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Your search keyword '"Tang, Changyu"' showing total 153 results
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153 results on '"Tang, Changyu"'

7. Self-cleaning and self-cooling paper

Author

Tian, Yanpei, Shao, Hong, Liu, Xiaojie, Chen, Fangqi, Li, Yongsheng, Tang, Changyu, and Zheng, Yi

Subjects
Physics - Applied Physics, Condensed Matter - Materials Science
Abstract

The technique of passive daytime radiative cooling (PDRC) is used to cool an object down by simultaneously reflecting sunlight and thermally radiating heat to the cold outer space through the Earth's atmospheric window. However, for practical applications, current PDRC materials are facing unprecedented challenges such as complicated and expensive fabrication approaches and performance degradation arising from surface contamination. Here, we develop a scalable paper-based material with excellent self-cleaning and self-cooling capabilities, through air-spraying ethanolic polytetrafluoroethylene (PTFE) microparticles suspensions embedded within the micropores of the paper. The formed superhydrophobic PTFE coating not only protects the paper from water wetting and dust contamination for real-life applications but also reinforces its solar reflectance by sunlight backscattering. The paper fibers, when enhanced with PTFE particles, efficiently reflect sunlight and strongly radiate heat through the atmospheric window, resulting in a sub-ambient cooling performance of 5$^{\circ}$C and radiative cooling power of 104 W/m$^2$ under direct solar irradiance of 834 W/m$^2$ and 671 W/m$^2$, respectively. The self-cleaning surface of the cooling paper extends its lifespan and keep its good cooling performance for outdoor applications. Additionally, dyed papers are experimentally studied for broad engineering applications. They can absorb appropriate visible wavelengths to display specific colors and effectively reflect near-infrared lights to reduce solar heating, which synchronously achieves effective radiative cooling and aesthetic varieties in a cost-effective, scalable, and energy-efficient way.

Published
2020

9. Mechanical Characteristics of Multi-Level 3D-Printed Silicone Foams.

Author

Yang, Zhirong, Wen, Jinpeng, Zhang, Guoqi, Tang, Changyu, Deng, Qingtian, Ling, Jixin, and Hu, Haitao

Subjects
SILICONE rubber, CUSHIONING materials, POROSITY, RESEARCH questions, STRUCTURAL design
Abstract

Three-dimensional-printed silicone rubber foams, with their designable and highly ordered pore structures, have shown exceptional potential for engineering applications, particularly in areas requiring energy absorption and cushioning. However, optimizing the mechanical properties of these foams through structural design remains a significant challenge. This study addresses this challenge by formulating the research question: How do different 3D-printed topologies and printing parameters affect the mechanical properties of silicone rubber foams, and how can we design a novel topological structure? To answer this, we explored the mechanical behavior of two common structures–simple cubic (SC) and face-centered tetragonal (FCT)–by varying printing parameters such as filament spacing, filament diameter, and layer height. Furthermore, we proposed a novel two-level 3D-printed structure, combining SC and FCT configurations to enhance performance. The results demonstrated that the two-level SC-SC structure exhibited a specific energy absorption of 8.2 to 21.0 times greater than the SC structure and 2.3 to 7.2 times greater than the FCT structure. In conclusion, this study provides new insights into the design of 3D-printed silicone rubber foams, offering a promising approach to developing advanced cushioning materials with superior energy absorption capabilities. [ABSTRACT FROM AUTHOR]

Published
2024
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30. Forming Effect of Plasma Treatment on Wettability and Water-Soluble Microneedles of Silicone Rubber.

Author

SUN Li, DENG Ke, WANG Jie, XIAO Haitao, LIU Yingzhi, SHAO Hong, and TANG Changyu

Subjects
WETTING, POLYVINYL alcohol, POVIDONE, SILICONE rubber, HYDROPHILIC surfaces, ADHESION
Abstract

