Article
Polymer Science
Haowen Sun, Kexuan Chen, Yuan Liu, Qi Wang
Summary: The flame retardant EVA composites were prepared by melt blending ethylene vinyl acetate copolymer with expandable graphite (EG), pyrophosphate piperazine (PAPP), and melamine polyphosphate (MPP). The optimal flame retardant effect was achieved with a PAPP/EG/MPP mixture of 2:2:1 mass ratio. EVA composites with an additive amount of 25 wt% reached UL-94 V-0 level (1.6 mm) and had a limiting oxygen index (LOI) of 35.2%. The incorporation of PAPP, EG, and MPP significantly reduced the heat release rate, total heat release, and total smoke release of the composites.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Thermodynamics
Yu Jia, Jun Zhang
Summary: In this study, the thermal conductivity of a series of EVA samples with different VAc contents at different temperatures was measured by the transient hot line method. A empirical formula between the thermal conductivity, temperature, and crystallinity of EVA was established, and the theoretical calculation based on this formula showed a good agreement with the experimental results within a 5% error. This empirical formula provides guidance for predicting the thermal conductivity of EVA samples with different VAc contents at different temperatures in the future.
THERMOCHIMICA ACTA
(2022)
Article
Energy & Fuels
Leo Brody, Luke Neal, Junchen Liu, Fanxing Li
Summary: The study demonstrates a system for converting ethane to liquid fuels based on a chemical looping oxidative dehydrogenation scheme, which features autothermal operation, high ethane conversion rate, and product selectivity. After long-term stable operation, the system shows good economic viability.
Article
Thermodynamics
Giselly M. G. Farias, Pankaj Agrawal, Ruth B. L. Hanken, Jeane P. de Araujo, Akidauana D. B. de Oliveira, Tomas J. A. de Melo
Summary: The concentration of ethylene vinyl acetate (EVA) and the vinyl acetate (VA) content in EVA have significant effects on the properties of bio-based high-density polyethylene (BioPE)/EVA blends. Increasing EVA concentration decreases the crystallinity of BioPE, while blends with higher VA content exhibit higher impact strength.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Polymer Science
Tiefeng Zhang, Chunfeng Wang, Yongliang Wang, Lijun Qian, Zhidong Han
Summary: In ethylene-vinyl acetate copolymer composites, the synergistic effect between polycarbosilane and magnesium hydroxide significantly improves flame-retardant properties while forming a cohesive and compact char layer.
Article
Materials Science, Multidisciplinary
Wen-Chao Hua, Ming-Qi Li, Yang-Long Guo, Guang-Tao Chai, Hao Liu, Yun Guo, Li Wang, Wang-Cheng Zhan
Summary: A series of Co3O4 catalysts prepared by different methods showed varying catalytic activity for the combustion of VCM emissions, with the Co-AP catalyst demonstrating the best performance without producing any chlorinated by-products.
Article
Chemistry, Applied
Dali Yang, Kevin C. Henderson, Robin M. Pacheco, Kevin M. Hubbard, David J. Devlin
Summary: The study showed that the addition of fillers accelerates the exudation of nitroplasticizer from EVA-OH composites and deteriorates the thermal stability of nitroplasticizer at moderate temperatures, leading to the degradation of EVA-OH polymer through oxidation and hydrolysis. Therefore, the importance of antioxidants in such phase blends was indicated.
JOURNAL OF VINYL & ADDITIVE TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Junwei Li, Penglun Zheng, Huaiyin Liu, Jichang Sun, Yawei Meng, Haihan Zhao, Jing Wu, Yun Zheng, Quanyi Liu
Summary: Flame retardant epoxy resin with improved fire resistance and microstructure has been developed by using Cu2+ and DOPO system, which effectively enhances the flame retardancy and tightness of the resin. The addition of flame retardant leads to well-defined fire resistance and improved physical properties of the resin.
