ACS Applied Nano Materials
·
2024
·
IF 5.3
Huawei Zhuo,Yaoyao Chen,Hongtao Xie,Xueli Huang,Vitaliy P. Guro,Kamil Tadjiev,Yizhao Li
The significant accumulation of fly ash has resulted in serious environmental issues. It is imperative to find a safe and high-value method for reusing fly ash to effectively address this problem. Additionally, silica aerogels have gained attention as a promising material for energy conservation and thermal management. However, producing a silica aerogel with low production costs and superior overall properties is still a major challenge. In this study, silica–chitosan composite aerogels (SCA) were prepared from fly ash and chitosan. Amorphous silica is polymerized in situ on chitosan by hydrogen bonding and silyl-oxygen condensation. The resulting aerogels exhibited a fully formed block structure, extremely low density, exceptional flame retardancy, and notable mechanical properties (able to withstand 24,000 times the stress of its own mass). It is noteworthy that the nanopores and three-dimensional network structure endow SCA with excellent thermal insulation performance (with a thermal conductivity of 0.0474–0.0521 W m–1 K–1). The strategy presented here provides a cost-effective and straightforward approach to prepare SCA. The results demonstrate its considerable potential for practical use in energy-efficient and thermally insulated structures. Moreover, this approach offers a direct and high value-added solution to the problem of fly ash.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2021
·
IF 9.078
Jiaming Sun,Zhenwei Wu,Bang An,Chunhui Ma,Lifei Xu,Zhanshuo Zhang,Sha Luo,Wei Li,Shouxin Liu
Inspired by the tubular structures found in naturally occurring thermal-insulating materials, tubular cellulose aerogels with improved mechanical resistant, thermal-insulating and flame-retardant properties were prepared from kapok fibers via a facile process. In contrast to fragileness of traditional organic-inorganic composites, an optimized sample exhibited an ultra-high compressive strength of 32 MPa. The tubular structure of this material resulted in a 37.4 °C increase in heat preservation compared with that obtained from a pulp aerogel without this morphology. The H 3 PO 4 decomposed from (NH 4 ) 2 HPO 4 in the formulation crosslinked the outermost cellulose fibers to generate a clay-reinforced dense carbon layer in conjunction with montmorillonite , which restricted the movement of flames and the outflow of volatile compounds. The gaseous voids of internal tubular fibers interrupted the heat transport pathways to inhibit thermal transmission and trapped combustible volatiles to reduce the penetration pressure experienced by the dense carbon layer greatly. The combined effects of the carbon layer and tubular structure effectively limited the transfer of heat, oxygen and volatiles, leading to non-combustion of the optimal sample. This study provided a cost-effective and facile approach to prepare of thermal-insulating, fire-safe and high-strength aerogel showing promising applications in exterior wall insulation and vehicle interior.
研究领域:
材料科学
·
生物启发工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Yan Sun,Youlu Chu,Chao Deng,Huining Xiao,Weibing Wu
In recent years, aerogel has been reported as a good thermal insulation material. However, it has remained a great challenge to realize high mechanical property and excellent anti-fouling performance concurrently of aerogel in practical applications. Here, a composite aerogel was developed via directional freezing and chemical vapor deposition (CVD) modification using chitosan (CS) and montmorillonite (MMT) as heat-resistant raw materials and cellulose nanofibrillated fiber (CNF) as reinforcing filler. The intercalation between the CS molecular chain and MMT endows the aerogel with excellent mechanical properties . Due to the anisotropic structure, the axial Young's modulus is high up to 630 KPa, and the radial thermal conductivity is as low as 31 mW m −1 K −1 . Meanwhile, the aerogel shows a high limiting oxygen index (LOI) value of 43%. Furthermore, CVD treatment increases the contact angles to water and various oils higher than 150°, which portects the aerogle from being contaminated by common liquids. Compared to conventional insulation materials, this aerogel can maintain excellent insulation performance in extreme environments such as heavy rain or oil leakage. The composite aerogel is expected to play an important role in the fields of house warmth, vehicle interior, aviation, and etc.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
He Huang,Jinliang Li,Wei Wang,Xiangyu Jin,Hebing Wang,Can Wu,Yiwu Pan,Wenbo Han,Changqing Hong,Xinghong Zhang
