A novel synthesis of polyurethane foam/polyurethane aerogel (PU-PU) composites is presented. Three different polyurethane reticulated foams which present the same density but different pore sizes (named S for small, M for medium, and L for large) have been used. After the characterization of the reference materials (either, foams, and pure aerogel), the obtained composites have been characterized in order to study the effect of the foam pore size on the final properties, so that density, shrinkage, porous structure, mechanical properties, and thermal conductivity are determined. A clear influence of the pore size on the density and shrinkage was found, and the lowest densities are those obtained from L composites (123 kg/m). Moreover, the aerogel density and shrinkage have been significantly reduced through the employment of the polyurethane (PU) foam skeleton. Due to the enhanced mechanical properties of polyurethane aerogels, the inclusion of polyurethane aerogel into the foam skeleton helps to increase the elastic modulus of the foams from 0.03 and 0.08 MPa to 0.85 MPa, while keeping great flexibility and recovery ratios. Moreover, the synthesized PU-PU composites show an excellent insulating performance, reducing the initial thermal conductivity values from 34.1, 40.3, and 50.6 mW/(m K) at 10 °C for the foams S, M, and L, to 15.8, 16.6, and 16.1 mW/(m K), respectively. Additionally, the effect of the different heat transfer mechanisms to the total thermal conductivity is herein analyzed by using a theoretical model as well as the influence of the measurement temperature.
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http://dx.doi.org/10.3390/nano12132232 | DOI Listing |
Curr Res Neurobiol
June 2025
Neuroscience Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, VIC, 3800, Australia.
Lesions of the primary visual cortex (V1) cause retrograde neuronal degeneration, volume loss and neurochemical changes in the lateral geniculate nucleus (LGN). Here we characterised the timeline of these processes in adult marmoset monkeys, after various recovery times following unilateral V1 lesions. Observations in NeuN-stained sections obtained from animals with short recovery times (2, 3 or 14 days) showed that the volume and neuronal density in the LGN ipsilateral to the lesions were similar to those in the contralateral hemispheres.
View Article and Find Full Text PDFSmall
January 2025
Beijing Advanced Innovation Center for Materials Genome Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Elastomer cure shrinkage during composite fabrication often induces wrinkling in conductive networks, significantly affecting the performance of flexible strain sensors, yet the specific roles of such wrinkles are not fully understood. Herein, a highly sensitive polydimethylsiloxane-filled graphene woven fabric (PDMS-f-GWF) strain sensor by optimizing the PDMS cure shrinkage through careful adjustment of the base-to-curing-agent ratio is developed. This sensor achieves a gauge factor of ∼700 at 25% strain, which is over 6 times higher than sensors using commercially formulated PDMS.
View Article and Find Full Text PDFJ Med Internet Res
December 2024
Department of Medical Informatics, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, China.
Background: Primary hypertension (PH) poses significant risks to children and adolescents. Few prediction models for the risk of PH in children and adolescents currently exist, posing a challenge for doctors in making informed clinical decisions.
Objective: This study aimed to investigate the incidence and risk factors of PH in Chinese children and adolescents.
J Am Chem Soc
January 2025
College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, National Laboratory of Solid State Microstructures, Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, P. R. China.
The rapid advancements in 3C electronic devices necessitate an increase in the charge cutoff voltage of LiCoO to unlock a higher energy density that surpasses the currently available levels. However, the structural devastation and electrochemical decay of LiCoO are significantly exacerbated, particularly at ≥4.5 V, due to the stress concentration caused by more severe lattice expansion and shrinkage, coupled with heterogeneous Li intercalation/deintercalation reactions.
View Article and Find Full Text PDFPLoS One
January 2025
Hebei Yingsheng New Material Technology Co., Ltd., Shijiazhuang, China.
Construction materials are significantly exposed to ecological hazards due to the presence of hazardous chemical constituents found in industrial and agricultural solid wastes. This study aims to investigate the use of sawdust particles (SDPs) and sawdust wastewater (SDW) in alkali-activated composites (AACs) made from a mixture of different silicon-aluminum-based solid wastes (slag powder-SP, red mud-RM, fly ash-FA, and carbide slag-CS). The study examines the impact of SDP content, treated duration of SDPs, and SDW content on both fresh and hardened properties of the AACs, including electrical conductivity, fluidity, density, flexural and compressive strengths, and drying shrinkage.
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