PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Chengyu Zheng,Dechao Hu,Zhengbiao Liu,Xiancheng Zhang,Kanghua Yu,Wenshi Ma
Thermal insulation coatings are an efficient thermal management material that can effectively prevent heat exchange between the building and outside world, realizing building energy efficiency. In this paper, a new thermal insulation coating was innovatively developed by synthesizing silica xerogel within acrylic emulsion via in situ polymerization. Compared to the pure acrylic coating, the thermal insulation coating with 30 % silane concentration forms a promising xerogel structure, resulting in a thermal conductivity of 0.07 W/(m·K), which is 61 % lower than that of pure acrylic coating. And the surface temperature of the thermal insulation coating with 30 % silane concentration was found to be 12.1 °C lower than pure acrylic coating after placing on the hot stage for some time. These findings indicate that silica xerogel network was effectively synthesized in the acrylic emulsion through in situ polymerization and that the thermal insulation coating displays low thermal conductivity and admirable thermal insulation qualities. The xerogel-acrylic composite coating produced by this research offers a novel form of thermal insulation coating, and the in situ polymerization of silica xerogel can also promote the synthesis of multifunctional composite coatings in various aqueous emulsions.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Guangbo Zeng,Dongqing Zhang,Liuming Yan,Baohua Yue,Ting Pan,Yidong Hu,Shufa He,Hongbin Zhao,Jiujun Zhang
Side-chain optimized poly (2,6-dimethyl-1,4-phenylene oxide)- g -poly (styrene sulfonic acid) (PPO- g -PSSA) is designed with balanced water-resistance and sulfonation degree. The PPO- g -PSSA is synthesized by controlled atom-transfer radical polymerization (ATRP) from brominated poly (2,6-dimethyl-1,4-phenylene oxide) (PPO- x Br) and ethyl styrene-4-sulfonate and followed by hydrolysis. A series of PPO-g-PSSA are prepared possessing different bromination degree (x) of PPO-xBr and polymerization degree (m) of the side-chains and the water-resistances of the fabricated membranes are investigated. The results show that a PPO-g-PSSA at relatively low x (x < 0.2) and high m (m > 4) exhibits good balance between the water-resistance and the sulfonation degree. Namely, it displays suitable proton conductivity with compromised water-resistance. Moreover, a maximum ion exchange capacity (IEC) of 3.24 mmol g −1 is reached without the sacrifice of water-resistance. In addition, PPO-g-0.08PSSA-13 and PPO-g-0.14PSSA-4 are chosen characterized by thermogravimetric analysis , proton conductivities and mechanical properties. At 90% RH, the optimized PPO-g-0.08PPSA-13 possesses a proton conductivity of 37.9 mS cm −1 at 40 °C and 45.5 mS cm −1 at 95 °C, respectively.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2025
·
IF 9.1
Shuyu Zhang,Yu Luo,Di Yu,Xianfeng Guan,Wanzhen Wu,Cuicui Li,Guangpeng Ma,Xinpu Zhou,Shuang Wang
Phosphoric acid (PA)-doped polybenzimidazole (PBI) is an ideal choice of membrane materials for high temperature proton exchange membrane fuel cells (HT-PEMFCs) as efficient clean energy devices. PA-doped PBI (PBI/PA) membranes exhibit favorable proton conductivity. However, extended usage results in the leaching of PA and the deterioration of mechanical qualities. Here, we prepared composite membranes of quaternised linear polymeric ionic liquid (PIL)/PBI containing side chains of quaternary ammonium (QA) and siloxane groups through a series of treatments. This design improves both proton conductivity and PA retention through the QA group, the conserved NH site and the high attraction of PIL to PA. Meanwhile, the introduced siloxane cross-linked structure ensures the mechanical properties and chemical stability of the membranes. Among them, QMPBI-P-O 10 -T 90 (P: PIL, O: TOPEA, T: TEA) membrane achieves a proton conductivity of 135.5 mS cm −1 at 180 °C and a PA retention of 85.3 % at 160 °C/0 % RH. In addition, at 160 °C without humidity, the peak power density of QMPBI-P-O 10 -T 90 membrane can reach 523.2 mW cm −2 . This synthesis strategy offers a promising new approach to fabricate polymeric ionic liquid-based crosslinked membranes for various applications.
研究领域:
高分子化学
·
燃料电池
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2017
·Vol. 19
·期 2
·1-8
·
IF 2.02
Qin Ji-Hua,Liu Zhao-Qing,Li Nan,Chen Yi-Bo,Wang Dong-Yao
The nanofluid as a pivotal role in heat transfer system has attracted more and more attention. Herein, the stearic acid-modified CuS (SA-CuS) nanoparticles with a uniform diameter of 60 nm were synthesized successfully by a facile two-phase approach. Accordingly, the CuS-oil nanofluids, with SA-CuS concentrations ranging from 0.01 to 0.04 vol%, were prepared by a one-step method in the heat transfer oil. These CuS-oil nanofluids exhibit good stability and considerable enhanced thermal conductivity. The improvement is even up to 20.5% with a volume fraction of 0.04 vol% at 30 °C. Furthermore, the effect of volume fraction and temperature on the viscosity of the nanofluids was also systematically investigated.
