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1.
Int J Biol Macromol ; : 135245, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39222780

RESUMO

Phosphorus-based flame retardants are widely employed in the study of flame retardancy for cotton fabrics due to their halogen-free nature and high efficiency. The addition of nitrogen and other elements can further enhance flame retardant properties through synergistic effects. However, the synthesis of flame-retardant multifunctional additives based on phosphoramidic ammonium salts has been scarcely reported. In this study, a halogen-free and formaldehyde-free phosphoramidite ammonium salt was synthesized as a synergistic flame retardant multifunctional additive. This compound, with phosphorus as the primary flame retardant element and a nitrogen-containing guanidine group, was used to modify cotton fabrics. The treated fabrics exhibited enhanced flame retardant and antibacterial properties. Notably, cotton fabrics treated with a 17.9 % weight gain showed a damaged length of 4 cm in the vertical flame test, and the LOI value increased to 41.5 %, remaining at 27.3 % even after 50 washing cycles. The results of the cone calorimeter test (CCT) revealed that the peak heat release rate (PHRR) and total heat release (THR) of treated cotton were 30.35 kW/m2 and 5.46 MJ/m2, respectively, representing reductions of 87.04 % and 36.07 % compared to untreated cotton. Physical performance tests indicated only a slight decrease in the strength and whiteness of the cotton fabrics, while softness increased after treatment. Moreover, the treated cotton fabric exhibited excellent antibacterial properties, with antibacterial rates of 99.26 % against E. coli and 98.54 % against S. aureus.

2.
Environ Pollut ; 361: 124890, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39236844

RESUMO

Humans are exposed to a range of endocrine disrupting chemicals (EDCs). Many studies demonstrate that exposures to EDCs during critical windows of development can permanently affect endocrine health outcomes. Most experimental studies address changes in secretion of hormones produced by gonads, thyroid gland and adrenals, and little is known about the ability of EDCs to produce long-term changes in the hypothalamic-pituitary (HP) control axes. Here, we examined the long-term effects of three common EDCs on male mouse HP gene expression, following developmental exposures. Pregnant mice were exposed to 0.2 mg/ml solutions of bisphenol S (BPS), 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), or 3,3',5,5'-tetrabromobisphenol A (TBBPA) from pregnancy day 8 through lactation day 21 (weaning day). Male offspring were left untreated until postnatal day 140, where pituitaries and hypothalami were collected. Pituitaries were assed for gene expression via RNA sequencing, while specific genes were assessed for expression in hypothalami via RT-qPCR. Differential expression, as well as gene enrichment and pathway analysis, indicated that all three chemicals induced long-term changes, (mostly suppression) in pituitary genes involved in its endocrine function. BPS and BDE-47 produced effects overlapping significantly at the level of effected genes and pathways. All three chemicals altered pathways of gonad and liver HP axes, while BPS altered HP-adrenal and BDE-47 altered HP-thyroid pathways specifically. All three chemicals reduced expression of immune genes in the pituitaries. Targeted gene expression in the hypothalamus indicates down regulation of hypothalamic endocrine control genes by BPS and BDE-47 groups, concordant with changes in the pituitary, suggesting that these chemicals suppress overall HP endocrine function. Interestingly, all three chemicals altered pituitary genes of GPCR-mediated intracellular signaling molecules, key signalers common to many pituitary responses to hormones. The results of this study show that developmental exposures to common EDCs have long-term impacts on hormonal feedback control at the hypothalamic-pituitary level.

3.
Materials (Basel) ; 17(15)2024 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-39124401

RESUMO

Cellulose aerogels are considered as ideal thermal insulation materials owing to their excellent properties such as a low density, high porosity, and low thermal conductivity. However, they still suffer from poor mechanical properties and low flame retardancy. In this study, mullite-fibers-reinforced bagasse cellulose (Mubce) aerogels are designed using bagasse cellulose as the raw material, mullite fibers as the reinforcing agent, glutaraldehyde as the cross-linking agent, and chitosan as the additive. The resulted Mubce aerogels exhibit a low density of 0.085 g/cm3, a high porosity of 93.2%, a low thermal conductivity of 0.0276 W/(m∙K), superior mechanical performances, and an enhanced flame retardancy. The present work offers a novel and straightforward strategy for creating high-performance aerogels, aiming to broaden the application of cellulose aerogels in thermal insulation.

