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1.
Carbohydr Polym ; 344: 122501, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39218540

RESUMO

Cellulose-based aerogel fibers are recognized as a promising candidate for wearable thermal insulation textiles due to their high porosity, extremely low thermal conductivity, and environmental friendliness. Unfortunately, their practical application in textiles is severely limited by their brittleness. Herein, a novel "long yarn-assisted interfacial polyelectrolyte complexation (YAIPC) spinning" technique is proposed to fabricate cellulose-based aerogel fibers with a unique core-shell structure. The as-prepared core-shell aerogel fibers show excellent thermal insulation performance (34.3 mW m-1 K-1) and robust mechanical strength (∼100 MPa, 31.5 MJ m-3), providing great potential as wearable thermal insulating materials. Accordingly, our research would open a new avenue for designing and constructing wearable aerogel fibers and textiles.

2.
Sci Rep ; 14(1): 18880, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39143186

RESUMO

The surrounding rock of tunnels in cold regions are susceptible to the freeze-thaw cycle resulting from the combination of low temperatures and moisture during tunnel service. The phenomenon will not only lead to the expansion of pores and fissures in the surrounding rock of the initial tunnel, but also destroy the integrity of the rock. This destruction will have a serious impact on tunnel structure and rail transit operation safety. At present, the commonly used thermal insulation measures have some problems such as maintenance difficulties, low economic efficiency, and safety hazards. Therefore, it is urgent to develop a kind of tunnel maintenance grouting material with insulation and anti-permeability, which has the characteristics of simple operation, easy preparation and application. We independently developed a composite grouting material composed of polyurethane (PU), epoxy resin (E-51) and acrylic powder (PMMA). Through the material combustion test, magnesium hydroxide was selected as the flame retardant additive. Moreover, we measured the thermal conductivity, water absorption, apparent density, porosity and strength characteristic parameters. The thermal insulation and anti-permeability characteristics of the composites were also analyzed. The results indicated that the thermal conductivity of the new composite grouting material is 6.3% lower than the PU before adding flame retardant. Compared with the PU with flame retardant, the water absorption decreased by 74.4% and the ultimate strength increased by 33.3%. For the area with an average temperature lower than - 10 °C, we recommend the ratio scheme of E-51: 3%; PMMA: 15%. For the area with high water content in the surrounding rock of the tunnel, we recommend the ratio scheme of E-51: 15%; PMMA: 3%. This study provides new ideas for material preparation and tunnel insulation methods for anti-freezing measures in tunnels during their operational period in cold regions.

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.
Materials (Basel) ; 17(15)2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39124532

RESUMO

Lightweight concrete offers numerous advantages for modular construction, including easier construction planning and logistics, and the ability to offset additional dead loads induced by double-wall and double-slab features. In a previous study, authors proposed incorporating lightweight aggregate into foamed concrete instead of adding extra foam to achieve lower density, resulting in lightweight concrete with an excellent strength-to-density ratio. This paper further investigated the performance aspects of foamed concrete with lightweight aggregate beyond mechanical strength. To evaluate the effect of aggregate type and foam content, three mix compositions were designed for the lightweight concrete. Specimens were prepared for experimental tests on thermal conductivity and drying shrinkage of lightweight concrete. Results showed that while both the increase in foam volume and the incorporation of lightweight aggregate led to higher drying shrinkage, they also contributed to improved insulating properties and reduced potential of cracking. Using typical multi-storey modular residential buildings in Hong Kong and three other Chinese cities as case studies, simulations were performed to assess potential savings in annual cooling and heating loads by employing the proposed lightweight concrete. These findings demonstrate the practical benefits of using foamed concrete with lightweight aggregate in modular construction and provide valuable insights for further optimization and implementation.

5.
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.