Graphical Abstract
研究领域:
材料科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2022
·
IF 8.907
Chengkun Zhang,Xiangjun Zheng,Ning Xie,Yutang Fang,Zhengguo Zhang,Xuenong Gao
Form-stable flexible composite phase change materials (PCMs) are widely studied on the application of thermal management of batteries . Usually, the latent heat of composite PCMs is lower than that of pure PCMs due to the existence of additive materials. More composite PCMs are needed when their latent heat is too low to meet the requirements, which limits the development of the compact structure of the thermal management system. In this work, a novel paraffin (PA) -based composite multi-phase change material (m-PCM) with high latent heat was fabricated for thermal management. PA thickened by adding styrene ethylene butene styrene block copolymer (SEBS) and expanded graphite (EG) as enhanced thermal conductivity material were loaded in phase change polymer skeleton (PPS) synthesized from polyethylene glycol (PEG). One side, PPS not only played a role on preventing the leakage of paraffin as supporting material, but also provided the extra latent heat of phase change for the composite m-PCM. On the other side, SEBS was added by increasing the viscosity of PA to solve the problem of poor compatibility between the polymer skeleton and PA. Benefiting from the additional latent heat provided by PPS and the addition of EG, the composite m-PCM exhibited the phase change enthalpies as high as about 221.3 J·g −1 while ensuring the thermal conductivity as high as 1.46 W·m −1 ·K −1 . When heated, the composite m-PCM exhibited the excellent shape-stability and flexibility. After 200 thermal cycles, the composite m-PCM performed the almost constant phase transition properties. The results demonstrate the composite m-PCM has extensive application prospects for efficient thermal management.
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
Nature Energy
·
2022
·Vol. 7
·期 2
·153-162
·
IF 67.439
Tang Hongying,Geng Kang,Wu Lei,Liu Junjie,Chen Zhiquan,You Wei,Yan Feng,Guiver Michael D.,Li Nanwen
Conventional proton exchange membrane fuel cells (PEMFCs) operate within narrow temperature ranges. Typically, they are run at either 80‒90 °C using fully humidified perfluorosulfonic acid membranes, or at 140‒180 °C using non-humidified phosphoric acid (PA)-doped membranes, to avoid water condensation-induced PA leaching. However, the ability to function over a broader range of temperature and humidity could simplify heat and water management, thus reducing costs. Here we present PA-doped intrinsically ultramicroporous membranes constructed from rigid, high free volume, Tröger’s base-derived polymers, which allow operation from −20 to 200 °C. Membranes with an average ultramicropore radius of 3.3 Å show a syphoning effect that allows high retention of PA even under highly humidified conditions and present more than three orders of magnitude higher proton conductivity retention than conventional dense PA-doped polybenzimidazole membranes. The resulting PA-doped PEMFCs display 95% peak power density retention after 150 start-up/shut-down cycles at 15 °C and can accomplish over 100 cycles, even at −20 °C.
研究领域:
材料科学
·
能源工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Zhengping Zhao,Zeping Zhou,J.I. Jianbing,Fang Xie
A type of poly(aminobenzene sulfonic)phosphazene derivative grafted SPEEK was synthesized which were confirmed by FT-IR and NMR analysis. And a series of grafted SPEEK proton exchange membranes with 65% sulfonation degree were prepared. Comparing to SPEEK membranes, all the properties increased. The proton conductivity reached 4.21×10 -3 S/cm with 15 % grafting degree and the methanol permeability coefficient increased at 2.72×10 -7 cm 2 ·s -1 to achieve the using requirements of DMFC proton exchange membrane.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Advanced Materials Interfaces
·
2023
·Vol. 10
·期 15
·2202508
·
IF 5.4
Zilong Jiang,Bo Jiang,Boyin Yang,Xin Liu,Yang Yang,Chunling Zhang,Yingshuang Shang,Haibo Zhang
Nanofiller reinforcement is an effective method to prepare high thermally conductive polymer-matrix composites. However, the poor dispersion of nanofillers and high interfacial thermal resistance between the filler and matrix seriously affect the thermal conductivity and mechanical properties of composites. To solve this problem, a small amount of conjugated fluorene group is introduced into the polymer chain of poly (ether ether ketone) (PEEK) to afford the fluorene-functionalized copolymer matrix (FD-PEEK). In an in situ polymerization procedure, the matrix non-covalently binds to multi-walled carbon nanotubes (MWCNT) to allow highly filled PEEK/MWCNT nanocomposites. With the filler dispersion and matrix–filler interfacial bonding improved, the prepared nanocomposites possess both high thermal conductivity and tensile strength. At the optimal ratio of 2 mol% fluorene groups in the polymer chain, the nanocomposite with 10 wt% MWCNT exhibits an excellent thermal conductivity of 2.41 W m −1 K −1 , which is 868% higher than pristine PEEK, with tensile strength remaining 104.3 MPa. The PEEK/MWCNT nanocomposites can be further used as matrix resins to build double-segregated network multi-component composites, which contributes to an innovative strategy to design high-performance thermally conductive materials.