4.
Molecules ; 29(15)2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39125111

RESUMO

Rigid polyurethane foam (RPUF) is widely utilized in construction and rail transportation due to its lightweight properties and low thermal conductivity, contributing to energy conservation and emission reduction. However, the inherent flammability of RPUF presents significant challenges. Delaying the time to ignition and preventing flame spread post-combustion is crucial for ensuring sufficient evacuation time in the event of a fire. Based on this principle, this study explores the efficacy of using potassium salts as a catalyst to promote the self-cleavage of RPUF, generating substantial amounts of CO2, thereby reducing the local oxygen concentration and delaying ignition. Additionally, the inclusion of a reactive flame retardant (DFD) facilitates the release of phosphorus-oxygen free radicals during combustion, disrupting the combustion chain reaction and thus mitigating flame propagation. Moreover, potassium salt-induced catalytic carbonization and phosphorus derivative cross-linking enhance the condensed phase flame retardancy. Consequently, the combined application of potassium salts and DFD increases the limiting oxygen index (LOI) and reduces both peak heat release rate (PHRR) and total heat release (THR). Importantly, the incorporation of these additives does not compromise the compressive strength or thermal insulation performance of RPUF. This integrated approach offers a new and effective strategy for the development of flame retardant RPUF.

5.
Int J Biol Macromol ; 278(Pt 2): 134881, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39163952

RESUMO

The flattened bamboo board (FB) represents a promising innovation in the bamboo industry. To address the challenges of flammability and hygroscopicity, composite coatings consisting of melamine (MEL), phytic acid (PA), cerium ions (Ce3+), and sodium laurate (La) are assembled on the FB surface through an in-situ impregnation strategy. The resulting MEL/PA-Ce3+@La FB exhibits exceptional flame retardancy. It achieves a V-0 rating in the vertical burning test (UL-94) and boasts a high limiting oxygen index (LOI) value of 38.5 %. The coated FB exhibits superhydrophobicity, evidenced by a water contact angle of 156.5°, which can be attributed to the in-situ growth of PA-Ce3+ complexes (for constructing micro/nanoscale coarse structures) and the modification with La (for reducing surface energy).This superhydrophobic surface imparts both self-cleaning and anti-mold properties to the coated FB. Moreover, the coated FB exhibits excellent mechanical stability, withstanding 36 cycles of sandpaper abrasion and tape peeling without losing its hydrophobicity. In summary, this work provides an innovative strategy for the bamboo processing industry to produce flattened bamboo boards with combined flame retardancy, superhydrophobic and anti-mold properties. Such versatility holds significant potential to facilitate the utilization of flattened bamboo boards in the construction and decorative materials industries.

6.
Artigo em Inglês | MEDLINE | ID: mdl-39168605

RESUMO

BACKGROUND: Plastic additives have adverse effects on human health. Children frequently use toys that contain various substances found in paints, plasticizers, and other materials, which heighten the risk of specific chemical exposure. Infants are particularly prone to chemical exposure through the "mouthing" behavior because of the possibility of placing toys in their mouths. Thus, this vulnerability should be considered during risk assessments of chemical exposure. METHODS: This study performed a comprehensive analysis of the chemical components in various 84 plastic toys including "designated toys" (toys that may be harmful to infant health if in contact with their mouths: Article 78 of the Enforcement Regulations of the Food Sanitation Law by the Minister of Health, Labor and Welfare) such as dolls, balls, blocks, bathing toys, toy vehicles, pacifiers, and household items, purchased in the Japanese market by nontargeted and targeted analysis. RESULTS: Plasticizers, flame retardants, and fragrances were the main compounds in almost all the toy products. The results showed that plastic products made in China tended to contain high levels of phthalate esters. In particular, hazardous plasticizers, such as diisodecyl, di-n-octyl, and diisononyl phthalates were detected above the regulatory limit (0.1%) in used products manufactured before regulations were passed in Japan. Furthermore, we detected alternative plasticizers, such as acetyl tributyl citrate (ATBC; 52%), diisononyl adipate (DINA; 50%), and di(2-ethylhexyl) terephthalate (DEHT; 40%). ATBC was detected at high concentrations in numerous toy products. Thus, infants with free access to indoor plastic toys might be exposed to these chemicals. CONCLUSIONS: This study observed that the chemical profiles of toy products were dependent on the year of manufacture. Furthermore, the detection of currently regulated plasticizers in secondhand products manufactured before regulations were enforced, along with the increasing trend of using alternative substances to regulated phthalate esters in products, suggests the potential exposure of infants to these plasticizers through the use of toys. Therefore, regular fact-finding surveys should continue to be conducted for the risk assessment and safety management of domestic toy products.


