CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Lin Wang,Dehua Ma,Chonghe Xu,Xinzhu Gan,Pinghui Ge,Luyi Zhu,Xinqiang Wang,Yadong Lv
With the increasingly serious issues of energy conservation and emission reduction, hollow fibers have attracted wide attention as materials that have structural advantages in terms of thermal insulation . Herein, we report the preparation of flexible hollow TiO 2 fibrous membranes via coaxial electrospinning. To optimize the thermal-insulation performance of the fibers, hollow fibers with different diameters and pore sizes were prepared by adjusting the feeding rate of the core spinning solution. Optimum conditions were achieved at a feeding rate of 2 mL/h for the shell solution and 0.4 mL/h for the core solution. The hollow fibers had a compact tube wall structure and good mechanical properties , and the tensile strength of the fibrous membranes reached 0.652 ± 0.119 MPa. In addition, the hollow fibrous membranes have excellent thermal insulation properties with an average reflectance of more than 89% and a room temperature thermal conductivity of less than 0.0294 ± 0.00015 W m −1 K −1 . In practical experiments, the temperature can be reduced from 1174.6 to below 273.6 °C using 15-mm-thick fibrous membranes, which confirms its excellent thermal insulation. Flexible hollow TiO 2 fibrous membranes have a wide range of insulation applications.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Dayi Yang,Jingxiao Liu,Fei Shi,Yi Li,Jiaxiang Wan,Xinyu Yuan,Ziwei Tian,Meiyu Wang,Chuangchuang Ma
Synthesis of cesium tungsten bronze (Cs x WO 3 ) nanorods with excellent near-infrared shielding performance by a one-step solvothermal method from cheap tungsten source is still challenging. In this work, small-sized Cs x WO 3 nanorods with excellent transparent thermal insulation performance were synthesized by a one-step solvothermal method. It was found that halogen acids played an important role in regulating the growth and microstructure of Cs x WO 3 nanorods. Moreover, different halogen acid can regulate the content of W 5+ =O and oxygen vacancies (V O ) in Cs x WO 3 nanorods, which is helpful to further improve the near-infrared shielding performance of Cs x WO 3 particles. Compared with HF and HBr, the Cs x WO 3 nanoparticles synthesized under the regulation of HCl contain more V O s and W 5+ =O content, showing more excellent near-infrared shielding performance, and the as-prepared Cs x WO 3 -PVA composite film exhibits low haze and high transparency, with the near-infrared light shielding rate at 1500 nm attaining to 97.7% when the visible light transmittance is 71.8%. The thermal insulation test results show that the Cs x WO 3 -PVA composite film synthesized under the regulation of HCl can effectively reduce the indoor temperature by 6.9 °C under the irradiation of sunlight. After 100 cycles of thermal insulation tests, the near-infrared shielding and thermal insulation performance have not declined, showing excellent photothermal stability. This work is of great significance for promoting the industrial production of high-performance Cs x WO 3 nanoparticles and its application in energy-saving windows.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2024
·
IF 2.7
Xiaohua Li,Kunfeng Li,Huilong Shao,Shuang Zhao,Guobing Chen,Zhen Zhang,Zhicong Gan,Yilong Song,Zichun Yang
The freeze-casting is widely utilized as a tool for regulating micro-scale pore structures in the fabrication of flexible polyimide (PI) aerogels for applications in adsorption, filtration, and fire-retardant. Herein, a confinement-controlled freeze-casting method is developed to fabricate PI aerogels with excellent thermal insulation properties by designing multi-scale structural adaptability. In a confinement-controlled system, the enhanced solid/solid and solid/liquid interface interactions in the solution dispersion system induce dendritic evolution of ice crystals. Under the directional freezing, grown dendritic ice crystals squeeze the loaded particles to form polyamic acid salt (PAAs) cryogels. Followed by template removal and thermal imidization, PI aerogels with a micro/nano-scale slit-like porous structure were obtained. The PI aerogels are characterized by ultra-low density (as low as 9.82 mg/cm 3 ) and exceptional thermal insulation performance (25.0 mW/(m·K) at 25 °C).