Fiber-reinforced phenolic resin aerogel (FRPRA) composite materials are seductive candidates for high-temperature thermal protection owing to their low density, excellent thermostability, and thermal insulation. However, the intrinsic stiffness restricts their further application for high efficiency. We report a homogeneous and chemical bonding strategy for fabricating lightweight and flexible FRPRA with good ablative thermal insulation performance. The compressible (cyclic strain of 60%) and bendable (cyclic strain of 30%) abilities as well as the structural stability during ablation all benefit from the compatibility between the phenolic resin aerogel matrix and the phenolic fiber reinforcement. Additionally, low bulk density and thermal conductivity of 0.20 g cm–3 and 0.043 W m–1 K–1, respectively, endow the composite with efficient thermal insulation capability. With an 8 mm-thick coupon, the temperature of 200 °C can be decreased to 70.6 °C and the temperature around 1200 °C can be camouflaged to 78 °C through combining with the Al panel. The material also enables a conformal stealth of 600 °C based on its bendability. Hence, the composite has potential in applications of both static and dynamic thermal insulation.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Buyue Zhao,Jie Huang,Qing Wang,Haiming Huang,Qunjiao Chen
Ceramic fibrous materials with good thermal insulation properties are in great demand for the thermal protection of vehicles and spacecraft. Here, ultra-fine flexible Y 2 Si 2 O 7 fibrous membranes with excellent thermal insulation performance are fabricated via electrospinning followed by high-temperature heat treatment. Benefiting from the ultra-fine fibrous structure, the Y 2 Si 2 O 7 fibrous membrane was lightweight (∼0.126 g/cm 3 ) and high porosity (97.11%). Meanwhile, the obtained fibrous membranes exhibited low thermal conductivity (∼0.067 W m −1 K −1 at 27 °C, ∼0.299 W m −1 K −1 at 1000 °C), high-temperature resistance (∼1300 °C), excellent flexibility, and good reflectance in the wavelength of 500–2500 nm (average 89.72%). This research demonstrates a novel fabrication process for preparing flexible Y 2 Si 2 O 7 fibrous membranes, but also the flexible Y 2 Si 2 O 7 fibrous membranes are promising thermal insulation materials at high temperature.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
Nano-Micro Letters
·
2022
·Vol. 14
·期 1
·1-16
·
IF 23.655
Yang Jie,Chan Kit-Ying,Venkatesan Harun,Kim Eunyoung,Adegun Miracle Hope,Lee Jeng-Hun,Shen Xi,Kim Jang‐Kyo
Highly porous aerogel with longitudinally aligned channels and whisker-like ligaments is constructed by solvent-assisted unidirectional freezing.
The thermal insulation and solar reflection capabilities of the composite aerogel reach a state-of-the-art level.
The composite aerogel capable of infrared stealth and temperature preservation presents great potential for application in energy-saving buildings.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Lu Shen,Binbin Sun,Long Ni,Xiaoting Liao,Yinfu Luo,Shengtai Zhou,Huawei Zou
Nowadays, it becomes imperative to develop polyimide (PI) aerogels with excellent thermal insulation and mechanical performance to suit the demanding needs in high-tech sectors such as aerospace, electronics and fire protection among others. Herein, a series of PI aerogels with different dianhydride structures were prepared by sol–gel method, with 2,2′-dimethylbenzidine (DMBZ) being used as the diamine. The microstructure, mechanical properties, thermal stability, and thermal insulation properties of PI aerogels were regulated by changing the dianhydride structure. The compressive strength of PI aerogels at 10% strain was in the range of 0.04–1.60 MPa, and PI PMDA-DMBZ aerogel exhibited the best compressive strength among the studied systems. In addition, PI BPDA-DMBZ aerogel had an initial degradation temperature up to 510°C and thermal conductivity as low as 0.032 W/(m⋅K), demonstrating excellent thermal stability and insulation properties that can withstand harsh conditions.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Shixian Xiong,Yue Yang,Sizhao Zhang,Yunyun Xiao,Hui Ji,Zhouyuan Yang,Feng Ding
Phenolic-based aerogel composites possess particular characteristics, such as low thermal conductivity, light weight, and superior ablative properties, in near-space vehicles. However, their machinability and flammability require further improvement, hampering their application for high-performance thermal protection systems in the aerospace field. Here, we prepare nanoporous polybenzoxazine (PBO) aerogels with outstanding thermally insulating and self-extinguishing properties by an effective-cost ambient pressure drying (APD) approach rather than a conventional high-pressure supercritical drying pattern. The PBO aerogels are prepared by adopting different exchange solvents of tert-butyl alcohol, ethanol, and n-hexane. The results obtained indicate that PBO aerogels (with n-hexane as the exchange solvent) by APD have an optimal three-dimensional nanoporous network structure, a pore size distribution in the range 20–140 nm, an obvious self-extinguishing property (extinguished itself instantly despite exposure to a 1200 °C flame), superior thermal insulation (the cold surface temperature of the sample reached only 36.4 °C after 400 s despite its opposite surface existing at a 65.8 °C atmosphere), and excellent machinable properties (easy-to-form special-shaped sample). PBO aerogels are a great potential candidate material system for thermal protection systems in aerospace applications in the future.