Assuntos
Plastificantes , Plásticos , Jogos e Brinquedos , Japão , Plastificantes/análise , Humanos , Plásticos/análise , Lactente , Retardadores de Chama/análise , Ácidos Ftálicos/análise
7.
Int J Biol Macromol ; 279(Pt 1): 135001, 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39182868

RESUMO

This study reports the successful synthesis of flame-retardant and smoke-suppressing epoxy resin (EP) via bio-based polyelectrolyte flame retardants. Herein, a novel polyelectrolyte flame retardant was prepared from chitosan (CS) and hexa-(4-carboxyl-phenoxy)-cyclotriphosphazene (HCPCP) by acid-base neutralization reaction, which the HCPCP was synthesized with hexachlorocyclotriphosphazene (HCCP) and methyl p-hydroxybenzoate (MP) by nucleophilic substitution reaction. The combined effect of the addition on the flame retardant, smoke suppression and mechanical properties of EP samples were systematically investigated. The presence of this bio-based polyelectrolyte provided excellent smoke suppression and flame-retardant properties of the prepared EP. Among them, the peak heat release rate (PHRR), peak smoke production rate (PSPR) and total smoke production (TSP) of EP/9wt%3CS-HCPCP composite (the ratio of CS to HCPCP was 3: 7, and the dosage was 9 wt%) were reduced by 45.42 %, 41.66 % and 22.56 %, respectively. In addition, the EP/CS-HCPCP composites showed a 207.80 % enhancement in char residue compared to pure EP. These results suggest a green and cost-effective strategy for the production of flame-retardant, drip-proof and smoke-suppressed EP composites.

8.
Materials (Basel) ; 17(16)2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39203206

RESUMO

Aramid fiber/epoxy resin (AF/EP) composite has been heavily used as an impact protection material due to its excellent mechanical properties and lightweight merits. Meanwhile, it is also necessary to concern the flammability of matrix resin and the wick effect of aramid fiber, which would constitute a fire risk in harsh environments. In this work, a multifunctional flame-retardant modifier (EAD) was incorporated into the AF/EP system to improve the flame retardation. The addition of 5 wt% EAD made the AF/EP composite exhibit a high limiting oxygen index (LOI) value of 37.5%, self-extinguishment, as well as decreased total heat release and total smoke release. The results from thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) demonstrated that the treated composites maintained good thermal stability. Due to the combined action of covalent and noncovalent bonds in the matrix-rich region, the interfacial bonding improved, which endowed AF/EP composite with strengthening and toughening effects. Compared with the control sample AF/EP, the tensile strength and ballistic parameter (V50) of the sample with 5 wt% EAD increased by 17% and 10%, accompanied with ductile failure mode. Furthermore, the flame-retardant mechanism was obtained by analyzing the actions in condensed and gaseous phases. Thanks to good compatibility and interfacial adhesion, the incorporation of EAD solved the inconsistent issue between flame retardancy and mechanical properties, which further expanded the application of AF/EP composite in the protection field.

9.
Int J Biol Macromol ; 278(Pt 2): 134873, 2024 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-39163958

RESUMO

To solve the problems of flammability and smoldering of cotton fabric, its flame-retardant finishing was executed with biomass wool keratin (WK) and cyclic phosphate ester (CPE) through the soaking and baking process. The synergistic mechanism of WK low-temperature melting and CPE catalytic dehydration prompted the formation of protective carbonization layer on cotton fabric surface, and this protective layer reduced its pyrolysis rate, inhibited the production of combustible materials and improved its flame retardancy. The results of synchronous thermal analysis indicate that the initial decomposition temperature of WK and CPE is lower than that of cotton fabric, and they precede the endothermic degradation before fabric main body. This effectively promotes the low-temperature carbonization of cotton fabric and inhibits its pyrolysis. The initial decomposition temperature of WK/CPE treated fabrics advances by 47.9 °C-97.8 °C, presenting significant low-temperature carbonization trend. Moreover, they form 3.0 %-20.0 % aromatic structural char before the pyrolysis of cotton cellulose due to the low-temperature dehydration and carbonization reactions. The damage length after vertical burning is only 4.0 cm for treated fabric with five layers, its after-flame and smoldering disappear, and its limiting oxygen index value increases to 28.7 %. This research provides an effective idea for the flammability and smoldering problems of cotton fabric.