Article
Chemistry, Physical
Haoyang Sun, Pengyuan Qiu, Yunxin Yang, Junxiao Liu, Libin Zhang, Zhen Liu
Summary: This study investigates the surface structure of bimetallic Pd/Au catalyst and the role of potassium acetate in the synthesis of vinyl acetate (VAc). By constructing different configurations of the Pd/Au (1 1 1) surface and using density functional theory, the research reveals that the presence of potassium ion enhances VAc formation. The configuration of Pd/Au (1 1 1) with two adjacent palladium atoms embedded on the gold surface shows the most favorable outcome for VAc synthesis.
APPLIED SURFACE SCIENCE
(2022)
Article
Polymer Science
Qinghong Zhang, Gongliang Wang, Xinlong Wen, Martin Hoch, Jie Mao, Xinyan Shi
Summary: In this study, APTES was used as a crosslinking monomer to graft onto the modified polymer EVM, forming Si-O-Si networks through moisture crosslinking, which increased the modulus and tensile strength of the samples.
Article
Chemistry, Multidisciplinary
Yue Gu, Linhua Jiang, Weizhun Jin, Zhenhua Wei, Xing Liu, Mingzhi Guo, Kailun Xia, Lei Chen
Summary: This paper investigates the thermal properties and characteristics of a new series of phase change materials composed of capric acid/ethylene-vinyl acetate/graphene. Experimental results show that adding an appropriate amount of graphene can improve the thermal conductivity and latent heat of the composite phase change materials, while excessive graphene can reduce the latent heat.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2021)
Article
Polymer Science
Lim Kean Chong, Azlin Fazlina Osman, Asfa Amalia Ahmad Fauzi, Awad A. Alrashdi, Khairul Anwar Abdul Halim
Summary: The study focused on using OMCD filler in PECoVA composite to replace non-recyclable silicone elastomer in biomedical applications. By modifying DOL to improve compatibility, OMCD showed better reinforcement effects in the copolymer matrix, enhancing its crystallinity and interfacial interactions. Regardless of the filler loading, PECoVA/OMCD composites exhibited superior mechanical and thermal properties compared to PECoVA/DOL composites, with the best performance achieved at 3 wt% OMCD loading.
Article
Environmental Sciences
Qiang Wu, Jizhong Meng, Hang Yao, Rui Tang, Shoujun Yuan, Yulan Wang, Wei Wang, Haiping Luo, Zhen-Hu Hu
Summary: In this study, a floating TiO2/EVA photocatalyst was successfully synthesized using a simple thermal crosslinking procedure with ethylene-vinyl acetate copolymer (EVA) as the support material. The photocatalyst exhibited uniform TiO2 dispersion and high stability, leading to a significant enhancement in the degradation efficiency of Rhodamine B.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Polymer Science
Siyu Jiang, Sheng Li, Xuhui Yang, Lubin Liu, Xiaoli Li, Miaojun Xu
Summary: In this study, flame retardant ethylene vinyl acetate (EVA) copolymer composites were prepared by combining cerium-containing metal organic framework (Ce-MOF) with piperazine pyrophosphate (PAPP). The addition of 17 wt% PAPP/Ce-MOF with a mass fraction of 97:3 resulted in EVA/PAPP/Ce-MOF samples achieving UL-94 V-0 rating with a limiting oxygen index (LOI) value of 31.3%. The introduction of Ce-MOF and PAPP effectively reduced the total heat release, total smoke production, and maximum smoke density of EVA. Furthermore, it enhanced the compatibility of PAPP with EVA matrix and improved the water resistance of EVA/PAPP/Ce-MOF. The analysis of residual char of EVA composites showed that the addition of Ce-MOF and PAPP generated a dense char layer with excellent intensity, effectively inhibiting heat, combustible gas, and smoke release.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Polymer Science
Puzhong Gu, Jun Zhang
Summary: The effect of varied vinyl acetate (VAc) contents on the thermal behavior and optical properties of ethylene-vinyl acetate (EVA) copolymers was investigated. It was found that the lamellar thickness decreased and the thermal stability weakened with increasing VAc content. However, the transmittance of EVA copolymers increased. The results provide a better perspective on the application areas of EVA copolymers with different VAc contents.
