MACROMOLECULES
·
2024
·
IF 5.1
Yikai Sun,Chengfeng Zhang,Shu Wang,Zhenghai Tang,Xinrang Li,Xianming Zhang,Baochun Guo
High gas barrier rubber composites are crucial for the applications requiring the combination of high resilience and gas impermeability. Layered fillers are commonly used to enhance the gas barrier performance by reducing free volume and creating tortuous gas diffusion paths. However, it remains challenging to strengthen interfacial interactions and manipulate filler distribution, which significantly affect free volume and gas diffusion paths. Herein, we present a facile strategy to build a segregated structure in modified rubber composites with dynamic interfacial cross-linking toward mechanically robust, high gas barrier elastomer composites. Concretely, boehmite (BM) nanoplatelets modified with biobased phytic acid (PA) are utilized to cross-link epoxidized natural rubber (ENR), forming dynamic β-hydroxy phosphate ester cross-links for strong interfacial interaction. This system allows a segregated structure to be readily established by hot pressing the compounds containing ENR gum, PA-modified BM, precross-linked ENR granules and zinc acetate. The volume exclusion effect of ENR granules drives the selective dispersion of BM, generating a two-phase segregated structure with the bridged interfaces across phases formed via bond exchange of dynamic cross-links. This results in excellent gas barrier performance along with distinctly improved mechanical properties. Notably, the N2 permeability of the segregated composites is reduced by 90% to 4.23 × 10–19 m3·m/(m2·s·Pa) compared to neat ENR. Additionally, improved fire safety is achieved benefiting from the combined effects of PA, BM, and the segregated structure. This work offers a promising and scalable approach for fabricating high-performance elastomer composites that combine outstanding gas barrier properties, mechanical durability and flame retardance, making them suitable for a wide range of demanding 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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Xiangyu Wang,Tao Wang,Jun Ma,Huiling Liu,Ping Ning
A novel composite based on hydrophilic boehmite-PVB/PVDF blended membrane- immobilized nanoscale zero-valent iron (nZVI) (BPPN) was synthesized. When the initial concentration of Cr(VI) was 20 mg/L, 100% Cr(VI) was removed by BPPN at an initial pH of 4.08 under room temperature of 25 °C within 90 min. In addition, the reactivity of the regenerated BPPN composites toward Cr(VI) removal were not obviously declined after 6 cycles. The resultant BPPN demonstrated high reactivity, preeminent stability and reusability in the reaction course. Meanwhile, the BPPN composites showed a higher removal efficiency toward the removal of Cr(VI) compared with alumina-PVB/PVDF-nZVI (APPN) composites. The plentiful hydroxyl groups of boehmit on the BPPN surface resulted in the enhancement in hydrophilicity and improved Fe 0 loading of the BPPN composites. For environmental parameters, results indicated that there was a negative effect of increasing the initial concentration or decreasing reaction temperature toward the removal of Cr(VI) by BPPN, and that the acidic and neutral conditions showed more favorable effect on Cr(VI) removal than the alkaline ones. The generated ferrous ions on the surface of BPPN were certified to play an important role in removal of Cr(VI). XPS analysis suggested that the reduction reaction of Cr(VI) occurred on the surface of the composite and produced precipitation of Cr(III). The Cr(VI) removal by BPPN composite was found to follow a revised kinetics well. This study suggests that the novel BPPN composite possessing excellent performance may be a promising functional material of heavy metal wastewater treatment.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Energy Technology
·
2022
·Vol. 10
·期 4
·2100982
·
IF 4.149
Liu Kefan,Yang Chengyuan,Li Xiaogang,Dong Nanxi,Liu Bingxue,Tian Guofeng,Qi Shengli,Wu Dezhen
With the continuous development of lithium-ion batteries (LIBs), the electrochemical performance and safety of LIBs have become increasingly challenged recently. Therefore, research on high-performance LIB separators has gradually attracted widespread attention. As an important component of lithium batteries, the diaphragm plays an important role in battery safety. Improving battery separator performance is an important way to improve batteries’ safety and electrochemical performance. Herein, to prepare a new type of LIB separator, a preparation strategy in which polyimide (PI) nanofibers can be coaxially encapsulated by the inorganic boehmite (AlOOH) ceramics through an adsorption and complexation process is developed. This strategy involves immersing partially imidized PI nanofiber membranes into anhydrous aluminum chloride ethanol solution and dilute ammonia, where the adsorption−complexation and hydrolysis processes are completed. During the hydrolysis process, the PI nanofibers are evenly coated with AlOOH. The amount of AlOOH can be controlled easily by adjusting the concentration of the anhydrous aluminum chloride ethanol solution. After being encapsulated with AlOOH, the separator exhibits better mechanical properties, wettability, thermal stability, cycling durability, and a high capacity, along with faster ion transport speed. All excellent features prove that the PI@AlOOH composite nanofiber membrane is an advanced high-performance LIB separator.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Express
·
2019
·Vol. 9
·期 1
·42-50
·
IF 1.465
Ahmed Saad,Cai Yangben,Ali Muhammad,Khannal Santosh,Xu Shiai
In this study, alkyl benzene sulfonic acid coated boehmite nanofillers (OS2) were incorporated into chitosan (CS) to prepare novel CS/OS2 nanocomposite membranes for proton exchange membrane fuel cell applications, and then their microstructure and physicochemical
properties were characterized. These nanocomposite membranes show high proton conductivity, good thermal stability, and improved mechanical characteristics. The electrostatic interactions between –SO3H groups of boehmite nanofillers and amine groups of CS can inhibit the mobility
of CS chains, resulting in a decrease in the swelling area of the nanocomposite membrane in water and thus an increase in its dimensional stability. The development of acid–base pairs at the nanofiller interface facilitates the formation of consecutive transfer pathways to improve the
proton conductivity of synthesized membranes. The maximum proton conductivity (0.033 S · cm–1) is obtained in the CS/OS2-5 nanocomposite membrane, which is equal to that of commercial Nafion 117. The eco-friendly and cost-effective nature of CS-based membrane
makes it as a promising candidate for proton exchange membrane fuel cell applications.
研究领域:
材料科学
·
能源工程
·
聚合物纳米复合材料
·
燃料电池技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）