10.
Int J Biol Macromol ; 277(Pt 3): 134316, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39094859

RESUMO

Due to dwindling petroleum resources and the need for environmental protection, the development of bio-based flame retardants has received much attention. In order to explore the feasibility of fully biomass polyelectrolyte complexes (PEC) for polyolefin flame retardant applications, chitosan (CS), sodium alginate (SA), and sodium phytate (SP) were used to prepare CS-based fully biomass PEC intercalated montmorillonite (MMT) hybrid biomaterials (SA-CS@MMT and SP-CS@MMT). The effects of two hybrid biomaterials on the fire safety and mechanical properties of intumescent flame-retardant polypropylene (PP) composites were compared. The SP-CS@MMT showed the best flame retardancy and toughening effect at the same addition amount. After adding 5 wt% SP-CS@MMT, the limiting oxygen index (LOI) value of PP5 reached 30.9 %, and the peak heat release rate (pHRR) decreased from 1348 kW/m2 to 163 kW/m2. In addition, the hydrogen bonding between polyelectrolyte complexes significantly improved the mechanical properties of PP composites. Compared with PP2, the tensile strength of PP5 increased by 59 %. This study provided an efficient and eco-friendly strategy for the large-scale production of renewable biomaterials with good thermal stability and expanded the application of macromolecular biomaterials in the field of fire safety.


Assuntos
Bentonita , Quitosana , Retardadores de Chama , Polieletrólitos , Polipropilenos , Quitosana/química , Bentonita/química , Polipropilenos/química , Polieletrólitos/química , Resistência à Tração , Química Verde/métodos , Materiais Biocompatíveis/química , Fenômenos Mecânicos
11.
J Hazard Mater ; 478: 135494, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39141940

RESUMO

The widespread use of organophosphate flame retardants (OPFRs), a serious type of pervasive environmental contaminants, has led to a global concern regarding their diverse toxicities to living beings. Using a combination of experimental and theoretical approaches, we systematically studied the adsorption, accumulation, and influence of a series of OPFRs on the lipid membranes of bacteria and cells. Our results revealed that OPFRs can aggregate in lipid membranes, leading to the destruction of membrane integrity. During this process, the molecular structure of the OPFRs is a dominant factor that significantly influences the strength of their interaction with the lipid membrane, resulting in varying degrees of biotoxicity. Triphenyl phosphate (TPHP), owing to its large molecular size and strong hydrophobicity, causes severe membrane disruption through the formation of nanoclusters. The corresponding severe toxicity originates from the phase transitions of the lipid membranes. In contrast, smaller OPFRs such as triethyl phosphate (TEP) and tris(2-chloroethyl) phosphate (TCEP) have weaker hydrophobicity and induce minimal membrane disturbance and ineffective damage. In vivo, gavage of TPHP induced more severe barrier damage and inflammatory infiltration in mice than TEP or TCEP, confirming the higher toxicity of TPHP. Overall, our study elucidates the structure-dependent adsorption of OPFRs onto lipid membranes, highlighting their destructive interactions with membranes as the origin of OPFR toxicity.


Assuntos
Retardadores de Chama , Organofosfatos , Retardadores de Chama/toxicidade , Adsorção , Animais , Organofosfatos/toxicidade , Organofosfatos/química , Lipídeos de Membrana/química , Camundongos , Interações Hidrofóbicas e Hidrofílicas , Escherichia coli/efeitos dos fármacos
12.
Int J Biol Macromol ; 277(Pt 4): 134357, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39102916

