Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.623
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-39238144

RESUMEN

Ionic gels are emerging as a promising solution for improving the functionality of electrochromic devices. They are increasingly drawing attention in the fields of electrochemistry and functional materials due to their potential to address issues associated with traditional liquid electrolytes, such as volatility, toxicity, and leakage. In extreme scenarios and/or the design of flexible devices, ionic gel electrolytes offer unique and invaluable advantages. This perspective delves into the application of ionic gels in electrochromic devices, exploring various methods to enhance their performance. After briefly introducing developments in ionic gels for electrochromic devices, the trends and key points of future development are discussed in detail.

2.
J Environ Manage ; 369: 122424, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39241601

RESUMEN

Fluvial systems are natural environments most affected by human interventions. River restoration emerges as a need to recover naturality and to provide environmental benefits to society. The aims of river restoration aims are diverse and depends on the conditions of the river reach or section to be restored, as well as the objectives of the restoration. Process based restoration are the ones mostly likely to succeed as the river reshapes, adapts, and redistributes sediment to slope, fluvial regime, flood frequency and sediment availability and calibre in a commonly named "auto-healing" process. However, information regarding the results and the degree of success of a restoration project is scarce due to the lack of monitoring after the restoration is undertaken, or lack of criteria to define when a restoration project is a success. The application of biological and ecological indexes has been used to assess the state of a river stretch. However, sometimes this information lacks complementary geomorphological assessment to fully understand the state of the river, especially in those that have been altered by humans. In this study, a quantitative evaluation, by means of biological, ecological, and geomorphological indicators, has been applied in two different sections of the same urban river in the metropolitan area of Barcelona. Scores obtained from the indexes applied indicate that the urbanized and unrestored river section has poorer ecological and biological quality and a very limited hydrogeomorphology dynamics than the self-restored section. Despite it, the self-restored section achieves moderate scores given the deep human modifications of the river section and the existing limitations for a fully restored river. The use of this combination of indexes has provided a useful information to assess different river sections. In addition to ecological and biological indexes, geomorphological indexes must be considered to fully understand the river dynamics and the improvement of a river system functioning.

3.
Artículo en Inglés | MEDLINE | ID: mdl-39251359

RESUMEN

Flexible solid-state supercapacitors (SCs) with hydrogel as an electrolyte and separator combine the advantages of wearability and energy storage and exhibit a broad application prospect in wearable energy textiles. However, irreversible electrolyte damage and unstable electrode-electrolyte interfaces during mechanical deformations remain bottlenecks in realizing truly wearable applications. Herein, poly(acrylic acid) (PAA)-Fe hydrogels were prepared through a simple thermal polymerization strategy. The dynamic reversible metal coordination bonds between Fe3+ and carboxylic acids confers the hydrogels with excellent self-healing properties. As expected, the prepared hydrogels exhibited superior mechanical strength (tensile stress of 45.80 kPa), ionic conductivity (0.076 S cm-1), and self-healing properties. Subsequently, the SCs were constructed using composite hydrogel electrodes (MnO2@CC embedded in the PAA-Fe hydrogels) as symmetrical electrodes (marked as MSCs). The reversible metal coordination bonds between composite hydrogel electrodes formed an ultrastable electrode/electrolyte interface in the all-in-one MSCs, thus revealing excellent mechanical durability. The all-in-one MSCs delivered a remarkable specific capacitance (30.98 F g-1 at 0.2 A g-1), excellent cyclic stability (87.24% after 5000 cycles), outstanding mechanical deformation stability, and impressive electrochemical output stability after self-healing (capacitance retention of 85.34% after five cycles of cutting/self-healing). It is noteworthy that the all-in-one MSCs employed NaCl as an electrolyte, which can be obtained from human sweat. As a proof of the self-charged concept, the all-in-one MSCs can be reused in sweat, whose capacitance was maintained at 90.05% of the initial state after three repetitions. This work is expected to shine light into the design of all-in-one and fabric-based SCs and the development of wearable energy textiles.