研究领域:
材料科学
·
复合材料
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 47
·29794-29805
·
IF 3.108
Abhishek N. Mondal,Yubin He,Liang Ge,Liang Wu,Kamana Emmanuel,Md. Masem Hossain,Tongwen Xu
A novel side-chain-type anion exchange membrane (AEM) is synthesized using thiol-ene click chemistry and the Menshutkin reaction. The prepared membranes are fully characterized and successfully mitigate the trade-off between conductivity and water uptake. Side-chain-type polymer electrolyte membranes with moderate hydroxide conductivity and improved water uptake are obtained. The thiol-ene click reaction is employed for the synthesis of active monomer 9-(2-((3-(triethoxysilyl)propyl)thio)ethyl)-9H-carbazole (TESPTEC). Using the Menshutkin reaction, TESPTEC is introduced into the brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) backbone. The NVC-50 membrane shows a maximum hydroxide conductivity of 19.84 ± 1.81 mS cm−1 at 20 °C, and 54.69 ± 2.91 mS cm−1 at 60 °C. However, at 20 °C, the water uptake of the membrane NVC-50 is only about 18.36 wt%. After 12 days of alkaline treatment, the NVC-50 membrane shows better alkaline stability than the conventional QPPO membrane.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2013
·
IF 2.072
Cheng Chen,Chunhui Shen,Gengjin Kong,Shanjun Gao
High temperature anhydrous proton exchange membranes based on phosphonic acid were prepared from epoxycyclohexylethyltrimethoxysilane (EHTMS) and amino trimethylene phosphonic acid (ATMP) by sol–gel process. The structures and properties of membranes with different phosphonic acid content were extensively characterized by FTIR, TG-DSC and XRD . Their proton conductivity under dry condition was also investigated under different temperature. The results show that the proton conductivity of the prepared membranes strongly depends on temperature, and the proton conductivity ranges from 8.81 × 10 −5 S cm −1 at 20 °C to 4.65 × 10 −2 S cm −1 at 140 °C under anhydrous condition. It indicates that the increasing temperature is favorable for congregating of the grafted–PO 3 H 2 and increasing of the proton mobility. In addition, from the results of AFM images, it was confirmed that the continuous distribution of phosphonic acid groups is favorable for the formation of the proton transport channel, which can significantly enhance the proton conductivity of the membranes.
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
Journal of Nanomaterials
·
2013
·
IF 1.547
Yuan-Xian Zeng,Xiu-Wen Zhong,Zhao-Qing Liu,Shuang Chen,Nan Li
The lipophilic MoS2 nanoparticles are synthesized by surface modification with stearic acid (SA). The heat transfer oil-based nanofluids, with the mass fraction of lipophilic nanoparticles varying from 0.25% up to 1.0%, are prepared and their thermal conductivity is determined at temperatures ranging from 40 to 200°C using an apparatus based on the laser flash method. It has been found that the nanofluids have higher thermal conductivity and the thermal conductivity enhancement increased not only with increasing mass fraction of nanoparticles, but also with increasing temperature in the range 40–180°C The results show a 38.7% enhancement of the thermal conductivity of MoS2 nanofluid with only 1.0% mass fraction at 180°C.
研究领域:
材料科学
·
热力学
·
化学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Sehreish Abrar,Zhuang Ma,Ling Liu,Faisal Nazeer,Abdul Malik
In this work, novel equiatomic high entropy (Dy 1/4 Ho 1/4 Tm 1/4 Yb 1/4 ) 2 Si 2 O 7 or (4RE 1/4 ) 2 Si 2 O 7 ceramic pyrosilicate was fabricated through a single solid solution method to use as environmental barrier coating. The SEM analysis of high entropy powders shows the homogenous mixing and XRD proves the formation of single β-phase after milling and sintering. The coefficient of thermal expansion was reported as (2.3–4.8 × 10 −6 K −1 ) from 400 K −1 to 1723 K −1 . The ultra-low thermal diffusivity (0.4 mm 2 s −1 ) and thermal conductivity (0.8 W/m°C) were reported at 1500 °C for this novel HE ceramic disilicate. The as fabricated (4RE 1/4 ) 2 Si 2 O 7 pyrosilicate shows an excellent CMAS resistant for even up to 48 h and negligible amount of Ca is able to penetrate in the substrate. Rare earth disilicate species with intermediate radii such as Tm 3+ helps in maintaining phase stability along with passive element Yb 3+ of smaller radii which also protect the interface from severe CMAS attack. However, the rare earth species with larger radii such as Dy 3+ and Ho 3+ actively take part in apatite formation leading to reduced corrosion activity of CMAS melt by changing its composition. This result confirms the application of (4RE 1/4 ) 2 Si 2 O 7 as a potential candidate to be used as protecting coating material in harsh combustion environments.
研究领域:
材料科学
·
高温材料
✓ 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）