DALTON TRANSACTIONS
·
2024
·Vol. 53
·期 35
·14648-14655
·
IF 3.5
Hong Su,Cong Dou,Fan Dou,Wen Li,Jiachen Li,Xiaolian Chao,Zupei Yang,Xiaoming Wang,Huan Jiao
The efficiency of silicon solar cells is still lower than theoretical values, partly due to their inability to utilize the ultraviolet and infrared portions of the solar spectrum. Herein, a novel method using a KCa2Mg2(VO4)3 phosphor with a down-shift effect to improve the photovoltaic performance of silicon solar cells and enhance the utilization of UV light in standard p-type silicon solar cells is proposed. The synthesized phosphors were mixed with an ethylene vinyl acetate (EVA) copolymer and pressed into a film, which was subsequently encapsulated in monocrystalline silicon solar cells. The results show that the addition of this film notably enhanced the photovoltaic performance of the silicon solar cells; the current density was increased by 2.89% (from 33.20 to 34.16 mA cm−2), and the photovoltaic conversion efficiency was improved by 5.69% (from 15.11% to 15.97%) at the optimal concentration compared to bare cells.
研究领域:
材料科学
·
光伏技术
·
无机功能材料
·
能源材料
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DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2020
·Vol. 27
·期 10
·1-11
·
IF 2.426
Wang Guo-hui,Wu Guang-hao,He Man-li,Xu Tian-han,Liu Yun-fu,Yao Chu-qing,Dai Yao-dong
Using a melt-mixing technique, ethylene–vinyl acetate (EVA) copolymers based composites containing Multi-Wall Carbon nanotubes (MWCNTs), aluminum trihydrate (ATH), zinc borate (ZB), and gadolinium oxide (Gd 2 O 3 ) were fabricated. Then, the as-prepared samples were irradiated with an electron beam (EB) at the dose range varied from 0 to 275 kGy. Moreover, we investigated the properties of irradiated and unirradiated samples. Morphological observation showed good dispersion of MWCNTs and other additives in EVA. Furthermore, the gel content, mechanical properties, the limit oxygen index (LOI) values of irradiated composites increased to 28.4% after 250 kGy after irradiated. All the conclusions indicated that the comprehensive properties of the WMCNTs/EVA composites were improved by using high energy electron beam irradiation.
研究领域:
材料科学
·
核工程
·
高分子化学
✓ 已验证
DOI
高影响因子
RADIATION PHYSICS AND CHEMISTRY
·
2020
·
IF 2.226
Fanchao Chai,Guohui Wang,Feng Liu,Danfeng Jiang,Chuqing Yao,Tianhan Xu,Yaodong Dai
Flame-retardant neutron shielding materials were synthesized based on ethylene-vinyl acetate (EVA) copolymer and with multi-walled carbon nanotubes (CNTs), boron carbide (B 4 C), zinc borate (ZB) as fillers. With the increase of filler content , the tensile strength of the composite increased primarily and then decreased, and the elongation at break continued to decrease. CNTs and ZB formed a synergistic flame-retardant system. The surface-modified CNTs improved the mechanical properties, thermodynamic properties, and flame retardancy of the composites. With the increase of the CNTs content, the flame-retardant properties of composites increased first and then remained stable. Electron beam (EB) radiation changed the mechanical properties, flame retardant properties and thermodynamic properties of the composites. Taking an Am–Be neutron source as the radiation source, the thermal neutron transmittance of 2 mm sample was 50.72%.