4.
Sci Rep ; 14(1): 20965, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39251612

RESUMEN

Single-layer isophorone diisocyanate (IPDI) are one of the most popular self-healing microcapsules but suffers from low shell strength, poor heat resistance, stability and aging properties. In this paper, IPDI microcapsules were encapsulated into double-layer phenolic (PF)/polyurethane (PU) by a two-step process involving interfacial polymerization and in-situ polymerization. The prepared microcapsule composites were comprehensively characterized for their physical and chemical properties using optical microanalysis, scanning electron microscope, Fourier transform infrared spectroscopy, thermal gravimetric analysis and depth-sensing indentation analysis. Compared with the single-layer PU-IPDI microcapsule counterpart, the mechanical performance, thermal resistance, aging property and environmental stability of double-layer PF/PU-IPDI microcapsules were significantly improved. The epoxy coating was enhanced with the incorporation of 10 wt.% PF/PU-IPDI microcapsules, whose self-healing performance was evaluated by scratch corrosion test. The results demonstrated successful repair of coating scratches, along with the absence of corrosion on the coated steel substrate soaked in a 10 wt.% NaCl solution for 7 days. By comparing the tensile strength of epoxy coating before and after crack formation, it could be found that the self-healing efficiency was 57.9% when loaded with 10 wt.% of PF/PU-IPDI microcapsules in coating. This study highlights that the rational design of double-layer microcapsules integrated into the epoxy coating matrix could provide excellent anti-corrosion and self-healing properties.

5.
Artículo en Inglés | MEDLINE | ID: mdl-39253872

RESUMEN

Recent advancements in flexible electronics have highlighted their potential in biomedical applications, primarily due to their human-friendly nature. This study introduces a new flexible electronic system designed for motion sensing in a biomimetic three-dimensional (3D) environment. The system features a self-healing gel matrix (chitosan-based hydrogel) that effectively mimics the dynamics of the extracellular matrix (ECM), and is integrated with a highly sensitive thin-film resistive strain sensor, which is fabricated by incorporating a cross-linked gold nanoparticle (GNP) thin film as the active conductive layer onto a biocompatible microphase-separated polyurethane (PU) substrate through a clean, rapid, and high-precision contact printing method. The GNP-PU strain sensor demonstrates high sensitivity (a gauge factor of ∼50), good stability, and waterproofing properties. The feasibility of detecting small motion was evaluated by sensing the beating of human induced pluripotent stem cell (hiPSC)-derived cardiomyocyte spheroids embedded in the gel matrix. The integration of these components exemplifies a proof-of-concept for using flexible electronics comprising self-healing hydrogel and thin-film nanogold in cardiac sensing and offers promising insights into the development of next-generation biomimetic flexible electronic devices.

6.
Artículo en Inglés | MEDLINE | ID: mdl-39221601

RESUMEN

One-dimensional nanomaterials have become one of the most available nanoreinforcing agents for developing next-generation high-performance functional self-healing composites owing to their unique structural characteristics and surface electron structure. However, nanoscale control, structural regulation, and crystal growth are still enormous challenges in the synthesis of specific one-dimensional nanomaterials. Here, oxygen-defective MoO3-x nanowires with abundant surface dynamic bonding were successfully synthesized as novel nanofillers and photothermal response agents combined with a polyurethane matrix to construct composite elastomers, thus achieving mechanically enhanced and self-healing properties. Benefiting from the surface plasmon resonance of the MoO3-x nanowires and interfacial multiple dynamic bonding interactions, the composite elastomers demonstrated strong mechanical performance (with a strength of 31.45 MPa and elongation of 1167.73%) and ultrafast photothermal toughness self-healing performance (20 s and an efficiency of 94.34%). The introduction of MoO3-x nanowires allows the construction of unique three-dimensional cross-linked nanonetworks that can move and regulate interfacial dynamic interactions under 808 nm infrared laser stimulation, resulting in controlled mechanical and healing performance. Therefore, such special elastomers with strong photothermal responses and mechanical properties are expected to be useful in next-generation biological antibacterial materials, wearable devices, and artificial muscles.