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
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jiahao Lu,Ruiying Zhai,Yijie Yang,Sisi Chen,Xiaoqi Sun
Herein, a series of environmentally friendly rare earth doped yellow pigments with near-infrared (NIR) properties were synthesized using solid-state reaction at a high temperature of 1200 °C, with the general formula Y 2−x Bi x MoO 6 . The prepared pigments were characterized using analytical techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), CIE 1976 color space system, ultraviolet–visible/near infrared (UV–Vis/NIR) spectroscopy. Results indicated that its color changes from white to yellow after doping with Bi 2 O 3 in Y 2 MoO 6 . As the doping amount of Bi increased, the yellow color gradually deepened. All the doped samples exhibited a monoclinic structure with space group C 2/ c (15). When the optimal doping ratio was Y 1.8 Bi 0.2 MoO 6 (i.e., x = 0.2), the NIR reflectance (R%) and NIR solar reflectance (R∗%) of the pigment sample both exceeded 100 %. In the study of acid and alkali resistance, the color difference value ΔE∗ before and after pigment soaking was less than 5, indicating good chemical stability. In the coating study, the temperature difference between the air inside the pigment-coated house model and the air inside the uncoated house model reached 7 °C after 20 min of irradiation using an infrared lamp, suggesting that the prepared pigment reflects solar thermal radiation well and demonstrates good thermal insulation performance.
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Yongshuai Xie,Ying Peng,Dehua Ma,Wei Liu,Zhezhe Deng,Luyi Zhu,Guanghui Zhang,Xinqiang Wang
Lightweight and flexible thermal insulation materials have gradually become a research focus. In this work, the flexible YAG fibrous membrane which can be folded in half after heat treatment at 1200 °C for 2 h was prepared. The crystallization process , mechanical properties , and thermal insulation properties of the YAG fibrous membrane were studied. The as-prepared YAG fibrous membrane has no mesophase formation during the crystallization process, and its tensile strength was 2.43 MPa. The self-supporting effect of single fibers made YAG fibrous membrane had ultra-high porosity. Its density was 27.34 mg/cm 3 , which made it have thermal insulation performance comparable to aerogel . When the hot surface is 1200 °C, a 10 mm thick YAG fibrous membrane can stabilize the temperature of the cold surface at 320 °C. The YAG fibrous membrane is expected to be used as a new generation of lightweight, high strength, flexible, and high-efficiency thermal insulation materials for extremely high temperature conditions.
研究领域:
材料科学
·
热能工程
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2024
·
IF 6.5
Dongdong Tang,Liangbo Zhu,Xie Li,Yuan Liu,Qi Wang
Intumescent fireproof coating (IFC) can effectively slow down the temperature rise of base materials by constructing intumescent heat isolation chars. Expandable graphite (EG), combined with a typical intumescent flame-retardant system, shows an excellent expansion effect. However, it is difficult to be evenly dispersed in the coating system due to its low surface energy, thus limiting its application in IFC. In this research, EG encapsulated by polyvinyl alcohol (PVA) film was used in combination with conventional intumescent flame retardants to prepare a fireproof coating. Due to the increased hydrophilicity caused by the hydroxy groups of the PVA, both the dispersion and adhesion of EG can be greatly improved in the coating. Additionally, PVA also plays the role of a charring agent to further upgrade the quality of the produced carbon layer . The prepared IFC displays a satisfying synergistic effect . The experimental results showed that the back-surface temperature of the steel plate coated by PVA@EG was reduced to 232 °C after 20 min, far lower than the 250 °C of the unmodified EG system, and the thermal insulation performance was enhanced significantly. Compared with the untreated EG coating, the HRR, THR, and TSR decreased by 79.5 %, 86.0 % and 24.8 %, respectively, and combustion and smoke suppression performance were improved greatly. All in all, PVA@EG endows the coating with superior flame-retardant and thermal insulation performance and greatly improves the safety of steel structures in buildings.