Silicone rubber molds were treated with air plasma and used to prepare polyvinyl alcohol/polyvinylpyrrolidone water-soluble microneedles. The effects of plasma treatment on mold wettability, coating adhesion, micro-needle yield and mechanical properties were discussed. The results showed that plasma treatment could generate polar hydrophilic groups on the surface of the mold, improve the wettability of the mold, the adhesion of polyvinyl alcohol/polyvinylpyrrolidone coating, and elevate the yield rate of micro-needles and the overall mechanical properties. With the prolongation of plasma treatment time, the wettability of the mold, the yield rate of microneedles and the mechanical properties increased increased and then decreased. When the silicone rubber mold was treated with air plasma for 6-8 minutes, water-soluble microneedles with a complete structure, good mechanical property and easy demolding ability could be prepared. [ABSTRACT FROM AUTHOR]

Published
2023
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47. Highly Sensitive Surface-Enhanced Raman Scattering Detection of Hydroxyl Radicals in Water Microdroplets Using Phthalhydrazide/Ag Nanoparticles Nanosensor

Author

Chao, Shengmao, Valsecchi, Chiara, Sun, Ji, Shao, Hong, Li, Xinxia, Tang, Changyu, and Fan, Meikun

Abstract

The spontaneous generation of hydrogen peroxide (H2O2) within atmospheric microdroplets, such as raindrops and aerosols, plays a crucial role in various environmental processes including pollutant degradation and oxidative stress. However, quantifying hydroxyl radicals (•OH), essential for H2O2formation, remains challenging due to their short lifespan and low concentration. This study addresses this gap by presenting a highly sensitive and selective surface-enhanced Raman scattering (SERS) nanosensor specifically designed for quantifying •OH within water microdroplets. Utilizing a phthalhydrazide (Phth) probe, the SERS technique enables rapid, interference-free detection of •OH at nanomolar concentrations. It achieves a linear detection range from 2 nM to 2 μM and a limit of detection as low as 0.34 nM. Importantly, the SERS sensor demonstrates robustness and accuracy within water microdroplets, paving the way for comprehensive mechanistic studies of H2O2generation in the atmosphere. This innovative approach not only offers a powerful tool for environmental research but also holds potential for advancing our understanding of atmospheric H2O2formation and its impact on air quality and pollutant degradation.

Published
2024
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49. Porous Ti2Nb10O29−x Microspheres Wrapped by Holey-Reduced Graphene Oxide as Superior Anode Material for High-rate Performance Lithium-ion Storage.

Author

Luo, Nan, Chen, Guoliang, Shang, Yunfan, Lu, Suyang, Mei, Jun, Tang, Changyu, He, Zhoukun, Zeng, Wenwen, and Zhan, Haoran

Subjects
MICROSPHERES, GRAPHENE oxide, IONIC conductivity, ANODES, OXIDE coating, POWER density
Abstract

Ti2 Nb 1 0 O 2 9 (TNO) is considered as a potential anode material due to its high capacity/power density and reliable safety. However, its poor electronic conductivity restricts its rate performance, which is important for its application in electric vehicles (EVs). In this study, we fabricated a hybrid of Ti2 Nb 1 0 O 2 9 − x /holey-reduced graphene oxide (TNOx/HRGO) by a two-step method. In the structure of TNOx/HRGO, TNOx microspheres with oxygen vacancies are wrapped by gossamer-like HRGO. The oxygen vacancies of TNOx and the high conductivity of HRGO can effectively enhance the electronic conductivity of the TNOx/HRGO hybrid, and the HRGO holes are beneficial for the transmission of lithium-ion ( Li + ). The synergy effect of above features improves the rate performance of the TNOx/HRGO hybrid. In addition, the existence of HRGO can buffer volume expansion during the insertion processes of Li + , which can improve cyclic stability of the TNOx/HRGO hybrid. Consequently, the TNOx/HRGO electrode has excellent lithium-ion storage capacity, with high-rate performance (242 mAh/g at 10∘C, 225 mAh/g at 20∘C and 173 mAh/g at 40∘C) and excellent cyclic stability (98.0% capacity retention after 300 cycles at 10∘C). This work reveals that TNOx/HRGO can be a potential anode material for high-rate-performance lithium-ion storage. TNOx/HRGO hybrid was fabricated through solvothermal method, annealing, and freeze-drying, and its performance as anode of LIB was investigated. Due to its porous microstructure, the existence of oxygen vacancies and holey-reduced graphene oxide coating, the electronic conductivity and ionic conductivity of TNOx/HRGO were greatly improved, thus obtaining excellent high-rate performance. [ABSTRACT FROM AUTHOR]

Published
2020
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