7.
Int J Biol Macromol ; 279(Pt 3): 135295, 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39233153

RESUMEN

Lignin, a biopolymer derived from plant biomass, is recognized as a highly promising substance for developing self-healing polymers owing to its dynamic linkages and functional groups. This paper provides a thorough review of lignin-based self-healing polymer, from the process of extracting lignin, chemical modification, synthesis techniques such as via reversible addition-fragmentation chain transfer (RAFT) polymerization, crosslinking with polymers like polyvinyl alcohol (PVA) and chitosan, and reactions with isocyanates to create lignin-based networks with reversible interactions. This work also summarizes the optimization of self-healing ability, such as including dynamic copolymers, encapsulating healing agents like dicyclopentadiene and polycaprolactone (PCL), and chain extenders with disulfide or Diels-Alder (DA) moieties. The material's characterization focuses on its capacity to recover via hydrogen bonding and dynamic re-associations, improved mechanical properties from lignin's rigid structure, and enhanced temperature resistance. Primary obstacles involve the optimization of lignin extraction, enhancement of polymer compatibility, and the establishment of efficient procedures for synthesis and characterization. Overall, lignin shows great potential as a renewable component of self-healing polymers, with plenty of opportunities for further development.

8.
Nano Lett ; 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39235119

RESUMEN

High safety and low cost are essential for energy-storage systems. Here, an aqueous zinc ion battery composed of a hydrogel-based water-in-salt electrolyte prepared by photoinitiated polymerization of acrylamide in ZnCl2 solution (named as PZC) and flexible electrodes is developed. The stable performance in Zn||Zn symmetric cells and high Coulombic efficiency of PZC in Zn||Cu asymmetric cells verify dendrite suppression. VO2 nanobelts coated with polyaniline (PANI) are grown on a carbon cloth (CC). The battery shows a capacity of 221.5 mAh g-1 after 200 cycles. The batteries present high recovery performance after bending/cutting. After bending of 60°, 90°, and 180°, capacities remain at 240.0, 205.4, and 175.2 mAh g-1, respectively; while the battery healed from 1, 2, 3, and 4 times of cutting shows 197.5, 174.3, 124.7, and 101.2 mAh g-1, respectively. Our findings enable the engineering of a quasi-solid-state battery to have good capability for flexible and portable electronics.

9.
Int J Biol Macromol ; 277(Pt 4): 134591, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39127289

RESUMEN

Spinal cord injury (SCI) is a debilitating condition that can result in significant functional impairment and loss of quality of life. There is a growing interest in developing new therapies for SCI, and hydrogel-based multimodal therapeutic strategies have emerged as a promising approach. They offer several advantages for SCI repair, including biocompatibility, tunable mechanical properties, low immunogenicity, and the ability to deliver therapeutic agents. This article provides an overview of the recent advances in hydrogel-based therapy strategies for SCI repair, particularly within the past three years. We summarize the SCI hydrogels with varied characteristics such as phase-change hydrogels, self-healing hydrogel, oriented fibers hydrogel, and self-assembled microspheres hydrogel, as well as different functional hydrogels such as conductive hydrogels, stimuli-responsive hydrogels, adhesive hydrogel, antioxidant hydrogel, sustained-release hydrogel, etc. The composition, preparation, and therapeutic effect of these hydrogels are briefly discussed and comprehensively evaluated. In the end, the future development of hydrogels in SCI repair is prospected to inspire more researchers to invest in this promising field.