RESUMO

Developing durable protective cotton fabrics (CF) against potential environmental dangers such as fire hazards and bacterial growth remains an imperative but tough challenge. In this study, flame retardant, antibacterial and hydrophobic CF were successfully prepared via two-step coating. The inner coating entailed polyelectrolyte complexes consisting of polyethyleneimine and ammonium polyphosphate with the goal of enhancing the flame retardancy of CF. Halloysite nanotubes (HNTs), a kind of tubular silicate mineral, were creatively modified and introduced to multifunctional coatings to improve flame retardant and antibacterial properties of CF. N-halamine modified HNTs (HNTs-EA-Cl) and polydimethylsiloxane were applied as the outer coating to endow CF with antibacterial and hydrophobic properties and further improve the flame retardancy of CF. After halloysite-based inorganic-organic hybrid coatings, the limiting oxygen index of the treated samples (PAHP-CF) was over 28 %, and the release of heat and smoke was significantly inhibited. PAHP-CF could inactivate 100 % E. coli and S. aureus within 2 h. More importantly, PAHP-CF showed excellent hydrophobicity with a water contact angle of 148° and exhibited great prevention of bacterial adhesion. PAHP-CF exhibited excellent washing durability undergoing 5 washing cycles. This study promotes the development of multifunctional coatings and offers a new way to manufacture multifunctional cotton fabrics.


Assuntos
Antibacterianos , Argila , Fibra de Algodão , Escherichia coli , Retardadores de Chama , Interações Hidrofóbicas e Hidrofílicas , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/química , Argila/química , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Nanotubos/química , Têxteis , Polietilenoimina/química , Aderência Bacteriana/efeitos dos fármacos , Aminas , Fosfatos
13.
Int J Biol Macromol ; 277(Pt 4): 134644, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39128740

RESUMO

This research describes the synthesis of a silane derivative containing phosphorus and nitrogen atoms, leveraging their synergistic flame retardant effect through the incorporation of a PH bond to the isocyanate moiety. The synthesized silane featured alkoxysilyl groups, facilitating permanent bonds with the cotton fabric surface via hydrolysis. Cotton fabrics were modified using silane solutions of varying concentrations (2.5 %, 5 %, and 10 %) through a dip-coating process to determine the effect of the modifier amount on fabric properties. The modified fabrics were subjected to FT-IR, TGA, SEM, and EDS analyses, as well as microcalorimetric and LOI tests, to assess changes in flammability. FT-IR, SEM/EDS, and add-on analyses confirmed effective coverage of the cotton fabric with the flame retardant. Thermogravimetric tests indicated a significant reduction in the mass loss rate during thermal degradation. LOI analyses demonstrated a decrease in flammability (increase in LOI value), while microcalorimetric tests showed a substantial decrease in the heat release rate, correlating with increased modifier concentration on the fabric surface. Post-washing analyses revealed that, although some of the modifier was washed out, the samples still retained reduced flammability.


Assuntos
Fibra de Algodão , Retardadores de Chama , Retardadores de Chama/síntese química , Silanos/química , Têxteis , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Organofosfonatos/química
14.
Polymers (Basel) ; 16(13)2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-39000619

RESUMO

Urea-formaldehyde (UF) resin is the most widely used adhesive resin. However, it is necessary to improve its flame-retardant performance to expand its applications. In this study, exploiting electrostatic interactions, anionic phytic acid and cationic chitosan were combined to form a bio-based intumescent flame-retardant, denoted phytic acid-chitosan polyelectrolyte (PCS). The molecular structure of the urea-formaldehyde resin was optimized by crosslinking with melamine and plasticizing with polyvinyl alcohol-124. Thus, by combining PCS with the urea-formaldehyde resin and with ammonium polyphosphate and ammonium chloride as composite curing agents, flame-retardant urea-formaldehyde resins (FRUFs) were prepared. Compared to traditional UF resin, FRUF showed excellent flame retardancy and not only reached the UL-94 V-0 level, but the limit of oxygen index was also as high as 36%. Compared to those of UF, the total heat release and peak heat release rate of FRUF decreased by 86.44% and 81.13%, respectively. The high flame retardancy of FRUF originates from the combination of oxygen and heat isolation by the dense carbon layer, quenching of phosphorus free radicals, and dilution of oxygen by a non-flammable gas. In addition, the mechanical properties of the FRUF remained good, even after modification. The findings of this study provide a reference for the flame-retardant application of FRUF for applications in multiple fields.

