Advanced Materials Interfaces
·
2023
·Vol. 10
·期 15
·2202508
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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
CHIRALITY
·
2015
·Vol. 27
·期 8
·449-453
·
IF 1.886
Wei Hu,Jing Cao,Yi-Ling Huang,Sai Liang
Novel optically active carbon anionic initiators bearing a chiral oxazole substituent on fluorene ring, (S)-1-(9H-fluoren-2-yl)-4-isopropyl-4, 5-dihydrooxazole lithium ((S)-1-FIDD-Li) and (S)-2-(9H-fluoren-2-yl)-4-isopropyl-4, 5-dihydrooxazole lithium ((S)-2-FIDD-Li), were synthesized. Anionic polymerizations of achiral polyisocyanates with the chiral initiators were investigated and optical rotation of the obtained polymers were attributed to asymmetric induction of the chiral initiators. The crowded substituent of initiator ((S)-2-FIDD-Li) seems to reduce the polymerizability of isocyanates and yet enhances the chiral induced ability in polymerization. Chirality 27:449–453, 2015 . © 2015 Wiley Periodicals, Inc.
研究领域:
高分子化学
·
有机化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 39
·e55997
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IF 2.7
Ao Nan Lai,Zhen Wang,Ren Ke Lin,Xin Zhi Han,Shu Feng Zhou
The anion exchange membrane (AEM) suffered from poor mechanical properties and low ionic conductivity in fuel cells. Herein, a series of novel block fluorene-contained poly(arylene ether ketone)s backbones are synthesized by a tandem one-pot process and then grafted with alkyl chains to form comb-shaped structure for preparing AEMs. The one-pot synthesis of block copolymer avoids the multiple purifications of oligomers. The membranes' structure–property relationship is studied by changing the ratios of hydrophilic and hydrophobic segments. The designed comb-shaped structures grafted on fluorene-containing block backbones can widen the space between chains and form clear microphase separation patterns, as determined by atomic force microscope (AFM) and small angle x-ray scattering (SAXS). Hence, resulting AEMs have a high ionic conductivity (117.4 mS cm −1 , 80°C). Meanwhile, they also present low swelling rate (SR) from 12.76% to 18.51% at 30°C, 16.84% to 24.36% at 60°C, and 18.33% to 25.81% at 80°C. In addition, excellent mechanical properties, that is, an elongation at break of 29.63% and a tensile strength of 28.72 MPa, are achieved and showed the promise of as-fabricated AEMs in fuel cell applications.
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
RSC Advances
·
2016
·Vol. 6
·期 47
·41453-41464
·
IF 3.289
Liuhong Li,Xi Yue,Wenjun Wu,Wuxin Yan,Mingjian Zeng,You Zhou,Shijun Liao,Xiuhua Li
In this study, we constructed a series of multi-block copolymer ionomers with fluorene-containing hydrophilic segments densely functionalized by side-chain quaternary ammonium groups as anion exchange membranes. These ionomers were synthesized via pre-polycondensation, block co-polycondensation, bromination, quaternization and alkalization. The sequential hydrophilic/hydrophobic structures were achieved by the co-polycondensation of precursor oligomers. Quaternary ammonium groups of high local density were successively introduced to the side chains of the fluorene-containing hydrophilic blocks by the following functionalization processes. Based on the well-controlled chemical structures, the multi-block copolymer ionomers membranes show well-defined hydrophilic/hydrophobic phase separations. The well-connected, broad ionic nano-channels with Bragg spacings of approximately 37.85 nm, which were confirmed by atomic force microscopy (AFM) and small angle X-ray scattering (SAXS), enhance the performances of the AEMs. The obtained multi-block AEMs show good dimensional stability. And these membranes have rather high ionic conductivity (23.0–85.0 mS cm−1, 80 °C) considering their relatively low IECm values (0.81–1.28 meq. g−1). Moreover, the membranes have adequate mechanical properties and good thermal properties. QMPAES-X7Y17, X5Y13 and X5Y17 with IECm values below 1.0 meq. g−1 lose only 20% of their original values after 600 h alkaline stability test. These results are promising as anion exchange membranes of alkaline fuel cells.
研究领域:
材料科学
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化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Lingxin Meng,Mengchi Ju,Jingmei Xu,Xuan Chen,Pengyun Zhao,Jinxuan Lei,Tian Lan,Fenglong Chen,Ziyi Hu,Zhe Wang
In this paper, sulfonated poly(arylene ether ketone sulfone)s containing fluorenyl groups (F-SPAEKS) were synthesized. MIL-101-NH 2 was prepared by hydrothermal reaction . The carboxyl group was modified to MIL-101-NH 2 by amidation reaction, then difunctional MIL-101-NH 2 was designed (MIL-101-NH 2 -COOH). The fillers of MIL-101-NH 2 and difunctional MIL-101-NH 2 -COOH were added into F-SPAEKS matrix to prepare the hybridized membranes, respectively. The structures and morphologies of MIL-101-NH 2 , MIL-101-NH 2 -COOH and hybridized membranes were characterized by SEM, FT-IR, 1 H NMR, XPS and XRD . Among these prepared hybridized membranes, FSMNC-4 (the weight percentage of MIL-101-NH 2 -COOH was 4%) had the highest proton conductivity (159.90 mS cm −1 at 80 °C). The proton conductivity of FSMNC-4 was 1.79 times higher than that of pure F-SPAEKS (89.30 mS cm −1 at 80 °C) and 1.25 times higher than that of FSMN-4 (the weight percentage of MIL-101-NH 2 was 4%) (127.55 mS cm −1 at 80 °C), respectively. Meanwhile, the increase of hydrophilic groups also resulted in the highest water absorption of FSMNC-4 (21.57% at 80 °C). The ionic cross-linked networks reduced the swelling ratio of the hybridized membranes. The swelling ratio of all hybridized membranes was lower than 10%. FSMNC-4 also had good thermal and oxidative stability . The open circuit voltage (OCV) and maximum power density of FSMNC-4 were 0.994 V and 466 mW/cm 2 , respectively. The above results indicated that FSMNC-4 had a promising potential to be applied in PEMFCs.
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
Polymer Chemistry
·
2017
·Vol. 8
·期 30
·4403-4413
·
IF 5.375
Bo Hu,Luyang Miao,Yang Bai,Changli Lü
A series of fluorenyl-containing polysulfone-based crosslinked anion exchange membranes with high conductivity and excellent stability were fabricated via click chemistry. Azide groups were firstly introduced into the side chains of fluorenyl-containing polysulfone via the quaternization reaction, and then the designed bifunctional crosslinking agents containing alkyne groups with different lengths and polarities (hydrophilicity) were used to construct the crosslinked structure via the click reaction between azides and alkynes. The degree of crosslinking of membranes can be adjusted by controlling the content of the crosslinking agent. The proper crosslinking of AEMs in this work can tighten the internal packing structure of membranes, which could not only enhance the mechanical strength of AEMs but also improve the fuel permeability, alkaline resistance and oxidative stability of membranes. The water uptake and swelling ratio of the crosslinked AEMs were also improved with the increase of polarity and length of crosslinking agents. The hydroxide conductivity of d-CPFSU-1 was not decreased by crosslinking rather it increased to 193.95 mS cm−1 at 80 °C due to the formation of a uniform nano-micro phase separation structure. Our study showed that AEMs with enhanced performance can be achieved by the design of crosslinking within the control of the micro-phase structure.
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）