Asunto(s)
Hidrogeles , Traumatismos de la Médula Espinal , Traumatismos de la Médula Espinal/terapia , Hidrogeles/química , Hidrogeles/uso terapéutico , Humanos , Animales , Materiales Biocompatibles/química
10.
Heliyon ; 10(14): e34131, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39092261

RESUMEN

In the process of research and development of self-healing concrete, it is observed that there are three main factors controlling the self-healing effect of concrete: first, the bacteria with repair ability and strong vitality; Second, the carrying capacity of the carrier and the matching degree with concrete; The third is the concentration of bacteria. This paper focuses on the mechanical properties of Bacillus subtilis self-healing concrete with sisal fiber, PVA, and expanded perlite as the carrier. To better study the mechanical properties of self-healing concrete caused by the carrier, the experiment adopts the design parameters of C30 concrete and conducts experiments on compressive resistance, flexural resistance, freeze-thaw cycle, and sulfate corrosion resistance to analyze the influence of different carriers on the mechanical properties of self-healing concrete, and obtains the best carrier. The concentration gradients of three groups of bacterial solution were set as 2od, 2.5od, and 3od, respectively, for comparison to avoid the influence of bacterial concentration. It compared the impact of bacterial solution concentrations on the specimen's mechanical properties, and the effect of carriers was also analyzed. The experimental results show that the mechanical properties of the specimen using 2.5od bacterial liquid concentration with PVA as the carrier have peaked. With the increase in bacterial solution concentration, the specimens' comprehensive mechanical properties increased first and then decreased. The compression resistance of the specimen with PVA is higher than that of the specimen with sisal fiber and expanded perlite. At the same time, the frost resistance and corrosion resistance of the PVA carrier specimen is also higher than that of the specimen with sisal fiber and expanded perlite carrier.

11.
Chemistry ; : e202402417, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39087567

RESUMEN

The absorbent expansion elastomer plays a crucial role in engineering sealing and holds a promising future in this field as infrastructure continues to develop. Traditional materials have their limitations, especially when used in large construction projects where the integrity and reliability of the material are of utmost importance. In this work, a self-healing water-absorbing expansion elastomer was developed for continuous production at a large scale to monitor the sealing conditions of massive infrastructure projects. At room temperature, the material exhibited a repairing efficiency of 57.77% within 2 h, which increased to 84.02% after 12 h. This extended reaction time allowed for effective repairs when defects were detected. The material's strength reached approximately 3 MPa, making it suitable for a wide range of applications. The volume expansion rate of the material reached 200-400% for effective sealing, and the fictionalization of the packing made it have a good external force sensing effect and prevent heat build-up effect. The conductive detection performance of the absorbent expansion elastomer was improved by utilizing triple self-healing strategies, including dipole-dipole interaction, ion cross-linked network, and externally-aided restoration materials.

12.
Angew Chem Int Ed Engl ; : e202410693, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39087854

RESUMEN

Variable stiffness materials have shown considerable application in soft robotics. However, previously reported materials often struggle to reconcile high stiffness, stretchability, toughness, and self-healing ability, because of the inherently conflicting requisite of these properties in molecular design. Herein, we propose a novel strategy that involves incorporating acid-base ionic pairs capable of from strong crosslinking sites into a dense and robust hydrogen-bonding network to construct rigid self-healing polymers with tunable stiffness and excellent toughness. To demonstrate these distinct features, the polymer was employed to serve as the strain-regulation layers within a fiber-reinforced pneumatic actuator (FPA). The exceptional synergy between the configuration versatility of FPA and the dynamic molecular behavior of the supramolecular polymers equips the actuator with simultaneous improvement in motion dexterity, multimodality, loading capacity, robustness, and durability. Additionally, the concept of integrating high dexterity at both macro- and micro-scale is prospective to inspire the design of intelligent yet robust devices across various domains.