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2026
·
IF 5.1
Zhipeng Liu,Wei Cui,Zhe Liu,Shicheng Zhao
The photostability of Ethylene-vinyl Acetate copolymer (EVA) photovoltaic encapsulation films is highly dependent on the Hindered Amine Light Stabilizer (HALS) used. However, the extensive screening of HALS via long-time aging tests is time-consuming and high-cost, hindering the design of EVA photovoltaic films with higher stability. In this paper, an efficient screening strategy for selecting optimal HALS for EVA was proposed based on molecular simulation and validated via long-time aging experiments. Firstly, several molecular simulations were performed to analyze three critical parameters: chemical activity, migration resistance, and compatibility with the EVA matrix of six HALS. The simulation results identified HALS-4 exhibiting optimal characteristics including high radical scavenging activity, superior migration resistance, and complete compatibility with EVA, suggesting its potential as an optimal HALS. Subsequently, it was found by long-term aging experiment combined with Fourier-Transform Infrared Spectroscopy and rheological analyses that EVA films undergo severe photo-degradation without HALS, while the incorporation of HALS delayed aging. Importantly, the anti-aging performance varied markedly among different HALS types, with HALS-4 exhibiting superior stabilization effects. Finally, based on the analysis of the experimental and molecular simulation results, it can be concluded that the computational predictions showed excellent agreement with experimental results of HALS-4′s outstanding anti-aging performance, thereby validating the rationality of the proposed screening strategy. The strategy presented in this work offers theoretical guidance for the development of high-performance HALS and provides an efficient tool for the design of EVA photovoltaic encapsulation films with higher photostability.
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产品关联
DOI
高影响因子
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
·
2025
·
IF 5.9
Lirong Gong,Yan Qiu,Haobo Zhai,Ruifan Dan,Yuan Dang,Weihua Liu,Long Hu,Yuhua Hang,Yongdong Li
Ethylene-Vinyl Acctate-copolymers (EVAs) are widely used in the manufacture of wires and cables as electrical insulating media in electric power fields. Oxidation is one of the primary mechanisms leading to the aging of polymer materials, and the addition of antioxidants can effectively slow the oxidation reaction. Current nondestructive testing methodologies face challenges in the measurement of antioxidant concentrations, which constitute a critical metric for aging assessments. In this article, we propose a method for measuring antioxidant concentration using terahertz time-domain spectroscopy (THz-TDS). In comparison to other techniques such as liquid chromatography, no elaborate sample preparation is necessary, and calibration measurements can be conducted rapidly. The spectral changes caused by the addition of different concentrations of antioxidants were investigated, and the results showed that the refractive index and dielectric constant increased significantly with a decrease in the antioxidant concentration. When the concentration of antioxidant 1010 in the sample was increased from 0% to 10%, the refractive index decreased from 1.55 to 1.42, and the dielectric constant decreased from 2.38 to 2.03 average over the band of 0.5–2.5 THz. Moreover, the numerical calculation using density functional theory (DFT) showed the introduction of oxygen-containing functional groups of antioxidant 1010 molecules into EVA molecules slightly reduced the polarization, resulting in a consistently decrease in the dielectric constant of the constructed materials compared with original EVA materials. The classification of antioxidant concentration in EVA was predicted using machine learning, including partial least squares regression (PLSR), random forest (RF), support vector regression (SVR), and extreme gradient boosting (XGboost). XGboost was found to have the highest prediction accuracy with an root mean square error (RMSE) of 0.0412. In order to ascertain the characteristic spectrum of the 1010 antioxidant, we selected the dielectric constant at the 0.9 THz position for a linear fit. The RMSE of cross-validation (RMSECV) value for leave-one-out cross validation (LOOCV) was found to be 0.38.