6.
Artigo em Inglês | MEDLINE | ID: mdl-39215694

RESUMO

In this paper, the preparation of a transparent superhydrophobic composite coating with a thermal insulation function using antimony-doped tin oxide (ATO) nanoparticles is proposed, which has advantages of being mass-producible and low-cost. In short, nanosilica and ATO are used as raw materials for constructing rough structures, and superhydrophobic coatings are obtained by mixing and adding binders after modification of each, which are then applied to the surface of various substrates by spraying to obtain a transparent superhydrophobic coating with a heat-insulating function. The specific role of each nanoparticle is discussed through comparative experiments that illustrate the mechanism by which the two particles construct rough structures. The coating achieves unique thermal insulation properties while possessing excellent superhydrophobicity (WCA of ∼163° and WSA of ∼3°) and high light transmission (∼70%). Heat-shielding experiments have demonstrated that the composite coating effectively reduces the room temperature by approximately 19% for the same irradiation time. The coating achieves a balanced improvement in visible transmittance, thermal insulation, and superhydrophobicity. In addition, the coating's self-cleaning properties, mechanical properties, chemical weathering resistance, high-temperature resistance, and anti-icing properties were verified through various experiments.

7.
Materials (Basel) ; 17(16)2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39203251

RESUMO

The article presents the results of research on the impact of the use of an original, innovative method of deposition of Parylene C on the functional properties of fabrics with various potential applications (e.g., thermal and chemical protective clothing, packaging, covers and others). Verification of the effects of the method used was based on interdisciplinary research taking into account the impact of coating fabrics on changes in their structure (micro-CT), surface properties (contact angle), barrier properties (water and chemical liquid wetting), electrostatic properties (charge decay), biophysical properties describing heat and mass transfer (by the Alambeta system and thermal imaging) and flammable properties. Four fabrics made of synthetic organic fibres (meta-aramid, para-aramid) and natural inorganic fibres (basalt) were selected for testing. Given the complex structure of textile substrates, the results confirmed that the two assumed thicknesses of the Parylene C coating were consistent with the actual measurements. The findings indicated that the coatings significantly reduced water and acid absorption in the fabrics compared to unmodified ones. Thermal insulation property tests revealed that coated fabrics exhibited higher thermal conductivity than unmodified fabrics. Additionally, the presence of Parylene C on aramid fabrics resulted in a modest increase in their ignition resistance.

8.
Materials (Basel) ; 17(16)2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39203259

RESUMO

Keratin waste, including keratin powder, is a significant byproduct of the poultry processing and meat industries. It is a major contributor to waste management problems due to its volume and the environmental pollutants that it can produce. The disposal of keratin waste is challenging due to the potential for odors and pathogens to enter the soil and water. The aim of this work is to present the possibility of using waste materials in accordance with the principles of upcycling and producing fully valuable products. In this research, the author focuses on the production and research of textile multilayer laminates using keratin flour that had been previously considered waste material. New textile composites should be characterized by increased thermal insulation properties with constant comfort in use. This research determines the physiological comfort interpreted as the state of the human-laminate system, which maintains the conditions of comfort in human perception, i.e., constant temperature and humidity of the body under changing conditions of a relative humidity environment.

9.
Polymers (Basel) ; 16(16)2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39204511

RESUMO

In response to the growing demand for lightweight yet robust materials in electric vehicle (EV) battery casings, this study introduces an advanced carbon fiber-reinforced composite (CFRC). This novel material is engineered to address critical aspects of EV battery casing requirements, including mechanical strength, electromagnetic interference (EMI) shielding, and thermal management. The research strategically combines carbon composite components with copper-plated polyester non-woven fabric (CFRC/Cu) and melamine foam board (CFRC/Me) into a sandwich-structure composite plus a series of composites with graphite particle-integrated matrix resin (CFRC+Gr). Dynamic mechanical analysis (DMA) revealed that the inclusion of copper-plated fabric significantly enhanced the stiffness, and the specific tensile strength of the new composites reached 346.8 MPa/(g/cm3), which was higher than that of other metal materials used for EV battery casings. The new developed composites had excellent EMI shielding properties, with the highest shielding effectives of 88.27 dB from 30 MHz to 3 GHz. Furthermore, after integrating the graphite particles, the peak temperature of all composites via Joule heating was increased. The CFRC+Gr/Me reached 68.3 °C under a 5 V DC power supply after 180 s. This research presents a comprehensive and innovative approach that adeptly balances mechanical, electromagnetic, and thermal requirements for EV battery casings.

