binder and carbon black. The bottom deposition, wherein Li plating ensues between the protective layer and the current collector, circumvents internal short circuits and facilitates uniform volumetric changes of Li. The prepared functional binder for the protective layer presents outstanding mechanical robustness and adhesive properties, which can withstand the volume expansion caused by metal growth. Furthermore, its excellent ion transfer properties promote uniform Li bottom deposition even under a current density of 6 mA·cm-2 . Also, scanning electron microscopy analysis reveals a consistent plating/stripping morphology of Li after cycling. Consequently, the proposed system exhibits enhanced electrochemical performance when assessed within the ASSB framework, operating under a configuration marked by a high Li utilization rate reliant on an ultrathin Li.

19.
RSC Adv ; 14(2): 1284-1303, 2024 Jan 02.
Article En | MEDLINE | ID: mdl-38174250

Graphene, the most fascinating 2D form of carbon with closely packed carbon atoms arranged in a layer, needs more attention in various fields. For its unique electrical, mechanical, and chemical properties with a large surface area, graphene has been in the limelight since its first report. Graphene has extraordinary properties, making it the most promising electrode component for applications in supercapacitors. However, the persistent re-stacking of carbon layers in graphene, caused by firm interlayer van der Waals attractions, significantly impairs the performance of supercapacitors. As a result, many strategies have been used to get around the aforementioned problems. The utilization of graphene-based nanomaterials has been implemented to surmount the aforementioned constraints and considerably enhance the performance of supercapacitors. This review highlights recent progress in graphene-based nanomaterials with metal oxide, sulfides, phosphides, nitrides, carbides, and conducting polymers, focusing on their synthetic approach, configurations, and electrochemical properties for supercapacitors. It discusses new possibilities that could increase the performance of next-generation supercapacitors.

20.
ACS Omega ; 9(1): 294-303, 2024 Jan 09.
Article En | MEDLINE | ID: mdl-38222635

In this study, to improve the electrical properties and impact strength of phenolic formaldehyde (PF) resin, PF-based composites were prepared by mixing graphene and the ionic liquid 3-decyl-bis(1-vinyl-1H-imidazole-3-ium-bromide) (C10[VImBr]2) via hot blending and compression-curing processes. The graphene surface was modified using a silane coupling agent. The synergistic effect of graphene and C10[VImBr]2 on the electrical properties, electromagnetic shielding efficiency, thermal stability, impact strength, and morphology of PF/graphene and PF/graphene/C10[VImBr]2 composites was then investigated. It was found that the electrical conductivity of the composites significantly increased from 2.3 × 10-10 to 4.14 × 10-3 S/m with an increase in the graphene content from 0 to 15 wt %, increasing further to 0.145 S/m with the addition of 5 wt % C10[VImBr]2. The electromagnetic shielding efficiency of the composite increased from 4.70 to 28.64 dB with the addition of 15 wt % graphene, while the impact strength of the composites rose significantly from 0.59 to 1.13 kJ/m2 with an increase in the graphene content from 0 to 15 wt %, reaching 1.53 kJ/m2 with the addition of 5 wt % C10[VImBr]2. Scanning electron microscopy images of the PF/GNP/C10[VImBr]2 composites revealed a rough morphology with numerous microcracks.

...