研究领域:
材料科学
·
防火技术
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Jundong Zhu,Jiang Hu,Chongwen Jiang,Siyuan Liu,Ying Li
Konjac glucomannan (KGM) aerogel was prepared by a facile freeze-drying process, which was used as green sustainable biopolymer matrix to synthesis three-dimensional (3D) network interpenetrated KGM-SiO 2 aerogel with thermal insulation performance and high mechanical properties. Herein, we explored that the potential structure–performance relationship of KGM aerogel between the physical parameters, morphology and thermal insulation. Besides, the preparation conditions of KGM aerogel including concentration of KGM, Na 2 CO 3 -to-KGM mass ratio were investigated. Meanwhile, the KGM aerogel and KGM-SiO 2 aerogel were characterized using scanning electron microscopy, Fourier transform infrared spectrometer, Brunauer-Emmett-Teller method, thermogravimetric analysis and contact angle test. Results showed that the as-prepared KGM aerogel exhibited excellent thermal insulation performance (λ = 0.021 W m −1 K −1 ) and low bulk density (ρ = 0.030 g cm −3 ) when concentration of KGM was 2 wt% and Na 2 CO 3 -to-KGM mass ratio of 0.12. In order to improve the mechanical properties and high hydrophobicity of biopolymer aerogel, a novel of KGM-SiO 2 aerogel was successful fabricated by incorporating methylsilsesquioxane (MTES) derived SiO 2 into the KGM matrix via the freeze-drying method. The obtained aerogel exhibited remarkable compressive strength (δ max = 1.65 MPa at 80% strain), high specific surface area of 416.1 m 2 g −1 , high hydrophobicity (θ = 146° for water) and low thermal conductivity of 0.032-0.039 W m −1 K −1 . Thus, the high-performance KGM-SiO 2 aerogel would be further expand the thermal insulation application in sustainable development and energy-saving building.
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 APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 42
·e53033
·
IF 3.057
Jiaoyang Li,Zhaoqing Lu,Jizhen Huang,Li Hua
Designing aramid nanofiber (ANF) aerogel with excellent microstructure and high thermal insulation property is benefit for applications in integrated thermal management system. To obtain a structurally controllable ANF-based aerogel, the cellulose nanofiber (CNF) and poly (vinyl alcohol) (PVA) were ‘stiff–soft’ synergistic to improve the microstructure. The cobweb like structures distributed in the honeycomb layered pores of the CNF/PVA/ANF composite aerogel which was conducive to the performance and application of composite aerogel. The resulting CNF1/PVA1/ANF composite aerogels are highly porous (99.12%) and tiny volume shrinkage (4.65%), leading to excellent thermal insulation performance (26.83 mW/m·K). The ‘stiff–soft’ feature endows the composite aerogels high flexibility as well as large compression strength. These favorable multi-features make the CNF/PVA/ANF composite aerogels ideal advanced material for aerospace, industrial, and commercial applications.
研究领域:
材料科学
·
热管理工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Juan Wang,Mingwang Pan,Jinfeng Yuan,Gang Liu,Lei Zhu
The current syntheses of spheres-on-sphere (SOS) microsphere, which possesses both hollow cavity and hierarchical structure, mainly rely on complicated routes and template removal. In this study, a one pot nanoengineering strategy inspired by the automatic transport behavior of water in plants is successfully developed to fabricate SOS microsphere in tandem with a traditional soft template method in the preparation of hollow structure. Amphiphilic siloxane oligomers generated in situ from methyltriethoxylsilane (MTES) under acidic conditions are anchored on the surface of soft template St monomer droplets, sequentially completing hydrolysis-polycondensation and forming a mesoporous polysilsesquioxane (PSQ) shell. Then, the St monomers located in cavity migrate outward under the combined action of capillary force stemming from mesoporous and osmotic pressure generating from inside–outside of the PSQ shell and polymerize on the outside of the hollow PSQ shell, in which residual siloxane oligomers further anchor on the polystyrene (PS) surface to reduce the surface energy of the system, finally resulting in the successful formation of SOS particles. To reduce thermal insulation coefficient of the material, the PS phase in SOS particles is removed to obtain the particles with multiscale hollow structure (SOS-MH), which have more hollow cavities to encapsulate more air. The presence of a much hollow structure in SOS-MH particles enables the thermal conductivity of polyacrylonitrile (PAN)/SOS-MH composite fibrous membranes (0.0307 W m–1 K–1) to decrease by about 40% compared to that of pure PAN fibrous films (0.0520 W m–1 K–1) at the same thickness of 1 mm, and the material also has moisture resistance due to the existence of a hierarchical shell.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2023
·
IF 5.9
Ying-Ming Li,Wen-Juan Hu,Shuang-Lin Hu,Yi-Ran Li,Dan-Ping Zhu,De-Yi Wang
The rigid polyurethane foam (RPUF) with excellent flame retardancy, high compressive strength and good thermal insulation performance is of great importance to its widely application, especially the application in high-rise building exterior wall materials. In this work, two kinds of flame-retarding polyols (DADP and APDP) containing phosphorus and nitrogen elements were prepared via a simple salinization reaction and reacted into RPUF chains. When only 15 wt% of APDP was incorporated, the material passed the UL-94 V-0 rating with a limiting oxygen index (LOI) of 24.5% while 20 wt% of DADP incorporated to realize the same flame-retarding effect. For the RPUF/APDP 15 , the peak heat release rate (PHRR) decreased by 28.2% comparing to the neat RPUF and the fire growth rate (FIGRA) was the lowest 8.3, indicating the lowest flame spread speed among all the flame-retarding RPUF. The compressive strength of the RPUF/APDP 15 material increased by 41.8% comparing to that of neat RPUF, mainly causing by the good compatibility and the enhancement of hardness of polyurethane via the benzene ring. Moreover, it was concluded that the gas-phase mechanism dominated in enhancing the flame-retarding effect for the RPUF material, and the APDP showed a higher flame-retarding effect with a higher content of phosphorus and nitrogen elements than that of DADP.
研究领域:
材料科学
·
防火材料
·
建筑保温材料
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Xinfu Zhao,Mengqing Su,Shimo Yu,Jing Zhang,Xiaochan Liu,Kang Qiu,Xibin Yi,Jian Zhang,Guoliang Dou,Mengdi Wang
Polyimide (PI) aerogel is a good thermal insulation material with the highest temperature resistance in practical application. But the mechanical strength of PI aerogels prepared by freeze-drying or thermoimide methods is weak. In this research, TPU was selected as an aging solution to solve the problem of the low mechanical strength of PI aerogel prepared by the freeze-drying method. Previous work has certified that the coupling of PI and thermoplastic polyurethane (TPU) can enhance the mechanical strength of PI aerogel to a certain extent due to the flexibility of TPU. But excessive TPU will change the PI structure in the cross-linking process and decrease the mechanical strength of the aerogel. Thus, a new kind of PI gel modification method was provided by using TPU as an aging solution, and the mechanical strength of PI aerogel is improved to 3.06 MPa. Furthermore, the shrinkage, specific surface area, waterproof angle, and thermal conductivity all show good performance, thus enabling PI aerogel to be used in many aspects. Specially, the method is simple and can be used to prepare some other high-strength aerogels.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Yuanfang Ai,Weixi Chen,Xi Wu,Na Zheng,Longcheng Tang,Dongqi Wang,Huang Tang,Kun Cao
Intumescent flame-retardant coatings offer excellent passive fire protection for flammable materials and steel. However, a key challenge is the conflict between increased melt viscosity from additive catalyst and chemical foaming behavior. Herein, “interfacial autocatalytic” strategy-guided design of a double dopant-free epoxy coating is reported with a 100 µm boron-rich upper layer and a 300 µm phosphorus-rich bottom layer. This coating generates BPO 4 catalyst in situ at the interface during combustion, synergistically catalyzing charcoal formation with the expansion process. BPO 4 , with its better lattice arrangement, is able to form a dense ceramic layer of 5.5 µm ceramic layer from a stack of 10–40 nm nanoparticles, encapsulating an underlying 1.8 cm intumescent char layer. The coating demonstrates the superior thermal insulation with the heat-resistant time for up to 50 min, a 271% delay in ignition time, an ultra-low fire growth rate with 58% reduction, and a 33% reduction in total heat release. In addition to high transparency, this coating presents easy self-healing, good mechanical properties, and water resistance. This autocatalytic strategy in a confined space-time introduces a new method for enhancing catalytic charring flame retardancy.
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
危险品化学品经营许可证（带存储）