研究领域:
高分子材料科学
·
电力绝缘材料
·
非破坏性检测
·
光谱分析
·
材料老化评估
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS A-PHYSICAL
·
2024
·
IF 4.1
Shuolei Wang,Zhonggui Zhang,Zhao Li,Ziyue Zhang,MD. Zahidul Islam,Xiaojian Jiang,Hongyu Gao,Shi Xu,Yubing Dong
The sensor fabricated from high-molecular polymer is soft, lightweight, and biocompatible; however, traditional high-molecular polymers suffer from viscoelasticity and poor cycle stability. To address these issues, it is essential to develop flexible matrix materials that can overcome viscoelasticity, ensuring high sensitivity and long-term use under large strains for next-generation wearable intelligent devices. In this study, ethylene-vinyl acetate (EVA) with a shape memory effect was utilized as the substrate for a flexible sensor，the shape memory effect of EVA can eliminate the residual strain generated by each long time of use to improve its service life. A polydopamine@reduced graphene oxide (PDA@RGO)/EVA fiber flexible strain sensor was fabricated through melt extrusion, swelling ultrasound, and in-situ polymerization techniques. The resulting sensor exhibits high sensitivity (gauge factor=1801.21), a wide strain detection range (strain = 193 %), and excellent stability and durability (2000 cycles). Notably, the PDA@RGO/EVA fiber flexible strain sensor demonstrates exceptional dual thermal and light repair functions, with light repair achieving a repair speed of 5 seconds, 100 % electrical performance repair efficiency, and perfect consistency in relative resistance response before and after repair. Furthermore, the PDA@RGO/EVA strain sensor can monitor finger and wrist movements in real-time with high accuracy, highlighting its significant potential application in the wearable technology field.
研究领域:
材料科学
·
生物医学工程
·
可穿戴技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 134
·期 2
·1071-1082
·
IF 2.209
Zhou Shaojie,Qian Yi,Chen Xilei,Li Long
Layered double hydroxides-silicon dioxide hybrids (LDH-Si) were in situ synthesized by a co-precipitation method. Flame-retardant, smoke suppression and thermal degradation properties of the LDH-Si in ethylene-vinyl acetate (EVA) composites were studied using cone calorimeter test (CCT), limiting oxygen index (LOI), smoke density test (SDT), and thermogravimetry–Fourier transform infrared spectrometry. The CCT results indicated that the peak heat release rate and peak smoke production rate of the EVA/LDH-Si composite with 2.5 mass% SiO 2 were decreased by 28.5 and 21.9% compared to EVA/LDH composite, respectively. The LOI results showed that a suitable addition of SiO 2 can significantly enhance the LOI values of the EVA composites. It was obtained from SDT that SiO 2 could help smoke suppression. The EVA/LDH-Si composites possessed a higher thermal stability than the EVA/LDH composites at high temperatures.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 30
·e54102
·
IF 3
Pengwei Wu,Jie Liu,Song Wang,Sanxi Li,Tao Tang
Organically modified montmorillonite (OMMT) and Ni 2 O 3 were simultaneously introduced into flame-retardant linear low-density polyethylene/ethylene-vinyl acetate/magnesium hydroxide (LEM) composites. Compared with the LEM composite, the thermal stability, and tensile properties of LEM/ remained basically unchanged when 5 wt% of OMMT/Ni 2 O 3 was substituted for MH. The LOI value increased a little from 27.2 to 27.7%. The data from cone calorimeter test showed that the first and second peak heat release rate was reduced by 19% and 67%, respectively. The total heat release and total smoke production showed a significant reduction by 18% and 36% after incorporation of OMMT/Ni 2 O 3 , respectively. The mechanism study indicated that the combination of OMMT/Ni 2 O 3 cooperates promote the carbonization of the polymer itself into carbon naotubes, which form a more cohesive char layer with magnesium hydroxide during combustion. This is the core factor responsible for the synergistic effect on reducing the heat release and smoke production in the LEM composite.
研究领域:
材料科学
·
高分子化学
·
燃烧学
✓ 已验证
DOI
高影响因子
Smart Materials and Structures
·
2016
·Vol. 25
·期 8
·085023
·
IF 2.769
Chen Qian,Yubing Dong,Yaofeng Zhu,Yaqin Fu
Semi-crystalline shape memory polymers exhibit two-way shape memory effect (2W-SME) under constant stresses through crystallization-induced elongation upon cooling and melting-induced constriction upon heating. The applied constant stress influenced the prediction and usability of 2W-SME in practical applications without any external force. Here the reversible shape transition in EVA-shaped memory polymer was quantitative analyzed under a suitable temperature range and external stress-free condition. The fraction of reversible strain increased with increasing upper temperature (Thigh) within the temperature range and reached the maximum value of 13.62% at 70 °C. However, reversible strain transition was almost lost when Thigh exceeded 80 °C because of complete melting of crystalline scaffold, known as the latent recrystallization template. The non-isothermal annealing of EVA 2W-SMP under changing circulating temperatures was confirmed. Moreover, the orientation of crystallization was retained at high temperatures. These findings may contribute to design an appropriate shape memory protocol based on application-specific requirements.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Bin Shang,Yuan Zhan,Min Chen,Limin Wu
Although quite some self-healing coatings have been reported to date, underwater healable coatings were involved very limited. Here, we report a novel underwater healable superoleophobic coating through depositing functional SiO 2 @ [email protected] particles on the TPA/EVA-70% film. The obtained coating not only possess excellent underwater superoleophobic and antifouling properties, but also quick healable performance by remote NIR irradiation. Thus, it may provide stable and long-lasting underwater antifouling properties against marine growth and oil contamination.