15.
Small ; : e2403375, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-39031681

RESUMO

The single-layer MXene fully demonstrates the advantages of 2D materials, especially catalytic, conductive, and mechanical properties. However, the high energy consumption and low efficiency faced by MXene in the divestiture process are still challenges that need to be solved urgently. In this article, dimension mismatch and collaborative stripping strategies are skillfully combined to easily realize the transformation from multi-layer MXene to single layer. In addition, the functionalized MXene@SiC@polyaniline (MXene@SiC@PANI) nano-hybrid materials are used as fillers to improve the thermal conductivity, flame retardant, and antibacterial properties of thermoplastic polyurethane (TPU). The surface temperature of TPU/MXene@SiC@PANI composites increased from 33.4 °C to 59.8 °C within 10 s. In addition, the antibacterial efficiency of TPU composites against Escherichia coli and Staphylococcus aureus is 69.6% and 88.9%, respectively. Compared with pure TPU, the peak heat release rate and total heat release are reduced by 71.4% and 34.6%, respectively. The flame-retardant mechanism of MXene hybrid materials is systematically discussed. It is worth noting that the introduction of PANI enhances the compatibility between the filler and the polymer, effectively maintaining the mechanical properties of the TPU itself. This work provides a convenient method for the multi-functional practical application of TPU.

16.
Molecules ; 29(13)2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38999183

RESUMO

The growing requirements regarding the safety of using polymers and their composites are related to the emergence of more effective, sustainable, and hazardous-limited fire retardants (FRs). Significant amounts of FRs are usually required to effectively affect a polymer's burning behavior, while the knowledge of their recycling potential is still insufficient. At the same time, concerns are related not only to the reduced effectiveness of flame retardancy but also, above all, to the potential deterioration of mechanical properties caused by the degradation of temperature-affected additives under processing conditions. This study describes the impact of the four-time reprocessing of bio-based polyamide 11 (PA11) modified with an intumescent flame-retardant (IFR) system composed of ammonium polyphosphate (APP), melamine cyanurate (MC), and pentaerythritol (PER) and its composites containing additional short basalt fibers (BFs). Composites manufactured via twin-screw extrusion were subjected to four reprocessing cycles using injection molding. A comprehensive analysis of their structural, mechanical, and fire behavior changes in each cycle was conducted. The obtained results confirmed the safety of using the proposed fire-retarded polyamide and its composites while reprocessing under the recommended process parameters without the risk of significant changes in the structure. The partial increase in flammability of reprocessed PA-based materials caused mainly by polymer degradation has been described.

17.
Int J Biol Macromol ; 276(Pt 2): 133759, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38986983

RESUMO

The introduction of flame retardancy and low-temperature self-healing capacities in hydrogel electrolytes are crucial for promoting the cycle stability and durability of the flexible supercapacitors in extreme environments. Herein, biomass-based dual-network hydrogel electrolyte (named PSBGL), was synthesized with borax crosslinked peach gum polysaccharide/sisal nanofibers composite, and its application in flexible supercapacitors was also investigated in detail. The dynamic cross-linking of the dual-network endows the PSBGL with excellent self-healing performance, enabling ultrafast self-healing within seconds at both room temperature and extreme low temperatures. The PSBGL bio-based hydrogel electrolyte can maintain the integrity of the carbon layer structure with limiting oxygen index of 56 % after 60 s of combustion under a flame gun. Additionally, the PSBGL exhibits high ionic conductivity (30.12 mS cm-1), good tensile strength (1.78 MPa), and robust adhesion to electrodes (1.15 MPa). The assembled supercapacitors demonstrate a high specific capacitance of 187.8 F g-1 at 0.5 A g-1, with 95.9 % capacitance retention rate after 10,000 cycles at room temperature. Importantly, even under extreme temperatures of 60 °C and -35 °C, the supercapacitors can also maintain high capacitance retention rates of 90.1 % and 86.5 % after 10,000 cycles. This work fills the gap between biomaterial design and high-performance flexible supercapacitors.