13.
Sci Rep ; 14(1): 18419, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39117756

RESUMEN

In this study, we report observations of propagating radial carpet beams (RCBs) through a turbulent atmosphere at ground level with a 120 m path length. RCBs are a class of nondiffracting, accelerating, self-healing, and self-amplifying beams, and generated in the diffraction of a plane wave from amplitude/phase radial gratings having different spoke numbers. Observations were made at different times of the day. The intensity profile of an RCB becomes complicated when the number of grating spokes used to generate the beam is large, and includes high intensity spots, called main intensity spots (MISs), which are symmetrically placed at the central area around the beam axis and whose number is equal to (twice) the number of spokes of the amplitude (phase) grating used to generate the beam. With the aid of a telescope and a CCD camera, successive frames of the intensity pattern of the RCBs having different levels of structural complexity are recorded at the end of the path. For the data recorded at different times of the day, we calculate the variance of displacements of MISs along the radial direction. We observe that displacements of the MISs increase with increasing mean temperature of the air; on the other hand, as the complexity of the beam intensity pattern increases, the displacements of the MISs decrease. In order to compare the resilience of different RCBs and a well-known structured beam against atmospheric turbulence, we investigate deformation of the intensity profiles of a Laguerre-Gaussian (LG) beam having a topological charge 20 and different RCBs at the end of the path. It is shown that under the same turbulence condition, highly complex RCBs are more resilient to the destructive effects of the atmospheric turbulence. In particular, for the RCBs generated with gratings having 30 spokes and more, the number of MISs of the received intensity patterns is changed by less than 1% even when the turbulence strength is high. But for the LG beam, its intensity ring is clearly broken in different places, which makes it impossible to follow its maximum intensity in the radial direction.

14.
Acta Biomater ; 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39111681

RESUMEN

Catheter-related infections are one of the most common nosocomial infections with increasing morbidity and mortality, and robust antibacterial or antifouling catheter coatings remain great challenges for long-term implantation. Herein, multifunctional hydrogel coatings were developed to provide persistent and self-adaptive antifouling and antibacterial effects with self-healing and lubricant capabilities. Polyvinyl alcohol (PVA) with ß-cyclodextrin (ß-CD) grafts (PVA-Cd) and 4-arm polyethylene glycol (PEG) with adamantane and quaternary ammonium compound (QAC) terminals (QA-PEG-Ad) were crosslinked through host-guest recognitions between adamantane and ß-CD moieties to acquire PVEQ coatings. In response to bacterial infections, QACs exhibit reversible transformation between zwitterions (pH 7.4) and cationic lactones (pH 5.5) to generate on-demand bactericidal effect. Highly hydrophilic PEG/PVA backbones and zwitterionic QACs build a lubricate surface and decrease the friction coefficient 10 times compared with that of bare catheters. The antifouling hydrated layer significantly inhibits blood protein adsorption and platelet activation and reveals negligible hemolysis and cytotoxicity. The dynamic host-guest crosslinking achieves full self-healing of cracks in PVEQ hydrogels, and the mechanical profiles were recovered to over 90 % after rejuvenating the broken hydrogels, exhibiting a long-term stability after mechanical stretching, twisting, knotting and compression. After subcutaneous implantation and local bacterial infection, the retrieved PVEQ-coated catheters display no tissue adhesion and 3 log folds lower bacterial number than that of bare catheters. PVEQ coatings effectively prevent the repeated bacterial infections and there are few inflammatory reactions in the surrounding tissue, while substantial lymphoid infiltration and inflammatory cell aggregation occur in muscle tissues around the bare catheter. Thus, this study demonstrates a catheter coating strategy by on-demand bactericidal, self-adaptive antifouling, self-healing and lubricant hydrogels to address medical devices-related infections. STATEMENT OF SIGNIFICANCE: It is estimated over two billion peripheral intravenous catheters are annually used in hospitals around the world, and catheter-associated infection has become a great clinical challenge with rapidly rising morbidity and mortality. Surface coating is considered a promising approach, but substantial challenges remain in the development of coatings that simultaneously satisfy both anti-fouling and antibacterial attributes. Even more, few attempts have been made to design mechanically robust coatings and reversible antibacterial or antifouling capabilities, which are critical for long-term medical implants. To address these challenges, we propose a concise strategy to develop hydrogel coatings from commercially available poly(ethylene glycol) and polyvinyl alcohol. In addition to self-healing and lubricant capabilities, the reversible conversion between zwitterionic and cationic lactones of quaternary ammonium compounds enables on-demand bactericidal and self-adaptive antifouling effects.