研究领域:
材料科学
·
表面化学
·
海洋技术
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2026
·Vol. 19
·期 7
·1476
·
IF 3.7
Hong Zhang,Cheng Wang,Yiming Chen,Ning Li,Tao Zhou,Yu Mao,Yan Zhang
In response to the shortcomings still observed in polyethylene (PE)/ethylene-vinyl acetate (EVA)/styrene-butadiene-styrene (SBS) composite modified bitumen regarding storage stratification and low-temperature performance, this paper further introduces furfural extract, elemental sulphur, stabilisers and Z-6036 into this ternary system, and employs orthogonal design to screen the additive ratios. Tests were conducted on conventional physical properties, rotational viscosity, dynamic shear rheology and bending beam rheology, focusing on the material’s temperature sensitivity, rheological behaviour, low-temperature creep resistance and phase characteristics. The modification effects were analysed using fluorescence microscopy, scanning electron microscopy and infrared spectroscopy. Compared with the control group composed of 4% PE, 4% EVA and 2% SBS, the samples obtained from the orthogonal design showed an increase in elongation at 5 °C ranging from 52.5% to 213.9%; the difference in softening points decreased from 35.2 °C to a minimum of 0.1 °C, indicating improved storage stability. The temperature sensitivity of all sample groups was reduced, with the optimal group achieving a VTS of −0.4413, representing a 46.7% improvement over the control group. At −12 °C, the m-values of all nine orthogonal samples were higher than those of the control group, with seven groups reaching m ≥ 0.3, indicating improved low-temperature stress relaxation capability. A comprehensive analysis of the experimental results indicates that the selected chemical additives are beneficial for optimising the dispersion state and compatibility of the SBS/PE/EVA ternary modified bitumen, whilst also balancing rheological properties and low-temperature crack resistance to a certain extent. Microscopic and spectroscopic analyses further suggest that internal interactions within the system have been enhanced and the phase distribution has become more uniform; however, the current evidence is insufficient to conclusively determine that a specific form of chemical cross-linking reaction has occurred.
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DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2019
·
IF 3.78
D. Battegazzore,M. Lavaselli,B. Cheng,D. Li,R. Yang,A. Frache,G. Paul,L. Marchese
Silica derived from sol-gel approach was used as co-filler in aluminium hydroxide (ATH) or hydromagnesite (HM) ethylene-vinyl acetate (EVA) formulations. In this bottom-up approach, the silica network is formed inside the extruder in a first process step. The 3D silica structure is investigated by solid-state nuclear magnetic resonance (ssNMR) spectroscopy and a combined TGA-FTIR analysis revealing a partially incomplete reaction to form silica particles. In addition, 29 Si CPMAS NMR showed the formation of chemical Si–C bonds between EVA and silica networks. The performance enhancement of the fire retardant properties was established by comparing with composites prepared by a top-down approach, i.e by adding preformed silica. It is confirmed that the preformed silica acts as a synergistic agent with both ATH or HM, increasing the flame retardant properties (limiting oxygen index, UL-94 and cone calorimeter tests) of EVA composites, however, the sol-gel silica shows the best performances in reducing both heat release and smoke production. The role of the sol-gel structure was deeply investigated in correlation with combustion test.
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）