10.
J Colloid Interface Sci ; 677(Pt B): 804-815, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39173513

RESUMO

Carbon aerogel has gained intense attention as one of the most promising microwave absorption materials. It can overcome severe electromagnetic pollution, thanks to its 3D macroscopic structure and superb conductive loss capacity. However, there is still a big challenge to endow multifunctionality to carbon aerogel while maintaining its good electromagnetic wave absorption (EWA) so as to adapt wide practical application. Herein, a novel carbon-based aerogel consisting of Cu and TiO2 nanoparticles dispersed on carbon nanofiber framework was derived from carbonized bacterial cellulose (CBC) decorated with its mother bacteria via freeze-drying, in situ growth and carbonization strategies. The synthesized carbon-based CBC/Cu/TiO2 aerogel achieved an excellent EWA performance with a broad effective absorption bandwidth (EAB) of 8.32 GHz. It is attributed to the synergistic loss mechanism from multiple scattering, conductive network loss, interfacial polarization loss and dipolar polarization relaxation. Meanwhile, the obtained aerogel also shows an excellent thermal insulation with a 3-mm-thick sample generating a temperature gradient of over 42 °C at 85 °C and a maximum radar cross-section (RCS) reduction of 23.88 dB m2 owing to the cellular structure and synergistic effects of multi-components. Therefore, this study proposes a feasible design approach for creating lightweight, effective, and multifunctional CBC-based EWA materials, which offer a new platform to develop ultrabroad electromagnetic wave absorber under the guidance of RCS simulation.

11.
Polymers (Basel) ; 16(14)2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39065369

RESUMO

With the integration and miniaturization of modern equipment and devices, porous polymers, containing graphene and its derivatives, with flame-retardancy have become a research hotspot. In this paper, the expanded properties and high-end applications of flame-retardant porous materials containing graphene and its derivatives were discussed. The research progress regarding graphene-based porous materials with multiple energy conversion, thermal insulation, an electromagnetic shielding property, and a high adsorption capacity were elucidated in detail. The potential applications of materials with the above-mentioned properties in firefighter clothing, fire alarm sensors, flexible electronic skin, solar energy storage, energy-saving buildings, stealth materials, and separation were summarized. The construction strategies, preparation methods, comprehensive properties, and functionalization mechanisms of these materials were analyzed. The main challenges and prospects of flame-retardant porous materials containing graphene and its derivatives with expanded properties were also proposed.

12.
J Colloid Interface Sci ; 676: 1011-1022, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39068833

RESUMO

Polyimide (PI) aerogels have various applications in aerospace, national defense, military industry, and rail transit equipment. This paper reports a series of ultra-lightweight, high elasticity, high strength, low thermal conductivity, and high flame retardant rGO/PI nanocomposite aerogels prepared by the ice templating method. The effects of freezing processes (unidirectional freezing and random freezing), chemical composition, and environmental temperature (-196-200 °C) on the morphology, mechanical, and thermal properties of the aerogels were systematically studied. The results indicated that unidirectional aerogels exhibit anisotropic mechanical properties and thermal performance. Compression in the horizontal direction showed high elasticity, high fatigue resistance, and superior thermal insulation. Meanwhile, in the vertical direction, it demonstrated high strength (PI-G-9 reaching 14 MPa). After 10,000 cycles of compression in the horizontal direction (at 50 % strain), the unidirectional PI-G-5 aerogel still retains 90.32 % height retention, and 78.5 % stress retention, and exhibited a low stable energy loss coefficient (22.11 %). It also possessed a low thermal conductivity (32.8 mW m-1 K-1) and demonstrated good thermal insulation performance by sustaining at 200 °C for 30 min. Interestingly, the elasticity of the aerogels was enhanced with decreasing temperatures, achieving a height recovery rate of up to 100 % when compressed in liquid nitrogen. More importantly, the rGO/PI aerogels could be utilized over a wide temperature range (-196-200 °C) and had a high limiting oxygen index (LOI) ranging from 43.3 to 48.1 %. Therefore, this work may provide a viable approach for designing thermal insulation and flame-retardant protective materials with excellent mechanical properties that are suitable for harsh environments.