15.
J Microencapsul ; : 1-29, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39101751

RESUMEN

This article provides a brief description of microcapsule self-healing technique and its potential use in concrete structures. Because concrete is readily available and reasonably priced, it is widely utilised in the building industry globally, despite its susceptibility to the formation of cracks. The longevity and security of concrete buildings are greatly impacted by the existence of cracks and other deterioration occurring during the course of their use. Through the encapsulation of healing material inside microcapsules, which shows rupture upon cracking in cement-based materials, the microcapsule exhibits promise in accomplishing self-healing and increasing durability and strength in the structures. The article first explains the basic ideas behind the science of microcapsule self-healing and then looks at different ways to prepare microcapsules. It also looks into how adding microcapsules affects the basic characteristics of the concrete building. A summary of the efficiency and self-healing mechanisms of microcapsules is also provided.


The article explains the advantages of the microcapsule self-healing method in concrete.Preparation method and intrinsic properties of different microcapsules are discussed.Different self-healing measurement techniques in cement-based materials are discussed.The study examines the qualitative aspects of various self-healing methods.Looks into how adding microcapsules affects the properties of cementitious materials.

16.
Acta Biomater ; 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39089350

RESUMEN

The current techniques for antithrombotic coating on blood-contacting biomedical materials and devices are usually complex and lack practical feasibility with weak coating stability and low heparin immobilization. Here, a heparinized self-healing polymer coating with inflammation modulation is introduced through thermal-initiated radical copolymerization of methacrylate esterified heparin (MA-heparin) with methyl methacrylate (MMA) and n-butyl acrylate (nBA), followed by the anchoring of reactive oxygen species (ROS)-responsive polyoxalate containing vanillyl alcohol (PVAX) onto the coating through esterification. The aspirin, which is readily dissolved in the solution of MMA and nBA, is encapsulated within the coating after copolymerization. The copolymerization of MA-heparin with MMA and nBA significantly increases the heparin content of the coating, effectively inhibiting thrombosis and rendering the coating self-healing to help maintain long-term stability. ROS-responsive PVAX and aspirin released in a temperature-dependent manner resist acute and chronic inflammation, respectively. The heparinized self-healing and inflammation-modulated polymer coating exhibits the ability to confer long-term stability and hemocompatibility to blood-contacting biomedical materials and devices. STATEMENT OF SIGNIFICANCE: Surface engineering for blood-contacting biomedical devices paves a successful way to reduce thrombotic and inflammatory complications. However, lack of effectiveness, long-term stability and practical feasibility hinders the development and clinical application of existing strategies. Here we design a heparinized self-healing and inflammation-modulated polymer coating, which possesses high heparin level and self-healing capability to maintain long-term stability. The polymer coating is practically feasible to varied substrates and demonstrated to manipulate inflammation and prevent thrombosis both in vitro and in vivo. Our work provides a new method to develop coatings for blood-contacting biomedical materials and devices with long-term stability and hemocompatibility.

17.
ACS Nano ; 18(32): 21399-21410, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39094105

RESUMEN

To address the escalating power consumption of processors in data centers and the growing emphasis on environmental sustainability, the prospective shift from traditional air-cooling to immersion liquid cooling necessitates multiple functional integrations in polymer-based thermal conductive materials. Here, drawing inspiration from mussels, we showed a copolymer, poly(dimethylsiloxane-co-dopamine methacrylate) (PDMS-DMA), with a variety of reversible molecular interactions and simply combined with liquid metal (EGaIn) can yield a flexible, waterproof, and electrically insulating thermal conductive composite. The obtained PDMS-DMA/EGaIn composites demonstrate a harmonious blend of attributes, including a low modulus (75.8 kPa), high thermal conductivity of 6.9 W m-1 K-1, and rapid room-temperature self-healing capabilities, capable of complete repair within 20 min, even under water. Based on its electrically insulating and water resistance properties, PDMS-DMA/EGaIn emerges as a promising candidate for efficient and stable heat transfer in both air and underwater thermal management. Consequently, this water-resistant polymer-based composite holds significance for application in thermal protective layers for future immersion liquid cooling systems.