Assuntos
Capacitância Elétrica , Eletrólitos , Hidrogéis , Nanofibras , Gomas Vegetais , Nanofibras/química , Eletrólitos/química , Hidrogéis/química , Gomas Vegetais/química , Prunus persica/química , Polissacarídeos/química , Temperatura Baixa , Resistência à Tração
18.
Int J Biol Macromol ; 276(Pt 2): 134002, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39032909

RESUMO

Cellulose-based fabrics have significant advantages, but their application scenarios are limited due to their flammability. This work used biomass phytic acid and protein decomposition products, alkaline amino acids (arginine, lysine, histidine) to prepare alkaline amino acid flame retardants (PALA, PALL, PALH), and they were utilized to endow Lyocell fabrics with flame-retardant and antibacterial properties. When the weight gain was about 16.0 wt%, PALA exhibited better flame-retardant effect, and the limited oxygen index value of PALA-Lyocell reached 47.1 %. In the cone calorimetry test, PALA showed the best flame-retardant efficiency in reducing flame growth index with a 92.0 % decrease in peak heat release rate. The results of thermogravimetric analysis coupled with Fourier Transform Infrared spectroscopy (TG-FTIR) and char residues indicated that the flame-retardant property of alkaline amino acid flame retardants was formed through the combined action of gas and condensed phases. In the antibacterial test, PALA had the highest antibacterial rate against Staphylococcus aureus at 97.2 %. Mechanical property, handle feeling, and whiteness results had indicated that alkaline amino acid based flame retardants had little effect on the physical properties of Lyocell fabrics. This work confirms alkaline amino acid based flame retardants have functions of flame-retardant and antibacterial properties, providing reference for the practical value of biomass in cellulose-based fabrics.


Assuntos
Aminoácidos , Antibacterianos , Celulose , Retardadores de Chama , Ácido Fítico , Staphylococcus aureus , Têxteis , Celulose/química , Celulose/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Ácido Fítico/química , Ácido Fítico/farmacologia , Aminoácidos/química , Staphylococcus aureus/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier
19.
ACS Appl Mater Interfaces ; 16(30): 39886-39895, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39036935

RESUMO

It is of practical significance to develop aerogels with effective thermal insulation characteristics together with fireproof properties as well as high mechanical strength. Here, an interpenetrated multinetwork hybrid aerogel realizing thermal insulation, flame retardancy, and high compression modulus is demonstrated. Specifically, one-dimensional hydroxyapatite nanowires (HAP) played dual roles as the aerogel support skeleton to entangle with layered montmorillonite (MMT) each other to form a three-dimensional interpenetrated multinetwork structure and to optimize the thermal conductivity by adjusting the pore space in current HAP/MMT/PVA hybrid aerogels. Therefore, the interpenetrated multinetwork hybrid aerogels exhibit superior thermal insulation performance in room temperature (0.033 W m-1 K-1, 298 K, air conditions) and largely enhanced ultrahigh compression modulus (80 MPa). Moreover, the obtained hybrid aerogels also exhibit excellent flame retardancy and self-extinguishing smoke suppression properties (peak heat release rate and total smoke production as low as 92.44 kW m-2 and 0.1 m2, respectively), which is the outstanding interpenetrated multinetwork hybrid aerogel that has achieved synergistic improvement in heat and fire insulation and mechanical performance. Therefore, the interpenetrated multinetwork hybrid aerogels are promising candidates for efficient heat insulation, fire prevention, and mechanically robust applications.

20.
Int J Biol Macromol ; 275(Pt 2): 133766, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38992526

RESUMO

To mitigate environmental and health risks associated with the use of halogenated flame retardants, effective halogen-free solutions have been extensively explored. In this study, melamine/boric acid/phosphoric acid (MBP)­sodium alginate (SA) sponge was synthesized by treating MBP ternary supramolecules with microwave irradiation via one-pot, facile, and speedy synthesis, obtaining an MBP-SA sponge, a polysaccharide biopolymer. Crosslinking of SA with Ca2+ ion formed an intact network, and this was confirmed using scanning electron microscopy (SEM). Thereafter, the flame retardancy of the as-synthesized SA/MBP sponge was investigated by exposing it to a spirit lamp and a Bunsen burner; the sponge remained intact for up to 540 s and 370 s, respectively, demonstrating the enhanced flame retardancy of MBP supramolecules in the SA/MBP sponge. The limiting oxygen index of the SA/MBP sponge was up to 62 %, demonstrating the self-extinguishing and thermal insulation properties of the as-synthesized sponge. The findings of this study provide insights for developing a new strategy to use SA/MBP sponges for fire protection.


Assuntos
Alginatos , Retardadores de Chama , Alginatos/química , Triazinas/química , Ácidos Fosfóricos/química , Micro-Ondas
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