13.
ACS Appl Mater Interfaces ; 16(29): 38520-38530, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38980947

RESUMO

Lightweight ablative thermal protection materials (TPMs), which can resist long-term ablation in an oxidizing atmosphere, are urgently required for aerospace vehicles. Herein, carbon fabric/phenol-formaldehyde resin/siloxane aerogels (CF/PFA/SiA) nanocomposite with interpenetrating network multiscale structure was developed via simple and efficient sol-gel followed by atmospheric pressure drying. The ternary networks structurally interpenetrating in macro-, micron-, and the nanoscales, chemically cross-linking at the molecular scale, and silica layer generated by in situ heating synergistically bring about low density (∼0.3 g cm-3), enhanced mechanical properties, thermal stability, and oxidation resistance, and a low thermal conductivity of 81 mW m-1 K-1. More intriguingly, good thermal protection with near-zero surface recession at 1300 °C for 300 s and remarkable thermal insulation with a back-side temperature below 60 °C at 20 mm thickness. The interpenetrating network strategy can be extended to other porous components with excellent high-temperature properties, such as ZrO2 and SiC, which will facilitate the improvement of lightweight ablative TPMs. Moreover, it may open a new avenue for fabricating multifunctional binary, ternary, and even multiple interpenetrating network materials.

14.
Int J Biol Macromol ; 275(Pt 2): 133724, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38977054

RESUMO

Cellulose papers (CPs) possess a pore structure, rendering them ideal precursors for carbon scaffolds because of their renewability. However, achieving a tradeoff between high electromagnetic shielding effectiveness and low reflection coefficient poses a tremendous challenge for CP-based carbon scaffolds. To meet the challenge, leveraging the synergistic effect of gravity and evaporation dynamics, laminar CP-based carbon scaffolds with a bidirectional gradient distribution of Fe3O4 nanoparticles were fabricated via immersion, drying, and carbonization processes. The resulting carbon scaffold, owing to the bidirectional gradient structure of magnetic nanoparticles and unique laminar arrangement, exhibited excellent in-plane electrical conductivity (96.3 S/m), superior electromagnetic shielding efficiency (1805.9 dB/cm2 g), low reflection coefficients (0.23), and a high green index (gs, 3.38), suggesting its green shielding capabilities. Furthermore, the laminar structure conferred upon the resultant carbon scaffold a surprisingly anisotropic thermal conductivity, with an in-plane thermal conductivity of 1.73 W/m K compared to a through-plane value of only 0.07 W/m K, confirming the integration of thermal insulation and thermal management functionalities. These green electromagnetic interference shielding materials, coupled with thermal insulation and thermal management properties, hold promising prospects for applications in sensitive devices.