18.
Int J Biol Macromol ; 279(Pt 1): 135112, 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39197606

RESUMEN

As classical soft materials, conductive hydrogels have attracted wide attention in the field of strain sensors due to their unique flexibility and conductivity. However, there are still challenges in developing conductive hydrogels with comprehensive mechanical strength, self-healing ability and sensitive sensing properties. In this paper, a novel PAV/CMGG hydrogel was prepared by a simple one-pot method through the introduction of 1-vinyl-3-butylimidazolium bromide (VBIMBr), acrylic acid (AA), carboxymethyl guar gum (CMGG) and AlCl3. The coordination bond between Al3+ and -COO- groups on PAA and CMGG, the hydrogen bond between PAA and CMGG, and the electrostatic interaction between [VBIM]+ and -COO- endow the hydrogel with good mechanical properties, self-recovery ability, fatigue resistance and great self-healing properties. PAV/CMGG hydrogel had good conductivity of 2.31 S/m which could successfully light up the bulb. The hydrogel as the strain sensor had not only a wide strain sensing capability (strain ranging from 0 to 800 %), but also a high strain sensitivity (gauge factor (GF) = 28.50 for the strain ranging from 600 to 800 %). This study can provide inspiration for the construction of new high-performance flexible sensors.

19.
Gels ; 10(8)2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39195018

RESUMEN

Amino acid-derived self-assembled nanofibers comprising supramolecular chiral hydrogels with unique physiochemical characteristics are highly demanded biomaterials for various biological applications. However, their narrow functionality often limits practical use, necessitating the development of biomaterials with multiple features within a single system. Herein, chiral co-assembled hybrid hydrogel systems termed LPH-EGCG and DPH-EGCG were constructed by co-assembling L/DPFEG gelators with epigallocatechin gallate (EGCG) followed by cross-linking with polyvinyl alcohol (PVA) and hyaluronic acid (HA). The developed hybrid hydrogels exhibit superior mechanical strength, self-healing capabilities, and adhesive properties, owing to synergistic non-covalent interactions. Integrating hydrophilic polymers enhances the system's capacity to demonstrate favorable swelling characteristics. Furthermore, the introduction of EGCG facilitated the hybrid gels to display notable antibacterial properties against both Gram-positive and Gram-negative bacterial strains, alongside showcasing strong antioxidant capabilities. In vitro investigation demonstrated enhanced cell adhesion and migration with the LPH-EGCG system in comparison to DPH-EGCG, thus emphasizing the promising prospects of these hybrid hydrogels in advanced tissue engineering applications.

20.
ACS Appl Mater Interfaces ; 16(34): 45563-45576, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39162026

RESUMEN

The swift progression of high-density chiplet packaging, propelled by the artificial intelligence revolution, has precipitated a critical need for high-performance chip-scale thermal interface materials (TIMs). The elevated thermal resistance, limited interfacial adhesion, and mechanical flexibility intrinsic to silicone systems present a substantial challenge in meeting reliability standards amidst chip warpage. This particular matter underscores a significant performance bottleneck within existing high-end TIMs. In this study, we present poly(ionic liquid)s (PILs) as an innovative matrix for TIMs. Our findings highlight the unique properties of PILs, showcasing a low elastic modulus (60 kPa), exceptional flexibility and stretchability (>3800%), high adhesion to diverse substrates (up to 4.10 MPa), favorable filler compatibility, remarkable thermal stability, and prompt self-healing capabilities coupled with recyclability. The collective findings suggest that the PIL serves as an ideal matrix for heat transfer. As a proof of concept, PIL blended with liquid metal was straightforwardly combined to produce a TIM, exhibiting exceptional performance within practical encapsulated structures. The PIL-based TIM demonstrates substantial elongation at break (>350%), coupled with sustained high adhesion strength (up to 1.70 MPa), and exhibits favorable thermal conductivity in package testing. This study presents an innovative TIM matrix with the potential to enhance existing TIM systems, delivering significant performance benefits compared to silicones. Besides elucidating their multifaceted characteristics, this study forecasts an expanded range of applications for PILs, along with laying the groundwork for advancing next-generation TIMs.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA