CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Guangxu Ju,Danqian Wang,Yingzi Gu,Weining He,Yiming Niu,Guoxing Sun
Good thermal insulation performance is crucial for the application of cement materials, and reducing thermal conductivity is an effective strategy to enhance thermal insulation performance. Thermosensitive poly-N-isopropylacrylamide (PNIPAM) undergoes a phase transition around its lower critical solution temperature (LCST) of approximately 32 °C, and its incorporation can significantly improve the thermal insulation properties of cement. This study investigates the effects of adding PNIPAM in concentrations ranging from 0.3 % to 1.5 % on the thermal conductivity of cement-based materials at temperatures of 25 °C, 32 °C, and 37 °C. At 37 °C, the thermal conductivity of the cement sample decreased from 1.728 W/m·K to 0.811 W/m·K, representing a substantial reduction of 53.05 %. However, increasing the PNIPAM content also affected the hydration process of the cement mortars, leading to longer initial and final setting times and a slight decrease in both compressive and flexural strength. Additionally, the viscosity of the PNIPAM solution increased the overall viscosity of the cement mortar, resulting in reduced fluidity.
研究领域:
建筑材料学
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热物理
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 28
·15227-15236
·
IF 11.9
Bingjie Ma,Bing Wu,Peiying Hu,Ling Liu,Jin Wang
Aerogels have recently received extensive attention owing to their excellent thermal insulation performance. Thus, they are widely used for thermal management in buildings, aerospace, pipelines, and transportation for energy saving and emission reduction. However, silica aerogels have been confirmed to possess passive radiative cooling (PRC) capacities, which may seriously retard their thermal insulation performance. Therefore, whether PRC behavior is a universal property of aerogels is an urgent problem that can determine the eventual thermal management property of aerogels. Thus, in this study, six types of aerogels with different chemical components and microstructures, including silica aerogel, boron nitride aerogel, reduced-graphene oxide aerogel, Kevlar aerogel, poly(p-phenylene-2,6-benzobisoxazole) aerogel, and polyimide aerogels, are synthesized, and their PRC and thermal management behaviors are investigated. Impressively, all the above-mentioned aerogels showed extensive PRC performance, with a sub-ambient cooling ranging from 6.6 to 11.1 °C at night, regardless of their chemical component or color, confirming the universal PRC behavior of various aerogels. The PRC also significantly affects the thermal insulation properties of the aerogels. The reasons for the PRC of aerogels have been discussed. The findings of this study can help to a comprehensive understanding of the thermal management behavior of aerogels and guide to a better way to use aerogels in the actual environment by considering their PRC.
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
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Fangzhou Xu,Qianyu Dong,Shikai Zhang,Qicong Wu,Chunchun An,Xiaoqian Li,Xinchuang Chen,Yang Chen,Xincheng Zhang,Jinrong Li,Zhi Dong
Natural biopolymer-based liquid mulching films (LMF) have received widespread attention, whereas the fragile structure and limited functionality have severely restricted their application. Herein, polydopamine-coated montmorillonite micro/nanoparticles enhanced pectin-based sprayable multifunctional liquid mulching films (P-MMT@PDA LMF) were prepared. Dopamine has abundant active sites, and its self-polymerization onto the surface of MMT improves the compatibility of MMT with pectin chains, facilitates the homogeneous dispersion of MMT@PDA in pectin polymers, and makes them more tightly entangled through hydrogen bonding. Therefore, P-MMT@PDA LMF exhibits better mechanical properties (improved by 64.94 N) and wind erosion resistance (wind speed 30 m/s, >60 min). Moreover, MMT@PDA micro/nanoparticles can fill the voids of pectin chains, thus increasing the densification and complexity of the network structure in LMF, enabling better water retention (improved by 14.67 %) and heat preservation (increased by 3.14 °C). Meanwhile, the photothermal effect of PDA endows P-MMT@PDA LMF with a warming effect (increased by 2.84 °C). Hence, this LMF promote wheat growth and demonstrate good biodegradability. These results suggest that the application of P-MMT@PDA LMF is an effective strategy in the environments of drought and cold, which is expected to provide a green solution for sustainable agricultural development and environmental protection in the future.
研究领域:
农业科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）