IRANIAN POLYMER JOURNAL
(2022)
Article
Thermodynamics
Jingwen Weng, Changren Xiao, Dongxu Ouyang, Xiaoqing Yang, Mingyi Chen, Guoqing Zhang, Richard Kwok Kit Yuen, Jian Wang
Summary: Most existing organic composite phase change materials (CPCMs) are flammable, leading to thermal hazards in battery modules. A tubular CPCM-cell structure using physically flame-retardant-modified CPCMs was designed in this study, with a series of experiments conducted on CPCMs with/without real cells.
Article
Energy & Fuels
Xu Fang, Xiaolei Zhang, Richard K. K. Yuen, Longhua Hu
Summary: This study provides an experimental investigation and scaling analysis of diffusion flame side sag behavior, finding that the evolution of flame side sag can be clearly distinguished as four phases, with turning points related to crosswind speed, burner size, and heat release rate. The transition of four phases can also be quantified based on characteristic length scales derived from general dimensionless functions correlating experimental results of upstream and downstream flame side sag lengths.
Article
Mechanics
Liping Lian, Xu Mai, Weiguo Song, Jun Zhang, Kwok Kit Richard Yuen, Eric Wai Ming Lee
Summary: This paper investigates the merging characteristics of pedestrian flow with controlled experiments under laboratory conditions. The study finds that the space usage in the merging area is most efficient when the width of the two branches is half that of the main corridor. The results can be used as references for the design of public infrastructure and human safety management.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Thermodynamics
Junjiang He, Xinyan Huang, Xiaoyao Ning, Tiannian Zhou, Jian Wang, Richard Kwok Kit Yuen
Summary: The study used large eddy simulation to investigate smoke dynamics in high-rise building fires, focusing on the influence of ambient pressure and heat release rate on smoke movement. The results showed that the air mass flow rate into the stairwell decreased with reduced ambient pressure but increased with higher heat release rates. Additionally, an empirical model was proposed to predict the rising time of the smoke plume.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Green & Sustainable Science & Technology
Jingwen Wng, Changren Xiao, Xiaoqing Yang, Dongxu Ouyang, Mingyi Chen, Guoqing Zhang, Eric Lee Waiming, Richard Kwowk Kit Yuen, Jian Wang
Summary: This study investigates the thermal behaviors of liquid cooling and phase-change material cooling in advanced battery thermal management systems for electric vehicles. The results show the superior cooling effect of a thermal management module coupling the two methods. Additionally, a dynamic liquid cooling mode is proposed to reduce energy consumption.
Article
Thermodynamics
Hang Wan, Xinhua Xu, Tao Xu, Kwok Kit Richard Yuen, Gongsheng Huang
Summary: In this paper, a computationally efficient dynamic model for tube-capsulated PCM storage tanks was developed, which can simulate partially charging/discharging. The proposed quasi-2D VRC model achieved high accuracy and computational efficiency compared to the effectiveness-NTU model.
APPLIED THERMAL ENGINEERING
(2022)
Article
Polymer Science
Chunxiang Wei, Tianyu Gao, Yu Xu, Wenjie Yang, Guangjian Dai, Ruiting Li, SanE E. Zhu, Richard K. K. Yuen, Wei Yang, Hongdian Lu
Summary: In this study, a bio-based additive, derived from magnolol, was successfully synthesized and used to improve the mechanical toughness, impact strength, and flame-retardant properties of epoxy resins (EPs). By incorporating the additive into the EP matrix, the composite material exhibited significantly enhanced flame-retardant and mechanical properties.
CHINESE JOURNAL OF POLYMER SCIENCE
(2023)
Article
Transportation
Hongliu Li, Long Xia, Jun Zhang, Weiguo Song, Kwok Kit Richard Yuen
Summary: This study investigates the movement characteristics of 40 preschool children in a 1.0 m wide corridor under low and high motivations. It found that the individual speed of children decreases with increasing density, both in normal and emergency conditions. In the turning region, running children prefer the inner boundaries while walking children prefer the outer boundaries. These findings contribute to a better understanding of preschool children's movement characteristics.