研究领域:
材料科学
·
航天工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Xuening Liu,Congxuan Su,Ya Zhong,Xiaofei Zhu,Zhanwu Wu,Sheng Cui
Dimensions and thermal insulation properties of nanoporous ceramics are unstable at high temperatures due to structural disruptions. This work prepared high entropy (LaCeSmEuNd) 2 Zr 2 O 7 ceramic aerogel via non-alkoxide sol-gel, supercritical drying, and calcination . XRD and EDS analysis showed that the (LaCeSmEuNd) 2 Zr 2 O 7 ceramic existed as a single phase. SEM images demonstrated the successful synthesis of aerogel structure. After two hours of annealing at 1200 °C, the cylindrical sample pressed from (LaCeSmEuNd) 2 Zr 2 O 7 ceramic aerogel had a compressive strength of 58.75 MPa, and its diameter shrinkage was 0.56%, whereas the La 2 Zr 2 O 7 reached 13.68%. The thermal diffusivity of annealed (LaCeSmEuNd) 2 Zr 2 O 7 was as low as 0.119 mm 2 s −1 , and its thermal conductivity at room temperature was 0.073 W·m −1 K −1 , which was attributed to lattice disorder, stable porous structure, and abundance of grain boundaries caused by high entropy effects. Extending the high entropy effect to ceramic nano-insulation products is beneficial for enhancing their thermal stability.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2023
·
IF 3.5
Yudi Duan,Lijuan Wang,Shiyu Li,Xiaofei Liu,Jinsheng Liang,Jiachen Liu,Xinhui Duan,Hui Liu
In this work, a kind of superhydrophobic silica aerogels was prepared at ambient pressure using tetraethoxysilane (TEOS) as precursor. Particularly, N-hexane was added in the solvent to modulation pore microstructure and effect on the insulation properties of samples were analyzed. It is discovered that when the volume ratio of N-hexane to TEOS is 1:2.24 the thermal conductivity of samples can reach the lowest of 0.012 W/m·K. Compared with that of samples no addition of N-hexane, the density is decreased, the theoretical average pore size increases and the total pore volume increases. Due to N-hexane it leads cross-linking between the sol particles stronger and inhomogeneous. Thus gelation process is speeded up resulting in a change in pore structure. Low density can reduce the solid-phase heat transfer, perfect pore microstructure reduces the contribution of gas-phase heat transfer, and only when the two aspects forms a suitable combination it can exhibit optimal thermal insulation performance.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Chao Liu,Chunqin Huang,Yu Li,Yuqian Liu,Huiyang Bian,Zhouyang Xiang,Huijie Wang,Hao Wang,Huining Xiao
Cellulose aerogels exhibit biocompatibility and biodegradability , rendering them promising candidate for application in building energy conservation and insulation materials. However, the intrinsic inflammability of pristine cellulose aerogel causes unneglectable safety concerns, hindering their application in energy-efficient buildings. Herein, a thermal insulating, fire-retardant, strong, and lightweight aerogel was produced via freeze-casting suspensions of cellulose nanofibril (CNF) and l -glutamine functionalized boron nitride nanosheets (BNNS-g). The aerogel with a BNNS-g:CNF concentration ratio of 15:5 exhibited outstanding mechanical strength owing to the strong interaction between BNNS-g and CNF as well as satisfactory thermal insulating performance (0.052 W/m·K). Particularly, this aerogel showed excellent fire-retardant and self-extinguishing capabilities in the vertical burning test, which remained unscathed after over 60 s of burning in a butane flame. Further, the limit oxygen index (LOI) of this aerogel was 36.0 %, which was better than the LOIs of traditional petrochemical-based insulating materials. This study provides a promising strategy for producing aerogels with excellent properties using cellulose and other inorganic nano-fillers.
研究领域:
材料科学
·
能源与环境科学
·
生物材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yuhan Ren,Biao Zhang,Zhaoxin Zhong,Jian Ye,Jiawei Zhang,Zhiyong Fang,Feng Ye
In this study, monolithic Al 2 O 3 –SiO 2 aerogels with excellent thermal stability and high specific surface area were synthesized using boehmite nanorods (L=20–30 nm, D=3–5 nm). The high specific surface area of aerogels was maintained after calcination at 800 °C (663.54 m 2 /g), 1000 °C (486.91 m 2 /g), and 1100 °C (230.76 m 2 /g). The anti-sintering mechanism of the Al 2 O 3 -SiO 2 aerogels was discussed. Thanks to the composite of Al 2 O 3 -SiO 2 aerogel and mullite fibers, the disadvantages of brittleness and low strength of aerogel are overcome. The thermal conductivity of the composite is extremely low at 0.034 W/(m·K)-0.089 W/(m·K) (25 °C-1000 °C). Five muffle cycle back-temperature tests at 1000 °C and a butane blowtorch back-temperature test at 1350 °C also proved that the composites have excellent thermal insulation properties. Composites with excellent thermal insulation properties combined with lightweight, thinness, machinability, and good dielectric properties meet the need for high-temperature thermal insulating-wave transmitting integrated materials for hypersonic missile radomes.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）