SOLID STATE IONICS
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2018
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IF 2.751
Mingzhao Xu,Mingyue Gang,Li Cao,Xueyi He,Yimeng Song,Zhongyi Jiang,Hong Wu,Yanlei Su
Anion-exchange membranes (AEM) are prepared from chloromethylated poly(ether ether ketone) (CMPEEK), which is quaternized by N , N , N ′, N ′-tetramethyl-1,4-phenylenediamine (TMPD) and 1-methylimidazole using a two-step method. TMPD can not only improve the mechanical properties but also provide more ion exchange groups and improve the availability of quaternary ammonium (QA) groups. By varying the amount of TMPD in the membrane casting solution , the comprehensive properties of the membranes are optimized and intensified. The anion conductivity is increased from 0.028 S cm −1 of the imidazolium functionalized poly (ether ether ketone) (ImPEEK) control membrane to 0.042 S cm −1 of the TMPD/ImPEEK membrane with a TMPD content of 5 wt%. Meanwhile, a 31.5% increase in ultimate tensile strength and a 27.8% increase in Young's modulus of the TMPD/ImPEEK membrane are achieved. This study exploited a facile approach to solving the trade-off relation between anion conductivity and mechanical properties.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2023
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IF 13.6
Chenguang Li,Yanlei Zhang,Shiqi Yin,Qin Wang,Yuanyuan Li,Qiang Liu,Liuqingqing Liu,Xianxiang Luo,Lingyun Chen,Hao Zheng,Fengmin Li
p -Phenylenediamines (PPDs), an important type of rubber antioxidants, have received little study on their environmental fate , particularly for their vital photodegradation process in water environment. Accordingly, N -(1,3-dimethylbutyl)- N′ -phenyl-1,4-phenylenediamine (6PPD), as a representative of PPDs, was investigated experimentally and theoretically for its photodegradation in water. Rapid photodegradation occurred when 6PPD was exposed to illumination especially UV region irradiation. Under acidic conditions, the photodegradation of 6PPD accelerated mainly due to the increased absorption of long wavelength irradiation by ionized 6PPD. Nine photodegradation products (e.g., 6PPD - quinone (6PPDQ)) of 6PPD were identified by an ultra-performance liquid chromatography QTOF mass spectrometry . Molar yields of photoproducts such as 6PPDQ, aniline, 4-aminodiphenylamine, and 4-hydroxydiphenylamine were 0.03 ± 0.00, 0.10 ± 0.01, 0.03 ± 0.02, and 0.08 ± 0.01, respectively. Mechanisms involved in 6PPD photodegradation include photoexcitation , direct photolysis, self-sensitized photodegradation, and 1 O 2 oxidation , as demonstrated by electron paramagnetic resonance (EPR) analysis, scavenging experiments, and the time-dependent density functional theory (TD-DFT). Notably, the toxicity of the reaction solution formed during the photodegradation of 6PPD was increased by the formation of highly toxic products (e.g., 6PPDQ). This study provides the first explanation for photodegradation mechanisms of 6PPD and confirms the pathway of 6PPDQ produced by the photoreaction in water environment.
研究领域:
环境科学
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化学
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毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）