Assuntos
Carbono , Celulose , Carbono/química , Celulose/química , Condutividade Térmica , Condutividade Elétrica , Temperatura
15.
ACS Appl Mater Interfaces ; 16(27): 35613-35625, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38949183

RESUMO

Anti/deicing coatings that combine active and passive methods can utilize various energy sources to achieve anti/deicing effects. However, poor photothermal or electrothermal performance and inevitable heat loss often reduce their anti/deicing efficiency. Herein, copper sulfide loaded activated biochar (AC@CuS) as photo/electric material, polydimethylsiloxane as hydrophobic component, thermally expandable microspheres as foaming agent, and an anti/deicing coating integrating thermal insulation, superhydrophobicity, photo/electrothermal effects was successfully constructed. Benefiting from the synergistic effect of superhydrophobicity and thermal insulation, the freezing time of water droplets on the coating surface is extended from 150 to 2140 s, showing excellent passive anti-icing performance. AC@CuS exhibits photo/electrothermal effects, and porous expanded microspheres reduce heat loss, which endows the coating with desirable photo/electrothermal conversion performance. Under the conditions of 0.2 W/cm2 electric power density (EPD) and 0.1 W/cm2 optical power density (OPD), the temperature of the coating increases from 24 to 96.4 and 113 °C, respectively. Interestingly, with a coheating of 0.05 W/cm2 weaker OPD and 0.05 W/cm2 lower EPD, the ice on the coating surface can be quickly melted in 2.5 min, showing synergistic deicing performance. In addition, the WCA of the prepared coating remains above 150° after mechanical damage, rain impact, UV irradiation, chemical corrosion, and high-temperature treatment, and good superhydrophobic durability ensures the anti/deicing durability of the coating.

16.
Materials (Basel) ; 17(13)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38998318

RESUMO

Mullite fiber felt is a promising material that may fulfill the demands of advanced flexible external thermal insulation blankets. However, research on the fabrication and performance of mullite fiber felt with high-temperature resistance and thermal stability is still lacking. In this work, mullite fibers were selected as raw materials for the fabrication of mullite fibrous porous materials with a three-dimensional net structure. Said materials' high-temperature resistance and thermal stability were investigated by assessing the effects of various heat treatment temperatures (1100 °C, 1300 °C, and 1500 °C) on the phase composition, microstructure, and performance of their products. When the heat treatment temperature was below 1300 °C, both the phase compositions and microstructures of products exhibited stability. The compressive rebound rate of the product before and after 1100 °C reached 92.9% and 84.5%, respectively. The backside temperature of the as-prepared products was 361.6 °C when tested at 1500 °C for 4000 s. The as-prepared mullite fibrous porous materials demonstrated excellent high-temperature resistance, thermal stability, thermal insulation performance, and compressive rebound capacity, thereby indicating the great potential of the as-prepared mullite fibrous porous materials in the form of mullite fiber felt within advanced flexible external thermal insulation blankets.

17.
Materials (Basel) ; 17(13)2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38998419

RESUMO

In the current work, the performance properties of natural-fibre-based thermal insulation materials were examined. For this purpose, three different compositions of natural fibres were prepared: pure sheep wool (SW), wool and industrial hemp (SW/HF) fibres, and pure industrial hemp (HF) fibres. Low-melt bicomponent polylactide (PLA) fibres were used as a binding material. For specimens prepared from natural fibres, the dependence of the thermal conductivity, the tensile strength along and across the direction of product formation, and the short-term water absorption on the density of the specimens and the flammability parameters were determined. In addition, to reduce the water absorption and flammability, the specimens were coated with hydrophobic agents and flame retardants. The obtained research results were also statistically processed. The analysis of the results showed that the thermal conductivity of natural-fibre-based thermal insulation materials varied within the range of 0.0333 ÷ 0.0438 W/(m·K), the tensile strength varied from 2.5 to 130 kPa, the short-term water absorption varied from 0.5 to 8.5 kg/m2, and the water vapour diffusion resistance factor varied from 2.537 to 2.667. It was additionally determined that all the studied products were flammable. The water absorption and flammability values were significantly reduced by the use of hydrophobic agents and flame retardants.