TRANSPORTMETRICA A-TRANSPORT SCIENCE
(2023)
Article
Ecology
Ming Chian Yew, Ming Kun Yew, Richard Kwok Kit Yuen
Summary: Using lightweight fire-rated boards (LFRBs) is cost-effective for passive fire protection measures. The project aims to develop LFRBs with enhanced fire resistance, acoustic properties, and mechanical properties. The LFRBs were fabricated by blending vermiculite and perlite with flame-retardant binders, and they showed exceptional fire-resistant properties in comparison to commercially available flame-retardant boards.
Article
Public, Environmental & Occupational Health
Dongli Gao, Wei Xie, Ruifeng Cao, Eric Wai Ming Lee, Richard Kwok Kit Yuen, Jingwen Weng
Summary: Exit choice is crucial for pedestrian safety and evacuation efficiency in emergencies. This paper contributes by using cumulative prospect theory to predict exit choice and summarizing and examining different decision-making rules. The predictions from Max and Expo showed higher realism, while the results from Ratio were more robust, as indicated by the parameters of Accuracy and F1-score.
JOURNAL OF SAFETY SCIENCE AND RESILIENCE
(2023)
Article
Public, Environmental & Occupational Health
Rui Feng Cao, Eric Wai Ming Lee, Wei Xie, Dong Li Gao, Qian Chen, Anthony Chun Yin Yuen, Guan Heng Yeoh, Richard-Kwok-Kit Yuen
Summary: This study developed a fire-integrated evacuation model that considers the effects of spreading fire hazards on evacuees. It also introduced a quantitative approach to evaluate evacuees' fire risks and stress levels. The results demonstrate the importance of minimizing pre-evacuation time in fire emergencies.
JOURNAL OF SAFETY SCIENCE AND RESILIENCE
(2023)
Article
Public, Environmental & Occupational Health
Wei Xie, Dongli Gao, Ruifeng Cao, Eric Wai Ming Lee, Richard Kwok Kit Yuen, Jingwen Weng
Summary: This study developed a social force model integrated with a group force to understand leadership dynamics during evacuation. The transfer entropy (TE) method was applied to detect leadership based on movement information. The results showed that TE accurately measured leadership and found that leaders exerted increasing influence over time, while followers' influence diminished. Spatial positions were found to be correlated with leadership emergence.
JOURNAL OF SAFETY SCIENCE AND RESILIENCE
(2023)
Article
Engineering, Civil
Nan Jiang, Lizhong Yang, Richard Kwok Kit Yuen, Chunjie Zhai
Summary: This paper proposes a learning-based approach for modeling microscopic pedestrian movement behavior before bottleneck through two sub models - velocity direction model and velocity magnitude model. Performance evaluation using fifteen original scenarios shows consistency with corresponding experiments in trajectories, density, velocity, flow vs. time curves and fundamental diagrams. Evaluation metrics like FDE, DE, MTE, and RDE prove the precision of simulation. The proposed approach has good capability and reliability in simulating pedestrian motion before the bottleneck and can be applied in passenger flow management and architectural design.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2023)
Article
Chemistry, Physical
Junling Wang, Shui Yu, Chao Cheng, Zhirong Wang, Yuen Kwok Kit Richard, Qi Zhang, Junhui Gong, Wei Cai, Tengfei He
Summary: To address the high thermal runway hazard of epoxy resin, researchers have adapted the method of preparing fire retardant epoxy resin composite with inorganic filler, with a focus on MXenes as potential flame retardant materials. By utilizing the hydrogen bonding induced strategy and in-situ growth method, they successfully obtained P-MX@UIO flame retardant with high efficiency. The P-MX@UIO exhibited significant reductions in heat release, smoke production, and CO production, and also showed improved storage modulus.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Environmental
Yu Xu, Wen-Jie Yang, Qian-Kun Zhou, Tian-Yu Gao, Guo-Mei Xu, Qi-Long Tai, San-E Zhu, Hong-Dian Lu, Richard K. K. Yuen, Wei Yang, Chun-Xiang Wei
Summary: In this study, a highly functional bio-based flame retardant DPOR was successfully synthesized and added into epoxy resins, leading to excellent flame-retardant and mechanical properties. It shows great potential for future applications.
CHEMICAL ENGINEERING JOURNAL
(2022)