18.
ACS Appl Mater Interfaces ; 16(30): 39993-40003, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39016461

RESUMO

Aerogel fibers have sparked substantial interest as attractive candidates for thermal insulation materials. Developing aerogel fibers with the desired porous structure, good knittability, flame retardancy, and high- and low-temperature resistance is of great significance for practical applications; however, that is very challenging, especially by using an efficient method. Herein, mechanically strong and flexible aerogel fibers with remarkable thermal insulation performance are reported, which are achieved by constructing stiff-soft topological polymer networks and a multilevel hollow porous structure. The combination of polyamide-imide (PAI) with stiff chains and polyurethane (PU) with soft chains is first found to be able to form a topological entanglement architecture. More importantly, multilevel hollow pores can be constructed synchronously through just a one-step and green wet-spinning process. The resultant PAI/PU@340 aerogel fibers show an ultrahigh breaking strength of 94.5 MPa and superelastic property with a breaking strain of 20%. Furthermore, they can be knitted into fabrics with a low thermal conductivity of 25 mW/(m·K) and exhibit attractive thermal insulation property under extremely high (300 °C) and low temperatures (-191 °C), implying them as promising candidates for next-generation thermal insulation materials.

19.
Adv Mater ; 36(32): e2406055, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38829267

RESUMO

Elastic aerogels can dissipate aerodynamic forces and thermal stresses by reversible slipping or deforming to avoid sudden failure caused by stress concentration, making them the most promising candidates for thermal protection in aerospace applications. However, existing elastic aerogels face difficulties achieving reliable protection above 1500 °C in aerobic environments due to their poor thermomechanical stability and significantly increased thermal conductivity at elevated temperatures. Here, a multiphase sequence and multiscale structural engineering strategy is proposed to synthesize mullite-carbon hybrid nanofibrous aerogels. The heterogeneous symbiotic effect between components simultaneously inhibits ceramic crystalline coarsening and carbon thermal etching, thus ensuring the thermal stability of the nanofiber building blocks. Efficient load transfer and high interfacial thermal resistance at crystalline-amorphous phase boundaries on the microscopic scale, coupled with mesoscale lamellar cellular and locally closed-pore structures, achieve rapid stress dissipation and thermal energy attenuation in aerogels. This robust thermal protection material system is compatible with ultralight density (30 mg cm-3), reversible compression strain of 60%, extraordinary thermomechanical stability (up to 1600 °C in oxidative environments), and ultralow thermal conductivity (50.58 mW m-1 K-1 at 300 °C), offering new options and possibilities to cope with the harsh operating environments faced by space exploration.

20.
Int J Biol Macromol ; 275(Pt 2): 133367, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945720

RESUMO

To replace traditional petrochemical-based thermal insulation materials, in this work, the chitosan (CHI)/alginate (ALG) (CA) aerogels with three-dimensional hierarchical pore network structure were constructed by compositing CHI and ALG using a synergistic strategy of hydrogen bonding dissolution and covalent crosslinking. The structure and properties were further regulated by crosslinking the CA aerogels with epichlorohydrin (ECH). The CA aerogels exhibited various forms of covalent crosslinking, hydrogen bonding and electrostatic interactions, with hydrogen bonding content reaching 79.12 %. The CA aerogels showed an excellent three-dimensional hierarchical pore network structure, with an average pore size minimum of 15.92 nm. The structure regulation of CA aerogels obtained excellent compressive properties, with an increase of stress and strain by 137.61 % and 45.05 %, which can support a heavy object 5000 times its weight. Additionally, CA aerogels demonstrate excellent thermal insulation properties and low thermal conductivity, comparable to commercially available insulation materials. More importantly, CA aerogels have good cyclic insulation stability and thermal properties, and they have a flame retardancy rating of V-0, which shows the stability of insulation properties and excellent safety. CA aerogels provide new ideas for the development of biomass thermal insulation materials and are expected to be candidates for thermal management applications.


Assuntos
Alginatos , Quitosana , Géis , Ligação de Hidrogênio , Quitosana/química , Alginatos/química , Géis/química , Porosidade , Condutividade Térmica , Epicloroidrina/química , Temperatura , Reagentes de Ligações Cruzadas/química
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